Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016

Appendix A

Model Performance Evaluation of the 

CD-C CAMx 2005 and 2006 Base Case Simulations
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-1

A1. INTRODUCTION

The air quality impact assessment for the Continental Divide-Creston (CD-C) EIS is being 

performed using the photochemical grid model CAMx (Comprehensive Air quality Model with 

Extensions; ENVIRON, 2009; www.camx.com). The basic modeling strategy used in any EIS that 

employs a photochemical grid model, such as CAMx, is to first simulate a current year base case 

using a comprehensive regional emission inventory of actual emissions from all sources 

(including motor vehicles, power plants, oil and gas exploration and production sources, 

biogenic sources, etc.). It is preferable to run the model for more than one year so that as 

many different meteorological regimes as possible are simulated. Pollutants emitted from 

Project sources may only influence a particular sensitive receptor under certain conditions 

(wind direction, atmospheric stability) and a conservative estimate of AQ and AQRV impacts 

requires that those conditions be simulated. While it is not possible to ensure that all possible 

meteorological conditions that might lead to transport of pollutants from Project sources to 

sensitive receptors are simulated, modeling two full years increases the likelihood that the 

relevant conditions will occur. 

The base case simulation is evaluated with respect to ambient air quality measurements. If the 

base case simulation reproduces concentrations of observed species with reasonable fidelity, 

then the model can be used in the future year impact assessment. The future year modeling 

involves development of a future year Project emission inventory as well as a future year 

regional emission inventory. In the future year regional emission inventory, the emissions from 

human activities are projected from the base year to the future year and changes such as 

population growth and planned emissions controls (such as controls on motor vehicle 

emissions) are accounted for. Emissions that are not controllable, such as biogenics and 

wildfire emissions, are held fixed. The Project emissions are included in the future year 

emission inventory. The model is run using the future year regional emission inventory with 

the rest of the model (meteorological fields, boundary conditions, model settings, etc.) in the 

same configuration as in the base case. If multiple years were simulated in the base case, then 

the meteorological conditions for those same years are used together with the future year 

emissions scenario in the future year modeling. Project AQ and AQRV impacts are determined 

from the future year simulations.

For the CD-C EIS, a base case simulation has been developed and evaluated. CAMx has been 

applied for the calendar years 2005 and 2006 using a nested-grid modeling domain with 

horizontal spatial resolution 36/12/4 km (Figure A1-1). The primary function of the 36 km grid 

is to provide lateral boundary conditions to the 12 km grid. The 4 km grid encompasses the CDC Project Area and nearby Class I and sensitive Class II areas. The 2005 and 2006 base case 

model runs use actual emissions of NOx, SO2, PM10, PM2.5, VOC and CO from all sources for 

those years. The CAMx gas phase and particle phase model estimates have been compared 

against observed values for those two years and a model performance evaluation has been 

conducted. 

This Appendix summarizes the CD-C CAMx 2005 and 2006 base case simulations and model 

performance evaluation. The focus of the model performance evaluation is on the evaluation 

for ozone and PM2.5 and its component species in Southwest Wyoming and surrounding areas 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-2

in the 4 and 12 km domains. We also present the regional modeling performance evaluation of 

the CAMx model across the continental U.S. 36 km grid domain as 

Figure A1-1. 36 km, 12 km, and 4 km modeling domains.

that performance helps assess the reliability of the transport of ozone, PM2.5 and their 

precursors into the 12/4 km domains. This is important for characterizing the background 

reactivity of the atmosphere that affects the chemical transformation and consequently the 

ozone and PM2.5 impacts of oil and gas (O&G) emissions from the CD-C Project, which are the 

focus of this study. Less emphasis is placed on the model performance in the urban areas in the 

region (e.g., Salt Lake City and Denver), as to adequately simulate ozone and PM2.5 in these 

areas requires a model configuration that focuses on the urban areas, rather than on Southwest 

Wyoming (see, for example, Morris et al., 2008a,b; 2009).

A preliminary CAMx base case simulation and model performance evaluation was conducted 

using the same two years (2005 and 2006) and 36/12/4 km horizontal domain structure used in 

the CD-C study under the Hiawatha Regional Energy Development Project EIS (Kemball-Cook et 

al., 2009). At the August 2009 Hiawatha stakeholders meeting, concerns were raised regarding 

the performance of the Hiawatha CAMx base case simulation. In particular, concerns were 

raised regarding the underestimation of nitrate and, particularly, the underestimation of ozone 

at the southwest Wyoming industrial monitoring sites in Sublette County. In the fall of 2009, 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-3

the CD-C EIS study performed diagnostic sensitivity tests to determine a more optimal model 

configuration for simulating ozone and nitrate formation in southwestern Wyoming. Appendix 

E describes the diagnostic sensitivity tests and the resulting updates to the CAMx model 

configuration that were approved by the CD-C stakeholders early 2010 for use in the CD-C 

CAMx base case simulations. 2005-6 base case CAMx modeling was carried out in JanuaryFebruary 2010 with the understanding that the runs would be used for the CD-C base case. 

Because of the link between the CD-C revised and earlier Hiawatha preliminary CAMx base case 

simulations, the CAMx model performance for both base case simulations are presented in this 

document. Where the figures and captions in this Appendix cite the Hiawatha run, they refer to 

the Hiawatha base case run that was performed in 2009.

In this Appendix, the evaluation methodology and ambient data sets used in the evaluation are 

described. Next, the PM and ozone performance on the 36 km grid are summarized. We 

present the 12/4 km grid ozone model performance evaluation and finally, describe the 12/4 

km PM performance. A summary of the entire evaluation is provided at the end of the 

Appendix as well as recommendations regarding the use of the CD-C 2005-2006 base case 

simulations in the CD-C EIS future year AQ and AQRV impact assessment.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-4

A2. EVALUATION METHODOLOGY

In the 2005 and 2006 CD-C base case model performance evaluation, the CAMx results were 

compared with observations from the Interagency Monitoring of PROtected Visual 

Environments (IMPROVE), Speciated Trends Network (STN)1, Clean Air Status Trends Network 

(CASTNet), Federal Reference Method (FRM) PM2.5 mass, National Acid Deposition Program 

(NADP) and EPA Air Quality Station (AQS) study monitoring networks. The CD-C CAMx 

evaluation focuses primarily on the operational model evaluation of the air quality model’s 

performance with respect to ozone, the individual components of fine particulate matter 

(PM2.5), and total PM2.5 mass. Some elements of a diagnostic evaluation were also performed, 

including analysis of the ability of the model to reproduce gaseous PM precursor (e.g., SO2) and 

product (e.g., HNO3) species.

A2.1 EVALUATION APPROACH

EPA’s integrated ozone, PM2.5 and regional haze modeling guidance calls for a comprehensive, 

multi-layered approach to model performance testing, consisting of the four major 

components: operational, diagnostic, mechanistic (or scientific) and probabilistic (EPA, 2007). 

The CAMx model performance evaluation effort for PM2.5 discussed in this Appendix focused on 

the first two components of the EPA’s recommended evaluation approach, namely: 

 Operational Evaluation: Tests the ability of the model to estimate ozone, PM2.5 mass 

concentrations and the components of PM2.5, that is sulfate, nitrate, ammonium, organic 

carbon matter, elemental carbon, and other inorganic PM2.5. This evaluation examines 

whether the measurements are properly represented by the model predictions but does

not necessarily ensure that the model is getting “the right answer for the right reason”; 

and

 Diagnostic Evaluation: Tests the ability of the model to predict visibility and extinction, 

PM chemical composition including ozone and PM precursors (e.g., SOx, NOx, VOC and 

NH3) and associated oxidants (e.g., nitric acid); PM size distribution; temporal variation; 

spatial variation; mass fluxes; and components of light extinction (i.e., scattering and 

absorption).

The diagnostic evaluation also typically includes the performance of diagnostic tests to better 

understand model performance and identify potential flaws in the modeling system that can be 

corrected. As part of the CD-C EIS study, a series of diagnostic sensitivity tests were conducted 

as discussed in Appendix E.

In this model performance evaluation of the CD-C 2005 and 2006 CAMx 36/12/4 km base case 

simulations, the operational evaluation has been given the greatest attention since this is the 

primary thrust of EPA’s modeling guidance. However, we have also examined certain 

diagnostic features dealing with the model’s ability to simulate sub-regional and 

monthly/diurnal gas phase and aerosol concentration distributions. We also compare the CD-C 

 

1

The Speciated Trends Network (STN) is now referred to as the Chemical Speciation Network (CSN). The terms STN and CSN 

refer to the same PM2.5 speciation network.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-5

CAMx base case model performance with the preliminary CAMx 2005 and 2006 base case 

model performance performed under the Hiawatha EIS study.

A2.2 PARTICULATE MATTER AND COMPONENT SPECIES

PM2.5 attainment is based on PM2.5 mass measurements using Federal Reference Method (FRM) 

monitoring devices that consists of the following PM2.5 components:

 Sulfate (SO4)

 Nitrate (NO3)

 Ammonium (NH4)

 Organic Carbon Matter (OCM)

 Elemental Carbon (EC) [also called Black Carbon (BC) and Light Absorbing Carbon (LAC)]

 Other Inorganic PM2.5 that is also referred to as Soil (also known as crustal material, fine 

soil, major metal oxides, or other PM2.5)

 Particle Bound Water (PBW)

 Sea Salt (that is mostly NaCl) 

 Passive Mass (Blank Correction)

With the exception of the Passive Mass (that is assumed to be a constant 0.5μg/m3), PBW (that 

is associated with SO4 and NO3) and Sea Salt (which is an insignificant component of PM2.5

mass in Southwest Wyoming, Northern Colorado and Northern Utah) each of these 

components is evaluated.

Visibility is assessed using the IMPROVE equation that expresses light extinction as a series of 

PM species components multiplied by their extinction efficiency. In the original IMPROVE 

equation, the total light extinction (bext) is assumed to be the sum of the light extinction due to 

the six PM species listed above plus Rayleigh (blue sky) background (bRay) that is assumed to be 

10 Mm-1.

bext = bRay + bSulfate + bNitrate + bEC +bOCM + bSoil + bCM

The total light extinction (bext) in Mm-1is related to visual range (VR) in km using the following 

relationship:

VR = 3912 / bext,

for bext in Mm-1.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-6

The incremental visibility impairment is typically expressed in terms of deciviews where the 

haze index (HI) in units of deciviews (dv) is calculated as follows:

HI = 10 ln(bext/10

The original IMPROVE equation that converts PM species concentrations to light extinction is 

given as follows (Malm et al., 2000):

bSulfate = 3 x f(RH) x [Sulfate]

bNitrate = 3 x f(RH) x [Nitrate]

bEC = 10 x [EC]

bOCM = 4 x [OCM]

bSoil = 1 x [Soil]

bCM = 0.6 x [CM]

Here, f(RH) are relative humidity adjustment factors where both day-specific and monthly 

average values are used in the visibility assessment. Sulfate and nitrate are assumed to be 

completely neutralized by ammonium in the IMPROVE equation [SO4(NH4)2 and NO3NH4]. The 

model simulates total OCM concentration, whereas the IMPROVE and STN monitoring network 

only measure the Organic Carbon (OC) component of OCM. OCM/OC ratios tend to range from 

1.2 to 2.4 with lower ratios associated with fresh (e.g., urban) OCM emissions and higher ratios 

associated with OCM that has undergone photochemical processing and aging. There are 

significant uncertainties in the OCM evaluation as the selection of the incorrect assumed 

OCM/OC ratio can introduce errors approaching 50%. To convert the OC to OCM in the 12-4 

km model performance evaluation, we assumed an OCM/OC ratio of 1.8 for the IMPROVE 

monitors, which is more representative of rural areas. For the STN monitors, which are located 

within and near urban areas, a value of 1.2 was used for the OCM/OC ratio. In the evaluation 

of the 36 km grid performance, a ratio of 1.4 was used for consistency with the Western 

Regional Air Partnership (WRAP) 2002 36 km continental U.S. modeling, against which the 36 

km CD-C and Hiawatha base case simulations for 2005-2006 were compared.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-7

A2.3 AMBIENT AIR QUALITY DATA 

A ground-level model evaluation database for 2005 and 2006 was compiled using several 

monitoring networks that carry out routine measurements. The focus of the CD-C evaluation of 

the CAMx model was on the ozone and the PM components that make up total PM2.5 mass and 

can cause visibility impairment. The primary monitoring networks available to evaluate this 

component of the CAMx are: (a) Interagency Monitoring of Protected Visual Environments 

(IMPROVE); (b) Clean Air Status and Trends Network (CASTNET); (c) EPA Federal Reference 

Method (FRM) PM2.5 and PM10 Mass Networks (EPA-FRM); (d) EPA Speciation Trends Network 

(STN) of PM2.5 species; (e) National Acid Deposition Network (NADP); and (f) the EPA Air 

Information Retrieval System (AIRS) Air Quality Station (AQS) network. These ozone and PM 

monitoring networks may also provide other gas phase precursors, product species, and 

visibility measurements at some sites. Table A2-1 summarizes the species collected and 

averaging times of the monitoring sites for the IMPROVE, STN, CASTNet, NADP and FRM 

monitoring networks use in the CD-C model evaluation. The locations of the monitoring sites 

used in the model evaluation within the CD-C 36 km grid are shown in Figure A2-1 and sites 

within the 12/4 km domain are shown in Figure A2-2.

The IMPROVE and STN monitors collect 24-hour average PM samples on a 1:3 day sampling 

schedule and speciate the PM2.5 into its component species. STN collects ammonium but 

IMPROVE does not. IMPROVE also obtains coarse mass that is not collected at STN monitoring 

sites. The CASTNet PM monitoring network collects weekly samples of sulfate, nitrate, 

ammonium, nitric acid and SO2. Thus, the CASTNet monitoring network can also be used to 

evaluate the model for Total Nitrate (HNO3+NO3). This is a valuable diagnostic tool for helping 

to deduce whether any particulate NO3 performance problems may be related to the oxidation 

of the NOx to form Total Nitrate or to the aerosol thermodynamic partitioning of Total Nitrate 

between particulate NO3 and gaseous HNO3. The NADP monitoring sites collect weekly 

samples of wet deposited sulfate, nitrate and ammonium.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-8

Figure A2-1. Locations of sites in each of the PM ambient monitoring networks and the 36 km 

modeling domain.

Table A2-1.Ambient monitoring data available in the 12/4 km domains during 2005 and 2006.

Monitoring Network Chemical Species Measured Sampling Frequency; Duration

IMPROVE Speciated PM2.5 and PM10 1 in 3 days; 24 hr

CASTNET Speciated PM2.5, Ozone, HNO3 Hourly, Weekly; 1 hr, Week

NADP WSO4, WNO3, WNH4 Weekly

EPA-FRM Total fine PM mass (PM2.5) 1 in 3 days; 24 hr

EPA-STN Speciated PM2.5 1 in 3 days; 24 hr

AIRS/AQS CO, NO, NO2, NOx, O3 Hourly; Hourly

-2000 -1500 -1000 -500 0 500 1000 1500 2000

-1500

-1000

-500

0

500

1000

IMPROVE

CASTNet

SEARCH

STN

NADP

AQS
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-9

Figure A2-2. Locations of monitoring sites within the 12/4 km grid domain.

A2.4 MODEL PERFORMANCE STATISTICSAND GOALS

To quantify model performance, several statistical measures were calculated and evaluated for 

all the IMPROVE, STN, CASTNet, FRM, NADP and AQS monitors within the 12/4 km domains. 

The statistical measures selected were based on the recommendations outlined in section 18.4 

of the USEPA’s Guidance On The Use Of Models And Other Analyses for Demonstrating 

Attainment of Air Quality Goals for Ozone, PM2.5, and Regional Haze (EPA, 2007). Table 2-2 

lists the definitions of several statistical performance measures that are used in model 

performance evaluation discussed below.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-10

Table A2-2.Statistical metric calculations.

Statistical 

Measure

Shorthand 

Notation Mathematical Expression Units

Accuracy of Paired Peak Ap

peak

peak

O

P  O

Percent

Mean Bias MB

 





N

i

Pi Oi

N 1

1

Concentration

Mean Absolute Gross Error MAGE





N

i

Pi Oi

N 1

1

Concentration

Normalized Mean Bias NMB

 











N

i

i

N

i

i i

O

P O

1

1

Percent

Normalized Mean Error NME











N

i

i

N

i

i i

O

P O

1

1

Percent

Mean Normalized Bias MNB

  



N

i i

i i

O

P O

N 1

1

Percent

Mean Normalized Gross Error MNGE



N 

i i

i i

O

P O

N 1

1

Percent

Mean Fractionalized Bias 

(Fractional Bias)

MFB























N

i i i

i i

P O

P O

N 1

2

Percent

Mean Fractional Error MFE

 



N

i i i

i i

P O

P O

N 1

2

Percent

The issue of model performance goals and criteria in the model performance evaluation has 

undergone refinement over the last several decades. The main objective of the model 

performance evaluation is to ascertain whether the model is getting the right answer for the 

right reason and is an accurate and reliable tool for estimating future year air quality levels. 

Model performance goals and criteria are useful for helping interpret model performance and 

comparing model performance across studies, models and temporal and spatial periods. In 

1991, EPA established model performance goals for ozone State Implementation Plan (SIP) 

modeling that bias should be within ±15% and error should be within 35% (EPA, 1991). The EPA 

1991 ozone bias and error performance goals were based on the Mean Normalized Bias (MNB) 

and Mean Normalized Gross Error (MNGE) using predicted and observed hourly ozone pairs for 

which the observed value was greater than a 60 ppb ozone concentration threshold.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-11

In some of the early ozone SIP modeling, the model evaluation focused on achieving the model 

performance goals rather than whether the model was getting the right answer for the right 

reason and is a reliable future year air quality forecasting tool. Thus, in EPA’s latest air quality 

modeling guidance they have emphasized use of model performance measures and displays to 

ascertain whether the model is realistically simulating the observed air quality and deemphasized the use of model performance goals. EPA’s latest guidance provides a list of 

studies and the ranges of model performance they have achieved (EPA, 2007), rather than 

specifying performance goals that must be achieved. However, model performance goals and 

criteria are still useful tools for assisting in judging model performance and recent modeling 

studies have developed goals for particulate matter to complement EPA’s ozone performance 

goals.

Several Regional Planning Organizations (RPOs)2 have established model performance goals and 

criteria for components of fine particle mass based on previous model performance for ozone 

and fine particles (Boylan, 2004; e.g., Morris et al., 2004a,b,c; 2007; 2008a,b). EPA modeling 

guidance for fine particulate matter notes that PM models might not be able to achieve the 

same level of performance as ozone models. The RPOs reviewed numerous model 

performance evaluation metrics to evaluate their descriptive capabilities for summarizing the 

salient features of the model performance evaluation. Although numerous model performance 

statistics measures are routinely calculated, the RPOs have found that the mean fractional bias 

(MFB) and mean fractional error (MFE) provide the best descriptive power over a wide range of 

concentrations that occur for PM component species. The fractional bias and error are 

expressed as a percentage and are normalized by the average of the predicted and observed 

values (see Table A2-2). Consequently, they are bounded statistics, with the fractional bias 

bounded by -200% to +200% and the fraction error bounded by 0% to 200%. Table A2-3 lists 

the model performance goals and criteria developed by the RPOs to assist in evaluating regional 

model performance for PM species. These goals have been applied to fractional bias and error, 

but can also be applied for the mean normalized and normalized mean bias and error metrics as 

well (Table A2-3). The most stringent model performance goals are the same as the EPA 1991 

ozone performance goal with bias/error goals of within ±15%/35%. For PM species the 

bias/error performance goal has been relaxed to be within ±30%/50% to reflect the fact that 

there are many more processes and sources involved in PM and that PM measurements are 

much less accurate than for ozone (uncertainties in the measurements for some PM species, 

such as OCM, are as high or higher than the ozone model performance goal). Finally, the RPOs 

have a PM bias/error model performance criteria of within ±60%/75% above which concerns 

regarding the reliability of the model are raised.

 

2

Five RPOs were established in the U.S. consisting of States, Local and Federal Agencies and Stakeholders to perform the 

technical analysis needed to develop the regional haze SIPs.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-12

Table A2-3. RPO model performance goals and criteria for components of fine particle mass.

Fractional Bias Fractional Error Comment

<±15% <35% Goal for PM model performance based on ozone model 

performance, considered excellent performance 

<±30% <50% Goal for PM model performance, considered good 

performance 

<±60% <75%

Criteria for PM model performance, considered average 

performance. Exceeding this level of performance indicates 

fundamental concerns with the modeling system and triggers 

diagnostic evaluation.

For calculating ozone model performance statistics, a threshold is typically used to screen out 

predicted and observed hourly ozone pairs whose observed value is below the threshold. For 

1-hour ozone SIP modeling of urban nonattainment areas, an hourly observed ozone threshold 

of 60 ppb has typically been used in the past, but lower thresholds of 40 and 50 ppb were also 

adopted in the CD-C modeling, which is focused on rural areas with lower regional background 

ozone levels. This issue is discussed further in Section 4 of this Appendix.

As noted in EPA’s PM modeling guidance, less abundant PM species should have less stringent 

model performance goals than those PM species that make up a substantial portion of the 

PM2.5 mass or visibility degradation due to PM (EPA, 2001; 2007). To address this issue, the 

RPOs have used PM performance goals that are a continuous function of average concentration 

that have the following features (Boylan, 2004):

 Asymptotically approaching the proposed performance goal or criteria (e.g., the ±30% and 

±60% MFB performance goal and criteria given in Table A2-3) when the mean observed 

concentration is greater than 2.5 μg/m3.

 Approaching 200% error and ±200% bias when the mean observed concentrations 

approach zero.

The MFB and MFE are plotted as a function of average observed concentration (Figure A2-3). 

As the mean observed concentration approaches zero. The MFB performance goal and criteria 

flare out to ±200% creating a horn shape. Hence, these model performance plots have been 

named “Bugle Plots”. The RPOs have identified three levels of performance in the Bugle Plots 

(Boylan, 2004): (1) Zone 1 meets the ±30%/60% MFB/MFE PM performance goal and is 

considered “good” model performance for a PM model; (2) Zone 2 has MFB/MFE that lies 

between the ±30%/60% PM performance goal and ±60%/75% performance criteria and is an 

area where concern for model performance is raised, but is not uncommon model performance 

for PM models; and (3) Zone 3 is when the MFB/MFE lies outside of the ±60%/75% PM 

performance criteria and is an area of questionable model performance.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-13

Figure A2-3.Example Bugle Plots used for evaluation of model PM performance. Shown are 

monthly fractional bias (top) and error (bottom) for sulfate (SO4) performance for the CAMx 

2005 base case across CASTNet, IMPROVE and STN monitoring sites in 12 km modeling 

domain that are compared against the PM model performance goals (blue) and criteria (red).

CD-C 12km 2005

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

SO4 CD-C 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

SO4
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-14

A3.REGIONAL CAMx 36 KM MODEL PERFORMANCE EVALUATION

The CD-C CAMx 2005 and 2006 base case simulation of the continental U.S. 36 km domain was 

evaluated across two separate regions of the U.S. using monitoring sites that lie within the 

WRAP (western states) and VISTAS (southeastern states) Regional Planning Organization (RPO) 

regions (Figure A3-1). A broad-brush evaluation of the 2005 and 2006 36 km CAMx base case

simulations was made using monthly fractional bias and fractional error statistical performance 

metrics that were compared against the PM model performance goals and criteria as well as 

with the RPO model performance for 2002 using the CMAQ modeling system (Byun and Ching, 

1999) on the same 36 km U.S. modeling domain used in the CD-C CAMx modeling. The WRAP 

and VISTAS 2002 CMAQ modeling was used to develop regional haze State Implementation 

Plans (SIPs) and the comparison of the CD-C CAMx 2006-2006 36 km model performance with 

the CMAQ 2002 performance from WRAP and VISTAS is used as a point of reference and 

comparison. The focus of the evaluation of the 36 km base case simulations is on particulate 

matter (PM) species since EPA recommends that finer grid resolution (e.g., at least 12 km with 4 

km in high emission areas) be used for ozone modeling (EPA, 2007). The evaluation of the CD-C 

2005-2006 12/4 km base case modeling for ozone is presented in Section 4 of this Appendix.

Surface layer particulate matter (PM) fields from the CD-C CAMx base case simulation for 2005-

2006 were evaluated relative to speciated PM observations from the IMPROVE, CASTNet, and 

STN3ambient air quality monitoring networks. The location of monitoring sites within the 36 

km domain is shown in Figure A2-1. Although observations from other networks were available 

(i.e. NADP), the present evaluation of the CD-C 36 km base case simulation focuses on these 

three networks for the purposes of comparison with annual 36 km CMAQ modeling of 2002 

done by the WRAP and VISTAS RPOs. Note that the CD-C 36 km domain definition is identical to 

what WRAP and VISTAS used, although the CD-C modeling used 34 vertical layers versus 19 in 

WRAP and VISTAS. A more refined model performance evaluation of CD-C CAMx run PM 

performance on the 12/4 km domain was carried out using additional observational networks

and is discussed in Section 5 of this Appendix.

The comparison of the CD-C 2005 and 2006 36 km CAMx base case simulation with the WRAP 

2002 36 km CMAQ run was carried out over the WRAP RPO region, which encompasses most of 

the western U.S., including Wyoming and the CD-C Project Area (Figure A4-1). The comparison 

of the CD-C 2005 and 2006 36 km CAMx run with the VISTAS 2002 36 km CMAQ run was carried

out over the VISTAS RPO region, which covers the southeastern U.S (Figure A3-1). 

For the CD-C 2005 and 2006 CAMx, the VISTAS 2002 CMAQ and the WRAP 2002 CMAQ base 

case simulations, monthly fractional bias and fractional error statistics were calculated using 

paired predictions and observations from all available sites in the CASTNET, IMPROVE, and STN 

networks for all monitors across the WRAP and VISTAS regions. The resulting statistics are 

displayed in Bugle Plots of monthly fractional bias in order to compare model performance for 

the three runs and compare the performance with the PM performance goals and criteria. 

Note that the Bugle Plot performance goal and criteria lines as they approach the zero observed 

concentration are incorrectly placed on the WRAP 2002 CMAQ run Bugle Plots, but the monthly 

 

3

The STN is now referred to as the Chemical Speciation Network (CSN)
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-15

performance statistics may be compared directly with those of the CD-C 2005 and 2006 CAMx 

base case simulation.

Figure A3-1. Map of the five Regional Planning Organization (RPO) regions.

A3.1 SULFATE (SO4) MODEL PERFORMANCE

The bugle plots for the CD-C 2005 and 2006 CAMx 36 km base case simulations evaluated for 

SO4 across the WRAP and VISTAS regions and the comparisons with the WRAP and VISTAS 2002 

CMAQ model performance are shown in Figures A3-2 and A3-3, respectively. With the 

exception of one month in 2005 and 2006 across STN monitoring sites, the CD-C SO4 bias in the 

WRAP region always achieves the PM performance criteria (Figure A3-2). Of the 72 months 

across the two years of modeling and three networks, the CD-C 36 km CAMx simulation’s SO4

bias achieves the PM performances goal 85% of the time (61 out of 72). It appears that the 

WRAP 2002 CMAQ simulation achieves the performance goals and criteria more frequently 

than the CD-C simulation, but that is because WRAP used a much more lenient definition of the 

flare in the Bugle Plot, whereas in the CD-C study we adhered to the peer-reviewed formulation 

from the Bugle Plot’s developer (Boylan, 2004). 

Both the CD-C 2005-2006 CAMx 36 km and VISTAS 2002 CMAQ 36 km have much higher 

predicted SO4 concentrations across the southeastern U.S. VISTAS region (Figure A3-3). The SO4

bias and error across the VISTAS region always achieves the PM performance criteria and 

usually achieves the PM performance criteria for both the CD-C and VISTAS base case 

simulations. The models are characterized by a summer underestimation and winter 

overestimation bias. The VISTAS 2002 CMAQ simulation exhibits better SO4 model 

performance in the southeastern U.S. than the CD-C 2005-2006 CAMx simulations. This is 

probably due to the fact that VISTAS optimized their 2002 CMAQ modeling database for 

simulating PM in the southeastern U.S., whereas the CD-C focus was on Wyoming and adjacent 

regions.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-16

In general, SO4 model performance for both the CD-C CAMx and WRAP and VISTAS CMAQ 

simulations was good, meeting the performance goals most of the time and always meeting the 

performance criteria.

WRAP 2002 CMAQ SO4 Bias WRAP 2002 CMAQ SO4 Error

CD-C2005 SO4 Bias CD-C2005 SO4 Error

CD-C2006 SO4 Bias CD-C2006 SO4 Error

Figure A3-2. Bugle Plots of SO4 fractional bias (left) and fractional error (right) for the WRAP 2002 CMAQ 

(top), CD-C 2005 CAMx (middle) and CD-C 2006 CAMx (bottom) 36 km base case simulations for monitoring 

sites within the WRAP region.

Bugle Plot of Monthly SO4 Fractional Bias 

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0

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150

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0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3) Fractional Bias (%)

(+) Goal (-) Goal (+) Criteria (-) Criteria

CASTNET IMPROVE STN

Bugle Plot of Monthly SO4 Fractional Error

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3) Fractional Error (%)

Goal Criteria CASTNET IMPROVE STN

Bugle Plot of Monthly SO4 Fractional Bias 

-200

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-50

0

50

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150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3) Fractional Bias (%)

(+) Goal (-) Goal (+) Criteria (-) Criteria

CASTNET IMPROVE STN

Bugle Plot of Monthly SO4 Fractional Error

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3) Fractional Error (%)

Goal Criteria CASTNET IMPROVE STN
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-17

VISTAS 2002 CMAQ SO4 Bias VISTASA 2002 CMAQ SO4 Error

CD-C2005 SO4 Bias CD-C2005 SO4 Error

CD-C2006 SO4 Bias CD-C2006 SO4 Error

Figure A3-3. Bugle Plots of SO4 fractional bias (left) and fractional error (right) for the VISTAS 2002 

CMAQ (top), CD-C 2005 CAMx (middle) and CD-C 2006 CAMx (bottom) 36 km base case simulations for 

monitoring sites within the WRAP region.

Sulfate: 12 Months (2002) 

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Sulfate: 12 Months (2002) 

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Sulfate: 12 Months (2002) 

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Sulfate: 12 Months (2002) 

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Bugle Plot of Monthly SO4 Fractional Bias 

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0

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150

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0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3) Fractional Bias (%)

(+) Goal (-) Goal (+) Criteria (-) Criteria

CASTNET IMPROVE STN

Bugle Plot of Monthly SO4 Fractional Error

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3) Fractional Error (%)

Goal Criteria CASTNET IMPROVE STN

Bugle Plot of Monthly SO4 Fractional Bias 

-200

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-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3) Fractional Bias (%)

(+) Goal (-) Goal (+) Criteria (-) Criteria

CASTNET IMPROVE STN

Bugle Plot of Monthly SO4 Fractional Error

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3) Fractional Error (%)

Goal Criteria CASTNET IMPROVE STN
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-18

A3.2 NITRATE (NO3) MODEL PERFORMANCE

Over the WRAP region, the 2005 and 2006 CD-C CAMx runs show both overestimations and 

underestimations of NO3, whereas the WRAP 2002 CMAQ run show mainly underestimations 

(Figure A3-4). Because the observed NO3 concentrations at the IMPROVE and CASTNet 

monitoring sites in the western U.S. are so low, the monthly bias and error performance 

statistics are in the flared portions of the Bugle Plots. Thus, even though bias can approach 

±100%, the CD-C and WRAP base case simulations NO3 performance achieves the PM 

performance goal across the IMPROVE and CASTNet networks in the western U.S. Across the 

STN network in the western U.S., however, the observed NO3 concentrations are higher and fall 

outside the flare in the Bugle Plot resulting in many months not meeting even the PM 

performance criteria in both the CD-C CAMx and WRAP CMAQ plots due to excessive

underestimation bias.

Over the VISTAS region, the CD-C CAMx base case showed performance that was comparable to 

or better than the VISTAS 2002 CMAQ run (Figure A3-5), with better performance in the CD-C 

run coming at average concentrations higher than 1 μg/m3. Whereas both CAMx and CMAQ 

exhibit a summer underestimation bias for NO3 across the VISTAS region, it occurs under low 

observed NO3 conditions so many of the fractional bias points fall on the PM performance goal 

and criteria flare. During the winter, the VISTAS 2002 CMAQ concentrations exhibits an 

overestimation bias that occurs under much higher observed NO3 conditions and can be quite 

large not achieving the PM performance criteria. The CD-C CAMx runs do not exhibit this 

widespread overestimation bias and achieves the performance goals and criteria more often 

than the VISTAS CMAQ run.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-19

WRAP 2002 CMAQ NO3 Bias WRAP 2002 CMAQ NO3 Error

CD-C 2005 NO3 Bias CD-C 2005 NO3 Error

CD-C 2006 NO3 Bias CD-C 2006 NO3 Error

Figure A3-4. Bugle Plots of NO3 fractional bias (left) and fractional error (right) for the WRAP 2002 

CMAQ (top), CD-C 2005 CAMx (middle) and CD-C 2006 CAMx (bottom) 36 km base case simulations 

for monitoring sites within the WRAP region.

Bugle Plot of Monthly NO3 Fractional Bias 

-200

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-100

-50

0

50

100

150

200

0 2 4 6 8 10 12

Average Concentration (ug/m3) Fractional Bias (%)

(+) Goal (-) Goal (+) Criteria (-) Criteria

CASTNET IMPROVE STN

Bugle Plot of Monthly NO3 Fractional Error

0

50

100

150

200

0 2 4 6 8 10 12

Average Concentration (ug/m3) Fractional Error (%)

Goal Criteria CASTNET IMPROVE STN

Bugle Plot of Monthly NO3 Fractional Bias 

-200

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-50

0

50

100

150

200

0 2 4 6 8 10 12

Average Concentration (ug/m3) Fractional Bias (%)

(+) Goal (-) Goal (+) Criteria (-) Criteria

CASTNET IMPROVE STN

Bugle Plot of Monthly NO3 Fractional Error

0

50

100

150

200

0 2 4 6 8 10 12

Average Concentration (ug/m3) Fractional Error (%)

Goal Criteria CASTNET IMPROVE STN
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-20

VISTAS 2002 CMAQ NO3 Bias VISTAS 2002 CMAQ NO3 Error

CD-C 2005 NO3 Bias CD-C C 2005 NO3 Error

CD-C 2006 NO3 Bias CD-C 2006 NO3 Error

Figure A3-5. Bugle Plots of NO3 fractional bias (left) and fractional error (right) for the VISTAS 2002 

CMAQ (top), CD-C 2005 CAMx (middle) and CD-C 2006 CAMx (bottom) 36 km base case simulations 

for monitoring sites within the WRAP region.

Nitrate: 12 Months (2002) 

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Nitrate: 12 Months (2002) 

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Nitrate: 12 Months (2002) 

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Nitrate: 12 Months (2002) 

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Average Concentration (g/m3) Mean Fractional Error 

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Nitrate: 12 Months (2002) 

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Nitrate: 12 Months (2002) 

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Bugle Plot of Monthly NO3 Fractional Bias 

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Average Concentration (ug/m3) Fractional Bias (%)

(+) Goal (-) Goal (+) Criteria (-) Criteria

CASTNET IMPROVE STN

Bugle Plot of Monthly NO3 Fractional Error

0

50

100

150

200

0 1 2 3 4

Average Concentration (ug/m3) Fractional Error (%)

Goal Criteria CASTNET IMPROVE STN

Bugle Plot of Monthly NO3 Fractional Bias 

-200

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0

50

100

150

200

0 1 2 3 4

Average Concentration (ug/m3) Fractional Bias (%)

(+) Goal (-) Goal (+) Criteria (-) Criteria

CASTNET IMPROVE STN

Bugle Plot of Monthly NO3 Fractional Error

0

50

100

150

200

0 1 2 3 4

Average Concentration (ug/m3) Fractional Error (%)

Goal Criteria CASTNET IMPROVE STN
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-21

A3.3 ORGANIC CARBON MASS (OCM) PERFORMANCE

OCM is not directly measured in the atmosphere. Instead, OC is measured and must be 

converted to OCM for comparison with the modeled OCM and for constructing PM2.5 mass. 

Thus, the assumed OCM/OC ratio introduces a source of uncertainty and potential bias in the 

measured OCM. Even measuring OC is difficult, with different measurement technologies 

producing different OC values. For example, co-located STN and IMPROVE OC measurement 

technologies can produce measured OC that differs by 50%. Issues in simulating OC in air 

quality models are discussed further in Section 5 of this Appendix. During the course of the 

WRAP study, OCM/OC ratios of 1.4 and 1.0 have been used. It was unclear which OCM/OC 

ratio was used in generating the Bugle Plots downloaded from the WRAP modeling website. 

More recent information suggests that an average OCM/OC ratio of 1.8 is appropriate for the 

more rural IMPROVE monitor network, so that was adopted for the CD-C CAMx OCM 

evaluation. Thus, the OCM observations in the CD-C evaluation will be 30% to 80% higher than 

what was used in the WRAP OCM evaluation just due to the assumed observed OCM/OC ratios.

Figure A3-6 compares the CD-C CAMx and WRAP CMAQ OCM Bugle Plots across sites in the 

western U.S., Not surprisingly, the CD-C fractional bias values are 30-80% lower than seen for 

WRAP, which is due to different observed OCM/OC ratios. When accounting for that, the OCM 

performance is comparable.

Similar observed OCM/OC ratio issues exist in the comparisons with the VISTAS CMAQ OCM 

performance, only in this case we know VISTAS used a 1.4 factor to convert the observed OC to 

OCM so the CD-C OCM observations are 30% higher than assumed in VISTAS. Both models 

underestimate OCM across the southeastern U.S. with the VISTAS CMAQ OCM underestimation 

bias ranging from approximately 0% to -100% and the CD-C CAMx OCM underestimation bias 

ranging from approximately -30% to -130% (Figure A3-7). These differences in OCM model 

performance can be completely explained by the assumed observed OCM/OC ratios in the two 

studies.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-22

WRAP 2002 CMAQ OCM Bias WRAP 2002 CMAQ OCM Error

CD-C 2005 OCM Bias CD-C 2005 OCM Error

CD-C 2006 OCM Bias CD-C 2006 OCM Error

Figure A3-6. Bugle Plots of OCM fractional bias (left) and fractional error (right) for the WRAP 

2002 CMAQ (top), CD-C 2005 CAMx (middle) and CD-C 2006 CAMx (bottom) 36 km base case 

simulations for monitoring sites within the WRAP region.

Bugle Plot of Monthly OC Fractional Bias 

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-50

0

50

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150

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0 2 4 6 8 10 12

Average Concentration (ug/m3) Fractional Bias (%)

(+) Goal (-) Goal

(+) Criteria (-) Criteria

IMPROVE STN

Bugle Plot of Monthly OC Fractional Error

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Average Concentration (ug/m3) Fractional Error (%)

Goal Criteria

IMPROVE

STN

Bugle Plot of Monthly OC Fractional Bias 

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(+) Goal (-) Goal

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Bugle Plot of Monthly OC Fractional Error

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Average Concentration (ug/m3) Fractional Error (%)

Goal Criteria

IMPROVE

STN
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-23

VISTAS 2002 CMAQ OCM Bias VISTAS 2002 CMAQ OCM Error

CD-C 2005 OCM Bias CD-C 2005 OCM Error

CD-C 2006 OCM Bias CD-C 2006 OCM Error

Figure A3-7. Bugle Plots of OCM fractional bias (left) and fractional error (right) for the VISTAS 

2002 CMAQ (top), CD-C 2005 CAMx (middle) and CD-C 2006 CAMx (bottom) 36 km base case 

simulations for monitoring sites within the VISTA region.

Organics: 12 Months (2002) 

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Organics: 12 Months (2002) 

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Bugle Plot of Monthly OC Fractional Bias 

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Bugle Plot of Monthly OC Fractional Error

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Bugle Plot of Monthly OC Fractional Bias 

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(+) Goal (-) Goal

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Bugle Plot of Monthly OC Fractional Error

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Average Concentration (ug/m3) Fractional Error (%)

Goal Criteria

IMPROVE

STN
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-24

A3.4 ELEMENTAL CARBON (EC) PERFORMANCE

The CD-C 2005 and 2006 CAMx and WRAP 2002 CMAQ runs generally show good performance 

for EC that almost always achieves the PM performance goals and criteria (Figure A3-8). For 

one month from 2005 and two months from 2006 the EC bias did not achieve the PM 

performance criteria, whereas the WRAP CMAQ run always achieves it. Good EC performance 

is also seen in the CD-C CAMx and VISTAS CMAQ runs across the southeastern U.S. with both 

models always achieving the PM performance goal (Figure A3-9).

WRAP 2002 CMAQ EC Bias WRAP 2002 CMAQ EC Error

CD-C 2005 EC Bias CD-C 2005 EC Error

CD-C 2006 EC Bias CD-C 2006 EC Error

Figure A3-8. Bugle Plots of EC fractional bias (left) and fractional error (right) for the WRAP 2002 

CMAQ (top), CD-C 2005 CAMx (middle) and CD-C 2006 CAMx (bottom) 36 km base case simulations 

for monitoring sites within the WRAP region.

Bugle Plot of Monthly EC Fractional Bias 

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Average Concentration (ug/m3) Fractional Bias (%)

(+) Goal (-) Goal

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IMPROVE STN

Bugle Plot of Monthly EC Fractional Error

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Goal Criteria

IMPROVE

STN

Bugle Plot of Monthly EC Fractional Bias 

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Bugle Plot of Monthly EC Fractional Error

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Average Concentration (ug/m3) Fractional Error (%)

Goal Criteria

IMPROVE

STN
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-25

VISTAS 2002 CMAQ EC Bias VISTAS 2002 CMAQ EC Error

CD-C 2005 EC Bias CD-C 2005 EC Error

CD-C 2006 EC Bias CD-C 2006 EC Error

Figure A3-9. Bugle Plots of EC fractional bias (left) and fractional error (right) for the VISTAS 2002 

CMAQ (top), CD-C 2005 CAMx (middle) and CD-C 2006 CAMx (bottom) 36 km base case simulations 

for monitoring sites within the VISTAS region.

Elem. Carbon: 12 Months (2002) 

-200

-150

-100

-50

0

50

100

150

200

0.0 0.5 1.0 1.5 2.0 2.5 3.0

Average Concentration (g/m3) Mean Fractional Bias 

IMPROVE

STN

SEARCH

CASTNET

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

Elem. Carbon: 12 Months (2002) 

0

50

100

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200

0.0 0.5 1.0 1.5 2.0 2.5 3.0

Average Concentration (g/m3) Mean Fractional Error 

IMPROVE

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Goal

Criteria

Elem. Carbon: 12 Months (2002) 

-200

-150

-100

-50

0

50

100

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0.0 0.5 1.0 1.5 2.0 2.5 3.0

Average Concentration (g/m3) Mean Fractional Bias 

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(-) Goal

(+) Criteria

(-) Criteria

Elem. Carbon: 12 Months (2002) 

0

50

100

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200

0.0 0.5 1.0 1.5 2.0 2.5 3.0

Average Concentration (g/m3) Mean Fractional Error 

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Goal

Criteria

-200

-150

-100

-50

0

50

100

0.0 0.5 1.0 1.5 2.0 2.5 3.0

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IMPROVE

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(+) Criteria

(-) Criteria

Elem. Carbon: 12 Months (2002) 

0

50

100

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200

0.0 0.5 1.0 1.5 2.0 2.5 3.0

Average Concentration (g/m3) Mean Fractional Error 

IMPROVE

STN

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Goal

Criteria

-200

-150

-100

-50

0

50

100

0.0 0.5 1.0 1.5 2.0 2.5 3.0

Average Concentration (g/m3) Mean Fractional 

IMPROVE

STN

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CASTNET

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

Elem. Carbon: 12 Months (2002) 

0

50

100

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200

0.0 0.5 1.0 1.5 2.0 2.5 3.0

Average Concentration (g/m3) Mean Fractional Error 

IMPROVE

STN

SEARCH

CASTNET

Goal

Criteria

Bugle Plot of Monthly EC Fractional Bias 

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3) Fractional Bias (%)

(+) Goal (-) Goal

(+) Criteria (-) Criteria

IMPROVE STN

Bugle Plot of Monthly EC Fractional Error

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3) Fractional Error (%)

Goal Criteria

IMPROVE

STN

Bugle Plot of Monthly EC Fractional Bias 

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3) Fractional Bias (%)

(+) Goal (-) Goal

(+) Criteria (-) Criteria

IMPROVE STN

Bugle Plot of Monthly EC Fractional Error

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3) Fractional Error (%)

Goal Criteria

IMPROVE

STN
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-26

A3.5 COARSE MASS (CM OR PM2.5-10) PERFORMANCE

Coarse Mass (CM) is the coarse fraction of PM10 and is defined to be the difference PM10-PM2.5 

obtained by subtracting the fine PM contribution from the total PM10. The average observed 

coarse mass concentrations across the western states during 2005 and 2006 range from 

approximately 2 μg/m3in the winter to almost 7 μg/m3in the summer. Over the WRAP region,

the CD-C CAMx and the WRAP CMAQ base case simulations both failed to meet the 

performance goals and the performance criteria for CM for most months (Figure A3-10). CAMx 

and CMAQ both underestimate the observed CM for all months with a fractional bias greater 

than 100% for the summer months. In terms of CM performance, the 2005 and 2006 CD-C 

CAMx runs are comparable to the WRAP 2002 CMAQ run. 

The poor model performance in simulating CM by both CAMx and CMAQ is not surprising as the 

transport distance of CM is much shorter than for fine PM species so that much of the CM 

impacts measured at IMPROVE monitors is of local origin and is therefore not resolved by the 

model. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-27

WRAP 2002 CMAQ CM Bias WRAP 2002 CMAQ CM Error

CD-C 2005 CM Bias CD-C 2005 CM Error

CD-C 2006 CM Bias CD-C 2006 CM Error

Figure A3-10. Bugle Plots of CM fractional bias (left) and fractional error (right) for the WRAP 2002 

CMAQ (top), CD-C 2005 CAMx (middle) and CD-C 2006 CAMx (bottom) 36 km base case simulations 

for monitoring sites within the WRAP region.

Bugle Plot of Monthly CM Fractional Bias 

-200

-150

-100

-50

0

50

100

150

200

0 2 4 6 8 10 12

Average Concentration (ug/m3) Fractional Bias (%)

(+) Goal (-) Goal

(+) Criteria (-) Criteria

IMPROVE

Bugle Plot of Monthly CM Fractional Error

0

50

100

150

200

0 2 4 6 8 10 12

Average Concentration (ug/m3) Fractional Error (%)

Goal

Criteria

IMPROVE

Bugle Plot of Monthly CM Fractional Bias 

-200

-150

-100

-50

0

50

100

150

200

0 2 4 6 8 10 12

Average Concentration (ug/m3) Fractional Bias (%)

(+) Goal (-) Goal

(+) Criteria (-) Criteria

IMPROVE

Bugle Plot of Monthly CM Fractional Error

0

50

100

150

200

0 2 4 6 8 10 12

Average Concentration (ug/m3) Fractional Error (%)

Goal

Criteria

IMPROVE
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-28

A3.5 OZONE

The resolution of the CD-C CAMx 36 km base case simulations are too coarse to accurately 

simulate ozone concentrations, so a detailed ozone evaluation against observations was not 

performed using the 36 km modeling results. Because the primary purpose of the 36 km CAMx 

simulations are to provide boundary conditions to the 12/4 km CAMx simulations, we did 

evaluate the models ability to simulate ozone concentrations at the mainly rural CASTNet 

monitors near the location of the 12 km boundaries and they were determined to be 

reasonable. Details on the CAMx 2005 and 2006 base case simulation ozone model 

performance in the 12/4 km modeling domains is provided in Chapter 5. 

A3.6 CONCLUSIONS FROM EVALUATION OF 36 KM CAMX RUN

The performance of the 2005 and 2006 36 km CD-C CAMx runs was generally within accepted 

performance benchmarks for PM and is comparable to similar annual runs made by the WRAP 

and VISTAS RPOs for the year 2002. The WRAP and VISTAS 2002 CMAQ model performance 

was deemed sufficiently good that the modeling was accepted for use in regional haze SIP 

modeling, which is a more stringent task then simply providing boundary conditions to a 12/4 

km nested grid simulations. The broad brush evaluation indicates no serious performance 

issues that would prevent the CD-C CAMx 36 km runs from being used to supply boundary 

conditions to the 2005 and 2006 CD-C 12/4 km CAMx runs. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-29

A4. OZONE MODEL PERFORMANCE EVALUATION

The CAMx model performance for ozone was evaluated within the 12/4 km modeling domain 

for the revised 2005 and 2006 base case simulations (Figure A1-2). The CAMx modeling results 

were compared with observational data from the EPA’s Air Quality Station (AQS) and the Clean 

Air Status Trends Network (CASTNet) monitoring networks and at the Wyoming Department of 

Environmental Quality (WDEQ) industrial ozone monitors within the state of Wyoming. The 

evaluation focuses on the operational model evaluation of the air quality model’s performance 

with respect to ozone. 

Ozone monitoring sites within the 4 km modeling domain that were in operation during the 

2005 and 2006 modeling period were two CASTNet sites at Pinedale and Centennial and 

Wyoming state industrial site monitors at Jonah, Boulder, Daniel, OCI and Wamsutter (OCI and 

Wamsutter started operation in 2006). There were no AQS monitoring sites located within the 

4 km domain, as the AQS network is oriented toward urban areas and the region encompassed 

by the 4 km domain is generally rural. Within the 12 km domain were 18 AQS sites and a total 

of 6 CASTNet sites, including Centennial and Pinedale.

A majority of the AQS ozone monitoring sites in the 12 km grid are located in the Salt Lake City, 

Utah and Denver, Colorado urban areas. The CAMx 2005 and 2006 modeling was configured 

for simulating ozone and PM concentrations from O&G sources in southwestern Wyoming 

(SWWY) and was not designed for simulating ozone in the Salt Lake City and Denver ozone 

nonattainment areas. For example, the Colorado Department of Health and Environment 

(CDPHE) has spent considerable effort performing meteorological and photochemical modeling 

to identify the optimal model configuration for simulating ozone formation in the Denver area 

for their ozone State Implementation Plan (SIP)4. Thus, our ozone model performance 

evaluation focuses on the performance at the more rural CASTNet ozone monitoring sites 

within the 12/4 km domains and at the Southwest Wyoming industrial sites within the 4 km 

domain.

A4.1 COMPARISON OF HOURLY OZONE MODEL PERFORMANCE WITH PERFORMANCE GOALS 

IN THE 4 KM MODELING DOMAIN

The CAMx hourly average ozone performance across CASTNet and Wyoming industrial 

monitoring sites in the 4 km domain are compared against EPA’s ≤±15% and ≤35% performance 

goals for bias and error, respectively (EPA, 1991). Although these ozone performance goals 

were originally developed for the Mean Normalized Bias (MNB) and Mean Normalized Gross 

Error (MNGE) statistical performance metrics, we have also compared them to the Fractional 

Bias (FB), Normalized Mean Bias (NMB), Fractional Error (FE) and Normalized Mean Gross Error 

(NMGE) statistical performance metrics as well (See Table A2-2 for definitions). EPA procedures 

for calculating these performance goals are to use all predicted and observed hourly ozone 

pairs with the observed ozone concentration above a concentration threshold value. EPA’s 

original guidance suggested using an observed hourly ozone concentrations threshold of 60 ppb 

(EPA, 1991). However, this guidance was developed almost two decades ago for urban ozone 

modeling to address the 120 ppb ozone NAAQS under ozone conditions much higher than 

 

4

http://www.colorado.gov/airquality/documents/deno308/
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-30

currently occur in more rural southwest Wyoming. Use of a 60 ppb cutoff threshold may result 

in too few predicted and observed hourly ozone pairs to calculate robust model performance 

statistics. Thus, the hourly ozone bias and error performance statistics were calculated using 

three different observed hourly ozone cutoff thresholds: 60, 50 and 40 ppb. This ensures that 

the model performance evaluation is focused on times when ozone is high, rather than on 

relatively clean days or on nighttime conditions, and assures, at least for the lower cutoff 

concentration thresholds, that there are sufficient predicted and observed hourly ozone pairs 

so that the statistics are meaningful. 

Table A4-1 summarizes the hourly ozone performance statistics metrics for bias and error 

across the CASTNet and Wyoming industrial sites in the 4 km domain for 2005 and 2006 by 

Quarter. Performance statistics were calculated across all CASTNet and Wyoming industrial 

sites and separately at each site. The Wyoming industrial sites are located within or near the 

Jonah-Pinedale Anticline region of intensive oil and gas exploration and production in Sublette

County. Although the Pinedale CASTNet site lies adjacent to the Pinedale Anticline natural gas 

field, it is located at a higher elevation than the field, and ozone data gathered at Pinedale is 

more similar in character to Centennial CASTNet site located ~350 km to the southeast on the 

border of Carbon and Albany Counties than nearby monitors at lower elevations such as Jonah 

and Boulder. When the bias or error ozone statistical performance measure exceeds EPA’s 

ozone performance goal, the value is highlighted in yellow in Table A4-1. Table A4-1 contains 

the bias and error ozone performance statistics for the original (June 2009) CAMx base case 

simulation performed under the Hiawatha EIS (Kemball-Cook et al., 2009) as well as the latest 

revised CAMx base case simulation performed as part of the CD-C EIS study.

Across all monitoring sites in the 4 km modeling domain and for the entire 2005 year (“All Sites” 

entry in Table A4-1a), both the Hiawatha and CD-C CAMx base case simulations achieve EPA’s 

bias and error performance goals for the bias and error performance metrics using a 40 ppb 

ozone cutoff (Table A4-1a). However, looking at the individual monitoring sites in 2005, EPA’s 

performance goals are met or nearly met at the two CASTNet sites and Daniel, but there is an 

underestimation of -18% to -29% at the Jonah and Boulder sites; the CD-C revised CAMx base 

case simulation ozone performance is slightly better (bias being a couple percentage points 

closer to zero) than the preliminary Hiawatha base case simulation for the annual performance 

statistics in 2005.

It is not surprising that EPA’s bias performance goals during Q1 are not achieved since the 

model was not configured to reproduce the observed winter ozone events in SWWY. The 

WDEQ AQD has indicated that Q1 will not be included in the CD-C ozone impact analysis as 

simulation of winter ozone using photochemical grid models is an active area of scientific 

research and is therefore not appropriate for a NEPA analysis; this is discussed further in 

Section 4.2. During Q2 and Q3 in 2005, when the highest ozone occurs outside of the winter 

ozone events, both CAMx base case simulations achieve EPA’s performance goals across all 

monitoring sites in the 4 km domain using a 40 ppb cutoff (Table A4-1a). For 2005 Q2, both 

models achieve EPA’s performance goals individually across the monitoring sites with the 

exception of Jonah and the preliminary Hiawatha base case simulation that exhibits bias of -

16% to -20%. The diagnostic model tests that were performed to arrive at the CD-C model 

configuration was able to reduce the -16% to -20% bias at Jonah during 2005 Q2 to be able to 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS April 2016 A-31

achieve EPA’s bias performance goal (-13% to -15%) in the CD-C base case simulation. In 2005 

Q3, EPA’s performance goals are achieved across all sites but Jonah and Boulder for the 

Hiawatha base case. Again the model improvements implemented in the revised CD-C CAMx 

base case simulations are able to bring these two sites into achievement of EPA’s bias 

performance goals.

The use of the higher ozone cutoff thresholds results in larger ozone underestimation bias 

during 2005 (Tables A4-2b and 5-2c). Even so, the revised CD-C bias metrics exhibit much lower 

bias compared to the Hiawatha base case in most cases, resulting in improved ozone model 

performance.

In 2006, the two base case simulations exhibit better model performance than is seen in 2005 

(Table A4-1d). The revised CD-C CAMx base case is performing worse than the Hiawatha base 

case during the two colder quarters in 2006 (Q1 and Q4), but better during warmest quarter 

(Q3) and performance is slightly degraded during Q2. Across all sites, both the CD-C and 

Hiawatha CAMx base case simulations achieve EPA’s performance goals for the annual and byquarter time periods for 2006.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-32

Table A4-1a.Ozone model performance bias and error statistical measures with 40 ppb threshold for the CASTNet network and 

industrial sites for 2005by annual and quarter for all sites and for each site in the CD-C 4 km domain.

Site\Run Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C

All Sites -9.9 -14.6 17.4 18.5 -7.1 -11.9 15.3 16.1 -7.7 -12.2 15.5 16.3 24373

Jonah -28.6 -24.6 29.9 27.1 -21.8 -19.0 23.2 21.7 -22.1 -19.3 23.4 21.8 3688

Boulder -24.8 -22.0 26.9 25.0 -19.6 -17.7 21.8 20.9 -19.7 -18.0 21.7 20.9 4739

Daniel -14.2 -15.9 16.0 19.8 -12.5 -13.5 14.5 17.7 -13.0 -13.5 14.8 17.5 1960

Centennial 4.2 -7.4 11.4 12.5 5.3 -6.3 11.9 11.8 4.7 -6.4 11.8 11.8 7279

Pinedale -3.0 -11.3 10.7 15.4 -2.0 -9.6 10.3 14.0 -2.6 -9.9 10.5 14.2 6707

All Sites -11.0 -19.2 18.8 20.5 -7.2 -15.7 15.6 17.1 -8.4 -16.6 16.3 18.0 6025

Jonah -39.5 -43.6 41.0 44.1 -27.1 -31.3 28.7 31.9 -28.5 -32.6 29.8 33.1 965

Boulder -30.0 -24.4 31.6 25.0 -23.2 -20.7 24.8 21.3 -24.5 -22.2 25.9 22.7 1138

Centennial 7.0 -6.8 10.3 10.1 7.9 -6.0 10.9 9.5 7.6 -6.2 10.8 9.6 1903

Pinedale -3.5 -16.2 8.9 16.5 -2.8 -14.4 8.5 14.8 -3.3 -14.8 8.7 15.1 2019

All Sites -4.1 -10.0 16.0 15.4 -1.9 -8.1 15.2 14.0 -2.5 -8.6 15.0 14.1 6785

Jonah -20.0 -15.0 22.1 18.8 -16.2 -12.3 18.4 16.5 -16.3 -12.6 18.3 16.5 1319

Boulder -13.9 -13.4 18.0 18.3 -11.4 -11.0 15.9 16.4 -11.7 -11.6 15.7 16.4 1527

Centennial 9.7 -4.1 14.1 11.4 11.5 -3.1 15.5 11.0 10.8 -3.5 15.1 10.9 1989

Pinedale 0.2 -9.8 12.2 14.9 1.5 -8.1 12.2 13.6 0.6 -8.7 12.1 13.8 1950

All Sites -11.5 -9.3 17.3 15.9 -9.0 -7.4 15.3 14.6 -9.7 -7.9 15.4 14.6 7313

Jonah -30.0 -17.6 30.7 20.9 -24.0 -14.5 24.7 18.0 -23.8 -14.5 24.4 17.8 1074

Boulder -26.4 -16.1 27.5 20.5 -21.3 -13.2 22.5 18.1 -21.1 -13.7 22.2 17.8 1247

Daniel -13.6 -8.9 16.0 15.6 -11.9 -7.2 14.6 14.6 -12.6 -7.7 14.9 14.4 1083

Centennial 1.5 -5.3 10.3 12.8 2.3 -4.1 10.5 12.3 1.3 -4.3 10.4 12.3 2040

Pinedale -4.0 -4.8 11.3 13.6 -3.0 -3.3 10.9 13.0 -4.0 -4.0 11.2 13.1 1869

All Sites -14.7 -24.6 17.7 25.1 -11.9 -20.4 15.1 20.8 -12.1 -20.6 15.2 21.0 4250

Jonah -26.4 -30.1 26.6 30.3 -21.5 -24.1 21.7 24.3 -21.4 -24.1 21.6 24.3 330

Boulder -35.6 -43.5 35.9 43.8 -27.1 -32.7 27.3 32.9 -26.9 -32.5 27.1 32.8 827

Daniel -14.9 -24.7 15.9 25.0 -13.3 -21.3 14.3 21.6 -13.6 -21.6 14.6 21.9 877

Centennial -3.9 -16.6 10.5 17.2 -3.1 -14.8 10.1 15.5 -3.6 -15.1 10.2 15.8 1347

Pinedale -6.8 -17.1 9.9 17.5 -6.0 -15.1 9.3 15.5 -6.2 -15.2 9.3 15.6 869

Number

of

Points

MNB(%) ± 15% MNGE(%) ± 35% NMB(%) ± 15% NME(%) ± 35% Period EPA FB(%) ± 15% FGE(%) ± 35%

Q4

ANN

Q1

Q2

Q3
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-33

Table A4-1b.Ozone model performance bias and error statistical measures with 50 ppb threshold for the CASTNet network and 

industrial sites for 2005by annual and quarter for all sites and for each site in the CD-C 4 km domain.

Site\Run Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C

All Sites -12.2 -15.1 16.9 18.1 -9.8 -12.6 14.9 15.7 -10.5 -13.0 15.3 16.1 11263

Jonah -26.3 -22.7 27.1 24.6 -21.0 -17.8 21.8 19.9 -21.8 -18.6 22.5 20.6 2000

Boulder -22.6 -21.5 23.6 22.8 -18.7 -18.1 19.7 19.5 -19.3 -18.5 20.2 19.8 2364

Daniel -17.2 -14.3 17.9 17.1 -15.4 -12.4 16.0 15.4 -15.6 -12.4 16.2 15.3 763

Centennial 0.5 -7.7 10.4 12.5 1.4 -6.5 10.5 11.7 1.0 -6.7 10.6 11.8 3149

Pinedale -6.7 -12.9 11.5 16.0 -5.7 -11.0 10.7 14.3 -6.2 -11.4 11.0 14.6 2987

All Sites -18.7 -25.6 22.4 26.1 -13.8 -20.7 17.8 21.2 -15.6 -22.2 19.3 22.6 2192

Jonah -44.6 -48.8 45.2 49.1 -31.0 -34.6 31.6 34.9 -33.0 -36.7 33.5 36.9 394

Boulder -33.4 -30.3 33.8 30.5 -25.8 -25.2 26.2 25.4 -27.4 -26.7 27.8 26.8 577

Centennial 3.6 -9.1 8.9 10.9 4.2 -8.1 9.1 10.0 3.9 -8.4 9.1 10.2 455

Pinedale -7.6 -20.0 10.2 20.1 -6.6 -17.6 9.4 17.7 -7.1 -18.0 9.8 18.1 766

All Sites -5.7 -11.9 14.0 15.1 -4.0 -10.2 13.2 13.5 -4.6 -10.5 13.3 13.7 4130

Jonah -17.8 -15.2 19.1 17.8 -15.2 -12.8 16.6 15.6 -15.5 -13.1 16.8 15.8 806

Boulder -14.5 -16.2 16.4 18.4 -12.5 -13.9 14.5 16.2 -12.7 -13.9 14.5 16.2 891

Centennial 6.3 -6.3 11.6 10.8 7.5 -5.4 12.4 10.2 7.2 -5.6 12.3 10.3 1225

Pinedale -3.2 -12.3 11.4 15.2 -2.1 -10.5 10.9 13.6 -2.7 -10.9 11.1 13.9 1208

All Sites -14.1 -10.8 16.4 15.3 -12.2 -9.1 14.6 13.9 -12.7 -9.4 14.9 14.0 4333

Jonah -26.2 -16.6 26.6 18.9 -22.1 -14.0 22.5 16.5 -22.3 -14.1 22.7 16.5 732

Boulder -22.7 -17.7 23.1 19.1 -19.6 -15.4 20.0 16.8 -19.7 -15.4 20.2 16.7 754

Daniel -16.2 -11.0 17.0 14.4 -14.5 -9.6 15.3 13.2 -14.8 -9.8 15.6 13.2 635

Centennial -3.9 -5.7 9.1 12.7 -3.2 -4.6 8.8 12.1 -3.7 -4.9 9.0 12.2 1260

Pinedale -10.1 -7.4 12.4 13.4 -8.9 -5.9 11.3 12.3 -9.5 -6.5 11.8 12.6 952

All Sites -20.3 -29.1 20.6 29.1 -17.7 -24.4 18.0 24.4 -17.9 -24.5 18.1 24.5 608

Jonah -22.9 -25.4 22.9 25.4 -19.9 -21.7 19.9 21.7 -20.4 -22.2 20.4 22.2 68

Boulder -29.2 -39.3 29.2 39.3 -24.2 -30.4 24.2 30.4 -24.2 -30.3 24.2 30.3 142

Daniel -22.3 -30.6 22.3 30.6 -19.8 -26.3 19.8 26.3 -19.8 -26.2 19.8 26.2 128

Centennial -14.1 -24.6 14.8 24.6 -12.8 -21.7 13.5 21.7 -13.0 -21.8 13.7 21.8 209

Pinedale -14.1 -21.7 14.3 21.7 -12.5 -18.9 12.7 18.9 -12.7 -19.0 12.9 19.0 61

Period EPA FB(%) ± 15% FGE(%) ± 35% MNB(%) ± 15% MNGE(%) ± 35% NMB(%) ± 15% NME(%) ± 35%

Number

of

Points

Q3

Q4

ANN

Q1

Q2
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-34

Table A4-1c.Ozone model performance bias and error statistical measures with 60 ppb threshold for the CASTNet network and 

industrial sites for 2005by annual and quarter for all sites and for each site in the CD-C 4 km domain.

Site\Run Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C

All Sites -27 -25 28 26 -22 -21 23 22 -23 -22 24 22 1853

Jonah -36 -32 36 33 -28 -25 29 26 -30 -27 30 28 421

Boulder -30 -25 31 26 -25 -21 25 22 -26 -22 26 23 655

Daniel -24 -16 24 16 -21 -14 21 15 -21 -14 21 15 145

Centennial -12 -17 15 18 -11 -15 14 16 -11 -15 14 16 289

Pinedale -24 -27 24 28 -20 -22 20 24 -20 -23 21 24 343

All Sites -50 -51 50 51 -37 -39 37 39 -39 -40 39 40 362

Jonah -57 -66 57 66 -42 -47 42 47 -44 -49 44 49 113

Boulder -51 -44 51 44 -39 -35 39 35 -40 -36 40 36 186

Centennial -34 -47 34 47 -29 -38 29 38 -29 -38 29 38 8

Pinedale -30 -44 30 44 -25 -35 25 35 -25 -36 25 36 55

All Sites -18 -20 19 22 -15 -17 17 19 -15 -17 17 19 593

Jonah -26 -22 26 23 -22 -18 22 20 -22 -19 22 20 139

Boulder -18 -18 19 20 -16 -16 16 17 -16 -16 17 17 207

Centennial -4 -16 11 17 -2 -13 10 15 -3 -14 11 16 109

Pinedale -20 -26 21 28 -17 -21 17 23 -17 -21 18 23 138

All Sites -24 -18 24 18 -21 -15 21 16 -21 -16 21 16 891

Jonah -29 -18 29 19 -25 -15 25 16 -25 -16 25 16 167

Boulder -25 -17 25 17 -22 -15 22 16 -22 -15 22 16 260

Daniel -24 -15 24 16 -21 -14 21 14 -21 -14 21 14 143

Centennial -17 -16 17 17 -15 -15 15 16 -15 -15 16 16 171

Pinedale -25 -22 25 23 -21 -18 21 20 -22 -19 22 20 150

All Sites -39 -47 39 47 -31 -36 31 36 -33 -38 33 38 7

Jonah -71 -76 71 76 -52 -55 52 55 -53 -56 53 56 2

Boulder -14 -19 14 19 -13 -17 13 17 -13 -17 13 17 2

Daniel -41 -52 41 52 -34 -41 34 41 -34 -41 34 41 2

Centennial -25 -31 25 31 -22 -27 22 27 -22 -27 22 27 1

Pinedale N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0

FB(%) ± 15% FGE(%) ± 35%

Q2

Q3

Number

of

Points

Q4

MNB(%) ± 15% MNGE(%) ± 35% NMB(%) ± 15% NME(%) ± 35% Period EPA

ANN

Q1
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-35

Table A4-1d.Ozone model performance bias and error statistical measures with 40 ppb threshold for the CASTNet network and 

industrial sites for 2006by annual and quarter for all sites and for each site in the CD-C 4 km domain.

Site\Run Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C

All Sites -4.6 -9.9 13.2 15.8 -3.1 -7.9 12.5 14.5 -3.7 -8.2 12.4 14.4 29823

Jonah -19.1 -17.6 21.4 21.4 -15.1 -14.2 17.7 18.3 -15.2 -14.2 17.5 18.2 3119

Boulder -14.2 -19.1 18.0 23.2 -11.8 -15.3 15.9 19.9 -12.2 -15.5 15.9 19.7 4889

Daniel -6.2 -11.5 12.0 16.5 -5.1 -9.6 11.4 15.2 -5.8 -9.9 11.6 15.1 4658

Wamsutter 0.1 -0.2 12.2 14.2 1.3 1.5 12.3 14.4 0.4 0.8 12.1 14.0 2060

Centennial 4.2 -7.1 10.2 12.0 5.1 -6.0 10.7 11.4 4.4 -6.4 10.4 11.4 6777

OCI -6.8 -3.1 12.3 13.1 -5.6 -1.7 11.6 12.8 -6.1 -2.4 11.6 12.4 2185

Pinedale 0.9 -6.0 10.0 12.3 1.8 -4.9 10.2 11.7 1.2 -4.8 10.1 11.6 6135

All Sites -6.0 -19.5 13.4 20.2 -4.3 -16.6 12.3 17.3 -4.6 -16.7 12.3 17.3 8643

Jonah -22.8 -28.8 24.9 29.4 -17.6 -23.5 19.9 24.1 -17.6 -23.7 19.7 24.2 879

Boulder -18.2 -34.1 21.5 34.6 -14.7 -27.1 18.3 27.6 -14.9 -26.8 18.2 27.2 1610

Daniel -5.9 -18.1 11.1 18.7 -4.9 -15.9 10.5 16.6 -5.4 -16.1 10.7 16.7 1908

Wamsutter 0.5 -10.7 9.2 12.6 1.2 -9.4 9.1 11.4 1.1 -9.6 8.9 11.4 286

Centennial 2.7 -13.1 8.6 13.6 3.3 -11.9 8.8 12.4 3.3 -11.9 8.7 12.4 2010

OCI N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0

Pinedale 1.4 -12.7 9.5 13.7 2.1 -11.4 9.6 12.4 2.1 -11.4 9.5 12.3 1950

All Sites -3.8 -8.6 13.7 14.7 -2.3 -6.9 13.2 13.6 -3.1 -7.5 13.0 13.6 9801

Jonah -15.6 -16.6 19.0 20.4 -12.5 -13.3 16.2 17.5 -12.8 -13.6 16.1 17.4 1186

Boulder -9.3 -12.5 15.7 18.1 -7.5 -10.3 14.5 16.4 -8.5 -11.4 14.6 16.7 1597

Daniel -4.3 -8.7 13.5 15.8 -2.9 -6.8 13.1 14.8 -4.1 -8.0 13.2 14.8 1399

Wamsutter -4.9 -5.7 12.5 12.6 -3.7 -4.4 12.1 11.9 -4.3 -4.7 11.9 11.7 1194

Centennial 3.4 -7.9 11.3 11.9 4.5 -6.8 11.9 11.1 3.6 -7.3 11.5 11.3 2092

OCI -5.8 -3.6 13.4 12.8 -4.4 -2.3 12.7 12.4 -4.9 -3.2 12.5 12.2 888

Pinedale 4.0 -3.9 11.8 12.4 5.2 -2.6 12.4 11.9 4.0 -3.2 11.9 11.9 1445

All Sites -4.6 -1.1 13.4 13.0 -3.0 0.4 12.7 13.0 -3.9 -0.3 12.6 12.8 8448

Jonah -20.6 -9.7 22.0 16.2 -16.3 -7.4 17.8 14.6 -16.4 -7.4 17.7 14.3 969

Boulder -15.9 -7.0 17.7 15.4 -13.5 -5.1 15.4 14.8 -13.8 -6.0 15.4 14.7 1163

Daniel -9.4 -0.2 12.4 12.7 -8.4 1.2 11.5 13.0 -9.0 0.5 11.8 12.7 889

Wamsutter 10.1 16.5 13.1 18.3 11.6 19.2 14.4 20.9 11.1 19.1 14.1 20.9 577

Centennial 6.2 -0.6 11.2 11.2 7.3 0.5 12.0 11.2 6.3 -0.1 11.6 11.2 1885

OCI -7.3 -1.5 11.7 13.0 -6.3 -0.1 11.0 12.9 -7.0 -0.9 11.1 12.4 1104

Pinedale -0.8 1.0 10.1 10.3 0.0 1.9 10.2 10.4 -1.0 1.4 10.1 10.3 1861

All Sites -3.4 -11.0 10.2 14.6 -2.6 -9.3 9.9 13.2 -2.9 -9.5 10.0 13.3 2931

Jonah -12.4 -7.0 13.6 13.2 -11.1 -5.6 12.4 12.2 -11.3 -5.6 12.5 12.1 85

Boulder -13.4 -20.2 14.9 21.3 -12.0 -17.1 13.5 18.2 -12.3 -17.2 13.8 18.3 519

Daniel -7.4 -14.3 10.6 16.5 -6.6 -12.3 9.9 14.7 -6.9 -12.4 10.1 14.7 462

Wamsutter 9.9 1.8 20.8 18.0 12.3 3.5 22.4 18.0 12.4 3.6 22.4 17.9 3

Centennial 5.3 -5.3 8.6 10.3 5.9 -4.5 9.0 9.9 5.6 -4.7 8.9 10.0 790

OCI -8.6 -10.1 11.0 15.3 -7.6 -8.1 10.2 13.6 -7.7 -7.9 10.2 13.5 193

Pinedale -1.2 -9.6 8.2 13.6 -0.6 -8.2 8.1 12.6 -0.9 -8.3 8.1 12.6 879

MNGE(%) ± 35% NMB(%) ± 15% NME(%) ± 35% Period EPA FB(%) ± 15% FGE(%) ± 35%

Number

of

Points

MNB(%) ± 15%

ANN

Q1

Q2

Q3

Q4
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-36

Table A4-1e.Ozone model performance bias and error statistical measures with 50 ppb threshold for the CASTNet network and 

industrial sites for 2006by annual and quarter for all sites and for each site in the CD-C 4 km domain.

Site\Run Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C

All Sites -6.9 -10.8 12.4 14.8 -5.7 -9.1 11.6 13.5 -6.2 -9.3 11.7 13.6 15654

Jonah -17.2 -16.9 18.2 19.6 -14.7 -14.1 15.7 16.9 -15.0 -14.2 15.9 17.0 1861

Boulder -15.0 -18.3 17.1 20.5 -12.9 -15.4 15.1 17.8 -13.2 -15.5 15.3 17.9 2545

Daniel -9.9 -12.9 13.2 16.0 -8.6 -11.1 12.2 14.5 -9.1 -11.4 12.5 14.7 2172

Wamsutter -4.5 -3.9 10.8 12.5 -3.7 -2.6 10.4 12.2 -4.0 -2.8 10.4 12.1 1082

Centennial 1.4 -8.8 9.2 12.3 2.1 -7.7 9.3 11.4 1.7 -7.9 9.3 11.5 3919

OCI -8.9 -6.5 12.1 11.7 -7.9 -5.4 11.3 11.0 -8.1 -5.6 11.4 10.9 1234

Pinedale -2.2 -5.4 9.1 11.3 -1.6 -4.4 9.0 10.8 -2.0 -4.5 9.0 10.9 2841

All Sites -6.4 -18.7 12.8 19.0 -4.9 -16.2 11.6 16.5 -5.4 -16.5 11.8 16.8 3492

Jonah -20.1 -28.5 20.8 28.5 -16.4 -23.7 17.1 23.7 -16.8 -24.0 17.4 24.0 433

Boulder -18.1 -28.7 20.0 28.8 -14.8 -23.6 16.8 23.6 -15.2 -23.7 17.0 23.7 631

Daniel -9.4 -19.5 12.3 19.7 -8.2 -17.2 11.2 17.4 -8.8 -17.6 11.6 17.8 653

Wamsutter -0.3 -13.1 8.1 13.8 0.3 -11.5 7.9 12.1 0.2 -11.6 8.0 12.2 117

Centennial 3.0 -12.5 8.4 12.8 3.6 -11.4 8.5 11.7 3.5 -11.5 8.5 11.8 1082

OCI N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0

Pinedale 0.9 -12.5 8.6 13.3 1.5 -11.3 8.6 12.1 1.4 -11.4 8.6 12.3 576

All Sites -6.0 -10.9 12.4 14.4 -4.8 -9.3 11.7 13.0 -5.3 -9.7 11.8 13.2 6963

Jonah -15.5 -17.0 17.1 19.1 -13.3 -14.1 15.0 16.4 -13.5 -14.3 15.1 16.5 777

Boulder -12.4 -17.2 15.7 19.3 -10.6 -14.8 14.2 17.0 -11.2 -15.2 14.4 17.2 1081

Daniel -8.5 -13.2 13.4 15.9 -7.2 -11.3 12.6 14.3 -7.7 -11.7 12.8 14.5 946

Wamsutter -7.1 -6.4 11.6 11.1 -6.1 -5.4 10.9 10.4 -6.4 -5.5 10.9 10.4 803

Centennial 1.3 -9.3 10.1 12.1 2.1 -8.2 10.3 11.2 1.5 -8.5 10.1 11.4 1783

OCI -7.6 -7.6 12.4 11.9 -6.4 -6.5 11.6 11.0 -6.6 -6.7 11.6 11.0 566

Pinedale -0.4 -5.8 9.3 12.1 0.3 -4.7 9.2 11.4 -0.3 -5.0 9.3 11.5 1007

All Sites -8.2 -4.7 12.0 12.3 -7.1 -3.5 11.1 11.8 -7.6 -3.6 11.4 11.7 5046

Jonah -17.4 -9.2 17.7 14.3 -15.2 -7.5 15.6 13.0 -15.6 -7.6 15.9 13.0 646

Boulder -15.5 -10.9 16.2 15.3 -13.7 -9.2 14.4 14.1 -14.0 -9.3 14.7 14.1 778

Daniel -12.1 -4.3 13.2 11.6 -11.0 -3.2 12.2 11.2 -11.3 -3.2 12.4 11.2 551

Wamsutter 4.9 15.5 9.2 18.6 5.6 18.0 9.7 20.9 5.5 18.1 9.6 21.0 162

Centennial 0.4 -3.6 8.5 11.6 0.9 -2.6 8.5 11.2 0.5 -2.8 8.5 11.2 1007

OCI -10.1 -5.6 11.9 11.6 -9.1 -4.5 11.0 10.9 -9.4 -4.6 11.2 10.7 668

Pinedale -4.8 -1.5 9.0 9.6 -4.2 -0.8 8.7 9.6 -4.7 -0.8 8.9 9.6 1234

All Sites -19.6 -20.5 19.7 21.9 -17.1 -17.6 17.3 19.1 -17.6 -18.1 17.8 19.5 153

Jonah -26.2 -12.5 26.2 12.5 -23.1 -11.7 23.1 11.7 -23.2 -11.7 23.2 11.7 5

Boulder -26.3 -24.9 26.3 25.1 -22.7 -21.1 22.7 21.3 -23.1 -21.5 23.1 21.6 55

Daniel -26.3 -21.9 26.3 22.6 -22.6 -18.5 22.6 19.3 -23.2 -19.2 23.2 19.9 22

Wamsutter N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0

Centennial -7.3 -17.5 7.9 20.1 -6.7 -15.3 7.3 18.1 -7.1 -15.8 7.7 18.4 47

OCI N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0

Pinedale -20.6 -16.6 20.6 19.5 -18.1 -14.2 18.1 17.2 -18.6 -14.8 18.6 17.7 24

Period EPA FB(%) ± 15% FGE(%) ± 35% MNB(%) ± 15% MNGE(%) ± 35% NMB(%) ± 15% NME(%) ± 35%

Number

of

Points

ANN

Q1

Q2

Q3

Q4
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-37

Table A4-1f. Ozone model performance bias and error statistical measures with 60 ppb threshold for the CASTNet network and 

industrial sites for 2006 by annual and quarter for all sites and for each site in the CD-C 4 km domain.

Site\Run Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C Hiawatha CD-C

All Sites -14.4 -13.9 15.8 16.5 -12.7 -11.9 14.1 14.7 -12.9 -12.1 14.3 14.9 3791

Jonah -20.8 -18.6 21.0 20.5 -18.1 -15.5 18.3 17.5 -18.3 -15.7 18.6 17.7 493

Boulder -19.1 -19.9 20.1 21.3 -16.6 -17.0 17.6 18.6 -16.8 -17.1 17.8 18.7 887

Daniel -16.3 -15.7 17.6 18.2 -14.3 -13.5 15.8 16.1 -14.6 -13.8 16.0 16.3 589

Wamsutter -10.0 -6.7 12.3 10.9 -8.9 -5.9 11.3 10.3 -9.0 -6.0 11.4 10.4 263

Centennial -7.1 -12.7 9.7 14.4 -6.4 -11.2 9.1 13.0 -6.7 -11.4 9.3 13.2 658

OCI -11.3 -8.0 13.1 10.7 -10.2 -7.0 12.0 10.0 -10.4 -7.1 12.1 9.9 435

Pinedale -11.9 -6.6 12.6 12.7 -10.8 -5.3 11.6 11.9 -10.9 -5.6 11.7 12.0 466

All Sites -18.4 -27.3 19.0 27.4 -15.7 -23.3 16.4 23.3 -16.3 -23.6 16.9 23.7 483

Jonah -21.0 -30.7 21.1 30.7 -18.1 -25.9 18.2 25.9 -19.1 -26.4 19.2 26.4 103

Boulder -22.4 -29.1 22.8 29.1 -18.7 -24.4 19.2 24.4 -19.0 -24.6 19.5 24.6 159

Daniel -18.3 -25.9 19.0 26.0 -15.9 -22.3 16.6 22.4 -16.4 -22.7 17.0 22.8 149

Wamsutter N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0

Centennial -3.8 -21.1 6.4 21.1 -3.3 -18.8 6.1 18.8 -3.3 -18.8 6.0 18.8 41

OCI N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0

Pinedale -9.0 -22.3 9.1 22.3 -8.3 -19.6 8.4 19.6 -8.4 -19.7 8.4 19.7 31

All Sites -12.2 -14.7 14.3 16.3 -10.7 -12.8 12.9 14.5 -10.9 -13.0 13.1 14.6 2133

Jonah -18.2 -20.3 18.6 21.2 -15.9 -16.9 16.3 17.8 -16.0 -16.9 16.4 17.8 226

Boulder -17.0 -21.0 18.5 21.8 -14.7 -18.1 16.3 18.9 -15.1 -18.2 16.6 19.0 454

Daniel -14.7 -16.5 16.8 17.4 -12.9 -14.4 15.1 15.4 -13.1 -14.6 15.3 15.5 323

Wamsutter -10.2 -7.3 12.5 10.8 -9.2 -6.5 11.5 10.2 -9.3 -6.6 11.6 10.2 254

Centennial -6.5 -13.0 9.7 14.4 -5.9 -11.5 9.2 13.0 -6.1 -11.7 9.3 13.2 480

OCI -9.2 -9.4 12.2 11.7 -8.1 -8.4 11.3 10.8 -8.2 -8.6 11.3 10.9 201

Pinedale -9.1 -10.4 11.0 13.3 -8.1 -9.0 10.1 12.0 -8.5 -9.3 10.3 12.2 195

All Sites -16.7 -6.7 17.0 12.2 -15.0 -5.5 15.3 11.5 -15.1 -5.5 15.4 11.5 1169

Jonah -24.1 -8.6 24.1 13.1 -21.1 -7.1 21.1 12.0 -21.2 -7.0 21.2 11.9 164

Boulder -20.5 -12.2 20.7 15.7 -18.1 -10.6 18.4 14.4 -18.3 -10.5 18.5 14.4 269

Daniel -18.1 -0.7 18.2 10.4 -16.5 0.2 16.5 10.3 -16.5 0.3 16.5 10.2 117

Wamsutter -2.2 9.7 7.0 13.4 -1.9 10.9 6.8 14.4 -2.0 10.6 6.8 14.3 9

Centennial -9.9 -8.8 10.4 12.1 -9.1 -7.7 9.6 11.1 -9.3 -7.9 9.8 11.2 136

OCI -13.2 -6.7 13.8 9.9 -12.0 -5.8 12.7 9.3 -12.2 -5.8 12.8 9.1 234

Pinedale -14.4 -1.5 14.4 10.9 -13.3 -0.6 13.3 10.9 -13.3 -0.7 13.3 10.9 240

All Sites -42.2 -42.4 42.2 42.4 -34.8 -34.6 34.8 34.6 -34.9 -35.0 34.9 35.0 6

Jonah N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0

Boulder -41.2 -39.2 41.2 39.2 -34.1 -32.6 34.1 32.6 -34.1 -32.6 34.1 32.6 5

Daniel N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0

Wamsutter N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0

Centennial -47.6 -58.1 47.6 58.1 -38.4 -45.0 38.4 45.0 -38.4 -45.0 38.4 45.0 1

OCI N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0

Pinedale N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0

EPA FB(%) ± 15% FGE(%) ± 35% MNB(%) ± 15% MNGE(%) ± 35% NMB(%) ± 15% NME(%) ± 35%

Number

of

Points

Q3

Q4

ANN

Q1

Q2

Period
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-38

A4.2 HOURLY OZONE TIME SERIES FOR MONITORS IN 4 KM GRID

Time series plots of predicted and observed hourly ozone concentrations by Quarter at the 

Jonah, Boulder, Daniel, Pinedale and Centennial monitoring sites are presented in Figures A4-1 

and A4-2 for the 2005 and 2006 simulation years, respectively. Fractional bias and fractional 

gross error statistics using a 40 ppb cutoff concentration for each quarter are presented on the 

time series plot for each monitor. Early on in the CAMx base case modeling, the WDEQ-AQD

instructed the CD-C modeling team to not address the wintertime ozone exceedances as they 

are a research topic so should not be part of NEPA and instead focus on the summer ozone 

time periods. During the warmer quarters (Q2 and Q3) in 2005, the CAMx model is exhibits an 

ozone underestimation bias at the Wyoming industrial sites with the CD-C run generally 

displaying better performance (lower bias) than the Hiawatha base case run. Better 

performance is seen at the two CASTNET sites (Figures A4-1d and A4-1e) with both base case 

simulations achieving (or nearly achieving) EPA’s performance goals for all four Quarters in 

2005.

In 2006, the CAMx performance is again characterized by an underestimation bias at the 

monitoring sites within the 4 km domain, although EPA’s performance goals are achieved more 

often than in 2005 (Figure A4-2). Performance is better at the two CASTNet sites than the 

Sublette County sites. In 2006 new ozone monitoring sites came online at Wamsutter and OCI. 

The ozone bias and error metrics at the Wamsutter monitor achieve EPA’s performance goals in 

Q3 (Figure A4-2f). EPA’s performance goals are also achieved at the OCI monitor for Q2 and Q3 

(Figure A4-2g).
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-39

Jonah

Figure A4-1a. Time series of predicted and observed hourly ozone concentrations for 2005 

Quarter 1 (top row left column), Quarter 2 (top row right column), Quarter 3 (bottom row left 

column), and Quarter 4 (bottom row right column) at the Jonah monitoring sites. Ozone units 

are ppm and statistics are calculated using a 40 ppb observed ozone cutoff concentration.

Q1 Q2

Q3 Q4

Observation

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-40

Boulder

Figure A4-1b. Time series of predicted and observed hourly ozone concentrations for 2005 

Quarter 1 (top row left column), Quarter 2 (top row right column), Quarter 3 (bottom row left 

column), and Quarter 4 (bottom row right column) at the Boulder monitoring sites. Ozone 

units are ppm and statistics are calculated using a 40 ppb observed ozone cutoff 

concentration.

Q1 Q2

Q3 Q4

Observation

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-41

Daniel

Figure A4-1c. Time series of predicted and observed hourly ozone concentrations for 2005 

Quarter 3 (left column), and Quarter 4 (right column) at the Daniel monitoring sites. Ozone 

units are ppm and statistics are calculated using a 40 ppb observed ozone cutoff 

concentration.

Q3 Q4

Observation

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-42

Pinedale

Figure A4-1d. Time series of predicted and observed hourly ozone concentrations for 2005 

Quarter 1 (top row left column), Quarter 2 (top row right column), Quarter 3 (bottom row left 

column), and Quarter 4 (bottom row right column) at the Pinedale monitoring sites. Ozone 

units are ppm and statistics are calculated using a 40 ppb observed ozone cutoff 

concentration.

Q1 Q2

Q3 Q4

Observation

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-43

Centennial

Figure A4-1e. Time series of predicted and observed hourly ozone concentrations for 2005 

Quarter 1 (top row left column), Quarter 2 (top row right column), Quarter 3 (bottom row left 

column), and Quarter 4 (bottom row right column) at the Centennial monitoring sites. Ozone 

units are ppm and statistics are calculated using a 40 ppb observed ozone cutoff 

concentration.

Q1 Q2

Q3 Q4

Observation

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-44

Jonah

Figure A4-2a. Time series of predicted and observed hourly ozone concentrations for 2006 

Quarter 1 (top row left column), Quarter 2 (top row right column), Quarter 3 (bottom row left 

column), and Quarter 4 (bottom row right column) at the Jonah monitoring sites. Ozone units

are ppm and statistics are calculated using a 40 ppb observed ozone cutoff concentration.

Q1 Q2

Q3 Q4

Observation

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-45

Boulder

Figure A4-2b. Time series of predicted and observed hourly ozone concentrations for 2006 

Quarter 1 (top row left column), Quarter 2 (top row right column), Quarter 3 (bottom row left 

column), and Quarter 4 (bottom row right column) at the Boulder monitoring sites. Ozone 

units are ppm and statistics are calculated using a 40 ppb observed ozone cutoff 

concentration.

Q1 Q2

Q3 Q4

Observation

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-46

Daniel

Figure A4-2c. Time series of predicted and observed hourly ozone concentrations for 2006 

Quarter 1 (top row left column), Quarter 2 (top row right column), Quarter 3 (bottom row left 

column), and Quarter 4 (bottom row right column) at the Daniel monitoring sites. Ozone units 

are ppm and statistics are calculated using a 40 ppb observed ozone cutoff concentration.

Q1 Q2

Q3 Q4

Observation

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-47

Pinedale

Figure A4-2d. Time series of predicted and observed hourly ozone concentrations for 2006 

Quarter 1 (top row left column), Quarter 2 (top row right column), Quarter 3 (bottom row left 

column), and Quarter 4 (bottom row right column) at the Pinedale monitoring sites. Ozone 

units are ppm and statistics are calculated using a 40 ppb observed ozone cutoff 

concentration.

Q1 Q2

Q3 Q4

Observation

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-48

Centennial

Figure A4-2e. Time series of predicted and observed hourly ozone concentrations for 2006 

Quarter 1 (top row left column), Quarter 2 (top row right column), Quarter 3 (bottom row left 

column), and Quarter 4 (bottom row right column) at the Centennial monitoring sites. Ozone 

units are ppm and statistics are calculated using a 40 ppb observed ozone cutoff 

concentration.

Q1 Q2

Q3 Q4

Observation

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-49

Wamsutter

Figure A4-2f. Time series of predicted and observed hourly ozone concentrations for 2006 

Quarter 1 (top row left column), Quarter 2 (top row right column), Quarter 3 (bottom row left 

column), and Quarter 4 (bottom row right column) at the Wamsutter monitoring sites. Ozone 

units are ppm and statistics are calculated using a 40 ppb observed ozone cutoff 

concentration.

Q1 Q2

Q3 Q4

Observation

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-50

OCI

Figure A4-2g. Time series of predicted and observed hourly ozone concentrations for 2006 

Quarter 2 (top row right column), Quarter 3 (bottom row left column), and Quarter 4 (bottom 

row right column) at the OCI monitoring sites. Ozone units are ppm and statistics are 

calculated using a 40 ppb observed ozone cutoff concentration.

Q2

Q3 Q4

Observation

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-51

A4.3 DAILY MAX 8-HOUR RUNNING AVERAGE OZONE STANDARD FOR MONITORS IN 4 KM 

GRID

In January 2010, EPA proposed revising the primary 8-hour ozone NAAQS with a threshold 

between 0.060 and 0.070 ppm (60-70 ppb). In order to evaluate the model performance at 

these ozone levels we compared the predicted and observed daily maximum 8-hour ozone 

concentration at each monitor in the 4 km domain during 2005 and 2006 in which either the 

observed or predicted value was above either a 65 ppb (Table A4-2) or 70 ppb (Table A4-3) 

concentration threshold. Values equal to or exceeding the threshold are shown in yellow in 

each table. At Boulder during 2005 (Table A4-2a), there are 28 observed days with daily 

maximum 8-hour ozone concentrations that exceed the 65 ppb threshold and only 1 and 5 

predicted days for the Hiawatha and CD-C base case simulations, respectively. However, many 

of the observed ozone days > 65 ppb in 2005 at Boulder occur during the winter (Feb-Mar) for

conditions that the model was not configured to simulate. During the summer the CD-C base 

case simulation reproduces the high observed ozone days at Boulder with greater accuracy 

than the preliminary Hiawatha base case simulation. For example, the maximum observed 8-

hour ozone at Boulder during the summer of 2005 is 72.7 ppb on June 27th where the Hiawatha 

base case simulates 58.8 ppb (-19%) and CD-C base case simulation estimates a 66.8 ppb (-8%) 

8-hour ozone peak that is much closer to the observed value.

The 65 ppb threshold 2005 8-hour ozone model performance at the Centennial CASTNet site 

exhibits quite different performance from Boulder (Table A4-2b). Whereas there are only 6 

observed days with 8-hour ozone at Centennial in 2005 exceeding 65 ppb that occur mainly in 

late June and July, the Hiawatha base case simulation had 24 days that exceed the 65 ppb 

threshold with most of the days occurring in the spring. The CD-C base case simulation, on the 

other hand, had only 10 days with 8-hour ozone concentrations exceeding 65 ppb with most of 

the days occurring in the summer as was observed.

The Daniel monitor came online in July 2005 and recorded 4 days above 65 ppb as compared to 

no days for the Hiawatha base case and 3 days for the CD-C base case after the Daniel monitor 

started its measurements. The highest observed 8-hour ozone concentration at the Daniel 

monitor in 2005 occurred on July 8th (70.8 ppb) that was reproduced to within -19% (57.7 ppb) 

by the Hiawatha and within -4% (67.7 ppb) by the CD-C base cases.

The Jonah monitor had 22 days with observed 8-hour ozone concentrations exceeding 65 ppb 

with 13 of those days occurring early (January-April) in the year (Table A4-2d). Not surprisingly, 

neither the Hiawatha nor CD-C base case simulations estimate 8-hour ozone concentrations in 

excess of 65 ppb during January-April 2005. During the warmer May-August 2005 period, there 

were 9 observed days with 8-hour ozone exceeding 65 ppb as compared to none for the 

Hiawatha base case simulation and 8 days for the CD-C base case simulation. The maximum 

observed 8-hour ozone concentrations at the Jonah monitor was 73.9 ppb and occurred on 

June 27th which the Hiawatha base case underestimated by -19% (60.2 ppb) and the CD-C base 

case only underestimated by -4% (70.9 ppb). Clearly, the CD-C base case is better able to 

reproduce the observed high summer 8-hour ozone concentrations than the preliminary base 

case performed under Hiawatha.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-52

The Pinedale CASTNet monitoring site had 12 days in 2005 with 8-hour ozone greater than 65 

ppb, 5 in February-April and 7 during June and July (Table A4-2e). The Hiawatha base case had 

5 days over 65 ppb with 4 of them in April, but not overlapping with the observed 65 ppb 

exceedance days, and one day in June 27, 2005 when the highest observed 8-hour ozone 

concentration in 2005 at Pinedale occurred (76.4 ppb). The Hiawatha base case reproduced 

this highest observed ozone day to within -12% (66.9 ppb), which was not as good as the CD-C 

base case that reproduced it to within -8% (70.5 ppb). The CD-C base case had 7 days in 2005 

that exceeded 65 ppb at Pinedale, with all of them occurring during May-July and with 4 of the 

days overlapping with observed 65 ppb exceedance days.

The Wamsutter site was not operating in 2005 and there were 2 and 11 days that the estimated 

8-hour ozone concentrations exceeded the 65 ppb threshold in the Hiawatha and CD-C base 

case simulations, respectively (Table A4-2f).

In 2006, the Boulder monitoring site had the most days (43) with 8-hour ozone concentrations 

exceeding the 65 ppb threshold (Table A4-3a). Most of these days (26) occurred during JuneSeptember. The Hiawatha and CD-C base case simulations had 10 and 13 days, respectively, 

that exceeded the 65 ppb threshold at Boulder during 2006 with most days overlapping with 

observed 65 ppb exceedance days. The highest observed 8-hour ozone day at Boulder during 

2006 was April 21st (81.0 ppb) which the Hiawatha base case reproduced to within -14% (69.9 

ppb) and the CD-C base case reproduced to within -8% (74.2 ppb). It is interesting to note that 

the Hiawatha base case generally estimated higher ozone than the CD-C base case in June but 

the reverse is true in July. This effect was also seen using the Denver ozone SIP June-July 2006 

modeling database when it was updated from CAMx V4.51 to CAMx VV and is due to CAMx 

V4.51 bringing more ozone of stratospheric origin down to ground level from the top most 

layers of the model. The stratospheric ozone was introduced into the model through the lateral 

boundary conditions that were generated using output from the GEOS-Chem global chemistry 

model. 

As we saw in 2005, the Hiawatha base case had the most days with 8-hour ozone greater than 

65 ppb at the Centennial monitoring site (31) compared to 19 observed days and 15 days 

estimated in the CD-C base case (Table A4-3b).

The Daniel monitoring site had 26 days in 2006 with 8-hour ozone exceeding 65 ppb compared 

to 9 and 17 days for the Hiawatha and CD-C base case simulations, respectively (Table A4-3c). 

As expected, the very highest observed 8-hour ozone concentration on February 25, 2006 (82.7 

ppb) is greatly underestimated by both base case simulations (almost a factor of 2). The next 

highest observed ozone day (75.6 ppb on May 2) is underestimated by the Hiawatha and CD-C 

base case simulations by, respectively, -24% (57.7 ppb) and -18% (62.2 ppb). The 9 days 

estimated in the Hiawatha base case to exceed 65 ppb are approximately evenly split between 

the March-April (4 days) and June (5 days) time periods. Whereas the CD-C runs estimates that 

a vast majority (15 of 17 days) of the 65 ppb exceedance days occur during May-August 2006.

There were 22 observed 8-hour ozone 65 ppb exceedance days at Jonah in 2006 compared to 3 

and 8 days predicted in the Hiawatha and CD-C base case simulations, respectively (Table A4-

3d). During the June-August summer months, both base case simulations underestimate the 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-53

highest observed 8-hour ozone on June 11th (69.8 ppb) by -15%. However, the next highest 

summer observed 8-hour ozone concentration on July 15th (69.4 ppb) is reproduced better in 

the CD-C base case (within -1% at 68.4 ppb) than the Hiawatha base case (within -14% at 60.0 

ppb).

The OCI monitor came on line in May 2006 and had 24 observed 65 ppb 8-hour ozone 

exceedance days during May-December 2006 which was exactly matched by the CD-C base case 

simulation, with the Hiawatha base case simulation only having 10 days that exceeded 65 ppb 

(Table A4-3e). 

The Pinedale monitor had 11 65 ppb exceedance days in 2006 compared to 17 and 21 days in the 

Hiawatha and CD-C base case simulations, respectively (Table A4-3f). The peak observed 8-hour 

ozone concentration at Pinedale in 2006 was 80.1 ppb on April 21st that the Hiawatha base case 

reproduced to within -15% (68.0 ppb) and the CD-C base case reproduced to within -9% (72.9 ppb).

There are 11 observed 65 ppb exceedance days at the Wamsutter monitor in 2006 compared to 

9 and 18 days for the Hiawatha and CD-C base case simulations, respectively (Table A4-3g). 

However, the two base case simulations only have 2 65 ppb exceedance days that overlap with 

the observed 65 ppb exceedance days. The two models estimate many 65 ppb exceedance 

days during July-August when no observed values over 65 occurred.

Table A4-4 compares the observed and predicted days during 2005 and 2006 that the 8-hour 

ozone concentrations exceeded a 70 ppb threshold. As these days are also 65 ppb exceedance 

days, then much of the discussion above on Tables A4-2 and A4-3 also holds for Table A4-4.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-54

Table A4-2a. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

65 ppb at the Boulder monitoring site during 2005.

Site

2005

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

Boulder Total exceeding 28 1 5

Boulder Feb 02 66.0 44.2 42.3

Boulder Feb 03 82.0 41.4 43.3

Boulder Feb 04 80.2 54.3 50.2

Boulder Feb 19 79.9 46.1 49.8

Boulder Feb 20 89.3 38.5 35.2

Boulder Feb 22 75.9 51.5 48.3

Boulder Feb 24 80.9 45.7 49.2

Boulder Feb 25 72.2 44.4 45.9

Boulder Feb 26 70.2 53.2 54.7

Boulder Feb 27 74.5 49.1 49.2

Boulder Mar 03 71.9 45.3 49.3

Boulder Mar 04 66.2 54.1 56.0

Boulder Apr 16 56.4 65.6 55.6

Boulder Apr 18 68.6 56.9 53.1

Boulder May 11 67.5 44.4 48.7

Boulder May 21 66.2 54.5 54.1

Boulder May 25 65.0 60.5 72.8

Boulder May 26 63.9 58.9 68.4

Boulder Jun 13 65.4 58.7 52.2

Boulder Jun 26 65.1 55.7 58.1

Boulder Jun 27 72.7 58.8 66.8

Boulder Jul 03 66.3 50.8 63.0

Boulder Jul 08 45.2 61.2 69.0

Boulder Jul 12 68.1 55.3 56.0

Boulder Jul 17 59.2 51.0 66.3

Boulder Jul 20 66.2 52.0 52.6

Boulder Jul 22 69.7 54.0 57.7

Boulder Jul 23 70.7 57.1 58.1

Boulder Aug 05 65.6 53.8 57.0

Boulder Aug 06 66.6 52.7 57.3

Boulder Aug 08 67.9 52.8 60.1

Boulder Aug 26 66.6 49.0 62.6
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-55

Table A4-2b. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

65 ppb at the Centennial monitoring site during 2005.

Site

2005

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

Centennial Total exceeding 6 24 10

Centennial Mar 05 57.9 65.3 53.6

Centennial Apr 06 57.3 67.6 59.7

Centennial Apr 07 56.6 71.8 59.9

Centennial Apr 08 57.8 66.4 51.4

Centennial Apr 13 61.4 69.4 60.9

Centennial Apr 15 60.9 67.3 57.6

Centennial Apr 16 61.3 70.7 56.1

Centennial Apr 17 61.9 65.3 51.9

Centennial Apr 18 62.3 65.4 53.5

Centennial Apr 19 57.4 65.9 54.4

Centennial Apr 20 66.8 61.3 60.9

Centennial Apr 23 57.5 65.2 54.7

Centennial May 11 68.3 50.4 58.6

Centennial May 26 58.4 59.6 65.5

Centennial Jun 01 57.1 77.9 61.5

Centennial Jun 02 59.1 82.8 64.6

Centennial Jun 03 51.6 79.9 63.3

Centennial Jun 06 52.8 67.1 56.5

Centennial Jun 07 62.7 67.1 66.8

Centennial Jun 08 56.1 71.3 56.3

Centennial Jun 13 60.9 70.4 59.9

Centennial Jun 14 57.0 70.6 60.7

Centennial Jun 15 51.5 68.2 53.7

Centennial Jun 16 51.5 65.6 51.3

Centennial Jun 21 57.0 65.8 52.0

Centennial Jun 27 65.8 69.2 68.8

Centennial Jul 01 52.1 70.2 65.4

Centennial Jul 07 60.9 63.1 65.5

Centennial Jul 08 58.3 62.8 66.3

Centennial Jul 09 54.5 62.2 65.7

Centennial Jul 19 67.1 55.3 60.6

Centennial Jul 20 69.1 57.7 55.9

Centennial Jul 22 70.0 58.5 59.0

Centennial Aug 05 58.3 59.1 70.6

Centennial Aug 31 64.4 55.3 69.1

Centennial Sep 01 56.6 56.8 66.7
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-56

Table A4-2c. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

65 ppb at the Daniel monitoring site during 2005..

Site

2005

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

Daniel Total exceeding 4 2 6

Daniel Apr 16 N/A 66.0 56.8

Daniel Apr 17 N/A 66.5 54.8

Daniel May 25 N/A 62.1 72.2

Daniel May 26 N/A 59.0 68.9

Daniel Jun 27 N/A 60.9 69.3

Daniel Jul 06 56.7 55.8 66.1

Daniel Jul 07 67.3 54.4 61.0

Daniel Jul 08 70.8 57.7 67.7

Daniel Jul 11 66.6 44.5 50.4

Daniel Jul 17 56.0 50.4 66.8

Daniel Jul 22 66.9 53.2 56.9

Table A4-2d. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

65 ppb at the Jonah monitoring site during 2005.

Site

2005

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

Jonah Total exceeding 22 0 8

Jonah Jan 20 66.5 32.4 23.1

Jonah Jan 24 78.3 46.4 35.9

Jonah Jan 25 67.3 50.6 42.2

Jonah Jan 26 66.9 50.6 42.2

Jonah Feb 03 98.4 40.8 37.2

Jonah Feb 04 76.4 52.9 46.7

Jonah Feb 19 67.4 44.6 42.3

Jonah Feb 20 65.4 37.8 33.4

Jonah Feb 26 89.4 51.8 50.4

Jonah Feb 27 75.4 48.0 48.1

Jonah Feb 28 69.5 51.7 51.0

Jonah Apr 13 75.3 55.0 50.4

Jonah Apr 18 68.3 48.1 46.3

Jonah May 25 60.5 60.7 71.3

Jonah May 26 59.6 54.5 68.0

Jonah Jun 01 60.8 60.9 66.5

Jonah Jun 06 65.3 52.5 51.2

Jonah Jun 26 65.9 53.9 66.0

Jonah Jun 27 73.9 60.2 70.9

Jonah Jul 06 65.4 53.5 62.6

Jonah Jul 07 60.7 54.9 65.5

Jonah Jul 08 72.0 57.1 67.7

Jonah Jul 11 68.9 43.8 50.3

Jonah Jul 12 66.8 50.3 54.3

Jonah Jul 16 65.9 51.9 57.3

Jonah Jul 17 58.3 49.7 69.8

Jonah Jul 22 67.3 56.9 62.3
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-57

Table A4-2e. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

65 ppb at the Pinedale monitoring site during 2005.

Site

2005

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

Pinedale Total exceeding 12 5 7

Pinedale Feb 04 68.3 58.2 48.5

Pinedale Feb 19 71.0 50.9 48.8

Pinedale Feb 27 70.1 51.0 48.4

Pinedale Apr 06 58.6 65.6 57.3

Pinedale Apr 08 66.0 56.8 52.2

Pinedale Apr 15 58.1 65.1 53.9

Pinedale Apr 16 54.9 68.9 56.4

Pinedale Apr 17 59.3 70.4 58.4

Pinedale Apr 18 70.9 61.0 53.5

Pinedale May 25 63.1 62.8 72.9

Pinedale May 26 61.0 61.8 67.8

Pinedale Jun 27 76.4 66.9 70.5

Pinedale Jun 28 66.3 63.4 65.8

Pinedale Jul 07 65.5 61.0 66.0

Pinedale Jul 08 67.3 62.3 68.6

Pinedale Jul 11 66.4 47.0 48.3

Pinedale Jul 12 66.8 54.1 52.6

Pinedale Jul 17 53.4 54.0 67.5

Pinedale Jul 22 65.6 56.4 55.8

Table A4-2f. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

65 ppb at the Wamsutter monitoring site during 2005.

Site

2005

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

Wamsutter Total exceeding NA 2 11

Wamsutter May 26 N/A 55.2 65.5

Wamsutter May 28 N/A 60.9 67.2

Wamsutter Jun 27 N/A 69.3 76.5

Wamsutter Jun 29 N/A 56.6 65.8

Wamsutter Jul 01 N/A 67.9 65.5

Wamsutter Jul 03 N/A 54.1 65.5

Wamsutter Jul 06 N/A 61.7 74.1

Wamsutter Jul 08 N/A 57.7 65.5

Wamsutter Jul 17 N/A 51.9 72.4

Wamsutter Aug 05 N/A 59.9 67.9

Wamsutter Sep 01 N/A 51.1 65.8
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-58

Table A4-3a. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

65 ppb at the Boulder monitoring site during 2006.

Site

2006

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

Boulder Total exceeding 43 10 13

Boulder Jan 26 67.2 47.0 44.5

Boulder Feb 12 67.2 41.7 40.3

Boulder Feb 19 69.9 52.3 50.9

Boulder Feb 26 67.8 59.5 57.0

Boulder Feb 27 71.0 56.9 61.2

Boulder Mar 17 67.4 63.1 59.4

Boulder Apr 08 63.1 66.1 52.3

Boulder Apr 09 64.5 70.6 63.7

Boulder Apr 13 65.1 54.4 53.8

Boulder Apr 20 67.0 60.8 60.3

Boulder Apr 21 81.0 69.9 74.2

Boulder Apr 22 61.2 66.8 63.1

Boulder Apr 28 71.0 60.1 60.6

Boulder May 02 76.5 63.7 64.4

Boulder May 03 67.1 63.4 61.9

Boulder May 06 67.3 65.2 64.8

Boulder May 08 71.3 43.8 38.7

Boulder May 09 69.0 55.6 69.2

Boulder May 10 63.3 52.4 68.1

Boulder May 11 66.5 56.1 58.2

Boulder May 25 66.5 52.0 53.8

Boulder May 31 69.1 62.8 74.5

Boulder Jun 01 72.8 63.6 68.2

Boulder Jun 02 71.8 62.8 60.8

Boulder Jun 10 67.6 53.4 50.4

Boulder Jun 11 72.1 62.6 60.4

Boulder Jun 12 70.5 68.5 64.7

Boulder Jun 13 68.8 57.0 60.6

Boulder Jun 14 68.5 50.2 50.0

Boulder Jun 17 69.8 47.7 57.3

Boulder Jun 18 79.5 49.5 60.9

Boulder Jun 20 67.9 69.8 59.6

Boulder Jun 22 70.6 65.6 60.3

Boulder Jun 23 68.8 56.1 54.2

Boulder Jun 26 65.3 68.3 51.8

Boulder Jun 27 67.5 67.5 55.0

Boulder Jul 08 70.8 60.5 61.4

Boulder Jul 14 29.0 55.4 68.9

Boulder Jul 15 61.5 63.8 70.3

Boulder Jul 27 67.5 55.4 60.4

Boulder Jul 28 65.4 55.3 59.6

Boulder Jul 29 66.8 55.2 62.5

Boulder Aug 13 58.9 52.8 69.3

Boulder Aug 14 64.5 55.8 78.3

Boulder Aug 17 68.0 51.4 57.8

Boulder Aug 18 72.4 59.9 91.5

Boulder Aug 19 68.4 60.4 77.6

Boulder Aug 20 70.1 54.6 66.2

Boulder Aug 21 67.0 59.5 61.4

Boulder Aug 31 67.4 52.6 67.7

Boulder Sep 02 65.1 48.1 56.0
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-59

Table A4-3b. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

65 ppb at the Centennial monitoring site during 2006.

Site

2006

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

Centennial Total exceeding 19 31 15

Centennial Mar 01 59.0 65.2 51.9

Centennial Mar 02 54.1 66.0 52.8

Centennial Mar 03 54.1 66.3 53.5

Centennial Mar 27 59.3 68.4 53.4

Centennial Mar 28 62.9 66.1 55.1

Centennial Apr 04 55.4 65.4 54.6

Centennial Apr 08 63.0 65.8 58.7

Centennial Apr 09 64.1 65.5 59.6

Centennial Apr 13 68.4 63.1 59.7

Centennial Apr 20 66.3 58.0 64.4

Centennial Apr 21 73.0 69.6 79.8

Centennial Apr 22 73.6 66.1 66.8

Centennial Apr 27 65.5 62.0 60.3

Centennial Apr 28 66.0 52.9 51.2

Centennial Apr 29 67.6 56.4 61.9

Centennial May 01 61.6 69.9 61.7

Centennial May 02 73.3 63.0 59.3

Centennial May 03 70.4 60.7 56.5

Centennial May 06 59.0 57.6 67.5

Centennial May 09 70.0 62.3 63.4

Centennial May 10 61.6 56.8 75.0

Centennial May 11 66.3 64.5 66.5

Centennial May 12 64.0 65.2 68.8

Centennial May 31 61.3 68.0 61.7

Centennial Jun 01 62.3 67.7 63.0

Centennial Jun 02 65.5 67.6 60.7

Centennial Jun 03 69.5 63.5 55.3

Centennial Jun 06 53.0 68.5 54.0

Centennial Jun 07 50.5 68.8 55.0

Centennial Jun 10 62.9 67.8 54.9

Centennial Jun 11 59.0 68.3 54.8

Centennial Jun 12 64.0 72.1 69.9

Centennial Jun 19 57.5 66.1 56.3

Centennial Jun 20 56.6 69.0 55.3

Centennial Jun 21 59.3 69.5 58.0

Centennial Jun 22 69.1 69.2 58.6

Centennial Jun 23 65.4 69.6 58.7

Centennial Jun 24 58.4 67.2 54.6

Centennial Jun 26 56.3 71.3 54.0

Centennial Jun 27 55.1 74.2 57.6

Centennial Jun 28 53.9 74.9 58.1

Centennial Jun 29 59.1 66.4 55.6

Centennial Jul 02 49.8 66.6 45.9

Centennial Jul 13 69.3 63.1 69.2

Centennial Jul 14 62.8 63.4 70.7

Centennial Jul 15 61.6 63.4 66.4

Centennial Jul 28 66.9 61.4 65.1

Centennial Jul 29 54.9 62.9 67.7

Centennial Jul 30 64.8 59.5 65.9

Centennial Aug 02 67.0 58.8 60.8

Centennial Aug 14 59.6 60.0 73.2

Centennial Aug 15 59.3 60.7 70.6

Centennial Aug 20 65.4 61.9 59.6
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-60

Table A4-3c. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

65 ppb at the Daniel monitoring site during 2006.

Site

2006

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

Daniel Total exceeding 26 9 17

Daniel Feb 25 82.7 47.7 44.8

Daniel Feb 27 74.8 61.3 60.6

Daniel Mar 06 70.1 62.8 54.9

Daniel Mar 14 66.7 56.2 52.8

Daniel Mar 17 71.6 65.1 60.2

Daniel Mar 18 65.3 62.9 58.1

Daniel Apr 09 62.8 76.8 67.1

Daniel Apr 20 67.6 58.2 64.4

Daniel Apr 21 74.9 72.8 71.0

Daniel Apr 22 68.1 70.4 64.0

Daniel Apr 28 68.4 54.5 57.5

Daniel May 02 75.6 57.7 62.2

Daniel May 03 66.5 61.1 60.7

Daniel May 06 67.3 60.7 63.2

Daniel May 08 71.3 42.1 45.7

Daniel May 09 67.0 52.7 65.8

Daniel May 10 62.3 51.3 65.4

Daniel May 11 65.3 56.4 63.2

Daniel May 30 53.6 50.8 70.0

Daniel May 31 61.1 59.1 72.4

Daniel Jun 01 69.9 65.2 66.7

Daniel Jun 02 66.6 62.1 61.0

Daniel Jun 11 65.9 63.7 59.8

Daniel Jun 12 67.4 69.2 68.1

Daniel Jun 18 73.1 52.8 62.1

Daniel Jun 20 60.0 72.2 59.4

Daniel Jun 22 67.3 68.0 61.7

Daniel Jun 23 67.0 59.1 54.2

Daniel Jun 27 63.0 68.2 56.1

Daniel Jul 14 66.8 55.3 70.6

Daniel Jul 15 68.8 62.4 71.0

Daniel Aug 13 55.3 50.5 69.7

Daniel Aug 14 60.5 54.2 76.1

Daniel Aug 15 57.0 53.5 66.7

Daniel Aug 18 68.3 54.0 78.1

Daniel Aug 19 64.9 58.2 77.6

Daniel Aug 20 N/A 53.5 67.6

Daniel Aug 31 62.9 53.6 71.9
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-61

Table A4-3d. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

65 ppb at the Jonah monitoring site during 2006.

Site

2006

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

Jonah Total exceeding 22 3 8

Jonah Feb 25 81.0 50.5 49.1

Jonah Feb 26 69.1 59.9 59.3

Jonah Feb 27 93.0 57.2 60.2

Jonah Mar 24 68.1 50.4 39.3

Jonah Apr 08 65.8 58.8 49.8

Jonah Apr 09 67.5 68.0 57.2

Jonah Apr 10 65.8 54.8 55.2

Jonah Apr 21 66.6 63.1 77.4

Jonah Apr 28 68.0 56.5 59.5

Jonah May 02 71.5 56.5 56.6

Jonah May 09 63.1 52.0 65.8

Jonah Jun 02 65.4 60.0 62.3

Jonah Jun 11 69.8 58.6 59.5

Jonah Jun 12 66.1 66.4 62.6

Jonah Jun 20 68.7 68.8 60.1

Jonah Jul 14 66.5 52.1 67.5

Jonah Jul 15 69.4 60.0 68.4

Jonah Jul 16 67.0 53.5 63.0

Jonah Jul 29 65.3 54.0 64.2

Jonah Aug 14 61.8 53.5 75.4

Jonah Aug 17 66.8 51.0 60.5

Jonah Aug 18 68.0 54.9 77.0

Jonah Aug 19 67.4 56.1 75.5

Jonah Aug 20 66.3 51.5 65.8
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-62

Table A4-3e. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

65 ppb at the OCI monitoring site during 2006.

Site

2006

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

OCI Total exceeding 24 10 26

OCI Apr 20 N/A 56.5 69.8

OCI Apr 21 N/A 60.8 74.3

OCI May 02 66.8 57.1 56.9

OCI May 09 64.8 54.1 67.0

OCI May 10 61.4 56.0 65.6

OCI May 11 64.0 58.0 67.5

OCI May 31 66.6 66.9 65.9

OCI Jun 01 63.2 68.2 67.8

OCI Jun 02 69.8 64.7 66.0

OCI Jun 10 66.1 63.0 63.8

OCI Jun 11 72.8 62.9 62.5

OCI Jun 12 65.9 69.0 67.1

OCI Jun 18 71.4 51.0 56.7

OCI Jun 19 66.1 59.4 55.5

OCI Jun 20 65.9 63.0 59.8

OCI Jun 21 57.4 65.8 58.9

OCI Jun 22 67.9 65.6 62.6

OCI Jun 26 64.5 66.0 52.1

OCI Jun 27 64.5 73.8 58.6

OCI Jun 28 56.2 67.9 58.2

OCI Jun 29 60.6 66.4 58.6

OCI Jul 13 71.1 57.5 68.1

OCI Jul 14 71.9 59.1 73.2

OCI Jul 15 69.6 66.8 71.9

OCI Jul 16 72.3 64.6 70.6

OCI Jul 17 68.3 57.2 60.4

OCI Jul 18 67.2 64.2 70.5

OCI Jul 22 65.5 57.5 61.1

OCI Jul 25 68.0 53.5 52.3

OCI Jul 27 67.4 61.0 66.3

OCI Jul 28 69.2 62.2 65.9

OCI Jul 29 64.3 59.8 68.3

OCI Jul 30 61.2 52.5 65.2

OCI Aug 03 59.4 59.9 65.2

OCI Aug 10 61.7 60.1 65.1

OCI Aug 14 N/A 59.4 77.5

OCI Aug 18 71.7 62.4 78.5

OCI Aug 19 67.7 59.3 68.8

OCI Aug 20 67.5 57.8 68.2

OCI Aug 21 66.1 60.1 61.5

OCI Sep 03 53.5 58.3 65.6

OCI Sep 04 56.5 60.4 67.2
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-63

Table A4-3f. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

65 ppb at the Boulder monitoring site during 2006.

Site

2006

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

Pinedale Total exceeding 11 17 21

Pinedale Apr 08 61.1 67.5 63.1

Pinedale Apr 09 60.9 66.8 64.7

Pinedale Apr 20 68.4 62.1 70.5

Pinedale Apr 21 80.1 68.0 72.9

Pinedale Apr 22 64.1 67.0 64.7

Pinedale Apr 28 66.0 56.6 59.1

Pinedale May 02 73.4 66.0 66.2

Pinedale May 03 66.6 63.5 63.2

Pinedale May 05 52.5 64.4 71.5

Pinedale May 06 64.5 64.2 70.9

Pinedale May 08 69.1 43.3 45.2

Pinedale May 09 64.6 56.8 71.2

Pinedale May 10 59.3 56.2 69.6

Pinedale May 11 61.9 60.0 65.2

Pinedale May 30 53.1 54.8 67.7

Pinedale May 31 60.1 63.7 70.0

Pinedale Jun 01 66.6 67.5 67.4

Pinedale Jun 11 N/A 65.2 60.7

Pinedale Jun 12 N/A 67.1 63.9

Pinedale Jun 20 N/A 71.4 58.5

Pinedale Jun 21 N/A 68.3 57.2

Pinedale Jun 22 N/A 70.9 60.1

Pinedale Jun 25 N/A 69.7 50.2

Pinedale Jun 26 N/A 70.6 50.1

Pinedale Jun 27 58.2 71.4 57.3

Pinedale Jun 28 49.5 68.3 52.6

Pinedale Jul 01 53.9 65.1 44.7

Pinedale Jul 02 53.5 65.4 45.8

Pinedale Jul 14 63.5 57.7 68.5

Pinedale Jul 15 67.7 63.2 69.7

Pinedale Jul 29 64.1 58.5 65.3

Pinedale Aug 13 57.6 54.6 73.3

Pinedale Aug 14 61.6 58.6 79.8

Pinedale Aug 15 57.7 56.2 65.2

Pinedale Aug 17 67.8 53.9 62.3

Pinedale Aug 18 67.8 58.6 80.4

Pinedale Aug 19 65.0 60.1 77.0

Pinedale Aug 20 66.0 56.7 72.8

Pinedale Aug 31 62.3 54.0 71.8
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-64

Table A4-3g. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

65 ppb at the Wamsutter monitoring site during 2006.

Site

2006

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

Wamsutter Total exceeding 11 9 18

Wamsutter Apr 20 71.4 53.7 64.6

Wamsutter Apr 21 63.1 61.4 75.8

Wamsutter Apr 28 65.3 55.6 57.5

Wamsutter May 02 67.1 60.4 59.3

Wamsutter May 06 59.6 55.9 69.6

Wamsutter May 10 59.3 52.5 69.6

Wamsutter May 11 66.1 59.0 65.7

Wamsutter May 12 61.9 60.3 67.5

Wamsutter Jun 01 63.8 67.5 67.8

Wamsutter Jun 02 65.6 62.8 62.4

Wamsutter Jun 03 69.3 61.4 58.8

Wamsutter Jun 10 67.1 61.4 58.2

Wamsutter Jun 11 65.8 62.8 57.8

Wamsutter Jun 12 66.8 68.2 69.0

Wamsutter Jun 18 66.5 55.6 60.9

Wamsutter Jun 20 64.4 66.9 63.3

Wamsutter Jun 21 63.0 65.8 62.2

Wamsutter Jun 22 66.3 66.3 62.0

Wamsutter Jun 27 62.8 71.6 58.3

Wamsutter Jun 29 19.8 65.5 57.2

Wamsutter Jul 13 58.1 62.3 72.0

Wamsutter Jul 14 56.8 55.7 70.9

Wamsutter Jul 15 54.5 62.1 69.9

Wamsutter Jul 16 54.6 64.6 71.2

Wamsutter Jul 18 49.1 58.3 67.0

Wamsutter Jul 28 54.1 69.8 75.2

Wamsutter Jul 29 22.5 68.6 78.1

Wamsutter Jul 30 25.7 58.2 70.4

Wamsutter Aug 14 55.3 61.4 86.7

Wamsutter Aug 18 55.9 55.9 66.3

Wamsutter Aug 20 58.3 60.9 72.6
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-65

Table A4-4a. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

70 ppb during 2005.

Site

2005

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

Boulder Total exceeding 12 0 1

Boulder Feb 03 82.0 41.4 43.3

Boulder Feb 04 80.2 54.3 50.2

Boulder Feb 19 79.9 46.1 49.8

Boulder Feb 20 89.3 38.5 35.2

Boulder Feb 22 75.9 51.5 48.3

Boulder Feb 24 80.9 45.7 49.2

Boulder Feb 25 72.2 44.4 45.9

Boulder Feb 26 70.2 53.2 54.7

Boulder Feb 27 74.5 49.1 49.2

Boulder Mar 03 71.9 45.3 49.3

Boulder May 25 65.0 60.5 72.8

Boulder Jun 27 72.7 58.8 66.8

Boulder Jul 23 70.7 57.1 58.1

Centennial Total exceeding 0 9 1

Centennial Apr 07 56.6 71.8 59.9

Centennial Apr 16 61.3 70.7 56.1

Centennial Jun 01 57.1 77.9 61.5

Centennial Jun 02 59.1 82.8 64.6

Centennial Jun 03 51.6 79.9 63.3

Centennial Jun 08 56.1 71.3 56.3

Centennial Jun 13 60.9 70.4 59.9

Centennial Jun 14 57.0 70.6 60.7

Centennial Jul 01 52.1 70.2 65.4

Centennial Aug 05 58.3 59.1 70.6

Daniel Total exceeding 1 0 1

Daniel May 25 N/A 62.1 72.2

Daniel Jul 08 70.8 57.7 67.7

Jonah Total exceeding 8 0 2

Jonah Jan 24 78.3 46.4 35.9

Jonah Feb 03 98.4 40.8 37.2

Jonah Feb 04 76.4 52.9 46.7

Jonah Feb 26 89.4 51.8 50.4

Jonah Feb 27 75.4 48.0 48.1

Jonah Apr 13 75.3 55.0 50.4

Jonah May 25 60.5 60.7 71.3

Jonah Jun 27 73.9 60.2 70.9

Jonah Jul 08 72.0 57.1 67.7

Pinedale Total exceeding 4 1 2

Pinedale Feb 19 71.0 50.9 48.8

Pinedale Feb 27 70.1 51.0 48.4

Pinedale Apr 17 59.3 70.4 58.4

Pinedale Apr 18 70.9 61.0 53.5

Pinedale May 25 63.1 62.8 72.9

Pinedale Jun 27 76.4 66.9 70.5

Wamsutter Total exceeding NA 0 3

Wamsutter Jun 27 N/A 69.3 76.5

Wamsutter Jul 06 N/A 61.7 74.1

Wamsutter Jul 17 N/A 51.9 72.4
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-66

Table A4-4b. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

70 ppb during 2006.

Site

2006

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

Boulder Total exceeding 14 1 6

Boulder Feb 27 71.0 56.9 61.2

Boulder Apr 09 64.5 70.6 63.7

Boulder Apr 21 81.0 69.9 74.2

Boulder Apr 28 71.0 60.1 60.6

Boulder May 02 76.5 63.7 64.4

Boulder May 08 71.3 43.8 38.7

Boulder May 31 69.1 62.8 74.5

Boulder Jun 01 72.8 63.6 68.2

Boulder Jun 02 71.8 62.8 60.8

Boulder Jun 11 72.1 62.6 60.4

Boulder Jun 12 70.5 68.5 64.7

Boulder Jun 18 79.5 49.5 60.9

Boulder Jun 22 70.6 65.6 60.3

Boulder Jul 08 70.8 60.5 61.4

Boulder Jul 15 61.5 63.8 70.3

Boulder Aug 14 64.5 55.8 78.3

Boulder Aug 18 72.4 59.9 91.5

Boulder Aug 19 68.4 60.4 77.6

Boulder Aug 20 70.1 54.6 66.2

Centennial Total exceeding 4 4 5

Centennial Apr 21 73.0 69.6 79.8

Centennial Apr 22 73.6 66.1 66.8

Centennial May 02 73.3 63.0 59.3

Centennial May 03 70.4 60.7 56.5

Centennial May 10 61.6 56.8 75.0

Centennial Jun 12 64.0 72.1 69.9

Centennial Jun 26 56.3 71.3 54.0

Centennial Jun 27 55.1 74.2 57.6

Centennial Jun 28 53.9 74.9 58.1

Centennial Jul 14 62.8 63.4 70.7

Centennial Aug 14 59.6 60.0 73.2

Centennial Aug 15 59.3 60.7 70.6

Daniel Total exceeding 8 4 8

Daniel Feb 25 82.7 47.7 44.8

Daniel Feb 27 74.8 61.3 60.6

Daniel Mar 06 70.1 62.8 54.9

Daniel Mar 17 71.6 65.1 60.2

Daniel Apr 09 62.8 76.8 67.1

Daniel Apr 21 74.9 72.8 71.0

Daniel Apr 22 68.1 70.4 64.0

Daniel May 02 75.6 57.7 62.2

Daniel May 08 71.3 42.1 45.7

Daniel May 31 61.1 59.1 72.4

Daniel Jun 18 73.1 52.8 62.1

Daniel Jun 20 60.0 72.2 59.4

Daniel Jul 14 66.8 55.3 70.6

Daniel Jul 15 68.8 62.4 71.0

Daniel Aug 14 60.5 54.2 76.1

Daniel Aug 18 68.3 54.0 78.1

Daniel Aug 19 64.9 58.2 77.6

Daniel Aug 31 62.9 53.6 71.9
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-67

Table A4-4c. Summary of days having daily maximum 8-hour ozone concentrations exceeding 

70 ppb during 2006.

Site

2006

Daily Maximum 

Observed

Daily Maximum 

Predicted 

Hiawatha

Daily Maximum 

Month Day Predicted CD-C

Jonah Total exceeding 3 0 4

Jonah Feb 25 81.0 50.5 49.1

Jonah Feb 27 93.0 57.2 60.2

Jonah Apr 21 66.6 63.1 77.4

Jonah May 02 71.5 56.5 56.6

Jonah Aug 14 61.8 53.5 75.4

Jonah Aug 18 68.0 54.9 77.0

Jonah Aug 19 67.4 56.1 75.5

OCI Total exceeding 6 1 7

OCI Apr 21 N/A 60.8 74.3

OCI Jun 11 72.8 62.9 62.5

OCI Jun 18 71.4 51.0 56.7

OCI Jun 27 64.5 73.8 58.6

OCI Jul 13 71.1 57.5 68.1

OCI Jul 14 71.9 59.1 73.2

OCI Jul 15 69.6 66.8 71.9

OCI Jul 16 72.3 64.6 70.6

OCI Jul 18 67.2 64.2 70.5

OCI Aug 14 N/A 59.4 77.5

OCI Aug 18 71.7 62.4 78.5

Pinedale Total exceeding 2 4 11

Pinedale Apr 20 68.4 62.1 70.5

Pinedale Apr 21 80.1 68.0 72.9

Pinedale May 02 73.4 66.0 66.2

Pinedale May 05 52.5 64.4 71.5

Pinedale May 06 64.5 64.2 70.9

Pinedale May 09 64.6 56.8 71.2

Pinedale Jun 20 N/A 71.4 58.5

Pinedale Jun 22 N/A 70.9 60.1

Pinedale Jun 26 N/A 70.6 50.1

Pinedale Jun 27 58.2 71.4 57.3

Pinedale Aug 13 57.6 54.6 73.3

Pinedale Aug 14 61.6 58.6 79.8

Pinedale Aug 18 67.8 58.6 80.4

Pinedale Aug 19 65.0 60.1 77.0

Pinedale Aug 20 66.0 56.7 72.8

Pinedale Aug 31 62.3 54.0 71.8

Wamsutter Total exceeding 1 1 9

Wamsutter Apr 20 71.4 53.7 64.6

Wamsutter Apr 21 63.1 61.4 75.8

Wamsutter Jun 27 62.8 71.6 58.3

Wamsutter Jul 13 58.1 62.3 72.0

Wamsutter Jul 14 56.8 55.7 70.9

Wamsutter Jul 16 54.6 64.6 71.2

Wamsutter Jul 28 54.1 69.8 75.2

Wamsutter Jul 29 22.5 68.6 78.1

Wamsutter Jul 30 25.7 58.2 70.4

Wamsutter Aug 14 55.3 61.4 86.7

Wamsutter Aug 20 58.3 60.9 72.6
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-68

A4.4. OZONE TIME SERIES OF DAILY MAXIMUM 8-HOUR OZONE CONCENTRATIONS FOR

MONITORS IN 4 KM DOMAIN

Figures A4-3 and A4-4 compare the predicted and observed 8-hour ozone time series for 

monitors in the 4 km domain and the years 2005 and 2006, respectively. At the Boulder 

monitor for Quarter 1 (Q1) in 2005 (Figure A4-3a, top) neither base case simulation reproduces 

the observed high winter ozone concentrations. There is also a tendency for both models to 

underestimate the observed 8-hour ozone concentrations during Q4 in 2005 at Boulder, 

however both modeled and observed ozone values are below 60 ppb. During Q3 and Q4 of 

2005, the two base case simulations match the observed 8-hour ozone values better, albeit 

with a general underestimation bias with Hiawatha base case matching the observed values in 

June better and CD-C matching them better in July and August.

With the exception of a few observed high winter ozone events in January and February 2005, 

the two models do a much better job of reproducing the winter (Q1 and Q4) observed 8-hour 

ozone concentrations at the Jonah monitor (Figure A4-3b) than is seen at the Boulder monitor 

(Figure A4-3a). In Q3 during 2005, both models miss a few days with high observed ozone 

concentrations at Jonah in April with the CD-C base case generally predicting ozone closer to 

observed than the Hiawatha base case, including much better reproduction of the observed 

high ozone at the end of June 2005. During 2005 Q4, both models tend to underestimate the 

high observed ozone days at Jonah, with the CD-C base case generally higher and closer to the 

observed values than the Hiawatha base case.

Observed daily maximum ozone concentrations for Daniel during 2005 are only available for Q3 

and Q4 (Figure A4-3c). In general, the CD-C base case is exhibiting better performance in Q3, 

whereas the Hiawatha performance is superior in Q4.

2005 daily maximum 8-hour ozone comparisons for the Pinedale and Centennial CASTnet sites 

are shown in Figures A4-4d and 5-4e, respectively. The Hiawatha base case is performing 

better for Q1 and Q4 with the CD-C base case exhibiting an underestimation bias at these two 

sites. However, for Q2 and Q3 the CD-C base case is generally performing better than the 

Hiawatha base case that exhibits an overestimation bias at Centennial in Q2 that can be quite 

large on some days.

The daily maximum 8-hour ozone results for 2006 and Boulder are somewhat similar to 2005 

with the Hiawatha base case generally performing better in Q1 and the CD-C base case 

generally performing better in Q3, but there are some interesting differences (Figure A4-4a). In 

Q2 there are high observed ozone events in mid-April and the end of May and beginning of 

June that is captured better by the CD-C base case. The CD-C base case estimates the highest 

ozone concentrations in mid-August when high observed ozone also occurs, just not as high as 

estimated by the CD-C base case. The Wamsutter (Figure A4-4f) and OCI (Figure A4-4g) 

monitoring sites came online in 2006. At Wamsutter both models perform reasonable well in 

Q3 but have an overestimation bias in Q4. With the exception of a few days, the two base case 

simulations reproduce the observed ozone at OCI reasonably well. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-69

Figure A4-3a. Daily maximum 8-hour ozone concentration time series at Boulder site for 

2005.

Daily Max 8-Hr Ozone at Boulder Site for The Quarter 1, 2005

0

10

20

30

40

50

60

70

80

90

100

010101030105010701090111011301150117011901210123012501270129013102020204020602080210021202140216021802200222022402260228030203040306030803100312031403160318032003220324032603280330

[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Boulder Site for The Quarter 2, 2005

0

10

20

30

40

50

60

70

80

0401040304050407040904110413041504170419042104230425042704290501050305050507050905110513051505170519052105230525052705290531060206040606060806100612061406160618062006220624062606280630

[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Boulder Site for The Quarter 3, 2005

0

10

20

30

40

50

60

70

80

0701070307050707070907110713071507170719072107230725072707290731080208040806080808100812081408160818082008220824082608280830090109030905090709090911091309150917091909210923092509270929

[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Boulder Site for The Quarter 4, 2005

0

10

20

30

40

50

60

1001100310051007100910111013101510171019102110231025102710291031110211041106110811101112111411161118112011221124112611281130120212041206120812101212121412161218122012221224122612281230

[ppb]

Obs Hiaw atha CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-70

Figure A4-3b. Daily maximum 8-hour ozone concentration time series at Jonah site for 2005. Daily Max 8-Hr Ozone at Jonah Site for The Quarter 1, 2005

0

20

40

60

80

100

120

010101030105010701090111011301150117011901210123012501270129013102020204020602080210021202140216021802200222022402260228030203040306030803100312031403160318032003220324032603280330

[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Jonah Site for The Quarter 2, 2005

0

10

20

30

40

50

60

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Jonah Site for The Quarter 3, 2005

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Jonah Site for The Quarter 4, 2005

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1001100310051007100910111013101510171019102110231025102710291031110211041106110811101112111411161118112011221124112611281130120212041206120812101212121412161218122012221224122612281230

[ppb]

Obs Hiaw atha CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-71

Figure A4-3c. Daily maximum 8-hour ozone concentration time series at Daniel site for 2005. Daily Max 8-Hr Ozone at Daniel Site for The Quarter 1, 2005

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010101030105010701090111011301150117011901210123012501270129013102020204020602080210021202140216021802200222022402260228030203040306030803100312031403160318032003220324032603280330

[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Daniel Site for The Quarter 2, 2005

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0401040304050407040904110413041504170419042104230425042704290501050305050507050905110513051505170519052105230525052705290531060206040606060806100612061406160618062006220624062606280630

[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Daniel Site for The Quarter 3, 2005

0

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0701070307050707070907110713071507170719072107230725072707290731080208040806080808100812081408160818082008220824082608280830090109030905090709090911091309150917091909210923092509270929

[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Daniel Site for The Quarter 4, 2005

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1001100310051007100910111013101510171019102110231025102710291031110211041106110811101112111411161118112011221124112611281130120212041206120812101212121412161218122012221224122612281230

[ppb]

Obs Hiaw atha CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-72

Figure A4-3d. Daily maximum 8-hour ozone concentration time series at Pinedale site for 

2005.

Daily Max 8-Hr Ozone at Pinedale Site for The Quarter 1, 2005

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010101030105010701090111011301150117011901210123012501270129013102020204020602080210021202140216021802200222022402260228030203040306030803100312031403160318032003220324032603280330

[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Pinedale Site for The Quarter 2, 2005

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0401040304050407040904110413041504170419042104230425042704290501050305050507050905110513051505170519052105230525052705290531060206040606060806100612061406160618062006220624062606280630

[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Pinedale Site for The Quarter 3, 2005

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Pinedale Site for The Quarter 4, 2005

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1001100310051007100910111013101510171019102110231025102710291031110211041106110811101112111411161118112011221124112611281130120212041206120812101212121412161218122012221224122612281230

[ppb]

Obs Hiaw atha CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-73

Figure A4-3e. Daily maximum 8-hour ozone concentration time series at Centennial site for 

2005.

Daily Max 8-Hr Ozone at Centennial Site for The Quarter 1, 2005

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010101030105010701090111011301150117011901210123012501270129013102020204020602080210021202140216021802200222022402260228030203040306030803100312031403160318032003220324032603280330

[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Centennial Site for The Quarter 2, 2005

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Centennial Site for The Quarter 3, 2005

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Centennial Site for The Quarter 4, 2005

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1001100310051007100910111013101510171019102110231025102710291031110211041106110811101112111411161118112011221124112611281130120212041206120812101212121412161218122012221224122612281230

[ppb]

Obs Hiaw atha CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-74

Figure A4-4a. Daily maximum 8-hour ozone concentration time series at Boulder site for 

2006.

Daily Max 8-Hr Ozone at Boulder Site for The Quarter 1, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Boulder Site for The Quarter 2, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Boulder Site for The Quarter 3, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Boulder Site for The Quarter 4, 2006

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[ppb]

Obs Hiaw atha CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-75

Figure A4-4b. Daily maximum 8-hour ozone concentration time series at Jonah site for 2006. Daily Max 8-Hr Ozone at Jonah Site for The Quarter 1, 2006

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010101030105010701090111011301150117011901210123012501270129013102020204020602080210021202140216021802200222022402260228030203040306030803100312031403160318032003220324032603280330

[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Jonah Site for The Quarter 2, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Jonah Site for The Quarter 3, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Jonah Site for The Quarter 4, 2006

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[ppb]

Obs Hiaw atha CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-76

Figure A4-4c. Daily maximum 8-hour ozone concentration time series at Daniel site for 2006. Daily Max 8-Hr Ozone at Daniel Site for The Quarter 1, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Daniel Site for The Quarter 2, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Daniel Site for The Quarter 3, 2006

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0701070307050707070907110713071507170719072107230725072707290731080208040806080808100812081408160818082008220824082608280830090109030905090709090911091309150917091909210923092509270929

[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Daniel Site for The Quarter 4, 2006

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1001100310051007100910111013101510171019102110231025102710291031110211041106110811101112111411161118112011221124112611281130120212041206120812101212121412161218122012221224122612281230

[ppb]

Obs Hiaw atha CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-77

Figure A4-4d. Daily maximum 8-hour ozone concentration time series at Pinedale site for 

2006.

Daily Max 8-Hr Ozone at Pinedale Site for The Quarter 1, 2006

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010101030105010701090111011301150117011901210123012501270129013102020204020602080210021202140216021802200222022402260228030203040306030803100312031403160318032003220324032603280330

[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Pinedale Site for The Quarter 2, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Pinedale Site for The Quarter 3, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Pinedale Site for The Quarter 4, 2006

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[ppb]

Obs Hiaw atha CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-78

Figure A4-4e. Daily maximum 8-hour ozone concentration time series at Centennial site for 

2006.

Daily Max 8-Hr Ozone at Centennial Site for The Quarter 1, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Centennial Site for The Quarter 2, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Centennial Site for The Quarter 3, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Centennial Site for The Quarter 4, 2006

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1001100310051007100910111013101510171019102110231025102710291031110211041106110811101112111411161118112011221124112611281130120212041206120812101212121412161218122012221224122612281230

[ppb]

Obs Hiaw atha CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-79

Figure A4-4f. Daily maximum 8-hour ozone concentration time series at Wamsutter site for 

2006.

Daily Max 8-Hr Ozone at Wamsutter Site for The Quarter 1, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Wamsutter Site for The Quarter 2, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Wamsutter Site for The Quarter 3, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at Wamsutter Site for The Quarter 4, 2006

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[ppb]

Obs Hiaw atha CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-80

Figure A4-4g. Daily maximum 8-hour ozone concentration time series at OCI site for 2006. Daily Max 8-Hr Ozone at OCI Site for The Quarter 1, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at OCI Site for The Quarter 2, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at OCI Site for The Quarter 3, 2006

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[ppb]

Obs Hiaw atha CD-C Daily Max 8-Hr Ozone at OCI Site for The Quarter 4, 2006

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[ppb]

Obs Hiaw atha CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-81

A4.5 DIURNAL HOURLY OZONE PERFORMANCE DURING APRIL-OCTOBER 2005 AND 2006 

HIGH OZONE EVENTS

WDEQ-AQD has identified high ozone days that occurred in southwestern Wyoming during 

April-October of 2005 and 2006. Design values at the Wyoming monitors used in projecting 

future year ozone are determined by the ozone values on base year high ozone days, so good 

model performance on these days is critical for confidence in future year projections. In this 

section, we evaluate the CAMx model performance on high ozone days during 2005-2006. 

Figures A4-5 through 5-12 display hourly ozone time series for all available monitors in the 4 km 

grid during each high ozone event identified by the WDEQ-AQD. The time series begin one day 

before the first day with an 8-hour daily maximum ozone value greater than 70 ppb and end 

one day after the last episode day with 8-hour daily max ozone greater than 70 ppb. The hourly 

time series plots include the observed values (red) and predicted values for the CD-C (blue) and 

Hiawatha (green) base cases as well as a grey area that represents the maximum and minimum 

predicted value in a 7 x 7 array of grid cells centered on the monitor for the CD-C base case 

simulation.

June 26-28, 2005

The ozone time series for the June 26-28 episode are shown in Figure A4-5. As noted in the 

quarterly time series, the diurnal cycle has greater amplitude at Jonah and Boulder than at 

Pinedale and Centennial, likely due to the presence of local emissions sources. The two base 

case simulations perform well at Pinedale, although it does not replicate the hourly ozone 

spikes on June 28, which are likely measurement artifacts since they are not supported by 

observed hourly ozone concentrations on either side of the spike. At Centennial, the Hiawatha 

base case simulation generally overestimates ozone during the June 26-28 period, with the CDC base case showing good agreement with the hourly ozone observations on June 28, but 

underestimates on June 27 (Figure A4-5b, top). At the Jonah and Boulder monitoring sites, the 

CD-C base case is reproducing the observed hourly ozone concentrations much better than 

Hiawatha base case with hourly ozone concentrations in the afternoon that are 10-20 ppb 

higher and close to the observed values.

July 7-9, 2005

On July 7-9, 2005, The CD-C base case is simulating higher afternoon ozone concentrations that 

match the observed values at the Jonah monitoring site much better than the Hiawatha base 

case simulation (Figure A4-6a, top). Note that the Boulder monitor observations are missing 

during the periods of peak ozone in the afternoon for this episode (Figure A4-6a, bottom). The 

two model simulations underestimate the observed ozone variability at Daniel, with the 

Hiawatha base case undershooting the observed ozone peaks and the CD-C base case matching 

the observed ozone maximum much better (Figure A4-6c). Both base cases overestimate the 

observed ozone at Centennial during July 7-9, 2005 with CD-C matching the observed values 

slightly better at Pinedale, except during a few observed 1-hour long ozone spikes which may 

be measurement artifacts.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-82

April 20-22, 2006

Both models fail to capture the observed ~100 ppb hourly ozone peak at Boulder on April 21, 

2006 that occurs early in the day, although the CD-C matches the observed high ozone at Jonah 

(~80 ppb) later in the day (Figure A4-7a). Looking at the Pinedale hourly ozone traces (Figure 5-

8b) we see that although the maximum CD-C base case predicted ozone at the monitoring on 

April 21 (~75 ppb) is below the observed value (~90 ppb), there are CD-C base case predictions 

within the 7x7 array of 4 km grid cells that match the observed value quite well suggesting that 

the CD-C base case is predicting the right magnitude of ozone, but there is a spatial 

displacement. This is important since in EPA’s 8-hour ozone Design Value projection 

procedures the maximum predicted ozone concentration in a 7x7 array of 4 km grid cells is 

used in developing the Relative Response Factors (RRFs). 

May 1-9, 2006

The two base case simulations tend to underestimate the observed ozone peaks on May 2 and 

8, but simulate the observed ozone reasonably well in between (Figure A4-8). At Wamsutter, 

both base case simulations underestimate the observed ozone peak on May 2 by ~10 ppb then 

match the observed ozone very well until the CD-C base case overestimates the observed 

afternoon ozone on May 7, during which time the Hiawatha base case simulates the observed 

values well (Figure A4-8c, bottom). Both models underestimate the observed ozone at 

Wamsutter on May 8, but by May 9, the CD-C base case matches the observed ozone well, 

whereas Hiawatha base case underestimates it. Both models simulate the observed hourly 

ozone concentrations well at OCI (Figure A4-8d).

May 30-June 3, 2006

During the May 30-June 3 episode, the two base case simulations produce an excellent 

simulation of the observed ozone time series at OCI (Figure A4-9d). The two base case 

simulations have a high bias at the Pinedale CASTNet site, with the overestimation bias also 

seen at the Centennial CASTNet site for the Hiawatha base case, whereas the CD-C base case 

matches the observed ozone at Centennial well (Figure A4-9b). At the Jonah, Boulder, Daniel, 

and Wamsutter monitors (Figure A4-9a and 5-9c, top), the CD-C base case simulates the 

observed afternoon ozone concentrations better than the Hiawatha base case that has an 

underestimation bias, but night time minima are not accurately reproduced by either base case 

simulation.

June 10-19, 2006

The two base case simulations have a tendency to underestimate the observed ozone peaks for 

all monitors except Centennial during June 10-19, 2006 (Figure A4-10). This suggests that the 

regional background ozone is well simulated but that the underprediction of peak ozone may 

be due insufficient ozone formation from local sources of emissions. The CD-C base case 

generally simulates slightly higher afternoon ozone concentrations, and therefore matches the 

observed values better than the Hiawatha base case simulation. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-83

July 7-17, 2006

At Wamsutter, the two model simulations overestimate observed peak ozone values 

throughout most of the July 7-17 period, and predict nighttime minima that are ~30 ppb too 

high (Figure 5-11c, bottom). This is especially true for the CD-C base case simulation on July 13-

15, 2006 that predicts afternoon ozone maximum that are 10-20 ppb higher than observed. At 

Jonah, on the other hand, the CD-C base case matches the observed afternoon high and 

nighttime low ozone concentrations well, whereas the Hiawatha base case afternoon ozone 

concentrations are much too low and the nighttime values drop to zero (Figure A4-11a, top). 

Similar results are seen at Boulder (Figure A4-11a, bottom) and Daniel (Figure A4-11c, top) with 

the CD-C base case matching the observed high ozone much better than the Hiawatha base 

case simulation.

August 17-19, 2006

For this episode, the Hiawatha base case underestimates the observed ozone peaks at the 

three Sublette County industrial ozone monitors (Figure A4-12). The CD-C base case, on the 

other hand, reproduces the observed hourly ozone well on August 17 and 19 at these three 

sites, and overestimates on August 19. The Hiawatha base case underestimation bias is 

smallest at Wamsutter, where the CD-C base model exhibits an overestimation bias (Figure A4-

12c, bottom). The performance of the two base case simulations at the Pinedale and 

Centennial CASTNet monitoring sites is quite different (Figure A4-12b). At the Pinedale site, the 

CD-C base case matches the observed ozone well during August 17-18 and overestimates on 

August 19, whereas the Hiawatha base case underestimates the entire episode. But at 

Centennial the Hiawatha base case overestimates On August 17 and 19 when the CD-C base 

case matches the observed ozone well and both models underestimate the observed ozone on 

August 18.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-84

Figure A4-5a. 1-hour ozone time series for June 26-28, 2005.

Houly Ozone Plot, Jun 26 to Jun 28, 2005, at Jonah

0

10

20

30

40

50

60

70

80

90

Jun 26 0:00Jun 26 3:00Jun 26 6:00Jun 26 9:00

Jun 26 12:00Jun 26 15:00Jun 26 18:00Jun 26 21:00

Jun 27 0:00Jun 27 3:00Jun 27 6:00Jun 27 9:00

Jun 27 12:00Jun 27 15:00Jun 27 18:00Jun 27 21:00

Jun 28 0:00Jun 28 3:00Jun 28 6:00Jun 28 9:00

Jun 28 12:00Jun 28 15:00Jun 28 18:00Jun 28 21:00

Jun 29 0:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Jun 26 to Jun 28, 2005, at Boulder

0

10

20

30

40

50

60

70

80

Jun 26 0:00Jun 26 3:00Jun 26 6:00Jun 26 9:00

Jun 26 12:00Jun 26 15:00Jun 26 18:00Jun 26 21:00

Jun 27 0:00Jun 27 3:00Jun 27 6:00Jun 27 9:00

Jun 27 12:00Jun 27 15:00Jun 27 18:00Jun 27 21:00

Jun 28 0:00Jun 28 3:00Jun 28 6:00Jun 28 9:00

Jun 28 12:00Jun 28 15:00Jun 28 18:00Jun 28 21:00

Jun 29 0:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-85

Figure A4-5b. 1-hour ozone time series for June 26-28, 2005.

Houly Ozone Plot, Jun 26 to Jun 28, 2005, at Centennial

0

10

20

30

40

50

60

70

80

Jun 26 0:00Jun 26 3:00Jun 26 6:00Jun 26 9:00

Jun 26 12:00Jun 26 15:00Jun 26 18:00Jun 26 21:00

Jun 27 0:00Jun 27 3:00Jun 27 6:00Jun 27 9:00

Jun 27 12:00Jun 27 15:00Jun 27 18:00Jun 27 21:00

Jun 28 0:00Jun 28 3:00Jun 28 6:00Jun 28 9:00

Jun 28 12:00Jun 28 15:00Jun 28 18:00Jun 28 21:00

Jun 29 0:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Jun 26 to Jun 28, 2005, at Pinedale

0

20

40

60

80

100

120

Jun 26 0:00Jun 26 3:00Jun 26 6:00Jun 26 9:00

Jun 26 12:00Jun 26 15:00Jun 26 18:00Jun 26 21:00

Jun 27 0:00Jun 27 3:00Jun 27 6:00Jun 27 9:00

Jun 27 12:00Jun 27 15:00Jun 27 18:00Jun 27 21:00

Jun 28 0:00Jun 28 3:00Jun 28 6:00Jun 28 9:00

Jun 28 12:00Jun 28 15:00Jun 28 18:00Jun 28 21:00

Jun 29 0:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-86

Figure A4-6a. 1-hour ozone time series for Jul7-9, 2005.

Houly Ozone Plot, Jul 07 to Jul 09, 2005, at Jonah

0

10

20

30

40

50

60

70

80

90

Jul 7 0:00Jul 7 3:00Jul 7 6:00Jul 7 9:00

Jul 7 12:00Jul 7 15:00Jul 7 18:00Jul 7 21:00

Jul 8 0:00Jul 8 3:00Jul 8 6:00Jul 8 9:00

Jul 8 12:00Jul 8 15:00Jul 8 18:00Jul 8 21:00

Jul 9 0:00Jul 9 3:00Jul 9 6:00Jul 9 9:00

Jul 9 12:00Jul 9 15:00Jul 9 18:00Jul 9 21:00Jul 10 0:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Jul 07 to Jul 09, 2005, at Boulder

0

10

20

30

40

50

60

70

80

Jul 7 0:00Jul 7 3:00Jul 7 6:00Jul 7 9:00

Jul 7 12:00Jul 7 15:00Jul 7 18:00Jul 7 21:00

Jul 8 0:00Jul 8 3:00Jul 8 6:00Jul 8 9:00

Jul 8 12:00Jul 8 15:00Jul 8 18:00Jul 8 21:00

Jul 9 0:00Jul 9 3:00Jul 9 6:00Jul 9 9:00

Jul 9 12:00Jul 9 15:00Jul 9 18:00Jul 9 21:00Jul 10 0:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-87

Figure A4-6b. 1-hour ozone time series for July7-9, 2005.

Houly Ozone Plot, Jul 07 to Jul 09, 2005, at Centennial

0

10

20

30

40

50

60

70

80

Jul 7 0:00Jul 7 3:00Jul 7 6:00Jul 7 9:00

Jul 7 12:00Jul 7 15:00Jul 7 18:00Jul 7 21:00

Jul 8 0:00Jul 8 3:00Jul 8 6:00Jul 8 9:00

Jul 8 12:00Jul 8 15:00Jul 8 18:00Jul 8 21:00

Jul 9 0:00Jul 9 3:00Jul 9 6:00Jul 9 9:00

Jul 9 12:00Jul 9 15:00Jul 9 18:00Jul 9 21:00Jul 10 0:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Jul 07 to Jul 09, 2005, at Pinedale

0

10

20

30

40

50

60

70

80

90

Jul 7 0:00Jul 7 3:00Jul 7 6:00Jul 7 9:00

Jul 7 12:00Jul 7 15:00Jul 7 18:00Jul 7 21:00

Jul 8 0:00Jul 8 3:00Jul 8 6:00Jul 8 9:00

Jul 8 12:00Jul 8 15:00Jul 8 18:00Jul 8 21:00

Jul 9 0:00Jul 9 3:00Jul 9 6:00Jul 9 9:00

Jul 9 12:00Jul 9 15:00Jul 9 18:00Jul 9 21:00Jul 10 0:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-88

Figure A4-6c.1-hour ozone time series for July7-9, 2005.

Houly Ozone Plot, Jul 07 to Jul 09, 2005, at Daniel

0

10

20

30

40

50

60

70

80

Jul 7 0:00Jul 7 3:00Jul 7 6:00Jul 7 9:00

Jul 7 12:00Jul 7 15:00Jul 7 18:00Jul 7 21:00

Jul 8 0:00Jul 8 3:00Jul 8 6:00Jul 8 9:00

Jul 8 12:00Jul 8 15:00Jul 8 18:00Jul 8 21:00

Jul 9 0:00Jul 9 3:00Jul 9 6:00Jul 9 9:00

Jul 9 12:00Jul 9 15:00Jul 9 18:00Jul 9 21:00Jul 10 0:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-89

Figure A4-7a. 1-hour ozone time series for April20-22, 2006.

Houly Ozone Plot, Apr 20 to Apr 22, 2006, at Jonah

0

10

20

30

40

50

60

70

80

90

Apr 20 00:00Apr 20 03:00Apr 20 06:00Apr 20 09:00Apr 20 12:00Apr 20 15:00Apr 20 18:00Apr 20 21:00Apr 21 00:00Apr 21 03:00Apr 21 06:00Apr 21 09:00Apr 21 12:00Apr 21 15:00Apr 21 18:00Apr 21 21:00Apr 22 00:00Apr 22 03:00Apr 22 06:00Apr 22 09:00Apr 22 12:00Apr 22 15:00Apr 22 18:00Apr 22 21:00Apr 23 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Apr 20 to Apr 22, 2006, at Boulder

0

20

40

60

80

100

120

Apr 20 00:00Apr 20 03:00Apr 20 06:00Apr 20 09:00Apr 20 12:00Apr 20 15:00Apr 20 18:00Apr 20 21:00Apr 21 00:00Apr 21 03:00Apr 21 06:00Apr 21 09:00Apr 21 12:00Apr 21 15:00Apr 21 18:00Apr 21 21:00Apr 22 00:00Apr 22 03:00Apr 22 06:00Apr 22 09:00Apr 22 12:00Apr 22 15:00Apr 22 18:00Apr 22 21:00Apr 23 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-90

Figure A4-7b. 1-hour ozone time series for April20-22, 2006.

Houly Ozone Plot, Apr 20 to Apr 22, 2006, at Centennial

0

10

20

30

40

50

60

70

80

90

100

Apr 20 00:00Apr 20 03:00Apr 20 06:00Apr 20 09:00Apr 20 12:00Apr 20 15:00Apr 20 18:00Apr 20 21:00Apr 21 00:00Apr 21 03:00Apr 21 06:00Apr 21 09:00Apr 21 12:00Apr 21 15:00Apr 21 18:00Apr 21 21:00Apr 22 00:00Apr 22 03:00Apr 22 06:00Apr 22 09:00Apr 22 12:00Apr 22 15:00Apr 22 18:00Apr 22 21:00Apr 23 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Apr 20 to Apr 22, 2006, at Pinedale

0

10

20

30

40

50

60

70

80

90

100

Apr 20 00:00Apr 20 03:00Apr 20 06:00Apr 20 09:00Apr 20 12:00Apr 20 15:00Apr 20 18:00Apr 20 21:00Apr 21 00:00Apr 21 03:00Apr 21 06:00Apr 21 09:00Apr 21 12:00Apr 21 15:00Apr 21 18:00Apr 21 21:00Apr 22 00:00Apr 22 03:00Apr 22 06:00Apr 22 09:00Apr 22 12:00Apr 22 15:00Apr 22 18:00Apr 22 21:00Apr 23 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-91

Figure A4-7c.1-hour ozone time series for April20-22, 2006.

Houly Ozone Plot, Apr 20 to Apr 22, 2006, at Daniel

0

10

20

30

40

50

60

70

80

90

Apr 20 00:00Apr 20 03:00Apr 20 06:00Apr 20 09:00Apr 20 12:00Apr 20 15:00Apr 20 18:00Apr 20 21:00Apr 21 00:00Apr 21 03:00Apr 21 06:00Apr 21 09:00Apr 21 12:00Apr 21 15:00Apr 21 18:00Apr 21 21:00Apr 22 00:00Apr 22 03:00Apr 22 06:00Apr 22 09:00Apr 22 12:00Apr 22 15:00Apr 22 18:00Apr 22 21:00Apr 23 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Apr 20 to Apr 22, 2006, at Wamsutter

0

10

20

30

40

50

60

70

80

90

100

Apr 20 00:00Apr 20 03:00Apr 20 06:00Apr 20 09:00Apr 20 12:00Apr 20 15:00Apr 20 18:00Apr 20 21:00Apr 21 00:00Apr 21 03:00Apr 21 06:00Apr 21 09:00Apr 21 12:00Apr 21 15:00Apr 21 18:00Apr 21 21:00Apr 22 00:00Apr 22 03:00Apr 22 06:00Apr 22 09:00Apr 22 12:00Apr 22 15:00Apr 22 18:00Apr 22 21:00Apr 23 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-92

Figure A4-8a. 1-hour ozone time series for May 1-9, 2006.

Houly Ozone Plot, May 01 to May 09, 2006, at Jonah

0

10

20

30

40

50

60

70

80

May 01 00:00May 01 09:00May 01 18:00May 02 03:00May 02 12:00May 02 21:00May 03 06:00May 03 15:00May 04 00:00May 04 09:00May 04 18:00May 05 03:00May 05 12:00May 05 21:00May 06 06:00May 06 15:00May 07 00:00May 07 09:00May 07 18:00May 08 03:00May 08 12:00May 08 21:00May 09 06:00May 09 15:00May 10 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, May 01 to May 09, 2006, at Boulder

0

10

20

30

40

50

60

70

80

90

May 01 00:00May 01 09:00May 01 18:00May 02 03:00May 02 12:00May 02 21:00May 03 06:00May 03 15:00May 04 00:00May 04 09:00May 04 18:00May 05 03:00May 05 12:00May 05 21:00May 06 06:00May 06 15:00May 07 00:00May 07 09:00May 07 18:00May 08 03:00May 08 12:00May 08 21:00May 09 06:00May 09 15:00May 10 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-93

Figure A4-8b. 1-hour ozone time series for May 1-9, 2006.

Houly Ozone Plot, May 01 to May 09, 2006, at Centennial

0

10

20

30

40

50

60

70

80

May 01 00:00May 01 09:00May 01 18:00May 02 03:00May 02 12:00May 02 21:00May 03 06:00May 03 15:00May 04 00:00May 04 09:00May 04 18:00May 05 03:00May 05 12:00May 05 21:00May 06 06:00May 06 15:00May 07 00:00May 07 09:00May 07 18:00May 08 03:00May 08 12:00May 08 21:00May 09 06:00May 09 15:00May 10 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, May 01 to May 09, 2006, at Pinedale

0

10

20

30

40

50

60

70

80

90

May 01 00:00May 01 09:00May 01 18:00May 02 03:00May 02 12:00May 02 21:00May 03 06:00May 03 15:00May 04 00:00May 04 09:00May 04 18:00May 05 03:00May 05 12:00May 05 21:00May 06 06:00May 06 15:00May 07 00:00May 07 09:00May 07 18:00May 08 03:00May 08 12:00May 08 21:00May 09 06:00May 09 15:00May 10 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-94

Figure A4-8c.1-hour ozone time series for May 1-9, 2006.

Houly Ozone Plot, May 01 to May 09, 2006, at Daniel

0

10

20

30

40

50

60

70

80

90

May 01 00:00May 01 09:00May 01 18:00May 02 03:00May 02 12:00May 02 21:00May 03 06:00May 03 15:00May 04 00:00May 04 09:00May 04 18:00May 05 03:00May 05 12:00May 05 21:00May 06 06:00May 06 15:00May 07 00:00May 07 09:00May 07 18:00May 08 03:00May 08 12:00May 08 21:00May 09 06:00May 09 15:00May 10 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, May 01 to May 09, 2006, at Wamsutter

0

10

20

30

40

50

60

70

80

90

May 01 00:00May 01 09:00May 01 18:00May 02 03:00May 02 12:00May 02 21:00May 03 06:00May 03 15:00May 04 00:00May 04 09:00May 04 18:00May 05 03:00May 05 12:00May 05 21:00May 06 06:00May 06 15:00May 07 00:00May 07 09:00May 07 18:00May 08 03:00May 08 12:00May 08 21:00May 09 06:00May 09 15:00May 10 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-95

Figure A4-8d. 1-hour ozone time series for May 1-9, 2006.

Houly Ozone Plot, May 01 to May 09, 2006, at OCI

0

10

20

30

40

50

60

70

80

May 01 00:00May 01 09:00May 01 18:00May 02 03:00May 02 12:00May 02 21:00May 03 06:00May 03 15:00May 04 00:00May 04 09:00May 04 18:00May 05 03:00May 05 12:00May 05 21:00May 06 06:00May 06 15:00May 07 00:00May 07 09:00May 07 18:00May 08 03:00May 08 12:00May 08 21:00May 09 06:00May 09 15:00May 10 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-96

Figure A4-9a. 1-hour ozone time series for May 30-June 3, 2006.

Houly Ozone Plot, May 30 to Jun 03, 2006, at Jonah

0

10

20

30

40

50

60

70

80

90

May 30 00:00May 30 05:00May 30 10:00May 30 15:00May 30 20:00May 31 01:00May 31 06:00May 31 11:00May 31 16:00May 31 21:00

Jun 01 02:00Jun 01 07:00Jun 01 12:00Jun 01 17:00Jun 01 22:00Jun 02 03:00Jun 02 08:00Jun 02 13:00Jun 02 18:00Jun 02 23:00Jun 03 04:00Jun 03 09:00Jun 03 14:00Jun 03 19:00Jun 04 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, May 30 to Jun 03, 2006, at Boulder

0

10

20

30

40

50

60

70

80

90

May 30 00:00May 30 05:00May 30 10:00May 30 15:00May 30 20:00May 31 01:00May 31 06:00May 31 11:00May 31 16:00May 31 21:00

Jun 01 02:00Jun 01 07:00Jun 01 12:00Jun 01 17:00Jun 01 22:00Jun 02 03:00Jun 02 08:00Jun 02 13:00Jun 02 18:00Jun 02 23:00Jun 03 04:00Jun 03 09:00Jun 03 14:00Jun 03 19:00Jun 04 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-97

Figure A4-9b. 1-hour ozone time series for May 30-June 3, 2006.

Houly Ozone Plot, May 30 to Jun 03, 2006, at Centennial

0

10

20

30

40

50

60

70

80

May 30 00:00May 30 05:00May 30 10:00May 30 15:00May 30 20:00May 31 01:00May 31 06:00May 31 11:00May 31 16:00May 31 21:00

Jun 01 02:00Jun 01 07:00Jun 01 12:00Jun 01 17:00Jun 01 22:00Jun 02 03:00Jun 02 08:00Jun 02 13:00Jun 02 18:00Jun 02 23:00Jun 03 04:00Jun 03 09:00Jun 03 14:00Jun 03 19:00Jun 04 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, May 30 to Jun 03, 2006, at Pinedale

0

10

20

30

40

50

60

70

80

90

May 30 00:00May 30 05:00May 30 10:00May 30 15:00May 30 20:00May 31 01:00May 31 06:00May 31 11:00May 31 16:00May 31 21:00

Jun 01 02:00Jun 01 07:00Jun 01 12:00Jun 01 17:00Jun 01 22:00Jun 02 03:00Jun 02 08:00Jun 02 13:00Jun 02 18:00Jun 02 23:00Jun 03 04:00Jun 03 09:00Jun 03 14:00Jun 03 19:00Jun 04 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-98

Figure A4-9c.1-hour ozone time series for May 30-June 3, 2006.

Houly Ozone Plot, May 30 to Jun 03, 2006, at Daniel

0

10

20

30

40

50

60

70

80

90

May 30 00:00May 30 05:00May 30 10:00May 30 15:00May 30 20:00May 31 01:00May 31 06:00May 31 11:00May 31 16:00May 31 21:00

Jun 01 02:00Jun 01 07:00Jun 01 12:00Jun 01 17:00Jun 01 22:00Jun 02 03:00Jun 02 08:00Jun 02 13:00Jun 02 18:00Jun 02 23:00Jun 03 04:00Jun 03 09:00Jun 03 14:00Jun 03 19:00Jun 04 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, May 30 to Jun 03, 2006, at Wamsutter

0

10

20

30

40

50

60

70

80

May 30 00:00May 30 05:00May 30 10:00May 30 15:00May 30 20:00May 31 01:00May 31 06:00May 31 11:00May 31 16:00May 31 21:00

Jun 01 02:00Jun 01 07:00Jun 01 12:00Jun 01 17:00Jun 01 22:00Jun 02 03:00Jun 02 08:00Jun 02 13:00Jun 02 18:00Jun 02 23:00Jun 03 04:00Jun 03 09:00Jun 03 14:00Jun 03 19:00Jun 04 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-99

Figure A4-9d. 1-hour ozone time series for May 30-June 3, 2006.

Houly Ozone Plot, May 30 to Jun 03, 2006, at OCI

0

10

20

30

40

50

60

70

80

May 30 00:00May 30 05:00May 30 10:00May 30 15:00May 30 20:00May 31 01:00May 31 06:00May 31 11:00May 31 16:00May 31 21:00

Jun 01 02:00Jun 01 07:00Jun 01 12:00Jun 01 17:00Jun 01 22:00Jun 02 03:00Jun 02 08:00Jun 02 13:00Jun 02 18:00Jun 02 23:00Jun 03 04:00Jun 03 09:00Jun 03 14:00Jun 03 19:00Jun 04 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-100

Figure A4-10a. 1-hour ozone time series for June 10-19, 2006.

Houly Ozone Plot, Jun 10 to Jun 19, 2006, at Jonah

0

10

20

30

40

50

60

70

80

Jun 10 00:00Jun 10 10:00Jun 10 20:00Jun 11 06:00Jun 11 16:00Jun 12 02:00Jun 12 12:00Jun 12 22:00Jun 13 08:00Jun 13 18:00Jun 14 04:00Jun 14 14:00Jun 15 00:00Jun 15 10:00Jun 15 20:00Jun 16 06:00Jun 16 16:00Jun 17 02:00Jun 17 12:00Jun 17 22:00Jun 18 08:00Jun 18 18:00Jun 19 04:00Jun 19 14:00Jun 20 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Jun 10 to Jun 19, 2006, at Boulder

0

10

20

30

40

50

60

70

80

90

Jun 10 00:00Jun 10 10:00Jun 10 20:00Jun 11 06:00Jun 11 16:00Jun 12 02:00Jun 12 12:00Jun 12 22:00Jun 13 08:00Jun 13 18:00Jun 14 04:00Jun 14 14:00Jun 15 00:00Jun 15 10:00Jun 15 20:00Jun 16 06:00Jun 16 16:00Jun 17 02:00Jun 17 12:00Jun 17 22:00Jun 18 08:00Jun 18 18:00Jun 19 04:00Jun 19 14:00Jun 20 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-101

Figure A4-10b. 1-hour ozone time series for June 10-19, 2006.

Houly Ozone Plot, Jun 10 to Jun 19, 2006, at Centennial

0

10

20

30

40

50

60

70

80

Jun 10 00:00Jun 10 10:00Jun 10 20:00Jun 11 06:00Jun 11 16:00Jun 12 02:00Jun 12 12:00Jun 12 22:00Jun 13 08:00Jun 13 18:00Jun 14 04:00Jun 14 14:00Jun 15 00:00Jun 15 10:00Jun 15 20:00Jun 16 06:00Jun 16 16:00Jun 17 02:00Jun 17 12:00Jun 17 22:00Jun 18 08:00Jun 18 18:00Jun 19 04:00Jun 19 14:00Jun 20 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Jun 10 to Jun 19, 2006, at Daniel

0

10

20

30

40

50

60

70

80

Jun 10 00:00Jun 10 10:00Jun 10 20:00Jun 11 06:00Jun 11 16:00Jun 12 02:00Jun 12 12:00Jun 12 22:00Jun 13 08:00Jun 13 18:00Jun 14 04:00Jun 14 14:00Jun 15 00:00Jun 15 10:00Jun 15 20:00Jun 16 06:00Jun 16 16:00Jun 17 02:00Jun 17 12:00Jun 17 22:00Jun 18 08:00Jun 18 18:00Jun 19 04:00Jun 19 14:00Jun 20 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-102

Figure A4-10c.1-hour ozone time series for June 10-19, 2006.

Houly Ozone Plot, Jun 10 to Jun 19, 2006, at Wamsutter

0

10

20

30

40

50

60

70

80

Jun 10 00:00Jun 10 10:00Jun 10 20:00Jun 11 06:00Jun 11 16:00Jun 12 02:00Jun 12 12:00Jun 12 22:00Jun 13 08:00Jun 13 18:00Jun 14 04:00Jun 14 14:00Jun 15 00:00Jun 15 10:00Jun 15 20:00Jun 16 06:00Jun 16 16:00Jun 17 02:00Jun 17 12:00Jun 17 22:00Jun 18 08:00Jun 18 18:00Jun 19 04:00Jun 19 14:00Jun 20 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Jun 10 to Jun 19, 2006, at OCI

0

10

20

30

40

50

60

70

80

90

Jun 10 00:00Jun 10 10:00Jun 10 20:00Jun 11 06:00Jun 11 16:00Jun 12 02:00Jun 12 12:00Jun 12 22:00Jun 13 08:00Jun 13 18:00Jun 14 04:00Jun 14 14:00Jun 15 00:00Jun 15 10:00Jun 15 20:00Jun 16 06:00Jun 16 16:00Jun 17 02:00Jun 17 12:00Jun 17 22:00Jun 18 08:00Jun 18 18:00Jun 19 04:00Jun 19 14:00Jun 20 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-103

Figure A4-11a. 1-hour ozone time series for July 7-17, 2006.

Houly Ozone Plot, Jul 07 to Jul 17, 2006, at Jonah

0

10

20

30

40

50

60

70

80

Jul 07 00:00Jul 07 11:00Jul 07 22:00Jul 08 09:00Jul 08 20:00Jul 09 07:00Jul 09 18:00Jul 10 05:00Jul 10 16:00Jul 11 03:00Jul 11 14:00Jul 12 01:00Jul 12 12:00Jul 12 23:00Jul 13 10:00Jul 13 21:00Jul 14 08:00Jul 14 19:00Jul 15 06:00Jul 15 17:00Jul 16 04:00Jul 16 15:00Jul 17 02:00Jul 17 13:00Jul 18 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Jul 07 to Jul 17, 2006, at Boulder

0

10

20

30

40

50

60

70

80

90

Jul 07 00:00Jul 07 11:00Jul 07 22:00Jul 08 09:00Jul 08 20:00Jul 09 07:00Jul 09 18:00Jul 10 05:00Jul 10 16:00Jul 11 03:00Jul 11 14:00Jul 12 01:00Jul 12 12:00Jul 12 23:00Jul 13 10:00Jul 13 21:00Jul 14 08:00Jul 14 19:00Jul 15 06:00Jul 15 17:00Jul 16 04:00Jul 16 15:00Jul 17 02:00Jul 17 13:00Jul 18 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-104

Figure A4-11b. 1-hour ozone time series for July 7-17, 2006.

Houly Ozone Plot, Jul 07 to Jul 17, 2006, at Centennial

0

10

20

30

40

50

60

70

80

Jul 07 00:00Jul 07 11:00Jul 07 22:00Jul 08 09:00Jul 08 20:00Jul 09 07:00Jul 09 18:00Jul 10 05:00Jul 10 16:00Jul 11 03:00Jul 11 14:00Jul 12 01:00Jul 12 12:00Jul 12 23:00Jul 13 10:00Jul 13 21:00Jul 14 08:00Jul 14 19:00Jul 15 06:00Jul 15 17:00Jul 16 04:00Jul 16 15:00Jul 17 02:00Jul 17 13:00Jul 18 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Jul 07 to Jul 17, 2006, at Pinedale

0

10

20

30

40

50

60

70

80

90

Jul 07 00:00Jul 07 11:00Jul 07 22:00Jul 08 09:00Jul 08 20:00Jul 09 07:00Jul 09 18:00Jul 10 05:00Jul 10 16:00Jul 11 03:00Jul 11 14:00Jul 12 01:00Jul 12 12:00Jul 12 23:00Jul 13 10:00Jul 13 21:00Jul 14 08:00Jul 14 19:00Jul 15 06:00Jul 15 17:00Jul 16 04:00Jul 16 15:00Jul 17 02:00Jul 17 13:00Jul 18 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-105

Figure A4-11c.1-hour ozone time series for July 7-17, 2006.

Houly Ozone Plot, Jul 07 to Jul 17, 2006, at Daniel

0

10

20

30

40

50

60

70

80

Jul 07 00:00Jul 07 11:00Jul 07 22:00Jul 08 09:00Jul 08 20:00Jul 09 07:00Jul 09 18:00Jul 10 05:00Jul 10 16:00Jul 11 03:00Jul 11 14:00Jul 12 01:00Jul 12 12:00Jul 12 23:00Jul 13 10:00Jul 13 21:00Jul 14 08:00Jul 14 19:00Jul 15 06:00Jul 15 17:00Jul 16 04:00Jul 16 15:00Jul 17 02:00Jul 17 13:00Jul 18 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Jul 07 to Jul 17, 2006, at Wamsutter

0

10

20

30

40

50

60

70

80

90

Jul 07 00:00Jul 07 11:00Jul 07 22:00Jul 08 09:00Jul 08 20:00Jul 09 07:00Jul 09 18:00Jul 10 05:00Jul 10 16:00Jul 11 03:00Jul 11 14:00Jul 12 01:00Jul 12 12:00Jul 12 23:00Jul 13 10:00Jul 13 21:00Jul 14 08:00Jul 14 19:00Jul 15 06:00Jul 15 17:00Jul 16 04:00Jul 16 15:00Jul 17 02:00Jul 17 13:00Jul 18 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-106

Figure A4-11d. 1-hour ozone time series for July 7-17, 2006.

Houly Ozone Plot, Jul 07 to Jul 17, 2006, at OCI

0

10

20

30

40

50

60

70

80

90

Jul 07 00:00Jul 07 11:00Jul 07 22:00Jul 08 09:00Jul 08 20:00Jul 09 07:00Jul 09 18:00Jul 10 05:00Jul 10 16:00Jul 11 03:00Jul 11 14:00Jul 12 01:00Jul 12 12:00Jul 12 23:00Jul 13 10:00Jul 13 21:00Jul 14 08:00Jul 14 19:00Jul 15 06:00Jul 15 17:00Jul 16 04:00Jul 16 15:00Jul 17 02:00Jul 17 13:00Jul 18 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-107

Figure A4-12a. 1-hour ozone time series for August 17-19, 2006.

Houly Ozone Plot, Aug 17 to Aug 19, 2006, at Jonah

0

10

20

30

40

50

60

70

80

90

100

Aug 17 00:00Aug 17 03:00Aug 17 06:00Aug 17 09:00Aug 17 12:00Aug 17 15:00Aug 17 18:00Aug 17 21:00Aug 18 00:00Aug 18 03:00Aug 18 06:00Aug 18 09:00Aug 18 12:00Aug 18 15:00Aug 18 18:00Aug 18 21:00Aug 19 00:00Aug 19 03:00Aug 19 06:00Aug 19 09:00Aug 19 12:00Aug 19 15:00Aug 19 18:00Aug 19 21:00Aug 20 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Aug 17 to Aug 19, 2006, at Boulder

0

20

40

60

80

100

120

Aug 17 00:00Aug 17 03:00Aug 17 06:00Aug 17 09:00Aug 17 12:00Aug 17 15:00Aug 17 18:00Aug 17 21:00Aug 18 00:00Aug 18 03:00Aug 18 06:00Aug 18 09:00Aug 18 12:00Aug 18 15:00Aug 18 18:00Aug 18 21:00Aug 19 00:00Aug 19 03:00Aug 19 06:00Aug 19 09:00Aug 19 12:00Aug 19 15:00Aug 19 18:00Aug 19 21:00Aug 20 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-108

Figure A4-12b. 1-hour ozone time series for August 17-19, 2006.

Houly Ozone Plot, Aug 17 to Aug 19, 2006, at Centennial

0

10

20

30

40

50

60

70

Aug 17 00:00Aug 17 03:00Aug 17 06:00Aug 17 09:00Aug 17 12:00Aug 17 15:00Aug 17 18:00Aug 17 21:00Aug 18 00:00Aug 18 03:00Aug 18 06:00Aug 18 09:00Aug 18 12:00Aug 18 15:00Aug 18 18:00Aug 18 21:00Aug 19 00:00Aug 19 03:00Aug 19 06:00Aug 19 09:00Aug 19 12:00Aug 19 15:00Aug 19 18:00Aug 19 21:00Aug 20 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Aug 17 to Aug 19, 2006, at Pinedale

0

10

20

30

40

50

60

70

80

90

100

Aug 17 00:00Aug 17 03:00Aug 17 06:00Aug 17 09:00Aug 17 12:00Aug 17 15:00Aug 17 18:00Aug 17 21:00Aug 18 00:00Aug 18 03:00Aug 18 06:00Aug 18 09:00Aug 18 12:00Aug 18 15:00Aug 18 18:00Aug 18 21:00Aug 19 00:00Aug 19 03:00Aug 19 06:00Aug 19 09:00Aug 19 12:00Aug 19 15:00Aug 19 18:00Aug 19 21:00Aug 20 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-109

Figure A4-12c.1-hour ozone time series for August 17-19, 2006.

Houly Ozone Plot, Aug 17 to Aug 19, 2006, at Daniel

0

10

20

30

40

50

60

70

80

90

100

Aug 17 00:00Aug 17 03:00Aug 17 06:00Aug 17 09:00Aug 17 12:00Aug 17 15:00Aug 17 18:00Aug 17 21:00Aug 18 00:00Aug 18 03:00Aug 18 06:00Aug 18 09:00Aug 18 12:00Aug 18 15:00Aug 18 18:00Aug 18 21:00Aug 19 00:00Aug 19 03:00Aug 19 06:00Aug 19 09:00Aug 19 12:00Aug 19 15:00Aug 19 18:00Aug 19 21:00Aug 20 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs

Houly Ozone Plot, Aug 17 to Aug 19, 2006, at Wamsutter

0

10

20

30

40

50

60

70

80

Aug 17 00:00Aug 17 03:00Aug 17 06:00Aug 17 09:00Aug 17 12:00Aug 17 15:00Aug 17 18:00Aug 17 21:00Aug 18 00:00Aug 18 03:00Aug 18 06:00Aug 18 09:00Aug 18 12:00Aug 18 15:00Aug 18 18:00Aug 18 21:00Aug 19 00:00Aug 19 03:00Aug 19 06:00Aug 19 09:00Aug 19 12:00Aug 19 15:00Aug 19 18:00Aug 19 21:00Aug 20 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-110

Figure A4-12d. 1-hour ozone time series for August 17-19, 2006.

Houly Ozone Plot, Aug 17 to Aug 19, 2006, at OCI

0

10

20

30

40

50

60

70

80

90

Aug 17 00:00Aug 17 03:00Aug 17 06:00Aug 17 09:00Aug 17 12:00Aug 17 15:00Aug 17 18:00Aug 17 21:00Aug 18 00:00Aug 18 03:00Aug 18 06:00Aug 18 09:00Aug 18 12:00Aug 18 15:00Aug 18 18:00Aug 18 21:00Aug 19 00:00Aug 19 03:00Aug 19 06:00Aug 19 09:00Aug 19 12:00Aug 19 15:00Aug 19 18:00Aug 19 21:00Aug 20 00:00

Houly Average Ozone [ppb]

Max 

34L cdc.r01

Min 

34L cdc.r01

19L Hiawa 34L cdc.r01 Obs
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-111

A4.6 SPATIAL DISTRIBUTION OF DAILY MAXIMUM HOURLY AND 8-HOUR OZONE MODEL 

PERFORMANCE

Figure A4-13 displays the spatial distribution of the predicted daily maximum 1-hour (top) and 

8-hour (bottom) for the Hiawatha (left) and CD-C (right) base case simulations within the 4 km 

southwestern Wyoming modeling domain for each of the high ozone days identified for analysis 

by the WDEQ-AQD. The observed daily maximum 1-hour and 8-hour ozone concentrations are 

also provided in Figure A4-13 at the locations of the ozone monitoring sites in the 4 km domain.

June 27, 2005

On June 27, 2005 the observed daily maximum 8-hour ozone concentrations range from 73-76 

ppb at the Sublette County sites and is 66 ppb at the Centennial CASTNet site (Figure A4-13a). 

At the locations of the Sublette County monitoring sites the Hiawatha base case daily maximum 

8-hour ozone concentrations are in the 55-65 ppb range, which is much lower than observed. 

The CD-C base case simulation, on the other hand, estimates daily maximum 8-hour ozone 

concentrations at the Sublette County monitoring site locations of 60-72.5 ppb, which is much 

closer to what was observed. At the Centennial site both models estimates values in the 67.5-

70 ppb range, which is close to what was observed (66 ppb). Between the Sublette County and 

Centennial monitoring sites, the CD-C base case estimates daily maximum 8-hour ozone 

concentrations in the 75-80 ppb range that cannot be evaluated due to a lack of observed data. 

July 8, 2005

With the exception of a 45 ppb ozone value at Boulder that is due to missing afternoon 

observed ozone concentrations, the observed daily maximum 8-hour ozone concentrations at 

the Sublette County monitoring site range from 67-72 ppb (Figure A4-13b). The Hiawatha base 

case estimates values in the 55-65 ppb range, whereas the CD-C base case estimates values in 

the 67.5-72.5 ppb range that is much closer to the observed values. At Centennial, where a 58 

ppb daily maximum 8-hour ozone concentration is observed, the Hiawatha and CD-C base case 

simulations simulate values in the 60-65 ppb and 65-67.5 ppb range, respectively. Again, the 

CD-C base case simulates higher daily maximum 8-hour ozone concentrations in the 72.5-77.5 

ppb range diagonally across Sweetwater County between the locations of the monitoring sites.

April 21, 2006

Very high observed daily maximum 8-hour ozone concentrations of 81 ppb (Boulder) and 80 

ppb (Pinedale) occur in Sublette County on April 21, 2006 (Figure A4-13c). The CD-C base case 

estimates daily maximum 8-hour ozone concentrations in excess of 80 ppb on either side of the 

four Sublette County monitoring sites, but at the location of the 4 sites, it estimates values in 

the 70-77.5 ppb range. This is in contrast to the Hiawatha base case that estimates values in 

the 60-75 ppb range at the locations of the four Sublette County monitoring sites. At 

Wamsutter, the CD-C base case (72.5 ppb) overestimates the observed (63 ppb) daily maximum 

8-hour ozone concentration, whereas the Hiawatha base case (65-67.5 ppb) does a better job in 

reproducing the observed ozone value. The observed value at Centennial (73 ppb) is 

overestimated by the CD-C (77.5-80 ppb) and underestimated by the Hiawatha (67.5-70 ppb) 

base case simulations.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-112

May 2, 2006

Both base case simulations (60-67.5 ppb) underestimate the observed daily maximum 8-hour 

ozone concentrations in Sublette County (72-77 ppb) on May 2, 2006 (Figure A4-13d). The 

observed 8-hour ozone at Centennial (73 ppb) is also underestimated by the CD-C (55-60 ppb) 

and Hiawatha (60-65 ppb) base case simulations. Across Sweetwater County, both base case 

simulations estimate daily maximum 8-hour ozone concentrations in the 55-60 ppb when the 

observed values at Wamsutter and OCI are 67 ppb.

May 8, 2006

The observed daily maximum 8-hour ozone concentrations in Sublette County on May 8, 2006 

range from 65-71 ppb with the modeled values much lower ranging from 40-45 ppb for 

Hiawatha and 40-47.5 ppb for the CD-C base case (Figure A4-13e). The modeled 8-hour ozone 

across Sweetwater County (40-45 ppb) is also lower than observed (54-56 ppb). And at the 

Centennial monitoring site the Hiawatha base case (52.5-55 ppb) is closer to the observed value 

(61 ppb) than the CD-C base case (45-47.5 ppb).

June 1, 2006

The spatial distribution of the modeled daily maximum 8-hour ozone concentrations on June 1, 

2006 is fairly flat for both base case simulations (Figure A4-13f). At the Sublette County 

monitoring sites, where the observed 8-hour ozone concentrations are in the 65-73 ppb range, 

the modeled values range from 60-67.5 ppb for the Hiawatha and 60-70 ppb for the CD-C base 

case simulations. There is reasonable agreement in 8-hour ozone concentrations for both base

cases (65-70 ppb) at the Wamsutter (64 ppb), OCI (63 ppb) and Centennial (62 ppb) monitoring 

sites.

June 2, 2006

The two base case simulations tend to underestimate the highest observed ozone 

concentrations on June 2, 2006 (Figure A4-13g). Both base cases predict 8-hour ozone in the 

60-65 ppb range at the locations on the Sublette County monitors where 65-72 ppb is observed. 

Again, the spatial distribution of the modeled ozone concentrations is fairly flat, typically in the 

60-67.5 ppb, which is similar to the observed ozone concentrations at Wamsutter and 

Centennial (66 ppb) but lower than OCI (70 ppb).

June 11, 2006

On June 11, 2006 the observed ozone concentrations are in the high 60s to 70s across Sublette 

and Sweetwater Counties where the modeled ozone is lower, 60-65 for Hiawatha and 55-65 

ppb for CD-C base case simulations (Figure A4-13h). 

June 18, 2006

Observed daily maximum ozone concentrations of 73 and 80 ppb are recorded in Sublette 

County on June 18, 2006, along with values of 71 ppb at OCI and 67 ppb at Wamsutter (Figure 

A4-13i). The two base case simulations greatly underestimate the observed values on this day 

with the Hiawatha base case predicted values below 55 ppb and CD-C base case predicting 

values in the 55-65 ppb range.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-113

July 8, 2006

Both the modeled and observed daily maximum 8-hour ozone concentrations on July 8, 2006 

exhibit a concentration gradient going from the southeast to northwest with lower values in the 

southeast (< 50 ppb) to values as high as 71 ppb in Sublette County (Figure A4-13j). In Sublette 

County, where observed values range from 63-71 ppb, the predicted values range from 50-65 

ppb.

July 13, 2006

The CD-C base case exhibits better ozone model performance than the Hiawatha base case on 

July 13, 2006 (Figure A4-13k). In Sublette County, where the observed ozone ranges from 60-65 

ppb, the Hiawatha base case estimates values of 50-55 ppb with the CD-C base case being 

closer to the observed values (55-65 ppb). At the OCI monitor, where the highest observed 8-

hour ozone concentration occurs (71 ppb), the Hiawatha base case underestimates (55-60 ppb) 

and the CD-C base case reproduced the observation well (67.5-70 ppb). The Wamsutter 

observed ozone on this day (58 ppb) is better replicated by the Hiawatha base case than the 

CD-C base case which overestimates. However, the observed ozone at Centennial (69 ppb) is 

underestimated by the Hiawatha base case (60-65 ppb) but reproduced quite well in the CD-C 

base case simulation.

July 14, 2006

The differences in the modeled daily maximum 8-hour ozone concentrations on July 14, 2006 in 

the two base case simulations are quite dramatic (Figure A4-13l). Whereas the Hiawatha base 

case simulation estimates 8-hour ozone concentrations that are mostly in the 55-65 ppb range, 

the CD-C base case estimates values that are mostly in the 67.5 to 77.5 ppb range. Observed 8-

hour ozone concentrations in Sublette County range from 64-67 ppb which the Hiawatha base 

case underestimates (50-60 ppb) but the CD-C matches more closely (67.5-72.5 ppb. At the OCI 

monitor, where the highest observed 8-hour ozone concentration on this day occurs (72 ppb), 

the Hiawatha base case underestimates (55-60 ppb) and the CD-C base case reproduces the 

observed value quite well (72.5-75 ppb).

July 16, 2006

The CD-C base case estimates higher ozone than the Hiawatha base case on July 16, 2006 that 

better matches the observed values (Figure A4-13m). Although the CD-C base case slightly 

underestimates (55-65 ppb) the observed 8-hour ozone (64-67 ppb) in Sublette County, the 

Hiawatha underestimation bias is much more substantial (50-55 ppb). The highest observed 8-

hour ozone concentration on this day is 72 ppb at OCI that is reproduced very well by the CD-C 

base case (70-72.5 ppb), but underestimated by the Hiawatha base case (60-65 ppb).

August 18, 2006

The CD-C base case estimates 8-hour ozone concentrations in excess of 80 ppb in an area across 

Sublette and Lincoln Counties and further west including the locations of the Sublette County 

ozone monitors where 68-72 ppb is observed so it overestimates. The Hiawatha base case 

estimates lower ozone (60-67/5 ppb) in Sublette County that is lower than observed. At the 

OCI monitor where 72 ppb ozone is observed, the CD-C base case overestimates (75-77.5 ppb) 

and the Hiawatha base case underestimates (65-67.5 ppb).
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-114

Figure A4-13a. Comparison of predicted daily maximum 1-hour (top) and 8-hour (bottom) 

ozone concentrations from Hiawatha (left) and CD-C (right) base case simulations with 

superimposed observation sites within the 4 km domain on June 27, 2005. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-115

Figure A4-13b. Comparison of predicted daily maximum 1-hour (top) and 8-hour (bottom) 

ozone concentrations from Hiawatha (left) and CD-C (right) base case simulations with 

superimposed observation sites within the 4 km domain on July 8, 2005. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-116

Figure A4-13c. Comparison of predicted daily maximum 1-hour (top) and 8-hour (bottom) 

ozone concentrations from Hiawatha (left) and CD-C (right) base case simulations with 

superimposed observation sites within the 4 km domain on April 21, 2006. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-117

Figure A4-13d. Comparison of predicted daily maximum 1-hour (top) and 8-hour (bottom) 

ozone concentrations from Hiawatha (left) and CD-C (right) base case simulations with 

superimposed observation sites within the 4 km domain on May 2, 2006. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-118

Figure A4-13e. Comparison of predicted daily maximum 1-hour (top) and 8-hour (bottom) 

ozone concentrations from Hiawatha (left) and CD-C (right) base case simulations with 

superimposed observation sites within the 4 km domain on May 8, 2006. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-119

Figure A4-13f. Comparison of predicted daily maximum 1-hour (top) and 8-hour (bottom) 

ozone concentrations from Hiawatha (left) and CD-C (right) base case simulations with 

superimposed observation sites within the 4 km domain on June 1, 2006. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-120

Figure A4-13g. Comparison of predicted daily maximum 1-hour (top) and 8-hour (bottom) 

ozone concentrations from Hiawatha (left) and CD-C (right) base case simulations with 

superimposed observation sites within the 4 km domain on June 2, 2006. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-121

Figure A4-13h. Comparison of predicted daily maximum 1-hour (top) and 8-hour (bottom) 

ozone concentrations from Hiawatha (left) and CD-C (right) base case simulations with 

superimposed observation sites within the 4 km domain on June 11, 2006. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-122

Figure A4-13i. Comparison of predicted daily maximum 1-hour (top) and 8-hour (bottom) 

ozone concentrations from Hiawatha (left) and CD-C (right) base case simulations with 

superimposed observation sites within the 4 km domain on June 18, 2006. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-123

Figure A4-13j. Comparison of predicted daily maximum 1-hour (top) and 8-hour (bottom) 

ozone concentrations from Hiawatha (left) and CD-C (right) base case simulations with 

superimposed observation sites within the 4 km domain on July 8, 2006. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-124

Figure A4-13k. Comparison of predicted daily maximum 1-hour (top) and 8-hour (bottom) 

ozone concentrations from Hiawatha (left) and CD-C (right) base case simulations with 

superimposed observation sites within the 4 km domain on July 13, 2006. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-125

Figure A4-13l. Comparison of predicted daily maximum 1-hour (top) and 8-hour (bottom) 

ozone concentrations from Hiawatha (left) and CD-C (right) base case simulations with 

superimposed observations site within the 4 km domain on July 14, 2006. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-126

Figure A4-13m. Comparison of predicted daily maximum 1-hour (top) and 8-hour (bottom) 

ozone concentrations from Hiawatha (left) and CD-C (right) base case simulations with 

superimposed observation sites within the 4 km domain on July 16, 2006. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-127

Figure A4-13n. Comparison of predicted daily maximum 1-hour (top) and 8-hour (bottom) 

ozone concentrations from Hiawatha (left) and CD-C (right) base case simulations with 

superimposed observation sites within the 4 km domain on August 18, 2006. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-128

A4.7 COMPARISON OF 8-HOUR OZONE PERFORMANCE WITH MODEL PERFORMANCE GOALS

EPA’s 1999 draft 8-hour ozone modeling guidance presented a useful performance goal that 

compares the observed daily maximum 8-hour ozone concentrations with modeled values 

“nearthe monitor”, with the goal being that most of the observed and modeled values near the 

monitor be within ±20% of each other. This performance goal is particularly relevant because 

these are the very same modeled daily maximum 8-hour ozone concentrations near the 

monitor that are used in making 8-hour ozone projections. The Denver ozone SIP model 

evaluation (Morris et al., 2003; 2008) used three approaches for defining “near the monitor”. 

For two of the approaches we define “near” as the same NX by NY array of cells centered on 

the monitor as used in EPA’s procedures for making 8-hour ozone projections (e.g., 7 x 7 for 4 

km and 3 x 3 km 12 km grid) and the two tests differ in only which estimated value is selected 

from this array of cells. For the third test, we select the estimated value at the monitor (i.e., 

spatially paired). The three methods for defining “near the monitor” are as follows:

Maximum: Select the maximum estimated daily maximum 8-hour ozone concentration 

near the ozone monitor for each day. This is the same approach for selecting model 

daily maximum 8-hour ozone to construct relative response factors (RRFs) that are used 

in EPA’s 8-hour ozone attainment test.

Closest: Select the estimated daily maximum 8-hour ozone concentrations near the 

monitor that most closely matches the observed value.

Spatially Paired: Select the estimated 8-hour ozone concentrations at the location of the 

monitoring site.

Table A4-5 summarizes the performance goal for daily maximum 8-hour ozone concentrations 

using these three approaches for “near the monitor”.

Table A4-5.8-hour ozone model performance goal comparing observed daily maximum 8-hour 

ozone concentrations with predicted values “near the monitor” (EPA, 1999).

“Near The Monitor” Threshold Goal

Maximum modeled daily maximum 8-hour ozone concentrations 

within a 7 x 7 array of 4 km grid cells around monitor

<±20% Most pairs within ±20%

Modeled daily maximum 8-hour ozone concentrations within a 7 x 7 

array of 4 km grid cells around monitor that is closest to the 

observed value at the monitor.

<±20% Most pairs within ±20%

Spatially Paired modeled daily maximum 8-hour ozone concentration 

at the location of the monitoring site

<±20% Most pairs within ±20%

Figure A4-14 shows an example of how the three definitions of “near the monitor” are used in 

comparing observed and modeled values of 8-hour ozone. Consider a hypothetical ozone 

monitor located at center of a 3x3 array of 12km grid cells (within the central blue shaded cell). 

Assume that the monitor records a daily maximum 8-hour ozone value of 84 ppb within the 

center grid cell. The model output values of the daily maximum 8-hour ozone are shown in 

each grid cell, and red type indicates the modeled value selected by each method.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-129

Figure A4-14. Example of comparison of observed and modeled 8-hour daily maximum ozone 

using the three methods described in Table A4-5. Each of the three grids represents a 3x3 

array of 12 km model grid cells, and the blue shaded cell contains the monitor. Values shown 

in red type are the modeled value selected using each of the three methods for comparison 

with the observed value measured at the monitor.

The maximum method selects the highest value recorded anywhere within the 3 x 3 array, 86 

ppb, while the closest method selects the closest modeled value to the observed value of 84 

ppb, or 84 ppb. The spatially paired method selects the value in the blue shaded grid cell where 

the monitor is located. The spatially paired test is the most stringent, and the model 

performance statistics for this method with generally reflect higher values of bias and error 

than the closest method. 

Tables A4-6 and 5-7 summarize the number of monitor-days and percent of the monitor-days in 

which the predicted and observed daily maximum 8-hour ozone concentrations are within 

±20% of each other using all three definitions of near the monitor during the May-August 

periods during 2005 and 2006. During 2005 and using the maximum predicted ozone near the 

monitor, the Hiawatha base case estimated that the predicted daily maximum 8-hour ozone 

concentration is within ±20% of the observed value 82%-93% of the time for the four months 

examined. Similar results for 2005 and the CD-C base case are within ±20% 90%-96% of the 

time. Using the closest predicted value near the monitor results in modeled 8-hour ozone 

concentrations within ±20% of the observed values of 89%-97% for the Hiawatha and 93%-98% 

for the CD-C base case simulations. Finally, using the most stringent spatially paired definition 

of near the monitor, the Hiawatha and CD-C base case simulations estimate that the predicted 

8-hour ozone concentrations is within ±20% of the observed value 74%-88% and 84%-91% of 

the time, respectively. Thus, in 2005 both the CD-C and Hiawatha base case simulations satisfy 

the EPA 8-hour ozone performance goal that the predicted daily maximum 8-hour ozone near 

the monitor is within of the observed value most of the time, with the CD-C base case 

simulation satisfying this performance goal more often than the Hiawatha base case simulation. 

Results for 2006 are similar, with both bases cases typically predicting they would match the 

observed daily maximum 8-hour ozone concentrations 80-90% of the time.

84 83 86

82 82 75

81 77 76

84 83 86

82 82 75

81 77 76

84 83 86

82 82 75

81 77 76

84 83 86

82 82 75

81 77 76

84 83 86

82 82 75

81 77 76

84 83 86

82 82 75

81 77 76

Maximum Closest Spatially Paired

86 ppb 84 ppb 82 ppb
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-130

Figures A4-15 and 5-16 display scatter plots of predicted and observed daily maximum 8-hour 

ozone concentrations at CASTNet and WDEQ sites within the 4 km domain for May through 

August in 2005 and 2006 using the Closest (Nearest) and Spatially Paired definition of “near the 

monitor”. The 1:1 line of perfect agreement is a dashed line and the envelope of within ±20% 

agreement is shown with a dotted line in Figures A4-15 and 5-16. The scatter plots show that 

most of the observed-modeled pairs fall within the ±20% agreement line and that there are no 

serious systematic flaws in model performance.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-131

Table A4-6a.Summary of number of monitor-days predicted and observed daily maximum 8-hour ozone concentrations are within 

±20% of each other using the three definitions of “near the monitor” for the 2005 CD-C and Hiawatha, 4 km domain, May-August 

2005 and using the CASTNet network and WDEQ additional industrial sites.

Table A4-6b. Summary of percent of the monitor-days predicted and observed daily maximum 8-hour ozone concentrations are 

within ±20% of each other using the three definitions of “near the monitor” for the 2005 CD-C and Hiawatha, 4 km domain, MayAugust 2005 and using the CASTNet network and WDEQ additional industrial sites.

Month >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20%

May 5 110 4 4 106 9 0 115 4 0 110 9 0 104 1 4 0 105 1 3

Jun 2 1 9 6 0 6 107 4 1 3 104 0 0 113 4 1 7 9 7 3 2 9 8 1 7

Jul 7 137 5 8 135 6 3 141 5 3 140 6 4 125 2 0 4 133 1 2

Aug 2 127 1 2 5 135 1 0 129 1 2 2 138 1 1 104 3 6 4 128 9

Co-located with Monitor Within

Hiawatha CD-C

2005 Closest Near Monitor Within

Hiawatha CD-C

Maximum Near Monitor Within

Hiawatha CD-C

Month >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20%

May 4 % 93% 3 % 3 % 90% 8 % 0 % 97% 3 % 0 % 93% 8 % 0 % 88% 12% 0 % 89% 11%

Jun 18% 82% 0 % 5 % 91% 3 % 11% 89% 0 % 0 % 97% 3 % 15% 83% 3 % 2 % 84% 15%

Jul 5 % 92% 3 % 5 % 91% 4 % 2 % 95% 3 % 2 % 94% 4 % 3 % 84% 13% 3 % 89% 8 %

Aug 1 % 90% 9 % 4 % 96% 1 % 0 % 91% 9 % 1 % 98% 1 % 1 % 74% 26% 3 % 91% 6 %

CD-C Hiawatha CD-C

2005 Maximum Near Monitor Within Closest Near Monitor Within Co-located with Monitor Within

Hiawatha CD-C Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-132

Table A4-7a. Summary of number of monitor-days predicted and observed daily maximum 8-hour ozone concentrations are 

within ±20% of each other using the three definitions of “near the monitor” for the 2006CD-C and Hiawatha, 4 km domain, MayAugust 2006 and using the CASTNet network and WDEQ additional industrial sites.

Table A4-7b. Summary of percent of the monitor-days predicted and observed daily maximum 8-hour ozone concentrations are 

within ±20% of each other using the three definitions of “near the monitor” for the 2006CD-C and Hiawatha, 4 km domain, MayAugust 2006 and using the CASTNet network and WDEQ additional industrial sites.

Month >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20%

May 6 190 5 1 3 177 1 1 2 194 5 0 190 1 1 4 185 1 2 4 177 2 0

Jun 2 7 146 6 3 172 4 1 0 163 6 1 174 4 1 9 150 1 0 1 164 1 4

Jul 2 1 174 1 2 0 171 5 1 1 184 1 1 5 176 5 1 8 172 6 1 8 163 1 5

Aug 1 6 179 0 4 1 154 0 6 189 0 1 5 180 0 1 1 172 1 2 2 6 162 7

Co-located with Monitor Within

Hiawatha CD-C

2006 Closest Near Monitor Within

Hiawatha CD-C

Maximum Near Monitor Within

Hiawatha CD-C

Month >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20% >+20% 20% <-20%

May 3 % 95% 2 % 6 % 88% 5 % 1 % 97% 2 % 0 % 95% 5 % 2 % 92% 6 % 2 % 88% 10%

Jun 15% 82% 3 % 2 % 96% 2 % 6 % 91% 3 % 1 % 97% 2 % 11% 84% 6 % 1 % 92% 8 %

Jul 11% 89% 1 % 10% 87% 3 % 6 % 94% 1 % 8 % 90% 3 % 9 % 88% 3 % 9 % 83% 8 %

Aug 8 % 92% 0 % 21% 79% 0 % 3 % 97% 0 % 8 % 92% 0 % 6 % 88% 6 % 13% 83% 4 %

CD-C Hiawatha CD-C

2006 Maximum Near Monitor Within Closest Near Monitor Within Co-located with Monitor Within

Hiawatha CD-C Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-133

Figure A4-15a. Comparison of predicted and observed daily maximum 8-hour ozone 

concentrations at CASTNet (top) and WDEQ (bottom) monitoring sites within 4 km domain 

for May 2005.

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2005 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.4517

O - - O shows quantiles

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2005 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.4018

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2005 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.3505

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2005 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.1971

O - - O shows quantiles
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-134

Figure A4-15b. Comparison of predicted and observed daily maximum 8-hour ozone 

concentrations at CASTNet (top) and WDEQ (bottom) monitoring sites within 4 km domain 

for June 2005.

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2005 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.5365

O - - O shows quantiles

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2005 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.2958

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2005 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.3248

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2005 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.0556

O - - O shows quantiles
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-135

Figure A4-15c. Comparison of predicted and observed daily maximum 8-hour ozone 

concentrations at CASTNet (top) and WDEQ (bottom) monitoring sites within 4 km domain 

for July 2005.

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2005 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.155

O - - O shows quantiles

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2005 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.0865

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2005 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.028

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2005 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.0004

O - - O shows quantiles
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-136

Figure A4-15d. Comparison of predicted and observed daily maximum 8-hour ozone 

concentrations at CASTNet (top) and WDEQ (bottom) monitoring sites within 4 km domain 

for August 2005.

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2005 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.5186

O - - O shows quantiles

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2005 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.2406

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2005 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.3142

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2005 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.0719

O - - O shows quantiles
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-137

Figure A4-16a. Comparison of predicted and observed daily maximum 8-hour ozone 

concentrations at CASTNet (top) and WDEQ (bottom) monitoring sites within 4 km domain 

for May 2006.

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2006 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.4106

O - - O shows quantiles

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2006 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.3902

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2006 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.2273

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2006 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.1362

O - - O shows quantiles
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-138

Figure A4-16b. Comparison of predicted and observed daily maximum 8-hour ozone 

concentrations at CASTNet (top) and WDEQ (bottom) monitoring sites within 4 km domain 

for June 2006.

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2006 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.5724

O - - O shows quantiles

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2006 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.2944

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2006 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.3655

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2006 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.0891

O - - O shows quantiles
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-139

Figure A4-16c. Comparison of predicted and observed daily maximum 8-hour ozone 

concentrations at CASTNet (top) and WDEQ (bottom) monitoring sites within 4 km domain 

for July 2006.

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2006 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.4155

O - - O shows quantiles

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2006 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.2165

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2006 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.2268

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2006 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.0361

O - - O shows quantiles
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-140

Figure A4-16d. Comparison of predicted and observed daily maximum 8-hour ozone 

concentrations at CASTNet (top) and WDEQ (bottom) monitoring sites within 4 km domain 

for August 2006.

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2006 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.5429

O - - O shows quantiles

Nearest daily maximum 8-Hour ozone.

All sites and all days. Subregion = CDC 04km 2006 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.505

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2006 34L.r01

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.3496

O - - O shows quantiles

Daily maximum 8-Hour ozone at monitor.

All sites and all days. Subregion = CDC 04km 2006 19L.Hiawa

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140

Observed Ozone (ppb)

Predicted Ozone (ppb)

r

2=0.1344

O - - O shows quantiles
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-141

A4.8 FOURTH HIGHEST DAILY MAXIMUM 8-HOUR OZONE CONCENTRATION COMPARISONS

The 8-hour ozone National Ambient Air Quality Standard (NAAQS) is based on the three year 

average of the 4th highest daily maximum 8-hour ozone concentrations. The 1997 ozone 

NAAQS specified a threshold of 0.08 ppm (85 ppb) that was revised to 0.075 ppm (76 ppb) in 

March 2008, and keeping the same form of the NAAQS. The modeling results are evaluated in 

light of the 2008 NAAQS of 0.075 ppm that was in effect at the time of the CD-C Base Case 

simulation. 

Figure A4-17 shows the modeled 4th highest daily maximum 8-hour ozone concentration at 

each grid cell in the 4 km domain (Figure A4-17a) and the 12 km grid (Figure A4-17b) for the 

2005 and 2006 years, the Hiawatha and CD-C CAMx base case simulations and Quarters 2, 3 

and 4. Quarter 1 was excluded in this analysis due to the presence of wintertime high ozone 

concentrations that the WDEQ/AQD has advised us to not account for at this time. Figure A4-

17 shows that modeled ozone in the 4 km domain was generally higher in 2006 than in 2005 

and higher in the CD-C than Hiawatha base case simulations. The Q2-Q4 observed fourth 

highest daily maximum 8-hour ozone concentrations in Sublette County are in the 67-69 ppb 

range in 2005, compared to modeled values in the 60-65 ppb and 65-70 ppb ranges for the, 

respectively, Hiawatha and CD-C base case simulations (Figure A4-17a, top). Similar results in 

Sublette County for the 2006 model year were observed values in the 68-73 ppb range and 

predicted values in the 65-72.5 range for the Hiawatha and 70-77.5 ppb range for the CD-C base 

case simulations. Thus, in Sublette County the Hiawatha base case is underestimating the 

observed 4th highest ozone in 2005 with values closer to the observations in 2006 and the CD-C 

base case matches the observe 4th highest values in 2005 and overestimates in 2006.

At the Centennial monitoring site in 2005 (Figure A4-17a, top), the observed 4th highest 8-hour 

ozone concentration is 67 ppb and the Hiawatha base case predicts values in the 70-72.5 ppb 

range with the CD-C base case predicting closer values of ~67.5 ppb. In 2006 both base cases 

predict 4th highest 8-hour ozone in the 70-72.5 ppb range that is close to what was observed 

(70 ppb). The observed ozone concentrations at the OCI (72 ppb) site in 2006 is 

underestimated by the Hiawatha (67.5-70 ppb) and reproduced better by the CD-C (72.5-75 

ppb) base case simulations. Whereas for the Wamsutter site the reverse is true with the 

Hiawatha base case (67.5-70 ppb) matching the observed value (67 ppb) better and the CD-C 

base case that overestimates (72.5-75 ppb).

Figure A4-17b compares isopleths of the CAMx-estimated fourth highest daily maximum 8-hour 

ozone concentration with the observed values (numbers) from the CASTNet network for 2005 

and 2006 within the 12 km grid. At Yellowstone NP in Wyoming, the observed fourth highest 8-

hour ozone concentrations were 60 in 2005 and 70 in 2006. The Hiawatha base case predicts 

values to be in the 60-67.5 ppb range for both years, whereas the CD-C base case predicts 

values in the 60-65 ppb in 2005 and ~77.5 ppb in 2006. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-142

Figure A4-17a. Comparison of predicted 4th highest daily maximum 8-hour ozone 

concentrations from Hiawatha (left) and CD-C (right) simulations during Q2-Q4 with 

superimposed observed values at CASTNet and WDEQ industrial sites within 4 km domain for 

2005 (top) and 2006 (bottom) years.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-143

Figure A4-17b. Comparison of predicted 4th highest daily maximum 8-hour ozone 

concentrations from Hiawatha (left) and CD-C (right) simulations during Q2-Q4 with 

superimposed observed values at CASTNet and WDEQ industrial sites within 12 km domain 

for 2005 (top) and 2006 (bottom) years.

A4.9 SUMMARY OF OZONE PERFORMANCE ON 12/4 KM GRIDS

The original CAMx 2005 and 2006 base case simulation performed under the Hiawatha EIS 

mostly achieved EPA’s model performance goals but with an under predictions bias. This 

underprediction bias was most pronounced at the southwest Wyoming industrial sites in 

Sublette County. Based on the results of a series of diagnostic sensitivity tests (Appendix E), the 

configuration of the CAMx modeling system was revised and an updated base case simulation 

conducted under the CD-C EIS. The revised CD-C base case simulation generally exhibited 

better ozone model performance at the Sublette County monitoring sites and achieved EPA’s 

performance goals more frequently than the preliminary Hiawatha base case simulation. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-144

A5.12/4 KM GRID PM MODEL PERFORMANCE EVALUATION

This Section summarizes the CAMx 2005 and 2006 Base Case model performance evaluation for 

particulate matter (PM10 and PM2.5) and their component species in the 12 km and 4 km 

modeling domains. The CAMx base case model performance performed under the CD-C study 

is compared with the preliminary CAMx base case performed under the Hiawatha study 

(Kemball-Cook et al., 2009). The CAMx modeling results were compared with observational 

data from the Interagency Monitoring of PROtected Visual Environments (IMPROVE), Speciated 

Trends Network (STN)5, Clean Air Status Trends Network (CASTNet), Federal Reference Method 

(FRM) PM2.5 mass, and National Acid Deposition Program (NADP) monitoring networks. The 

evaluation focuses on the operational model evaluation of the air quality model’s performance 

with respect to the individual components of PM10 and fine (PM2.5), particulate matter as well 

as total PM10 and PM2.5 mass. These component species are NO3, SO4, OCM, EC, Soil, CM, and 

NH4. Some elements from a diagnostic evaluation analysis of the ability of the model to 

reproduce gaseous PM precursor (e.g., SO2 and NH3) and product (e.g., HNO3) species were 

also carried out.

Model performance was evaluated by quarter, using scatter plots showing observed versus 

modeled values for all monitors and all days along with quarterly bias and error statistics. 

Examining performance by quarter affords an overview of model performance, and shows 

seasonal trends in model performance. Model performance was also evaluated by month using 

monthly time series bar charts and bugle plots comparing model performance with PM 

performance goals that are a continuous function of average concentration. Monthly 

evaluation shows detailed changes in model performance with time of year. For species that 

are expected to play a critical role in the CD-C impact assessment (e.g. NO3 and SO4), the CAMx 

performance in the CD-C 2005-2006 modeling was compared with preliminary CAMx base case 

performed under the Hiawatha study.

Within the 4 km grid there are two IMPROVE monitoring sites [Bridger (BRID) and Mount Zirkel 

(MOZI)] and two CASTNet monitoring sites (Pinedale and Centennial, WY). No STN sites were 

available within the 4 km grid. The 12 km grid contained 12 IMPROVE sites: Bridger (BRID), 

Mount Zirkel (MOZI), Cloud Peak (CLPE), North Absaroka (NOAB), White River (WHRI), Wind 

Cave (WICA), Craters of the Moon (CRMO), Crescent Lake (CRES), Northern Cheyenne (NOCH), 

Sawtooth (SAWT), Yellowstone (YELL), Thunder Basin (THBA), Rocky Mountain NP headquarters 

(RMHQ). Also within the 12 km grid were 5 CASTNet Sites: Pinedale (PND), Centennial (CNT), 

Gothic (GTH), Rocky Mountain (ROM), and Yellowstone (YEL). There were 3 STN sites in the 12 

km domain that were located in the greater Salt Lake City and Denver Metro Areas.

A5.1 SULFATE MODEL PERFORMANCE

Figures A5-1 and A5-2 display scatter plots of predicted and observed sulfate (SO4) and related 

compounds (e.g., gaseous SO2 and wet SO4 deposition) by quarter for sites within the 12 km 

domain for the 2005 and 2006 modeling years, respectively. The Figures also include the mean 

fractional bias (MFB) and mean fractional error (MFE) statistical performance metrics that can 

be compared with the performance goals (Table A2-3). In these figures, the results for the 34 

 

5

The STN network is now referred to as the Chemical Speciation Network (CSN)
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-145

layer CD-C CAMx base case simulation are shown in red (34L.r01), whereas the results for the 

preliminary Hiawatha 19 layer CAMx base case simulation are shown in blue (19L.Hiawa). For 

both the IMPROVE (Figure A5-1a) and CASTNet (Figure A5-1b) monitoring networks, CAMx SO4 

performance from both base case simulations achieve PM bias/error performance criteria 

(≤±60%/≤75%) for all quarters. In 2005, both CAMx base case simulations SO4 bias achieves the 

PM performance goal (≤±30%) at the IMPROVE sites for Q2 and Q3 and the error achieves the 

PM performance goal (≤50%) in Q3 (Figure A5-1a). At the CASTNET sites (Figure A5-1b), both 

base case simulations achieve or nearly achieve the PM error performance goal for all four 

Quarters and SO4, but neither base case simulations achieves the bias PM performance goal for 

any Quarter in 2005. Although the SO4 performance in 2005 across the CASTNet monitoring 

sites does achieve the PM performance criteria for both bias and error and the CD-C and 

Hiawatha base case simulations. At the STN sites in 2005 (Figure A5-1c), SO4 model 

performance was better at the CASTNet and IMPROVE monitoring sites for both base case 

simulations with the CD-C and Hiawatha CAMx base case simulations achieving the PM 

performance goal for bias/error (≤±30%/≤50%) during Q1 and Q4. CD-C base case SO4 

performance at the STN sites in 2005 was better than the Hiawatha base case as the CD-C SO4 

bias achieved the bias performance goal in Q3 and error performance goal in Q2, but the 

Hiawatha base case simulation did not. However, both base case simulations’ 2005 SO4 bias 

and error performance achieves the PM performance criteria for all four quarters.

For 2005 and SO2 model performance (Figure A5-1d), CD-C base case mostly exhibits better 

performance than the Hiawatha base case, but both models are performing fairly well. Both 

models are within the PM performance goal for bias/error during Q2, Q3, and Q4 and are 

within the goal for bias during Q1. The error from both models during Q1 is well within 

performance criteria (≤75%) with SO2 error of 53% and 57% for the CD-C and Hiawatha base 

case simulations, respectively. The SO2 performance at the CASTNet sites showed smaller 

absolute values of bias than SO4 and values of error for SO2 that were comparable to those of 

SO4 at the CASTNet sites. 

The 2005 SO4 wet deposition model performance (Figure A5-1e) measured at the NADP sites 

shows both base case simulations achieving the bias performance goal during Q1 and Q3 and 

achieving the bias performance criteria during Q2 and Q4, but fail to achieve the criteria for 

error for any of the four quarters of 2005, except for CD-C base case during Q2. Simulation of 

wet deposition is a particularly challenging task for the model as it depends not only on 

predicting SO4 concentrations correctly, but also on accurate reproduction of the precipitation 

fields predicted by the meteorological model. For example, a monitoring site may be affected 

by rainfall from a thunderstorm that is a few kilometers wide, causing sulfate deposition at the 

site while nearby areas are unaffected. If the meteorological model places the storm a few grid 

cells away from the monitor and/or times the rainfall incorrectly, the sulfate deposition 

performance will suffer. The large values of error seen in the wet deposition model 

performance statistics are therefore due partly to the simulation of rainfall. The negative 

values of bias for all quarters of 2005 indicate that CAMx consistently underestimated the wet 

deposition of sulfate. The underestimate of wet deposition during summer is consistent with 

the model’s tendency to under predict summer SO4 concentrations. The reasons for the 

underestimate of SO4 wet deposition during winter, when the model has positive biases for 

SO4 concentrations at both the CASTNet and IMPROVE sites, are less clear.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-146

In 2006, the two base case simulations’ SO4 performance achieves the PM bias/error 

performance goal for Q2 and Q3 across the IMPROVE network and achieves the PM 

performance criteria for Q1, Q2, and Q3 (Figure A5-2a). For Q4, the CD-C base case 2006 SO4 

error was within the PM performance criteria, whereas the Hiawatha base case did not with 

both models exhibiting a large SO4 overestimation bias (65% for CD-C and 70% for Hiawatha) 

that falls outside of the PM performance criteria (≤±60%). Similar good SO4 performance is 

seen across the CASTNet monitoring sites in the 12 km domain for both base case simulations 

with the PM performance goal for bias/error (≤±30%/≤50%) being achieved for Q1 and Q3 and 

the PM performance criteria achieved throughout the year (Figure A5-2b). At the STN sites 

(Figure A5-2c), the 2006 SO4 model performance for both base case simulations achieves the 

bias/error performance goal for Q1 and Q3, and achieves only the error performance goal 

during Q2 and Q4 except the CD-C performance is within bias goal for Q4; the PM performance 

criteria is achieved throughout the year by both base case simulations. Performance for SO2 at 

the CASTNet sites is fairly good with the two base case simulations achieving the PM 

performance goal for Q1, Q2, and Q4, and the PM criteria for all four quarters (Figure A5-2d). 

Similar to 2005, 2006 SO2 performance is marked by a low bias and large error, indicating that 

the model does not have a systematic tendency to under- or overestimate SO2, but that there 

is considerable scatter of the observed/modeled pairs about the 1:1 line. As in 2005, wet SO4 

deposition is underpredicted across the NADP sites in the 12 km domain for 2006 (Figure A5-

2e). The model achieves the goal for bias for Q1 and Q3, and achieves the criteria during Q2 

and Q4, but does not achieve the PM performance criteria for error in any quarter.

Figure A5-3displays Bar Charts of SO4 monthly mean fractional bias across the IMPROVE, 

CASTNet and STN monitoring networks in the 4 km (Figure A5-3a) and 12 km (Figure A5-3b) 

modeling domains for 2005 and 2006 and the CD-C and Hiawatha CAMx base case simulations. 

Note that there are no STN monitors within the 4 km grid and the FRM monitoring network 

does not measure SO4. The Bar Charts make clear the model’s tendency to overestimate 

sulfate in winter and underestimate sulfate during summer. This pattern occurs for both years 

and is apparent on both the 4 km and 12 km grids. Figure A5-4 displays Bugle Plots of monthly 

SO4 model performance during 2005 and 2006 for the two base case simulations and compares 

them with the PM performance goals and criteria and the performance of the WRAP 2002 

CMAQ simulation model performance. The Bugle Plots plot the fractional bias and error 

performance metrics as a function of average observed concentration and relaxes the PM 

performance goals and criteria as the average observed SO4 concentration approaches zero to 

account for the fact that SO4 performance is not as important as SO4 concentrations become 

an insignificant component of PM2.5 mass or visibility impairment. Figure A5-3 and 6-4 show

that the model always achieves the PM performance criteria, but does not achieve the 

performance goal for some months and networks. The SO4 performance of both CD-C and 

Hiawatha CAMx 2005/2006 base case simulations are very similar and similar to the 

performance of the WRAP 2002 CMAQ performance.

In summary, the SO4 performance for the CD-C base case modeling is very similar to Hiawatha 

base case simulation. As seen in the Bugle Plots, the SO4 performance of the two models 

achieve the bias/error PM performance goal most of the time with only a few months falling 

outside of the PM performance goal range and always achieves the PM performance criteria.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-147

IMPROVE – SO4

Figure A5-1a. Comparison of predicted and observed 24-hour average SO4 concentration for 

IMPROVE sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 

(bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-148

CASTNet – SO4

Figure A5-1b. Comparison of predicted and observed 24-hour average SO4 concentration for 

CASTNet sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-149

STN – SO4

Figure A5-1c. Comparison of predicted and observed 24-hour average SO4 concentration for 

STN sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom left) 

and Q4 (bottom right).

Observation

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-150

CASTNet – SO2

Figure A5-1d. Comparison of predicted and observed 24-hour average SO2 concentration for 

CASTNet sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 

(bottom left) and Q4 (bottom right).

CD-C

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-151

NADP – SO4 wet deposition

Figure A5-1e. Comparison of predicted and observed weekly average SO4 wet deposition for 

NADP sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-152

IMPROVE – SO4

Figure A5-2a. Comparison of predicted and observed 24-hour average SO4 concentration for 

IMPROVE sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 

(bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-153

CASTNet – SO4

Figure A5-2b. Comparison of predicted and observed 24-hour average SO4 concentration for 

CASTNet sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 

(bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-154

STN – SO4

Figure A5-2c. Comparison of predicted and observed 24-hour average SO4 concentration for 

STN sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

Observation

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-155

CASTNet – SO2

Figure A5-2d. Comparison of predicted and observed 24-hour average SO2 concentration for 

CASTNet sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 

(bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-156

NADP – SO4 wet deposition

Figure A5-2e. Comparison of predicted and observed weekly average SO4 wet deposition for 

NADP sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-157

CD-C 04km 2005

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100

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 SO4

(1)

(2)

(3)

(4)

Figure A5-3a. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for SO4 in 4 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-158

CD-C 12km 2006

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60

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 SO4 CD-C 12km 2005

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2005 SO4 Hiawatha 12km 2005

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

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2005 SO4 Hiawatha 12km 2006

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0

20

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 SO4

(1)

(2)

(3)

(4)

Figure A5-3b. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for SO4 in 12 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-159

Figure A5-4a. Bugle Plots of SO4 model performance comparing mean fractional bias for the WRAP 2002 CMAQ 36 km simulation 

(top), Hiawatha (middle), and CD-C (bottom) 12 km CAMx 2005 (left)and 2006 (right) simulation with PM model performance 

goals (blue) and criteria (orange). Hiawa 12km 2005

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0

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0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

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(-) Goal

(+) Criteria

(-) Criteria

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FRM

IMPROVE

STN

SO4 CD-C 12km 2005

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FRM

IMPROVE

STN

SO4 Hiawa 12km 2006

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STN

SO4 CD-C 12km 2006

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(-) Criteria

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FRM

IMPROVE

STN

SO4

WRAP 2002
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-160

Figure A5-4b. Bugle Plots of SO4 model performance comparing mean fractional error for the WRAP 2002 CMAQ 36 km 

simulation (top), Hiawatha (middle), and CD-C (bottom) 12 km CAMx 2005 (left)and 2006 (right) simulation with PM model 

performance goals (blue) and criteria (orange).

Hiawa 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

SO4 CD-C 12km 2005

0

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STN

SO4 Hiawa 12km 2006

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Criteria

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SO4 CD-C 12km 2006

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SO4

WRAP 2002
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-161

A5.2 NITRATE MODEL PERFORMANCE

Figures A5-5 and A5-6 display scatter plots and performance statistics for nitrate (NO3) and 

nitrate-related species for CD-C and Hiawatha base case simulations by Quarter for2005 and 

2006, respectively. The species examined in these figures are: (a) IMPROVE NO3 (b) CASTNet 

NO3; (c) STN NO3; (d) CASTNet nitric acid (HNO3); (e) CASTNet total nitrate (NO3+HNO3); (f) 

CASTNet ammonium (NH4); (g) STN NH4; (h) wet NO3 deposition; and (i) wet NH4 deposition. 

With the exception of the STN sites, where NO3 is underpredicted year-round, the NO3 model 

performance is characterized by a winter (e.g., Q1 and Q4) overprediction and a summer (Q2 

and Q3) underprediction bias. However, during the summer and adjacent period (Q2 and Q3) 

the NO3 observations are very small, rarely exceeding 0.5 μg/m3. For the IMPROVE and 

CASTNet sites in 2005, as well as the IMPROVE network in 2006, the Q3 bias is within the PM 

performance criteria; however for all other quarters for both networks and both years the NO3 

bias and error do not achieve the PM performance criteria. At the STN sites both base cases 

underestimate the observed values throughout the year and both years with the CD-C base 

case underestimation bias being greater than the Hiawatha base case.

The performance for nitric acid (HNO3) across the CASTNet network is much better with CD-C 

base case bias and error values achieving the PM performance goal for all Quarters and both 

years except for Q1 error in 2005 and Q4 error in 2006 (Figures A5-6d and A5-7d). The 

Hiawatha nitric acid performance error does not achieve the PM performance goal in Q4 in 

both 2005 and 2006. The two base case simulations performance for total nitrate (NO3+HNO3; 

Figures A5-6e and A5-7e) achieve the PM performance goal during Q2 and Q3 of both 2005 and 

2006, but do not even achieve the PM performance criteria during Q1 and Q4 when they are 

affected by the large overestimation of NO3. The Q2 and Q3 nitric acid and total nitrate 

performance are better than the NO3 performance, which suggests that the summer NO3 

performance issues may be partly related to the aerosol equilibrium between HNO3 and NO3 

rather than the oxidation rate of NOx. Ammonia emissions are highly uncertain and have a 

large effect on the NO3 equilibrium. There may also be additional crustal basic compound 

available to form particulate NO3 that are not fully accounted for in the modeling (e.g., 

sodium). In Q1 and Q4 both NO3 and total NO3 are greatly overestimated, which may be 

related to oxidation rates and loss mechanisms in additional to aerosol thermodynamics. 

Ammonium (NH4) performance results are presented in Figures A5-6f-g andA5-7f-g. Note that 

ammonium is not measured directly at IMPROVE sites, but can be derived assuming that NO3 

and SO4 are completely neutralized. The ammonium concentrations are underestimated for 

Q2-Q4 for both 2005 and 2006 (Figures A5-6f and A5-7f). The Q2 and Q3 (summer) ammonium 

underprediction is very large with the Hiawatha base case exhibiting a larger underestimation 

bias than the CD-C base case. Both wet deposited NO3 and NH4 are underestimated, with the 

underestimation highest in the summer (e.g., Q2 and Q3), when the NO3 and NH4 

concentration underprediction is greatest.

Figure A5-7 displays the monthly bias bar charts that clearly show the large seasonal 

dependence of the NO3 model performance, with a summer underestimation and winter 

overestimation bias. At the IMPROVE and CASTNet sites, the NO3 winter overprediction bias 

occurs roughly from November through February and the summer underprediction bias occurs 

roughly from April through August. March and September-October are transition periods when 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-162

the NO3 bias is typically closest to zero. At the STN sites, there is a year round underestimate 

of NO3, with the largest underestimation bias coming during summer. Although the magnitude 

of the summer NO3 underestimation fractional bias is large, it is of less concern than the winter 

overestimate because both the observations and model estimates have near zero NO3 in the 

summer. This is illustrated in the Bugle Plots in Figure A5-9. NO3 can get fairly high at the STN 

sites in the winter (e.g. >12 μg/m3; Figure A5-6c), but across the IMPROVE and CASTNet sites,

the average observed NO3 is quite low, averaging less than 0.2 μg/m3. Thus, the CD-C and 

Hiawatha NO3 bias and error metrics are in the flared portion of the PM performance goal and 

criteria in the Bugle Plots for the IMPROVE and CASTNet sites. The Hiawatha base case NO3 

performance at the STN sites is better than the CD-C STN NO3 performance; the reasons for 

this are unclear. Overall, the CD-C and Hiawatha base case NO3 performance is comparable to 

that of the 2002 WRAP RPO simulation, with the Hiawatha NO3 performance better than WRAP 

at the STN sites. 

Like NO3, NH4 (Figure A5-8) performance shows a strong seasonality, with both model runs 

exhibiting a smaller bias in winter than in summer. There is a low bias in summer in both the 

Hiawatha and the CD-C runs, with CD-C showing s smaller bias overall than Hiawatha. The NH4 

bugle plots for 2005 and 2006 (Figure A5-10) show that performance is fairly comparable for 

the Hiawatha and CD-C runs, but CD-C performing better overall at the IMPROVE monitors and 

slightly worse at the STN monitors. Both simulations are generally within the performance 

criteria.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-163

IMPROVE – NO3

Figure A5-5a. Comparison of predicted and observed 24-hour average NO3 concentration for 

IMPROVE sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-164

(bottom left) and Q4 (bottom right).

CASTNet – NO3

Figure A5-5b. Comparison of predicted and observed 24-hour average NO3 concentration for 

CASTNet sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 

(bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-165

STN – NO3

Figure A5-5c. Comparison of predicted and observed 24-hour average NO3 concentration for 

STN sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-166

CASTNet – HNO3

Figure A5-5d. Comparison of predicted and observed 24-hour average HNO3 concentration 

for CASTNet sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 

(bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-167

CASTNet – Total Nitrate

Figure A5-5e. Comparison of predicted and observed 24-hour average Total Nitrate 

(NO3+HNO3) concentration for CASTNet sites in the CD-C 12 km domain for 2005 and Q1 (top 

left), Q2 (top right), Q3 (bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-168

CASTNet – NH4

Figure A5-5f. Comparison of predicted and observed 24-hour average NH4 concentration for 

CASTNet sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 

(bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-169

STN – NH4

Figure A5-5g. Comparison of predicted and observed 24-hour average NH4 concentration for 

STN sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-170

NADP – NO3 wet deposition

Figure A5-5h. Comparison of predicted and observed weekly average NO3 wet deposition for 

NADP sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-171

NADP – NH4 wet deposition

Figure A5-5i. Comparison of predicted and observed weekly average NH4 wet deposition for 

NADP sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-172

IMPROVE – NO3

Figure A5-6a. Comparison of predicted and observed 24-hour average NO3 concentration for 

IMPROVE sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 

(bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-173

CASTNet – NO3

Figure A5-6b. Comparison of predicted and observed 24-hour average NO3 concentration for 

CASTNet sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 

(bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-174

STN – NO3

Figure A5-6c. Comparison of predicted and observed 24-hour average NO3 concentration for 

STN sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-175

CASTNet – HNO3

Figure A5-6d. Comparison of predicted and observed 24-hour average HNO3 concentration 

for CASTNet sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 

(bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-176

CASTNet – Total Nitrate

Figure A5-6e. Comparison of predicted and observed 24-hour average Total Nitrate 

(NO3+HNO3) concentration for CASTNet sites in the CD-C 12 km domain for 2006 and Q1 (top 

left), Q2 (top right), Q3 (bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-177

CASTNet – NH4

Figure A5-6f. Comparison of predicted and observed 24-hour average NH4 concentration for 

CASTNet sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 

(bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-178

STN – NH4

Figure A5-6g. Comparison of predicted and observed 24-hour average NH4 concentration for 

STN sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-179

NADP – NO3 wet deposition

Figure A5-6h. Comparison of predicted and observed weekly average NO3 wet deposition for 

NADP sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-180

NADP – NH4 wet deposition

Figure A5-6i. Comparison of predicted and observed weekly average NH4 wet deposition for 

NADP sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-181

CD-C 04km 2005

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 NO3 Hiawatha 04km 2006

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Fractional Bias [%]

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2006 NO3 Hiawatha 04km 2005

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

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2005 NO3 CD-C 04km 2006

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 NO3

(1)

(2)

(3)

(4)

Figure A5-7a. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for NO3 in 4 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-182

Hiawatha 12km 2005

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2005 NO3 CD-C 12km 2005

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2005 NO3 Hiawatha 12km 2006

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Fractional Bias [%]

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2006 NO3 CD-C 12km 2006

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 NO3

(1)

(2)

(3)

(4)

Figure A5-7b. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for NO3 in 12 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-183

Hiawatha 04km 2006

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0

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Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 NH4 Hiawatha 04km 2005

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Fractional Bias [%]

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2005 NH4 CD-C 04km 2005

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Fractional Bias [%]

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2005 NH4 CD-C 04km 2006

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Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 NH4

(1)

(2)

(3)

(4)

Figure A5-8a. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for NH4 in 4 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-184

CD-C 12km 2006

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Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 NH4 Hiawatha 12km 2006

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Fractional Bias [%]

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2006 NH4 CD-C 12km 2005

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 NH4 Hiawatha 12km 2005

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0

40

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 NH4

(1)

(2)

(3)

(4)

Figure A5-8b. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for NH4 in 12 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-185

Figure A5-9a. Bugle Plots of NO3 model performance comparing mean fractional bias for the WRAP 2002 CMAQ 36 km simulation 

(top), Hiawatha (middle), and CD-C (bottom) 12 km CAMx 2005 (left)and 2006 (right) simulation with PM model performance 

goals (blue) and criteria (orange).

Hiawa 12km 2005

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100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

NO3 CD-C 12km 2005

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0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

NO3 Hiawa 12km 2006

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-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

NO3 CD-C 12km 2006

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

NO3

WRAP 2002
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-186

Figure A5-9b. Bugle Plots of NO3 model performance comparing mean fractional error for the WRAP 2002 CMAQ 36 km 

simulation (top), Hiawatha (middle), and CD-C (bottom) 12 km CAMx 2005 (left)and 2006 (right) simulation with PM model 

performance goals (blue) and criteria (orange). Hiawa 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

NO3 CD-C 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

NO3 Hiawa 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

NO3 CD-C 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

NO3

WRAP 2002
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-187

Figure A5-10a. Bugle Plots of NH4 model performance comparing mean fractional bias for the WRAP 2002 CMAQ 36 km 

simulation (top), Hiawatha (middle), and CD-C (bottom) 12 km CAMx 2005 (left)and 2006 (right) simulation with PM model 

performance goals (blue) and criteria (orange).

Hiawa 12km 2005

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

NH4 CD-C 12km 2005

-200

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-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

NH4 Hiawa 12km 2006

-200

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-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

NH4 CD-C 12km 2006

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

NH4
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-188

Figure A5-10b. Bugle Plots of NH4 model performance comparing mean fractional error for the WRAP 2002 CMAQ 36 km 

simulation (top), Hiawatha (middle), and CD-C (bottom) 12 km CAMx 2005 (left)and 2006 (right) simulation with PM model 

performance goals (blue) and criteria (orange).

Hiawa 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

NH4 CD-C 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

NH4 Hiawa 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

NH4 CD-C 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

NH4
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-189

A5.3 ORGANICCARBON MASS (OCM) MODEL PERFORMANCE

Organic Carbon (OC) is measured at the IMPROVE and STN monitoring sites. It must be 

converted to Organic Carbon Mass (OCM, also called Organic Aerosol or OA) for comparisons 

with the modeled PM2.5 concentrations. OCM/OC ratios tend to range from 1.2 to 2.4, with 

lower values associated with fresh OCM emissions and higher values associated with aged OA 

that has undergone photochemical processing. For the CD-C and Hiawatha OCM evaluation, we 

used an OCM/OC ratio of 1.8 for the rural IMPROVE sites, as 1.8 is the value used in the New 

IMPROVE equation, and is the best available and most current estimate of this quantity for 

rural areas. For the more urban STN sites, a OCM/OC ratio value of 1.2 was used, reflecting the 

fact that the urban STN sites are more influenced by fresh OCM emissions.

Figures A5-11 through A5-15 display the CAMx/OCM performance for 2005 and 2006 for the 

CD-C and Hiawatha base case simulations. The OCM model performance is characterized by 

systematic underprediction with monthly fractional bias values that range from approximately 

-30% to -130%. The two base case simulations fail to achieve the criteria for any quarter for 

2005 and 2006 across the IMPROVE and STN monitors. Temporal patterns in bias are not 

readily apparent in the model performance. 

When the OCM performance of the CD-C and Hiawatha base case simulations is compared with 

the WRAP 2002 36 km run performance in Bugle Plots (Figure A5-15), the WRAP run shows 

marginally better performance at both the IMPROVE and the STN sites, but modeled 

concentrations do not reproduce ambient OCM well in any of the simulations. As for NO3 and 

SO4, the ambient OCM concentrations were somewhat lower in 2005-2006 than in 2002. 

Differences in OCM performance may also be related to different observed OCM/OC ratio 

assumptions. (WRAP used an OCM/OC ratio of 1.4 for all monitors.) Comparison of the CD-C 

and Hiawatha runs shows that the results of the two runs are very similar.

The development of OCM emissions, simulation of OCM in the atmosphere, and the 

monitoring of OC are all areas of current research. Although the measurement of OCM is 

very uncertain, use of different measurement techniques (e.g., IMPROVE vs. STN) can 

produce large differences (e.g., 50%), the emissions inventories also have several 

deficiencies that are known to produce an underprediction bias:

 Current mobile source OCM emissions estimates (MOBILE6) fail to account for 

temperature and speed effects that can have large influences on the primary OCM 

emissions.

- Recent comparisons between EPA’s new MOVES mobile source emissions model and 

MOBILE6 suggest that on-road mobile source particulate matter emissions are 

underestimated by MOBILE6 buy a factor of approximately 3 (Beardsley and Dolce, 

2009).

 MOBILE6 fails to account for semi-volatile organic compound (SVOC) emissions from 

gasoline and diesel combustion. Recent SVOC emission measurements from gasoline 

vehicles were 3 times higher than the primary OCM emissions; if only a third of the SVOC 

emissions were to condense to particulate secondary organic aerosol (SOA) that would 

double the amount of OCM due to mobile sources.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-190

 Other combustion sources (e.g., fires) also have SVOC emissions that are not accounted 

for in the current emission inventories.

 Given these important missing OCM processes, we are not surprised by the OCM 

underprediction tendency in the CAMx base case runs. Fortunately, most of these 

deficiencies in OCM have little effect on the AQ and AQRV impacts due to the oil and gas 

emission sources that are the focus of the CD-C impact assessment.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-191

IMPROVE – OCM

Figure A5-11a. Comparison of predicted and observed 24-hour average OCM concentration for 

IMPROVE sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-192

STN – OCM

Figure A5-11b. Comparison of predicted and observed 24-hour average OCM concentration 

for STN sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-193

IMPROVE – OCM

Figure A5-12a. Comparison of predicted and observed 24-hour average OCM concentration 

for IMPROVE sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 

(bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-194

STN – OCM

Figure A5-12b. Comparison of predicted and observed 24-hour average OCM concentration 

for STN sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-195

Figure A5-13. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for OCM in the 4 km grid.

Hiawatha 04km 2005

-140

-120

-100

-80

-60

-40

-20

0

20

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 OC CD-C 04km 2005

-140

-120

-100

-80

-60

-40

-20

0

20

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 OC Hiawatha 04km 2006

-140

-120

-100

-80

-60

-40

-20

0

20

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 OC CD-C 04km 2006

-140

-120

-100

-80

-60

-40

-20

0

20

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 OC
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-196

Hiawatha 12km 2005

-140

-120

-100

-80

-60

-40

-20

0

20

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 OC CD-C 12km 2005

-140

-120

-100

-80

-60

-40

-20

0

20

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 OC Hiawatha 12km 2006

-140

-120

-100

-80

-60

-40

-20

0

20

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 OC CD-C 12km 2006

-140

-120

-100

-80

-60

-40

-20

0

20

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 OC

(1)

(2)

(3)

(4)

Figure A5-14. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for OCM in the 12 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-197

Figure A5-15a. Bugle Plots of OCM model performance comparing mean fractional bias for the WRAP 2002 CMAQ 36 km 

simulation (top), Hiawatha (middle), and CD-C (bottom) 12 km CAMx 2005 (left)and 2006 (right) simulation with PM model 

performance goals (blue) and criteria (orange).

Hiawa 12km 2005

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 1011121314151617181920

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

OC CD-C 12km 2005

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 1011121314151617181920

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

OC Hiawa 12km 2006

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 1011121314151617181920

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

OC CD-C 12km 2006

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 1011121314151617181920

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

OC

WRAP 2002
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-198

Figure A5-15b. Bugle Plots of OCM model performance comparing mean fractional error for the WRAP 2002 CMAQ 36 km 

simulation (top), Hiawatha (middle), and CD-C (bottom) 12 km CAMx 2005 (left)and 2006 (right) simulation with PM model 

performance goals (blue) and criteria (orange).

Hiawa 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 1011121314151617181920

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

OC CD-C 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 1011121314151617181920

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

OC Hiawa 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 1011121314151617181920

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

OC CD-C 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 1011121314151617181920

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

OC

WRAP 2002
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-199

A5.4 ELEMENTAL CARBON (EC) MODEL PERFORMANCE

The scatter plots and bias and error plots for Elemental Carbon (EC) model performance are 

shown in Figures A5-16 through A5-20. Across the IMPROVE network, both the modeled and 

observed EC are typically just a few tenths of a μg/m3. However, there are some exceptions to 

this that are likely due to impacts from wildfires that impacted monitors in the CAMx 

simulations but did not impact the monitor during the actual fire event and vice versa. The bias 

performance statistics in the 4 km(FigureA5-18) and 12 km (Figure A5-19) domains indicate that 

the model generally underestimates EC during winter, spring, and early summer and 

overestimates EC during late summer and fall across the IMPROVE network. Higher predicted 

and observed EC concentrations are seen in the STN network (Figure A5-16b, 6-17b and 6-19), 

where the model exhibits much lower bias that achieves the PM performance goal for all 

quarters for 2005 and 2006, except Q2 of 2006. There is however, sufficient scatter that the 

error does not achieve the PM performance goal except for Q3 of 2005. The overall EC 

underprediction bias across the IMPROVE network is apparent in the monthly bias time series 

plots (FiguresA5-18 and A5-19). 

The Bugle Plots of bias and error in Figure A5-21 put the EC performance into context. Because 

EC concentrations are so low across the IMPROVE network, the bias and error are well within 

the flared portion of the PM performance goal for bias and error for these sites, so the CD-C 

and Hiawatha base case simulations achieve the PM performance goals. Therefore, the errors 

in prediction of EC at the IMPROVE sites are not expected to introduce significant bias into the 

Hiawatha impact assessment. EC is generally larger at the STN sites, and performance across 

this network is nearly always within the goal and always within the criteria. EC performance in 

the WRAP simulation of 2002 was comparable to that in the Hiawatha 2005-2006 runs. Note 

that the WRAP Bugle Plots used a different and more lax definition of the flare in the goals and 

criteria, whereas we followed the definitions of their developers (Dr. James Boylan, see Boylan, 

2004 or Morris et al., 2009a,b). 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-200

IMPROVE – EC

Figure A5-16a. Comparison of predicted and observed 24-hour average EC concentration for 

IMPROVE sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-201

STN – EC

Figure A5-16b. Comparison of predicted and observed 24-hour average EC concentration for 

STN sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom left) 

and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-202

IMPROVE – EC

Figure A5-17a. Comparison of predicted and observed 24-hour average EC concentration 

for IMPROVE sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 

(bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-203

STN – EC

Figure A5-17b. Comparison of predicted and observed 24-hour average EC concentration for 

STN sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 (bottom left) 

and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-204

Hiawatha 04km 2005

-80

-60

-40

-20

0

20

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 EC CD-C 04km 2005

-80

-60

-40

-20

0

20

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 EC Hiawatha 04km 2006

-80

-60

-40

-20

0

20

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 EC CD-C 04km 2006

-80

-60

-40

-20

0

20

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 EC

(1)

(2)

(3)

(4)

Figure A5-18. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for EC in 4 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-205

Hiawatha 12km 2005

-80

-60

-40

-20

0

20

40

60

80

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 EC CD-C 12km 2005

-80

-60

-40

-20

0

20

40

60

80

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 EC Hiawatha 12km 2006

-80

-60

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-20

0

20

40

60

80

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 EC CD-C 12km 2006

-80

-60

-40

-20

0

20

40

60

80

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 EC

(1)

(2)

(3)

(4)

Figure A5-19. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for EC in 12 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-206

Figure A5-20a. Bugle Plots of EC model performance comparing mean fractional bias for the WRAP 2002 CMAQ 36 km simulation 

(top), Hiawatha (middle), and CD-C (bottom) 12 km CAMx 2005 (left)and 2006 (right) simulation with PM model performance 

goals (blue) and criteria (orange).

Hiawa 12km 2005

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

EC CD-C 12km 2005

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

EC Hiawa 12km 2006

-200

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0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

EC CD-C 12km 2006

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0

50

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150

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0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

EC

WRAP 2002
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-207

Figure A5-20b. Bugle Plots of EC model performance comparing mean fractional error for the WRAP 2002 CMAQ 36 km 

simulation (top), Hiawatha (middle), and CD-C (bottom) 12 km CAMx 2005 (left)and 2006 (right) simulation with PM model 

performance goals (blue) and criteria (orange).

Hiawa 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

EC CD-C 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

EC Hiawa 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

EC CD-C 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

EC

WRAP 2002
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-D CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-208

A5.5 SOIL MODEL PERFORMANCE

IMPROVE Soil observations are composed of a weighted linear combination of elements, 

whereas the CAMx Soil species consists of PM emissions that have not been explicitly speciated 

as SO4, NO3, OCM, EC or CM and therefore actually define an “other” PM2.5 species. Thus, the 

modeled and observed Soil species are not directly comparable. The CAMx 2005 and 2006 Soil 

model performance for the CD-C and Hiawatha base case simulations are summarized in 

Figures A56-21 through A5-25. Most of the predicted and observed 24-hour average Soil 

concentrations are less than 2 μg/m3and agree reasonably well. The exception to this are a 

few predicted Soil values that exceed 2 μg/m3, when the observed values do not and vice versa. 

In both 2005 and 2006, the Hiawatha base case underestimates Soil concentrations in April and 

May on the 4 km and 12 km domains by a large margin, whereas the CD-C base case has an 

overestimation bias for these two months that is closer to zero. Both models overestimate Soil 

at the end of the year (Oct-Dec) in both years (Figures A5-23 and A5-24). Because the 

observed Soil concentrations at the IMPROVE sites tend to be low, the CD-C and Hiawatha base 

case Soil fractional bias and error generally fall within the range of the PM performance goal in 

the Bugle Plots (Figure A5-25) and always fall within the PM performance criteria.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-209

IMPROVE – Soil

Figure A5-21. Comparison of predicted and observed 24-hour average Soil concentration for 

IMPROVE sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-210

IMPROVE – Soil

Figure A5-22. Comparison of predicted and observed 24-hour average Soil concentration for 

IMPROVE sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-211

Hiawatha 04km 2005

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-40

0

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80

120

160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 SOIL CD-C 04km 2005

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-40

0

40

80

120

160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 SOIL Hiawatha 04km 2006

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-40

0

40

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120

160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 SOIL CD-C 04km 2006

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-40

0

40

80

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160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 SOIL

(1)

(2)

(3)

(4)

Figure A5-23. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for Soil in 4 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-212

Hiawatha 12km 2005

-60

-20

20

60

100

140

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 SOIL CD-C 12km 2005

-60

-20

20

60

100

140

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 SOIL Hiawatha 12km 2006

-60

-20

20

60

100

140

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 SOIL CD-C 12km 2006

-60

-20

20

60

100

140

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 SOIL

(1)

(2)

(3)

(4)

Figure A5-24. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for Soil in 12 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-213

Figure A5-25a. Bugle Plots of Soil model performance comparing mean fractional bias for the WRAP 2002 CMAQ 36 km 

simulation (top), Hiawatha (middle), and CD-C (bottom) 12 km CAMx 2005 (left)and 2006 (right) simulation with PM model 

performance goals (blue) and criteria (orange).

Hiawa 12km 2005

-200

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-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

SOIL CD-C 12km 2005

-200

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-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

SOIL Hiawa 12km 2006

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

SOIL CD-C 12km 2006

-200

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-100

-50

0

50

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150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

SOIL

WRAP 2002
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-214

Figure A5-25b. Bugle Plots of Soil model performance comparing mean fractional error for the WRAP 2002 CMAQ 36 km 

simulation (top), Hiawatha (middle), and CD-C (bottom) 12 km CAMx 2005 (left)and 2006 (right) simulation with PM model 

performance goals (blue) and criteria (orange).

Hiawa 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

SOIL CD-C 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

SOIL Hiawa 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

SOIL CD-C 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

SOIL

WRAP 2002
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-215

A5.6 COARSE MASS (CM) MODEL PERFORMANCE

The CAMx IMPROVE Coarse Mass (CM, i.e., PM2.5-10) model performance is summarized in 

Figures A5-26 through A5-30. The CM model performance for both base case simulations is 

characterized by an underprediction bias that is greatest in the summer. The Hiawatha base 

case CM underprediction bias is much greater than is seen for the CD-C base case 

underprediction bias which is near zero for several fall and winter months in 2005 and 2006. 

CM has a much shorter transport distance than fine particulate matter. CM tends to be 

dominated by crustal material that comes mainly from dust sources. For CAMx and other 

photochemical grid models, EPA has developed fugitive dust transport factors (FDTF) that 

represent the fraction of fugitive dust emissions that is transported aloft in the air and does not 

get deposited near the source. The FDTFs are applied to the fugitive dust emissions so they 

only represent the amount that gets transported out of the grid cell where they are emitted. 

FDTFs are land use dependent and can vary from 5% for grid cells that are heavily forested (i.e., 

95% of the fugitive dust emissions in a forest are deposited locally and are not included in the 

modeling emissions inventory) to 95% for barren ground where very little (5%) of the fugitive 

dust is deposited locally. Although the use of FDTF is appropriate for regional modeling, if there 

are local source impacts at the monitor (e.g., wind-blown dust), then these will be 

underestimated in the model. Thus, the underestimation bias of CM is expected as the 

contributions of these local source impacts are not being fully accounted for in the model. As 

such local source impacts will be higher in the summer when dust emissions are more frequent, 

the higher underprediction bias in the summer than winter is also expected. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-216

IMPROVE – CM

Figure A5-26. Comparison of predicted and observed 24-hour average CM concentration for 

IMPROVE sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-217

IMPROVE – CM

Figure A5-27. Comparison of predicted and observed 24-hour average CM concentration for 

IMPROVE sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-218

Hiawatha 04km 2005

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-80

-40

0

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 CM CD-C 04km 2005

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-40

0

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 CM Hiawatha 04km 2006

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-80

-40

0

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 CM CD-C 04km 2006

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-80

-40

0

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 CM

(1)

(2)

(3)

(4)

Figure A5-28. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for CM in 4 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-219

Hiawatha 12km 2005

-200

-160

-120

-80

-40

0

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 CM CD-C 12km 2005

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-40

0

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 CM Hiawatha 12km 2006

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-40

0

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 CM CD-C 12km 2006

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-80

-40

0

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 CM

(1)

(2)

(3)

(4)

Figure A5-29. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for CM in 12 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-220

Figure A5-30a. Bugle Plots of CM model performance comparing mean fractional bias for the WRAP 2002 CMAQ 36 km 

simulation (top), Hiawatha (middle), and CD-C (bottom) 12 km CAMx 2005 (left)and 2006 (right) simulation with PM model 

performance goals (blue) and criteria (orange). Hiawatha 12km 2005

-200

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0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

CM CD-C 12km 2005

-200

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0

50

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150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

CM Hiawatha 12km 2006

-200

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0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

CM CD-C 12km 2006

-200

-150

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-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

CM

WRAP 2002
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-221

Figure A5-30b. Bugle Plots of CM model performance comparing mean fractional error for the WRAP 2002 CMAQ 36 km 

simulation (top), Hiawatha (middle), and CD-C (bottom) 12 km CAMx 2005 (left)and 2006 (right) simulation with PM model 

performance goals (blue) and criteria (orange).

Hiawatha 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

CM CD-C 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

CM Hiawatha 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

CM CD-C 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

CM

WRAP 2002
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-222

A5.7 PARTICULATE MATTER (PM) MODEL PERFORMANCE

Figures A5-31 through A5-40 display model performance summaries for total fine particulate 

(PM2.5) and PM10 mass concentrations. Across the IMPROVE network (Figures A5-31a and A5-

32b), PM2.5 is overestimated in the winter and underestimated in the summer for both 2005 

and 2006 and both base case simulations. However, across the FRM monitoring network the 

two base case simulations exhibit an underestimation bias that is year round. This is shown 

more clearly in the monthly fractional bias Bar Charts across monitors in the 4 km and 12 km 

domains in Figures A5-35 and A5-36, respectively. Across the IMPROVE network the two base 

cases PM2.5 model performance achieves the PM performance criteria for most months in the 

summer and during the transition periods, but the winter overestimation bias exceeds the PM 

performance criteria. At the more urban FRM monitoring sites, many months achieve the PM 

performance criteria, with some months even achieving the PM performance goal, albeit with 

an underestimation bias (Figures A5-35 and A5-36). However, most of the FRM sites lie in the 

12 km portion of the modeling domain and we would not expect a 12 km coarse grid spacing to 

capture the urban PM2.5 concentrations at the FRM monitoring sites. The Bugle Plots for PM2.5

(Figure A5-37) indicate that for both 2005 and 2006 the CD-C and Hiawatha base case model 

performance is generally within the criteria for bias, and nearly always within the criteria for 

error.

The CD-C base case PM10 performance achieves the PM performance criteria in Q1, Q2 and Q4 

in 2005 (Figure A5-32c) and 2006 (Figure 4-33c) and exhibits slightly better performance than 

the Hiawatha base case, whose PM10 bias does not achieve the PM performance goal in Q2 in 

either 2005 or 2006. However, both base case simulations exhibit a large summer 

underestimation bias in PM10 such that neither simulation’s bias achieves the PM performance 

criteria in Q3 in either year. The Bar Charts of PM10 monthly fractional bias in the 4 km and 12 

km domains (Figures A5-38 and A5-39) show that PM10 exhibits the same pattern of summer 

underprediction and winter overprediction as PM2.5. The PM10 bugle plots show the same 

pattern of increasing negative bias with increasing ambient concentration as the coarse matter 

Bugle Plots. The Bugle Plots for PM2.5 (Figure A5-40) show that performance is generally within 

the criteria for 2005, but more months lie outside the criteria in 2006, with error increasing as 

ambient concentration increases.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-223

IMPROVE – PM2.5

Figure A5-31a. Comparison of predicted and observed 24-hour average PM2.5 concentration for 

IMPROVE sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-224

FRM – PM2.5

Figure A5-31b. Comparison of predicted and observed 24-hour average PM2.5 concentration for 

FRM sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom left) 

and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-225

IMPROVE – PM10

Figure A5-31c. Comparison of predicted and observed 24-hour average PM10 concentration 

for FRM sites in the CD-C 12 km domain for 2005 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-226

IMPROVE – PM2.5

Figure A5-32a. Comparison of predicted and observed 24-hour average PM2.5 concentration 

for IMPROVE sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 

(bottom left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-227

FRM – PM2.5

Figure A5-32b. Comparison of predicted and observed 24-hour average PM2.5 concentration 

for FRM sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-228

IMPROVE – PM10

Figure A5-32c. Comparison of predicted and observed 24-hour average PM10 concentration 

for FRM sites in the CD-C 12 km domain for 2006 and Q1 (top left), Q2 (top right), Q3 (bottom 

left) and Q4 (bottom right).

CD-C

Hiawatha
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-229

Hiawatha 04km 2005

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0

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80

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160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 PM25 CD-C 04km 2005

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0

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160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 PM25 Hiawatha 04km 2006

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0

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160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 PM25 CD-C 04km 2006

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0

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 PM25

(1)

(2)

(3)

(4)

Figure A5-35. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for PM2.5 in 4 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-230

Hiawatha 12km 2005

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0

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80

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160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 PM25 CD-C 12km 2005

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0

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 PM25 Hiawatha 12km 2006

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0

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160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 PM25 CD-C 12km 2006

-120

-80

-40

0

40

80

120

160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 PM25

(1)

(2)

(3)

(4)

Figure A5-36. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 

2005(2), Hiawatha 2006(3) and CD-C 2006(4) for PM2.5 in 12 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-231

Figure A5-37a. Bugle Plots of PM2.5model performance that compare mean fractional bias for the 

Hiawatha (left) and CD-C (right) CAMx 2005 (top) and 2006 (bottom) base case simulations in the 12 

km domain with PM model performance goals (blue) and criteria (orange) (Note: WRAP did not 

generate Bugle Plots for PM2.5).

Figure A5-37b. Bugle Plots of PM2.5model performance that compare mean fractional error for the 

Hiawatha (left) and CD-C (right) CAMx 2005 (top) and 2006 (bottom) base case simulations in the 12 

km domain with PM model performance goals (blue) and criteria (orange) (Note: WRAP did not 

generate Bugle Plots for PM2.5). Hiawatha 12km 2005

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

PM2

5

CD-C 12km 2005

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

PM2

5

Hiawatha 12km 2006

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

PM2

5

CD-C 12km 2006

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

PM2

5

Hiawatha 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

PM25 CD-C 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

PM25 Hiawatha 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

PM25 CD-C 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

PM25
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-232

Hiawatha 04km 2005

-120

-80

-40

0

40

80

120

160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 PM10 CD-C 04km 2005

-120

-80

-40

0

40

80

120

160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 PM10 Hiawatha 04km 2006

-120

-80

-40

0

40

80

120

160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 PM10 CD-C 04km 2006

-120

-80

-40

0

40

80

120

160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 PM10

(1)

(2)

(3)

(4)

Figure A5-38. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 2005(2), 

Hiawatha 2006(3) and CD-C 2006(4) for PM10 in 4 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-233

Hiawatha 12km 2005

-120

-80

-40

0

40

80

120

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 PM10 CD-C 12km 2005

-120

-80

-40

0

40

80

120

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2005 PM10 Hiawatha 12km 2006

-120

-80

-40

0

40

80

120

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 PM10 CD-C 12km 2006

-120

-80

-40

0

40

80

120

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Q1 Q2 Q3 Q4 ANN

Fractional Bias [%]

CASTNET IMPROVE STN FRM

2006 PM10

(1)

(2)

(3)

(4)

Figure A5-39. Monthly mean fractional bias performance metrics for Hiawatha 2005(1), CD-C 2005(2), 

Hiawatha 2006(3) and CD-C 2006(4) for PM10 in 12 km grid.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-234

Figure A5-40a. Bugle Plots of PM10model performance that compare mean fractional bias for the 

Hiawatha (left) and CD-C (right) CAMx 2005 (top) and 2006 (bottom) base case simulations in the 12 

km domain with PM model performance goals (blue) and criteria (orange) (Note: WRAP did not 

generate Bugle Plots for PM10).

Figure A5-40b. Bugle Plots of PM10model performance that compare mean fractional error for the 

Hiawatha (left) and CD-C (right) CAMx 2005 (top) and 2006 (bottom) base case simulations in the 12 

km domain with PM model performance goals (blue) and criteria (orange) (Note: WRAP did not 

generate Bugle Plots for PM10). Hiawatha 12km 2005

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

PM1

0

CD-C 12km 2005

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

PM1

0

Hiawatha 12km 2006

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

PM1

0

CD-C 12km 2006

-200

-150

-100

-50

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Average Concentration (ug/m3)

Fractional Bias (%)

(+) Goal

(-) Goal

(+) Criteria

(-) Criteria

CASTNET

FRM

IMPROVE

STN

PM1

0

Hiawatha 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

PM10 CD-C 12km 2005

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

PM10 Hiawatha 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

PM10 CD-C 12km 2006

0

50

100

150

200

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Average Concentration (ug/m3)

Fractional Error (%)

Goal

Criteria

CASTNET

FRM

IMPROVE

STN

PM10
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-235

A5.8 NITRATE(NO3) PERFORMANCE ASSESSMENT

The largest emissions associated with oil and gas emissions sources, such as those associated 

with the CD-C project, are Volatile Organic Compounds (VOC) and oxides of nitrogen (NOX), 

both of which are ozone precursors. In Section 4 of this Appendix, we addressed the CD-C 

CAMx base case ozone performance and showed much improvement on ozone model 

performance over the Hiawatha base case simulation. However, nitrate (NO3) represents a 

major potential contributor to visibility impairment at Class I areas due to O&G emissions in the 

12/4 km modeling domain. The NO3 evaluation presented in Section A5.2 indicated that both 

the CD-C and Hiawatha CAMx 2005 and 2006 base case simulations overpredicted NO3 in the 

winter and underpredicted NO3 in the summer. In this section we discuss the implications of 

the NO3 performance issues and their potential effects on the calculation of O&G visibility 

impacts at Class I areas.

Figures A5-41and A5-42 displays time series plots of predicted and observed 24-hour average 

NO3 concentrations during 2005 and 2006 at the Bridger (BIRD) and Mount Zirkel (MOZI) 

IMPROVE monitoring sites in Wyoming and Colorado within the 4 km domain. These time 

series plots clearly show the seasonal dependence of NO3 concentrations in the observations 

and model predictions with much higher values in the winter and much lower values in the 

summer, when the modeled values approach zero. There are questions regarding the accuracy 

of the low observed NO3 values in the summer and whether the handling and transport of the 

filters could contaminate the samples producing small nitrate values when in reality the real 

atmosphere had none because the high summer temperatures volatilize the particulate NO3. 

In any event, both the observed and modeled summer nitrate are extremely low and not an 

important component of the PM2.5 mass and visibility impairment during the summer. 

Figures A5-41and A5-42 also compares the predicted and observed frequency distribution of 

24-hour NO3 concentrations at each IMPROVE monitoring site during 2005 and 2006. When 

the measured NO3 concentration is above approximately 0.1 μg/m3, both CAMx base case 

simulations have a marked overprediction bias of 50% to 100%, and even more for the highest 

model estimated NO3 concentrations. Thus, the CD-C and Hiawatha CAMx modeling systems 

will overestimate the maximum NO3 impacts and consequently overestimate the maximum 

visibility impacts due to O&G emissions at Class I areas. 

The formation of particulate nitrate depends on the ambient concentration of ammonia, which 

reacts preferentially with SO4. If ambient concentrations of ammonia are not well-represented 

in the model, nitrate formation will not be simulated correctly. Routine measurements of NH3 

within the modeling domain for 2005-6 were not available, however, Shell sponsored ammonia 

monitoring during 2007-2008 at the Boulder monitoring site southwest of the Wind River Range 

in Sublette County, WY. No direct comparison of the 2005-2006 modeled NH3 and the 2007-8 

measured NH3 is possible, but this data set offers a unique observational database for use in 

general evaluation of the CAMx ammonia performance, which is critical to nitrate performance. 

Figure A5-43 displays the observed monthly frequency distribution of ammonia (NH3) 

concentrations during 2007 at the Boulder monitoring site using box and whisker plots from 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-236

Molenar and co-workers (2008)6 as well as similar plots using the CD-C and Hiawatha CAMx 

model predictions in 2005 and 2006 at the Boulder site. The amplitude of the modeled 

seasonal cycle is smaller in the two model simulations than in the observations, with the model 

estimating a fairly flat monthly average NH3 profile of approximately 0.05 to 0.20 ppb whereas 

the observed monthly average NH3 profile ranges from near zero in the winter to ~0.8 ppb in 

July and August. The underestimate of summer NH3 in the model may contribute to the 

general low bias in model nitrate predictions during summer. Ammonia emissions are highly 

uncertain, and better representation of ammonia within the model may improve nitrate 

performance. 

As a final test of the implications of using the CD-C CAMx modeling database to make AQRV 

assessment at Class I areas, we examined the number of predicted and observed days during 

2005 and 2006, and each Quarter in 2005 and 2006, that visibility impairment due to NO3 

exceeds a 0.5 and 1.0 deciview (dv) thresholds. For each of the 1:3 sampling days from 2005 

and 2006 and the two IMPROVE monitors in the 4 km domain (Mount Zirkel and Bridger), the 

observed and CD-C and Hiawatha base case predicted 24-hour NO3 concentrations were 

converted to light extinction using the IMPROVE extinction equation and monthly average 

relative humidity adjustment factors [f(RH)] and then converted to deciview assuming a change 

in deciview over clean natural background conditions. The number of days that the observed 

and predicted visibility impairment exceeded the 0.5 and 1.0 dv thresholds at Mount Zirkel and 

Bridger are tabulated in Table A5-1. At Mount Zirkel there were 49 days during 2005 that the 

observed visibility impairment due to NO3 exceeded the 0.5 dv threshold compared to 77 days 

and 67 days for the Hiawatha and CD-C base case simulations respectively. That is, the 

Hiawatha and CD-C base cases overestimate the number of days that NO3 visibility impairment 

exceeds 0.5 dv at Mount Zirkel in 2005 by 57% and 37%, respectively. The conservatism in the 

modeling systems in regards to NO3 AQRVs using the 1.0 dv threshold is even greater with the 

model estimating over 2 times as many days than observed at Mount Zirkel (Table A5-1a). The 

results at Mount Zirkel in 2006 are similar with over 10 more modeled days in 2006 (~25% more 

days) than observed having NO3 visibility impairment > 0.5 dv (Table A5-1b). And there were 

over 2.5 times more modeled days at Mount Zirkel in 2006 than observed days with NO3 

visibility impairment exceeding the 1.0 dv threshold.

The conservatism of the Hiawatha and CD-C CAMx base case simulations in estimating NO3 

visibility impairment at Class I areas is even greater at the Bridger IMPROVE monitoring site. In 

2005, there are over twice as many modeled days than observed that the NO3 visibility 

impairment exceeds the 0.5 dv threshold at Bridger and over 5 times as many modeled days 

than observed days that the 1.0 dv threshold is exceeded (Table A5-1c). In 2006, the CD-C base 

case has 24 more days (45% more days) when the 0.5 dv threshold is exceeded due to NO3 

than are observed and there are over 2.5 more modeled days than observed days that the 1.0 

dv threshold is exceeded due to NO3 (Table A5-1d).

 

6 Available at: 

http://wrapair.org/forums/toc/meetings/080515m/NH3_Monitoring_in_the_Upper_Green_River_Basin.ppt#309,25,Neutralization
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-237

Figure A5-41a. Time series of 2005 predicted and observed 24-hour average NO3 concentrations at the Bridger IMPROVE monitoring site (top 

left panel). Cumulative frequency distribution of predicted and observed 24-hour NO3 concentrations unpaired in space and time for 

Hiawatha (top right panel) and CD-C (bottom right panel) and paired in time (bottom left panel) for the Bridger IMPROVE monitoring site for 

2005.

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360

Day

NO3 Concentration (ug/m3)

IMPROVE_obs

Hiawatha_19L

CD-C

BRID1

0.0

1.0

2.0

3.0

0.0 1.0 2.0 3.0

Improve Measured NO3 (ug/m3)

Predicted NO3 (ug/m3)

BRID1

Overpredicted

Underpredicted

0.0

1.0

2.0

3.0

0.0 1.0 2.0 3.0

Improve Measured NO3 (ug/m3)

Predicted NO3 (ug/m3)

BRID1

0.0

1.0

2.0

3.0

0.0 1.0 2.0 3.0

Improve Measured NO3 (ug/m3)

Predicted NO3 (ug/m3)

BRID1

Overpredicted

Underpredicted

Hiawatha

CD-C

BIRD1

Hiawatha

CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-238

Figure A5-41b. Time series of 2006 predicted and observed 24-hour average NO3 concentrations at the Bridger IMPROVE monitoring site (top 

left panel). Cumulative frequency distribution of predicted and observed 24-hour NO3 concentrations unpaired in space and time for 

Hiawatha (top right panel) and CD-C (bottom right panel) and paired in time (bottom left panel) for the Bridger IMPROVE monitoring site for 

2006.

0.0

0.5

1.0

1.5

2.0

2.5

0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360

Day

NO3 Concentration (ug/m3)

IMPROVE_obs

Hiawatha_19L

CD-C

BRID1

0.0

1.0

2.0

3.0

0.0 1.0 2.0 3.0

Improve Measured NO3 (ug/m3)

Predicted NO3 (ug/m3)

BRID1

Overpredicted

Underpredicted

0.0

1.0

2.0

3.0

0.0 1.0 2.0 3.0

Improve Measured NO3 (ug/m3)

Predicted NO3 (ug/m3)

BRID1

0.0

1.0

2.0

3.0

0.0 1.0 2.0 3.0

Improve Measured NO3 (ug/m3)

Predicted NO3 (ug/m3)

BRID1

Overpredicted

Underpredicted

Hiawatha

CD-C

BIRD1

Hiawatha

CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-239

Figure A5-42a. Time series of 2005 predicted and observed 24-hour average NO3 concentrations at the Mount Zirkel IMPROVE monitoring 

site (top left panel). Cumulative frequency distribution of predicted and observed 24-hour NO3 concentrations unpaired in space and time for 

Hiawatha (top right panel) and CD-C (bottom right panel) and paired in time (bottom left panel) for the Bridger IMPROVE monitoring site for 

2005.

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360

Day

NO3 Concentration (ug/m3)

IMPROVE_obs

Hiawatha_19L

CD-C

MOZI1

0.0

1.0

2.0

3.0

0.0 1.0 2.0 3.0

Improve Measured NO3 (ug/m3)

Predicted NO3 (ug/m3)

MOZI1

Overpredicted

Underpredicted

0.0

1.0

2.0

3.0

0.0 1.0 2.0 3.0

Improve Measured NO3 (ug/m3)

Predicted NO3 (ug/m3)

MOZI1

0.0

1.0

2.0

3.0

0.0 1.0 2.0 3.0

Improve Measured NO3 (ug/m3)

Predicted NO3 (ug/m3)

Overpredicted

Underpredicted

MOZI1

Hiawatha

CD-C

MOZI1

Hiawatha

CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-240

Figure A5-42b. Time series of 2006 predicted and observed 24-hour average NO3 concentrations at the Mount Zirkel IMPROVE monitoring 

site (top left panel). Cumulative frequency distribution of predicted and observed 24-hour NO3 concentrations unpaired in space and time for 

Hiawatha (top right panel) and CD-C (bottom right panel) and paired in time (bottom left panel) for the Bridger IMPROVE monitoring site for 

2006.

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360

Day

NO3 Concentration (ug/m3)

IMPROVE_obs

Hiawatha_19L

CD-C

MOZI1

0.0

1.0

2.0

3.0

0.0 1.0 2.0 3.0

Improve Measured NO3 (ug/m3)

Predicted NO3 (ug/m3)

MOZI1

Overpredicted

Underpredicted

0.0

1.0

2.0

3.0

0.0 1.0 2.0 3.0

Improve Measured NO3 (ug/m3)

Predicted NO3 (ug/m3)

MOZI1

0.0

1.0

2.0

3.0

0.0 1.0 2.0 3.0

Improve Measured NO3 (ug/m3)

Predicted NO3 (ug/m3)

Overpredicted

Underpredicted

MOZI1

Hiawatha

CD-C

MOZI1

Hiawatha

CD-C
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-241

Figure A5-43. Observed and modeled ammonia concentrations. Upper left panel: monthly 

mean and standard deviation of ammonia measurements taken at the Shell site in Boulder, 

WY. Upper (lower) right panel: monthly mean and standard deviation of modeled ammonia 

for the 4 km grid cell that contains the Boulder monitoring site for the year 2005 (2006).

2007

OBS

2005 Frequency distribution of monthly modeled 24-hour

ammonia (NH3) concentratons for the Boulder monitoring site

0.0

1.0

2.0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Month

(ppbV)

Hiaw atha

CD-C

mean

2006 Frequency distribution of monthly modeled 24-hour

ammonia (NH3) concentratons for the Boulder monitoring site

0.0

1.0

2.0

Jan Feb Mar Apr Ma Jun Jul Aug Sep Oct Nov Dec

Month

(ppbV)

Hiaw atha

CD-C

mean
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-242

Table A5-1a. Number of days during 2005 that predicted and observed visibility impairment 

due NO3 exceeds a 0.5 and 1.0 deciview (dv) threshold at the Mount Zirkel IMPROVE 

monitoring site using the same 1:3 day sampling frequency for the CD-C and Hiawatha base 

case simulations.

Number Days NO3 Visibility > 0.5 dv Number Days NO3 Visibility > 1.0 dv

Observed Hiawatha CD-C Observed Hiawatha CD-C

2005 Q1 12 30 27 9 27 24

2005 Q2 18 10 15 6 7 4

2005 Q3 10 8 4 1 7 1

2005 Q4 9 29 21 5 22 19

All 2005 49 77 67 21 63 48

Table A5-1b. Number of days during 2006 that predicted and observed visibility impairment 

due NO3 exceeds a 0.5 and 1.0 deciview (dv) threshold at the Mount Zirkel IMPROVE 

monitoring site using the same 1:3 day sampling frequency for the CD-C and Hiawatha base 

case simulations.

Number Days NO3 Visibility > 0.5 dv Number Days NO3 Visibility > 1.0 dv

Observed Hiawatha CD-C Observed Hiawatha CD-C

2005 Q1 17 27 26 5 24 21

2005 Q2 17 5 10 7 2 1

2005 Q3 11 9 4 3 7 0

2005 Q4 7 26 25 2 25 21

All 2005 52 67 65 17 58 43

Table A5-1c. Number of days during 2005 that predicted and observed visibility impairment 

due NO3 exceeds a 0.5 and 1.0 deciview (dv) threshold at the Bridger IMPROVE monitoring 

site using the same 1:3 day sampling frequency for the CD-C and Hiawatha base case 

simulations.

Number Days NO3 Visibility > 0.5 dv Number Days NO3 Visibility > 1.0 dv

Observed Hiawatha CD-C Observed Hiawatha CD-C

2005 Q1 12 30 29 6 29 26

2005 Q2 18 18 22 3 13 10

2005 Q3 8 13 10 2 9 0

2005 Q4 5 29 28 0 27 23

All 2005 43 90 89 11 78 59

Table A5-1d. Number of days during 2006 that predicted and observed visibility impairment 

due NO3 exceeds a 0.5 and 1.0 deciview (dv) threshold at the Bridger IMPROVE monitoring 

site using the same 1:3 day sampling frequency for the CD-C and Hiawatha base case 

simulations.

Number Days NO3 Visibility > 0.5 dv Number Days NO3 Visibility > 1.0 dv

Observed Hiawatha CD-C Observed Hiawatha CD-C

2005 Q1 14 30 29 11 29 26

2005 Q2 16 18 16 3 12 9

2005 Q3 17 10 4 7 7 1

2005 Q4 6 28 28 3 28 27

All 2005 53 86 77 24 76 63
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-243

A5.9 PM MODEL PERFORMANCE EVALUATION CONCLUSIONS

The CD-C and Hiawatha CAMx 2005 and 2006 base case simulations exhibited overall PM 

performance comparable to that of the WRAP’s 2002 CMAQ simulations that were judged 

suitable for use in developing regional haze State Implementation Plans (SIPs). Sulfate (SO4) 

performance was fairly good, whereas nitrate (NO3) performance had a winter overestimation 

and summer underestimation bias. The elemental carbon performance was variable, but 

because concentrations were low it achieved the PM performance goals and criteria in the 

Bugle Plots. Organic Carbon Mass (OCM) was underestimated throughout the year which is a 

common issue in PM modeling. The reasons for the OCM underestimation bias are: missing 

emissions of primary OCM, insufficient formation of Secondary Organic Aerosols (SOA) and 

missing Semi-Volatile Organic Compound (SVOC) in the current generation of emissions and air 

quality modeling systems.

Probably the biggest concern regarding the assessment of the potential impacts of O&G 

emissions in southwestern Wyoming on air quality and AQRVs is the NO3 model performance 

and the effects that the winter overestimation and summer underestimation will have on 

visibility impacts at Class I areas. A focused analysis was performed that found the model 

predicted many more days than observed in which visibility impacts due to nitrate exceeded 

the 0.5 and 1.0 dv thresholds at the two Class I areas in the 4 km domain. Based on these 

results, we conclude that the CD-C CAMx base case simulation will provide a conservative 

estimate for assessing visibility impacts at Class I areas.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-244

A6. MODEL PERFORMANCE EVALUATION CONCLUSIONS

The CD-C 12/4 km CAMx ozone performance at the rural CASTNet monitors and Wyoming 

industrial sites in southwestern Wyoming generally achieved EPA’s performance goals for 

hourly and 8-hour ozone concentrations and ozone performance at these monitors was 

comparable to ozone performance seen in ozone SIP modeling, such as for the Denver 8-hour 

ozone EAC and more recent SIP modeling (Morris et al., 2008a,b). Ozone performance was not 

as good at Wyoming industrial sites monitors within areas of O&G development, however there 

was marked improvements in the ozone performance at these sites in the CD-C CAMx base case 

over what was obtained previously with the preliminary Hiawatha CAMx base case simulation 

(Kemball-Cook et al., 2009). There are numerous uncertainties in the O&G emissions, including 

the occurrence of episodic emissions that are currently modeled as continuous releases. 

The CD-C CAMx 36/12/4 km 2005 and 2006 base case simulations exhibited PM performance 

comparable to that of the RPO 2002 CMAQ simulations that were judged suitable for use in 

developing regional haze State Implementation Plans (SIPs). The main PM performance issue in 

the CD-C base case simulations in regards to using the modeling system to evaluate the 

potential air quality and AQRV impacts of the CD-C Project is the overestimation of nitrate 

during winter and underestimation of nitrate during summer. There is a concern that the 

nitrate underestimation bias may result in the model understating the potential visibility 

impacts of the CD-C Project at Class I areas. This issue was evaluated by comparing the number 

of days of observed versus predicted that the visibility impairment due to NO3 was above 0.5 

dv and 1.0 dv and found that the CD-C CAMx modeling system was sufficiently conservative.

The model also underestimates wet deposition of sulfate, nitrate, and ammonium. Wet 

deposition is particularly challenging for the model to simulate because it requires skillful 

prediction of the timing and amount of the precipitation as well as accurate representation of 

the nitrate, sulfate and ammonium fields. Note that the model will be used to predict 

incremental changes in deposition due to future year CD-C Project impacts, and that the effects 

of the underestimation of wet deposition will be minimized because the model will be used in a 

relative sense. 

Because the CD-C CAMx base case PM and ozone performance were comparable to similar 

applications used in regional haze and ozone regulatory modeling, and because it meets most 

of the relevant performance benchmarks, the model is judged to be suitable for use in the CD-C 

Project AQ/AQRV impact assessment.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-245

A7. REFERENCES

Anthes, R.A. and T.T. Warner. 1978. “The Development of Mesoscale Models Suitable for Air 

Pollution and Other Mesometeorological Studies”, Mon. Wea. Rev., Vol. 106, pp, 1045-

1078.

Bar-Ilan, A., R. Friesen, A. Pollack, and A. Hoats, 2007.“WRAP Area Source Emissions Inventory 

Projections and Control Strategy Evaluation, Phase II”. Prepared for the Western 

Governors’ Association, Denver, CO. September.

Baron, J.S. 2006.Hindcasting nitrogen deposition to determine an ecological critical load.

Ecological Applications, 16(2): 433–439. 

Beardsley, M. and G. Dolce. 2009. Air Pollution from Highway Vehicles: What MOVES Tells Us. 

Presentation for the International Emissions Inventory Conference. U.S. EPA Office if 

Transportation and Air Quality (OTAQ). April 15.

Boylan, J. W. 2004. “Calculating Statistics: Concentration Related Performance Goals”, paper 

presented at the EPA PM Model Performance Workshop, Chapel Hill, NC. 11 February.

Byun, D.W., and J.K.S. Ching. 1999. “Science Algorithms of the EPA Models-3 Community 

Multiscale Air Quality (CMAQ) Modeling System”, EPA/600/R-99/030.

Carter Lake and ENVIRON. 2010. Air Quality Impact Assessment Protocol for the Continental 

Divide-Creston Project Environmental Impact Statement. Revised Draft.Carter Lake 

Consulting, Laramie, Wyoming. ENVIRON International Corporation, Novato, California. 

March.

Chang, J.S., R.A. Brost, I.S.A. Isaksen, S. Madronich, P. Middleton, W.R. Stockwell, and C.J, 

Walcek. 1987. A Three-dimensional Eulerian Acid Deposition Model: Physical Concepts 

and Formulation. J. Geophys. Res., 92, 14,681-14,700.

Coats, C.J. Jr. 1996.High-performance algorithms in the Sparse Matrix Operator Kernel 

Emissions (SMOKE) modeling system. Proc. Ninth AMS Joint Conference on Applications 

of Air Pollution Meteorology with AWMA. Amer. Meteor. Soc., Atlanta, GA, 584-588.

Coats, C. J., Jr. and M.R. Houyoux. 1996. "Fast Emissions Modeling with the Sparse Matrix 

Operator Kernel Emissions (SMOKE) Modeling System," to appear in The Emission 

Inventory: Key to Planning, Permits, Compliance, and Reporting, Air & Waste 

Management Association: New Orleans, Louisiana.

Cooperative Institute for Research in the Atmosphere. 2006. Interagency Monitoring of 

Protected Visual Environments (IMPROVE) summary data provided by Scott Copeland, 

Cooperative Institute for Research in the Atmosphere, Colorado State University, 

February.

Corbett, J.J., 2006. “North American Commercial Marine Vessel Emissions.” Prepared for the 

State of California Air Resources Board, February.

Environmental Protection Agency. 1990. Draft New Source Review Workshop Manual –

Prevention of Significant Deterioration and Nonattainment Area Permitting. Office of 

Air Quality Planning and Standards, Research Triangle Park, North Carolina. October.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-246

. 1991. Guidance for Regulatory Application of the Urban Airshed Model (UAM), Office 

of Air Quality Planning and Standards, Research Triangle Park, North Carolina. 

______. 1993. Superfund's Standard Default Exposure Factors for the Central Tendency and 

Reasonable Maximum Exposure. Preliminary Review Draft.

. 1995. Compilation of Air Pollutant Emission Factors (AP-42), Vol. 1, Stationary Point 

and Area Sources, Fifth Edition. Office of Air Quality Planning and Standards, Research 

Triangle Park, North Carolina.

. 2001. Guidance for Demonstrating Attainment of Air Quality Goals for PM2.5 and 

Regional Haze, Draft Report. U.S. Environmental Protection Agency, Research Triangle 

Park, North Carolina.

. 2003a. Guidance for Tracking Progress Under the Regional Haze Rule. Office of Air 

Quality Planning and Standards, Research Triangle Park, North Carolina.

. 2003b. Guidance for Estimating Natural Visibility Conditions Under the Regional Haze 

Rule. Office of Air Quality Planning and Standards, Research Triangle Park, North 

Carolina.

______. 2005a. Guideline on Air Quality Models. Updated 2005.Environmental Protection 

Agency Office of Air Quality Planning and Standards, Research Triangle Park, North 

Carolina. Published in Federal Register, Vol. 70, No. 216, November 9.

. 2005b. Air Toxics Database, Table 2, Acute Dose-Response Values for Screening Risk 

Assessments (6/02/2005). Office of Air Quality Planning and Standards 

(OAQPS).Technology Transfer Network Air Toxics 

Website.(http://www.epa.gov/ttn/atw/ toxsource/Table2.pdf). Data accessed February 

2, 2006.

. 2005c. Air Toxics Database, Table 1, Prioritized Chronic Dose-Response Values 

(2/28/2005). Office of Air Quality Planning and Standards (OAQPS).Technology Transfer 

Network Air Toxics Website. (http://www.epa.gov/ttn/atw/toxsource/ Table1.pdf). 

Data accessed February 2, 2006.

. 2005d. Regional Haze Regulations and Guidelines for Best Available Retrofit 

Technology (BART) Determinations; Final Rule, Federal Register Volume 70, No. 128, July 

6.

______. 2006. 40 CFR Chapter 1. Section 89.112 Oxides of nitrogen, carbon monoxide, 

hydrocarbon, and particulate matter exhaust emission standards. Environmental 

Protection Agency. Accessed March 2006.

______. 2007. Guidance on the Use of Models and Other Analyses for Demonstrating 

Attainment of Air Quality Goals for ozone, PM2.5, and Regional Haze. U.S. Environmental 

Protection Agency, Office of Air Quality and Planning Standards, Research Triangle Park, 

North Carolina.(EPA-454/B-07-002). April.

ENVIRON. 2004. “Determining Fugitive Dust Emissions from Wind Erosion”. Prepared for

Western Governors’ Association by ENVIRON International Corporation, Novato, 

California; ERG, Inc., Sacramento, California; Desert Research Institute, Reno, Nevada. 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-247

ENVIRON. 2007. “Speciation Tool User's Guide Version 2.0”. Prepared by Jimenez M., 

Nopmongcol U., and Yarwood G. September.

ENVIRON. 2008. “User’s Guide Comprehensive Air Quality Model With Extensions (CAMx) 

Version 4.50.” ENVIRON International Corporation, Novato, California. 

(www.camx.com). September.

ENVIRON, T&B Systems Inc. and Meteorological Solutions Inc. 2008.“2008 Upper Green River 

Ozone Study”. Prepared for Cara Keslar, Air Quality Division, Wyoming Department of 

Environmental Quality. October.

Federal Land Managers' Air Quality Related Values Workgroup. 2000. Federal Land Managers' 

Air Quality Related Values Workgroup (FLAG) Phase I Report. U.S. Forest Service-Air 

Quality Program, National Park Service-Air Resources Division, U.S. Fish and Wildlife 

Service-Air Quality Branch. December.

Field, P. and M. Wolf. 2007. “Technical Memorandum, WRAP 2018 Preliminary Reasonable 

Progress Emissions Inventory – Final”. June 

18.http://www.wrapair.org/forums/ssjf/documents/eictts/projections.htmlhttp://www.wra

pair.org/forums/ssjf/documents/eictts/projections.html

Fox, Douglas, Ann M. Bartuska, James G. Byrne, Ellis Cowling, Rich Fisher, Gene E. Likens, Steven 

E. Lindberg, Rick A. Linthurst, Jay Messer, and Dale S. Nichols. 1989. A Screening 

Procedure to Evaluate Air Pollution Effects on Class I Wilderness Areas. General 

Technical Report RM-168.U.S.D.A. Forest Service, Rocky Mountain Forest and Range 

Experiment Station, Fort Collins, Colorado.36 pp.

Guenther, A., T. Karl, P. Harley, C. Wiedinmyer, P. I. Palmer, C. Geron. 2006. Estimates of global 

terrestrial isoprene emissions using MEGAN (Model of Emissions of Gases and Aerosols 

from Nature). Atmos. Chem. Phys., 6, 3181-3210.

Guenther, A. and C. Wiedinmyer. 2007. MEGAN Homepage. 

[http://cdp.ucar.edu/browse/browse.htm?uri=http://dataportal.ucar.edu/metadata/ac

d/software/megan/megan.thredds.xml&ID=ucar.ncar.acd.software.megan&history=0], 

accessed on June.

Houyoux, M. and J. Vukovich. 1999. "Updates to the Sparse Matrix Operator Kernel Emissions 

(SMOKE) Modeling System and Integration with Models-3", Presented at The Emissions 

Inventory: Regional Strategies for the Future Conference, Air & Waste Management 

Association, Raleigh, NC, October

Interagency Workgroup on Air Quality Modeling. 1998. Interagency Workgroup on Air Quality 

Modeling (IWAQM) Phase 2 Summary Report and Recommendations for Modeling Long 

Range Transport Impacts. EPA-454/R-98-019.Office of Quality Planning and Standards.

U.S. EPA, Research Triangle Park, North Carolina. December.

IPCC. 2007. Intergovernmental Panel on Climate Change, Fourth Assessment Report: Climate 

Change 2007 http://www.ipcc.ch/publications_and_data/ar4/syr/en/contents.html

Karl, T. G.; Christian, T.J.; Yokelson, R.J.; Artaxo, P.; Hao, W.M.; and Guenther, A. 2007. The 

tropical forest and fire emissions experiment: method evaluation of volatile organic 
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-248

compound emissions measured by PTR-MS, FTIR, and GC from tropical biomass burning. 

Atmos. Chem. Phys., 7, 8755-8793.

Kemball-Cook, S., Y. Jia, C. Emery, R. Morris, Z. Wang and G. Tonnesen. 2004. 2002 Annual 

MM5 Simulation to Support WRAP CMAQ Visibility Modeling for the Section 308 SIP/TIP 

– MM5 Sensitivity Simulations to Identify a More Optimal MM5 Configuration for 

Simulating Meteorology in the Western United States. Western Regional Air 

Partnership, Regional Modeling 

Center.http://pah.cert.ucr.edu/aqm/308/reports/mm5/MM5SensitivityRevRep_Dec_10

_2004.pdf December 10.

Kemball-Cook, S., R. Morris, J. Johnson, B. Koo, T. Sakulyanontvittaya, L. Parker, T. Shah, U. 

Nopmongcol and P. Piyachaturawat. 2009. Hiawatha CAMx 2005-2006 Base Case 

Model Performance Evaluation. ENVIRON International Corporation, Novato, California. 

June 26.

Malm, W., M. Pitchford, M. Scruggs, J. Sisler, R. Ames, S. Copeland, K. Gebhart and D. Day. 

2000. Spatial and Seasonal Patterns and Temporal Variability of Haze and its 

Constituents in the United States. Cooperative Institute for Research in the 

Atmosphere, Colorado State University, Fort Collins, CO. May.

Mansell, G. 2005. An Improved Ammonia Inventory for the WRAP Domain. Final Report, 

Volume I. ENVIRON International , Novato, California. 

http://pah.cert.ucr.edu/aqm/308/ppt_files/emissions/nh3/Volume_I_FinalReport.3-

07.pdf. March 7.

Mansell G., J. Johnson, G. Yarwood, A. Guenther. 2007. Biogenic Emission Inventory for Texas 

from the MEGAN model, prepared for Texas Commission on Environmental Quality. 

August.

McNally, D. 2007. Four Corners PSD Increment: Met Modeling Update. PowerPoint 

presentation prepared by Alpine Geophysics, LLC and ENVIRON International 

Corporation. Prepared for Giant Refining and New Mexico Environment Division.

Morris, R., B. Koo, T. Tesche, C. Loomis, G. Stella, G. Tonnesen and Z. Wang. 2004a. Modeling 

Protocol for the VISTAS Phase II Regional Haze Modeling. ENVIRON International 

Corporation, Alpine Geophysics, UC Riverside and UC Davis. 

(http://pah.cert.ucr.edu/vistas/vistas2/reports/vistasII_Final_Protocol_05_10_2004.pdf)

. May 6.

Morris, R., G. Mansell, B. Koo, G. Tonnesen, M. Omary and Z. Wang. 2004b. Modeling Protocol 

for the CENRAP 2002 Emissions and Air Quality Modeling, Draft 2.0. ENVIRON 

International Corporation, Novato, California 

(http://pah.cert.ucr.edu/aqm/cenrap/docs/CENRAP_Draft2.0_Modeling_Protocol_1208

04.pdf). December 8.

Morris, R.E., B. Koo, S. Lau, D. McNally, T. Tesche, C. Loomis, G. Stella, G. Tonnesen, C-J. Chien. 

2004c. VISTAS Phase II Emissions and Air Quality Modeling – Task 4a Report: Evaluation 

of the Initial CMAQ 2002 Annual Simulation. ENVIRON International Corporation, 

Novato, California. (http://pah.cert.ucr.edu/vistas/vistas2/reports/VISTASPII_RevDrftRept_092704.pdf). September 27.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-249

Morris R.E., G.E. Mansell, E. Tai, D.E. McNally and T.W. Tesche. 2004d. Air Quality Modeling 

Analysis of the Denver Early Action Ozone Compact: 2007 Control Strategy Modeling for 

the Denver EAC. ENVIRON International Corporation, Novato, California. February 27.

Morris, R.E., D.E. McNally, T.W. Tesche, G. Tonnesen, J.W. Boylan and P. Brewer. 2005. 

Preliminary Evaluation of the Community Multiscale Air Quality Model for 2002 over the 

Southeastern United States. J. of Air and Waste Manag. Assoc. Vol. 55: 1694-1708. 

November.

Morris, R., B. Wang, E. Tai, D. McNally, C. Loomis, G. Stella and T.W. Tesche. 2007. Modeling 

Protocol for the Denver 8-Hour Ozone Attainment Demonstration Modeling. Prepared 

for Denver Regional Air Quality Council. Prepared by ENVIRON International 

Corporation, Novato, California. November. 

(http://www.ozoneaware.org/documents/DraftFinalProtocolDenver8-

HourOzoneNov282007.pdf)

Morris R., E. Tai, L. Parker, J. Johnson, D. McNally and C. Loomis. 2008a. Initial Ozone Model 

Performance Evaluation of the June-July 2006 Denver Ozone Episode and Diagnostic 

Testing and Analysis. ENVIRON International Corporation, Novato, California. Prepared 

for Denver Regional Air Quality Council (RAQC), Denver, Colorado. May 13. 

(http://www.ozoneaware.org/documents/Prelim_Ozone_Eval_Denver_SIP_Feb27_2008

.pdf)

Morris R., E. Tai, T. Sakulyanontvittaya, D. McNally and C. Loomis. 2008b. Model Performance 

Evaluation for the June-July 2006 Ozone Episode for the Denver 8-Hour Ozone State 

Implementation Plan. ENVIRON International Corporation, Novato, California. Prepared 

for Denver Regional Air Quality Council (RAQC), Denver, Colorado. August 29. 

(http://www.ozoneaware.org/documents/modeling/Denver_2006MPE_DraftFinal_Aug2

9_2008.pdf)

Morris, R.E., S. Kemball-Cook, T. Shah, and B. Koo, 2009. “Assessment of the Ozone, Air Quality 

and AQRV Impacts of Proposed Oil and Gas Production Projects in the Western U.S. 

using Photochemical Grid Models”. Conference Proceedings of the American Waste 

Management Association Annual Conference and Exhibition, 2009.

National Park Service. 2001. Guidance on Nitrogen and Sulfur Deposition Analysis Thresholds. 

National Park Service and U.S. Fish and Wildlife Service. National Park Service Air 

Resources Division. (http://www.aqd.nps.gov/ard/flagfree/2001), Data accessed July 

2003.

Nenes, A, C. Pilinis, and S.N. Pandis. 1998. ISORROPIA: A New Thermodynamic Model for 

Multiphase Multicomponent Inorganic Aerosols. Aquatic Geochemistry, 4, 123-152.

Nenes, A, C. Pilinis, and S.N. Pandis. 1999. Continued Development and Testing of a New 

Thermodynamic Aerosol Module for Urban and Regional Air Quality Models. Atmos. 

Environ. 33, 1553-1560.

Pace, T.G., 2003.A Conceptual Model to Adjust Fugitive Dust Emissions to Account for Near 

Source Particle Removal in Grid Model Applications. U.S. EPA. August 22.

Pace, T.G., 2005.Methodology to Estimate the Transportable Fraction (TF) of Fugitive Dust 

Emissions for Regional and Urban Scale Air Quality Analyses. U.S. EPA. June 2.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-250

Russell, J. and A. Pollack, 2005.“Oil and Gas Emission Inventory for the Western States”.

Prepared for the Western Governors’ Association, Denver, CO. December 27.

Scire, J.S., D.G. Strimaitis, R.J. Yamartino. 2000a. “A User's Guide for the CALPUFF Dispersion 

Model.” Earth Tech, Concord, MA, January.

Scire, J.S., F. Robe, F.E. Fernau, R.J. Yamartino. 2000b. “A User's Guide for the CALMET 

Meteorological Model.” Earth Tech, Concord, MA, January.

Solomon, P.S., T. Klamser-Williams, P. Egeghy, D. Crumpler and J. Rice. 2004. "STN/IMPROVE 

Comparison Study Preliminary Results”. Presented at PM Model Performance 

Workshop. Chapel Hill, NC. February 10.

Stauffer, D.R. and N.L. Seaman. 1990. Use of four-dimensional data assimilation in a limitedarea mesoscale model. Part I: Experiments with synoptic data. Mon. Wea. Rev., 118, 

1250-1277.

Tai, Ed; Jimenez, M.; Nopmongcol, U.; Wilson, G.; Mansell, G.; Koo, B.; Yarwood, G. 2008. 

Boundary Conditions and Fire Emissions Modeling. Prepared for Texas Commission on 

Environmental Quality. September.

Tesche, T.W., D.E. McNally, C.F. Loomis, R.E. Morris and G.E. Mansell. 2003. Air Quality 

Modeling Analysis for the Denver Early Action Ozone Compact: Modeling Protocol, 

Episode Selection, and Domain Definition. Alpine Geophysics, LLC, Ft. Wright KY and 

ENVIRON, Novato CA. May 21.

Tesche, T.W., R. Morris, G. Tonnesen, D. McNally, J. Boylan and P. Brewer. 2006. CMAQ/CAMx 

annual 2002 performance evaluation over the eastern U.S. Atmos Env. 40: 4906-4919.

Tonnesen, G., R. Morris and Z. Adelman. 2004. Quality Assurance Project Plan for the Western 

Regional Air Partnership (WRAP) Regional Modeling Center (RMC). UCR, ENVIRON and 

UNC. (http://pah.cert.ucr.edu/aqm/308/reports/QAPP/wrap_qapp_01_20_05.pdf). 

December 31.

Tonnesen, G., Z. Wang, M. Omary, C-J.Chien, R. Morris, G Mansell, S. Kemball-Cook, Greg 

Yarwood, Z. Adelman, A. Holland and K. Hanisak. 2005. Final Report for the Western 

Regional Air Partnership (WRAP) Regional Modeling Center (RMC). For the Project 

Period March 1, 2004 through February 28, 2005. University California at Riverside, 

Riverside, 

California.(http://pah.cert.ucr.edu/aqm/308/reports/final/2004_RMC_final_report_mai

n_body.pdf)August 16.

Tonnesen, G. et al., 2006. Final Report for the Western Regional Air Partnership (WRAP) 2002 

Visibility Model Performance Evaluation. Prepared for the Western Governors 

Association.February.http://pah.cert.ucr.edu/aqm/308/reports/final/2002_MPE_report_ma

in_body_FINAL.pdf

UMD. 2006. “GEWEX Continental Scale International Project (GCIP) and GEWEX Americas 

Prediction Project (GAPP) Surface Radiation Budget (SRB) Data.” 

www.atmos.umd.edu/~srb/gcip/ data available at www.atmos.umd.edu/~srb/gcip/cgibin/historic.cgi?auth=no¶meter=par, accessed on June.
APPENDIX A – MODEL PERFORMANCE EVALUATION OF THE 

CD-C CAMX 2005 AND 2006 BASE CASE SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 A-251

U.S.D.A. Forest Service. 2000. Screening Methodology for Calculating ANC Change to High 

Elevation Lakes, User's Guide. U.S. Department of Agriculture (USDA) Forest Service, 

Rocky Mountain Region. January.

______. 2008. Lake water chemistry data provided by the USDA Forest Service, December 

2008. www.fs.fed.us/armdata.

Visibility Improvement State and Tribal Association of the Southeast. 2006. Protocol for the 

Application of the CALPUFF Model for Analyses of Best Available Retrofit Technology 

(BART), Revision 2. Visibility Improvement State and Tribal Association of the Southeast 

(VISTAS), March.

Wesely, M.L. 1989. Parameterization of Surface Resistances to Gaseous Dry Deposition in 

Regional-Scale Numerical Models. Atmos. Environ., 23, 1293-1304. 

Western Governors Association/Western Regional Air Partnership. 2004. “2002 Fire Emission 

Inventory for the WRAP Region – Phase I – Essential Documentation.” Prepared by Air 

Sciences Inc. Draft report. September.

Western Governors Association/Western Regional Air Partnership. 2005. “2002 Fire Emission 

Inventory for the WRAP Region – Phase II.” Prepared by Air Sciences Inc. July.

Western Governors Association/Western Regional Air Partnership. 2005. “2002 Fire Emission 

Inventory for the WRAP Region – Phase II.” Prepared by Air Sciences Inc. July.

Wiedinmyer, C. and H. Friedli. 2007. Mercury Emission Estimates from Fires: An Initial 

Inventory for the United States, in press, Environmental Science & Technology, 41 (23), 

8092–8098.

Wiedinmyer, C.; Quayle, B.; Geron, C.; Belote, A.; McKenzie, D.; Zhang, X.; O’Neill, S.; Klos 

Wynne, K. 2006. Estimating emissions from fires in North America for air quality 

modeling. Atmospheric Environment 40, 3419-3432.

Wyoming Department of Environmental Quality. 2001. Oil and Gas Production Facilities 

Chapter 6, Section 2 Permitting Guidance, Wyoming Department of Environmental 

Quality-Air Quality Division. June 1997 with revisions through August.

______. 2004. Jonah & Pinedale Anticline Gas Fields Additions to Oil and Gas Production 

Facility Emission Control and Permitting Requirements. State of Wyoming Department 

of Environmental Quality, Air Quality Division. July 28.

Yarwood, G., S. Rao, M. Yocke and G. Whitten. 2005. Updates to the Carbon Bond Chemical 

Mechanism: CB05. ENVIRON International Corporation, Novato, California. December 8.

Zhang, X; Kondragunta, S.; Schmidt, C.; Kogan, F. 2008. Near real time monitoring of biomass 

burning particulate emissions (PM2.5) across contiguous United States using multiple 

satellite instruments. Atmospheric Environment 42, 6959-6972.

Zhang, L., J. R. Brook, and R. Vet, 2003.A revised parameterization for gaseous dry deposition in 

air-quality models. Atmos. Chem. Phys., 3, 2067–2082.

Zhang, L., Vet, R., Brook, J.R., Legge, A.H. 2006. Factors affecting stomatal uptake of ozone by 

different canopies and a comparison between dose and exposure. Science of the Total 

Environment, 370 (1), pp. 117-132.
Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016

Appendix B

WRAP Phase III O&G Surrogate Development
APPENDIX B – WRAP PHASE III O&G SURROGATE DEVELOPMENT

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 B-1

WRAP PHASE III O&G SURROGATE DEVELOPMENT

A new set of spatial allocation surrogates were developed to allocate the county-level WRAP 

Phase III O&G area source emissions to the appropriate oil and gas fields. The locations of wells 

within Uinta, Piceance, and Denver-Julesburg basins, based on the 2006 IHS database for the 

WRAP Phase III basins, were used. The spatial allocation surrogate profiles developed are 

provided in Table B1. Each of the oil and gas emission source categories was assigned to one of 

the surrogate categories designed to represent the location of emissions (also shown in Table 

B1). 

Surrogates were developed for the 4km, 12km and 36km modeling domains. Latitude and 

longitude coordinates for oil and gas wells and drilling events were obtained from the IHS 

database. The oil and gas production surrogates were based on production data at known well 

locations, while the drilling surrogate was based solely on the number and location of wells 

drilled. 

Table B1. Spatial Allocation Surrogates.

SCC SCC Description

Surrogate 

Code Surrogate Description

2310000110 Drill Rigs 692 Spud count

2310000120 Workover Rigs 693 Well count - all wells

2310010100 Crude Petroleum, Truck Loading 694 Oil production at Oil wells

2310010200

Crude Petroleum, Tanks - Flashing & 

Standing/Working/Breathing 694 Oil production at Oil wells

2310010300 Crude Petroleum, Pneumatic devices 695 Well count - oil wells

2310010400 Crude Petroleum, Fugitives 695 Well count - oil wells

2310020100 Natural Gas, Dehydrators 696 Gas production at gas wells

2310020200 Natural Gas, Venting - Initial Completions 698 Well count - gas wells

2310020300 Natural Gas, Venting – Recompletions 698 Well count - gas wells

2310020400 Natural Gas, Venting - Blowdowns 696 Gas production at gas wells

2310020500 Natural Gas, Venting - Compressor Startup 696 Gas production at gas wells

2310020600 Natural Gas, Venting - Compressor Shutdown 696 Gas production at gas wells

2310020700 Natural Gas, Fugitives 698 Well count - gas wells

2310020800 Natural Gas, Pneumatic Devices 698 Well count - gas wells

2310020900 Natural Gas, Pneumatic Pumps 698 Well count - gas wells

2310020110 Natural Gas, Amine Units 696 Gas production at gas wells

2310023100 CBM, Dehydrators 699 Gas production at CBM wells

2310023200 Venting - Initial Completions 700 Well count - CBM wells

2310023300 Venting - Recompletions 700 Well count - CBM wells

2310023400 CBM, Venting - Blowdowns 699 Gas production at CBM wells

2310023500 CBM, Venting - Compressor Startup 699 Gas production at CBM wells

2310023600 CBM, Venting - Compressor Shutdown 699 Gas production at CBM wells

2310023700 CBM, Fugitives 700 Well count - CBM wells

2310023800 CBM, Pneumatic Devices 700 Well count - CBM wells

2310023900 CBM, Pneumatic Pumps 700 Well count - CBM wells

2310023110 CBM, Amine Units 699 Gas production at CBM wells

2310030100 Natural Gas Liquids, Gas Plant Truck Loading 697 Oil production at gas wells

2310030200 Natural Gas Liquids, Truck Loading 697 Oil production at gas wells

2310030300

Natural Gas Liquids, Tanks - Flashing & 

Standing/Working/Breathing 697 Oil production at gas wells

2310030400 Natural Gas Liquids, Water Tank Losses 697 Oil production at gas wells

2310024100 Natural Gas, Heaters 698 Well count - gas wells
APPENDIX B – WRAP PHASE III O&G SURROGATE DEVELOPMENT

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 B-2

SCC SCC Description

Surrogate 

Code Surrogate Description

2310024200 Natural Gas, Initial Completion Flaring 692 Spud count

2310024300 Natural Gas, Condensate Tank Flaring 697 Oil production at gas wells

2310024400 Natural Gas, Dehydrator Flaring 689 Gas production at all wells

2310025100 Natural Gas, Compressor Engines 689 Gas production at all wells

2310025200 Natural Gas, Miscellaneous Engines 693 Well count - all wells

2310025300 Natural Gas, Artificial Lift 694 Oil production at Oil wells

The creation of the surrogates took place in several steps, and relied on the use of ARC/GIS 

software.

1. All wells and drill rigs were spatially joined with the modeling grid cells using ARC/GIS.

2. For each individual well, the oil, gas and water production values were divided by the 

total oil, gas and water production values corresponding to the county in which the well 

was located. This division resulted in determination of the fraction of a county’s total 

production taking place at each well. In the case of the drilling surrogate, the number of 

wells drilled, rather than the production values, was used.

3. For each grid cell (intersecting a county) and county combination, well production 

fraction were summed for wells inside the given grid cell to obtain the surrogate value.

The surrogate values for each grid cell / county combination were reformatted to comply with 

the SMOKE emissions processor Area Gridding Profile (AGPRO) file format. A separate file for 

each modeling domain was created, and a single accompanying SMOKE Area Gridding Cross 

Reference (AGREF) file was created for use with either domain. The purpose of the AGREF file 

is to define the relationship between the 3-digit codes chosen to represent each of the four 

surrogate categories in the AGPRO file and the SCC codes for the twelve oil and gas emission 

categories to be allocated with these surrogates. 

To display the surrogates, each grid cell / county surrogate value was multiplied by the county’s 

total production, and then production was summed for each grid cell. Figure B1 depicts the 36 

km domain surrogate values. 
APPENDIX B – WRAP PHASE III O&G SURROGATE DEVELOPMENT

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 B-3

(a) All wells - Gas production (profile # 689) (b) All wells - Oil production ( profile # 690)

(c) All wells – Spud count (profile # 692) (d) All wells – Well count (profile # 693)

(e) Oil wells – Oil production (profile # 694) (f) Oil wells – Well count (profile # 695)

(g) Gas wells – Gas production (profile # 696) (h) Gas wells – Oil production (profile # 697)
APPENDIX B – WRAP PHASE III O&G SURROGATE DEVELOPMENT

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 B-4

(i) Gas wells – Well count ( profile # 698 ) (j) CBM wells – Gas production (profile # 699)

(k) CBM wells – Well count ( profile # 700) (l) Gas wells – Spud count ( profile # 701)

Figure B1. 36 km Domain Oil and Gas Spatial Surrogates.
Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016

Appendix C

VOC Speciation Profiles for O&G Sources
APPENDIX C – VOC SPECIATION PROFILES FOR O&G SOURCES

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 C-1

VOC SPECIATION PROFILES FOR O&G SOURCES

Table C1. WRAP Phase III Speciation Code by Basin.

Basin County Process Profile Code

Uinta All basin counties Gas Composition at CBM Wells UNT01

Uinta All basin counties Gas Composition at Conventional Wells UNT02

Uinta All basin counties Flashing Gas Composition for Oil UNT03

Uinta All basin counties Flashing Gas Composition for Condensate UNT04

Piceance All basin counties Gas Composition at Conventional Wells PNC01

Piceance All basin counties Gas Composition at Oil Wells PNC02

Piceance All basin counties Flashing Gas Composition for Condensate PNC03

Denver-Julesburg All basin counties Flashing Gas Composition for Condensate DJ01

Table C2. WRAP Phase III VOC CB-05 Speciation Profiles.

Profile Code

Model Species

CH4 ETHA MEOH PAR TOL UNR XYL

DJ01 0.1049 0.1695 0.5718 0.0028 0.1504 0.0006

PNC01 0.8103 0.1007 0.0671 0.0009 0.0208 0.0002

PNC02 0.2590 0.0887 0.5493 0.0004 0.1025 0.0001

PNC03 0.1315 0.1630 0.5644 0.0056 0.1342 0.0013

UNT01 0.9812 0.0112 0.0053 0.0024

UNT02 0.5470 0.1192 0.0002 0.2714 0.0035 0.0570 0.0017

UNT03 0.0001 0.0006 0.8574 0.0689 0.0300 0.0430

UNT04 0.0318 0.0285 0.8920 0.0003 0.0473 0.0001
APPENDIX C – VOC SPECIATION PROFILES FOR O&G SOURCES

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 C-2

Table C3. Southwest Wyoming Speciation Profile Code by Process by County.

Basin O&G Field / County O&G production –Processes Profile Code

SW Wyoming Carbon flash CBN01

SW Wyoming Carbon fugitive - sales CBN02

SW Wyoming Carbon fugitive - produced CBN03

SW Wyoming Carbon fugitive - condensate CBN04

SW Wyoming Carbon pneumatic pumps CBN05

SW Wyoming Carbon well venting CBN06

SW Wyoming Jonah flash JON01

SW Wyoming Jonah fugitives JON02

SW Wyoming Jonah pneumatic pumps JON05

SW Wyoming Jonah well venting JON06

SW Wyoming Lincoln flash LNC01

SW Wyoming Lincoln fugitive - sales LNC02

SW Wyoming Lincoln fugitive - produced LNC03

SW Wyoming Lincoln fugitive - condensate LNC04

SW Wyoming Lincoln pneumatic pumps LNC05

SW Wyoming Lincoln well venting LNC06

SW Wyoming Pinedale flash PND01

SW Wyoming Pinedale fugitives PND02

SW Wyoming Pinedale pneumatic pumps PND05

SW Wyoming Pinedale well venting PND06

SW Wyoming Sublette flash SBL01

SW Wyoming Sublette fugitive - sales SBL02

SW Wyoming Sublette fugitive - produced SBL03

SW Wyoming Sublette fugitive - condensate SBL04

SW Wyoming Sublette pneumatic pumps SBL05

SW Wyoming Sublette well venting SBL06

SW Wyoming Sweetwater - East flash SWE01

SW Wyoming Sweetwater - East fugitive - sales SWE02

SW Wyoming Sweetwater - East fugitive - produced SWE03

SW Wyoming Sweetwater - East fugitive - condensate SWE04

SW Wyoming Sweetwater - East pneumatic pumps SWE05

SW Wyoming Sweetwater - East well venting SWE06

SW Wyoming Sweetwater - West flash SWW01

SW Wyoming Sweetwater - West fugitive - sales SWW02

SW Wyoming Sweetwater - West fugitive - produced SWW03

SW Wyoming Sweetwater - West fugitive - condensate SWW04

SW Wyoming Sweetwater - West pneumatic pumps SWW05

SW Wyoming Sweetwater - West well venting SWW06

SW Wyoming Uinta flash UNT01

SW Wyoming Uinta fugitive - sales UNT02

SW Wyoming Uinta fugitive - produced UNT03

SW Wyoming Uinta fugitive - condensate UNT04

SW Wyoming Uinta pneumatic pumps UNT05

SW Wyoming Uinta well venting UNT06
APPENDIX C – VOC SPECIATION PROFILES FOR O&G SOURCES

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 C-3

Table C4. Southwest Wyoming VOC CB-05 Speciation Profiles.

Model Species

Profile Code CH4 ETHA PAR TOL UNR XYL

CBN01 0.1397 0.1025 0.6374 0.0090 0.1066 0.0048

CBN02 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

CBN03 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

CBN04 0.1400 0.1015 0.6393 0.0090 0.1055 0.0047

CBN05 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

CBN06 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

JON01 0.2372 0.1141 0.5530 0.0037 0.0842 0.0078

JON02 0.5389 0.0583 0.3373 0.0180 0.0189 0.0287

JON05 0.8146 0.0878 0.0744 0.0012 0.0215 0.0006

JON06 0.8146 0.0878 0.0744 0.0012 0.0215 0.0006

LNC01 0.1545 0.1512 0.5528 0.0146 0.1198 0.0071

LNC02 0.8045 0.0902 0.0812 0.0241

LNC03 0.8045 0.0902 0.0812 0.0241

LNC04 0.1400 0.1015 0.6393 0.0090 0.1055 0.0047

LNC05 0.8045 0.0902 0.0812 0.0241

LNC06 0.8045 0.0902 0.0812 0.0241

PND01 0.2527 0.1272 0.5170 0.0116 0.0854 0.0061

PND02 0.5517 0.1076 0.2759 0.0035 0.0594 0.0019

PND05 0.8146 0.0878 0.0744 0.0012 0.0215 0.0006

PND06 0.7743 0.0990 0.0953 0.0010 0.0298 0.0005

SBL01 0.1545 0.1512 0.5528 0.0146 0.1198 0.0071

SBL02 0.8045 0.0902 0.0812 0.0241

SBL03 0.8045 0.0902 0.0812 0.0241

SBL04 0.1555 0.1127 0.6547 0.0100 0.0618 0.0053

SBL05 0.8045 0.0902 0.0812 0.0241

SBL06 0.8045 0.0902 0.0812 0.0241

SWE01 0.1397 0.1025 0.6374 0.0090 0.1066 0.0048

SWE02 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

SWE03 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

SWE04 0.1400 0.1015 0.6393 0.0090 0.1055 0.0047

SWE05 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

SWE06 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

SWW01 0.1545 0.1512 0.5528 0.0146 0.1198 0.0071

SWW02 0.8045 0.0902 0.0812 0.0241

SWW03 0.8045 0.0902 0.0812 0.0241

SWW04 0.1400 0.1015 0.6393 0.0090 0.1055 0.0047

SWW05 0.8045 0.0902 0.0812 0.0241

SWW06 0.8045 0.0902 0.0812 0.0241

UNT01 0.1545 0.1512 0.5528 0.0146 0.1198 0.0071

UNT02 0.8045 0.0902 0.0812 0.0241

UNT03 0.8045 0.0902 0.0812 0.0241

UNT04 0.1400 0.1015 0.6393 0.0090 0.1055 0.0047

UNT05 0.8045 0.0902 0.0812 0.0241

UNT06 0.8045 0.0902 0.0812 0.0241
Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016

Appendix D

Model Performance Evaluation of the 2005-2006 MM5 

Meteorological Model Simulations Used for the 

Continental Divide-Creston CAMx Photochemical Grid Modeling
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-1

INTRODUCTION

For the Continental Divide-Creston (CD-C) oil and gas (O&G) development project 

Environmental Impact Statement (EIS), the Comprehensive Air-quality Model with extensions 

(CAMx; ENVIRON, 2009) photochemical grid model is being run for the 2005 and 2006 base 

case years. To provide a meteorological database for these CAMx simulations, the MM5 

mesoscale meteorological model (Dudhia, 1993; Grell, Dudhia and Stauffer, 1994) was run for 

the 2005-2006 period. An overview of the MM5 modeling domain and model configuration is 

given in Section 4.4.1. The 2005 and 2006 MM5 runs were evaluated against observed surface 

and aloft meteorological data, with a focus on Southwest Wyoming (SWWY). The model 

performance evaluation addresses the following question: is the performance of the 2005-2006 

MM5 run sufficiently good to allow CAMx to accurately characterize transport, chemistry, and 

removal processes and accurately simulate pollutant concentrations over SWWY and 

surrounding states?

To provide a reasonable meteorological characterization to CAMx, MM5 must represent with 

some fidelity the large-scale and mesoscale wind, temperature, humidity and precipitation

fields. If errors in the meteorological fields are too large, the ability of the air quality model to 

replicate regional pollutant levels over the two-year base case period will be hampered and the 

predicted air quality and visibility impacts from future year growth and controls will be 

unreliable. Accurate simulation of winds is critical to model transport of pollutants from 

emissions sources to receptors within the domain. For visibility impact analysis, the moisture 

and condensate fields are particularly important as they impact PM chemical formation, 

removal, and light scattering efficiency. In addition, cloud and precipitation fields are a good 

integrated measure of the performance of the model since these are model-derived quantities 

and are not nudged to observations. Because of the model's coarse resolution of 36/12/4 km, 

the present runs cannot be expected to faithfully simulate the high frequency pattern or 

variability of the convective precipitation, but should reproduce the synoptic precipitation 

patterns. 

In this evaluation, we focus on the model’s simulation of near-surface wind, temperature, and 

humidity and precipitation. Annual MM5 runs generate a very large amount of data to be 

analyzed, so we evaluate the overall model performance by month, focusing on Southwest 

Wyoming monitors. In the Western Regional Air Partnership (WRAP) 2002 regional haze 

modeling annual run, the MM5 evaluation focused on model performance during sample 

winter, summer, and transitional months (i.e. January, July, April, and October) as these months 

were determined to have performance representative of their entire season (Kemball-Cook et 

al., 2004). In the 2005/2006 MM5 evaluation presented in this Appendix, we focus on months 

within the January-July period, since most high ozone events and many high nitrate events in 

SWWY occurred during these months in 2005-2006. To place the MM5 performance in context 

of other annual simulations, we compare the performance of the CD-C MM5 runs with other 

annual MM5 modeling efforts such as 2002 WRAP, VISTAS, CENRAP Regional Planning 

Organization (RPO) runs made for regional haze modeling. Finally, we provide an overview of 

the 2005/2006 MM5 model performance and discuss how the MM5 performance may be 

expected to affect the CAMx simulations. 
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-2

The 2005 36/12/4 km MM5 model output used in the CD-C CAMx modeling was built off of 

2005 36/12 km MM5 modeling that was originally performed to support an NO2 PSD increment 

consumption analysis for the New Mexico Environment Department (NMED) that was funded 

by Western Refining (ENVIRON and Alpine, 2009) and subsequently used for CAMx modeling in 

the Four Corners Air Quality Task Force (FCAQTF) study (ENVIRON, 2009). Additional 2005 4 km 

MM5 modeling was performed under the Continental Divide-Creston (CD-C) EIS Project for 

SWWY using a nest down from the FCAQTF 12 km MM5 output. Similarly, 2006 36/12 km MM5 

modeling was conducted using the same 36/12 km grid structure as in the FCAQTF and then 

one-way 4 km MM5 modeling conducted for SWWY. 

MODEL CONFIGURATION

CUMULUS PARAMETERIZATION

The physics options used for the final MM5 simulations for 2005 and 2006 on the 4 km domain 

are listed in Table 4.2. The MM5 simulations for the 36/12 km grids were run with same 

options as for the 4 km domain, except that cumulus parameterization not used in the 12 km 

run from the PSD Increment Consumption/FCAQTF projects that was used for the CD-C 4 km 

boundary conditions. The 2006 CD-C 4 km run was performed before the 2005 run and no 

cumulus parameterization (CuP) was used in order to maintain consistency with the 12 km grid. 

The model performance evaluation of the initial 2006 4 km run showed that rainfall was 

overestimated in summer. Overstated model resolved convective rainfall can adversely 

influence wind fields and CAMx simulation of wet deposition, so a sensitivity test was carried 

out in order to improve MM5’s performance in simulating summer rainfall. The 2005 CD-C 4 

km run was subsequently made with the Kain-Fritsch II CuP in order to enhance the release of 

sub-grid scale convective instability and reduce excessive rainfall. Because this run showed 

better precipitation performance than the 2006 run, a second 2006 run was then made with 

Kain-Fritsch II CuP and with additional surface observation wind nudging within the 4 km 

domain. In the text and figures below, the original 2006 run that was not run with a CuP is 

referred to as the Old Run and the second run that was performed with the Kain-Fritsch CuP 

and additional observation nudging is called the New Run.

OBSERVATION NUDGING

Observation nudging to the National Center for Atmospheric Research (NCAR) ds472 airport 

surface wind data was performed for both the 2005 and 2006 runs; both runs were also nudged 

to the observed winds from the Jonah, Boulder, and Daniel industrial site monitors in 

Southwest Wyoming. For 2006, additional Wyoming industrial sites were used for surface wind 

observation nudging in the New Run (with CuP), some of which were not in operation during 

2005. The additional stations are Simplot, OCI, Whitney Canyon, Riverton, Centennial, Rock 

Springs, Evanston, and Wamsutter. The locations of the ds472 and additional stations used for 

observation nudging as well as model performance evaluation are shown as red crosses in 

Figure D.1 and the additional Wyoming industrial sites are shown by the blue circles. For both 

2005 and 2006, analysis nudging was performed for winds, temperature, and humidity above 

the boundary layer. MM5 default nudging coefficients were used for all observation and 

analysis nudging.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-3

Figure D.1. 4 km Grid Meteorological Station Locations used in the Observation Nudging.

-1200 -1150 -1100 -1050 -1000 -950 -900 -850 -800 -750 -700 -650

50

100

150

200

250

300

350

400

450

500

KBOU

KCAG

KZDV

KFNL

KHDN KCHE

KEEO

KPLT

KSBS

KFCL

K4FC KC96 KCRV

K33V

KIDA

KU78

K36U

KLGU

KMTU

KPUC

KPVU

KU67

KVEL

KBPI

KBOY

KCPR

KDDY

KCYS

KCZI

KBYG

KCPR

KDDY

KCOD

KLND

KLAR

KRWL KPRO

KRIW

KRKS KOCS

KWRL

K4DG

KCTD

KVDW

KPUM

KARL

KBIT KCMS

KFIR

KIDV

KTMH

KDHS

KBFU

KWTR

KPAT

KBVR

KSIB

KHLD

KDRC

KBRX

KSKL

KRIM

KSGE

KSHC

Wamsutter

Rock Springs

OCI

Evanston

Centennial

Whitney

Simplot

Riverton

Jonah

Daniel

Boulder

ds472 Station

Additional Site
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-4

EVALUATION OF PERFORMANCE ACROSS THE 4 KM DOMAIN

As a starting point for the MM5 model performance evaluation, we examine overall surface 

performance across the 4 km domain during January and July of 2005 and 2006. Observed and 

modeled surface wind, temperature, humidity time series were averaged for all ds472 sites 

within the 4 km domain. January and July surface time series were found to be representative 

of winter and summer performance for individual stations within Wyoming and are presented 

in Figures D.2-D.9. 

SURFACE WINDS

The 2005 and 2006 January surface wind time series are shown in Figures D.2 and D.3, 

respectively. Many of the main features of the observed wind speed time series are captured 

by the model, but there is an overall low wind speed bias that persists through most of the 

month in both years. The gross features of the observed wind direction time series are 

controlled by the large-scale flow following the progression of frontal systems through the 

region. Superimposed on the large-scale flow are more rapid wind shift changes that may be 

due to variability at smaller spatial scales, such as drainage flows in mountainous areas. MM5 

does not reproduce some of the high frequency variability in wind direction, but wind direction 

performance is generally very good.

The July wind time series (Figures D.6 and D.7) are similar to January in that the performance 

for winds is generally good, but there is an overall low bias in wind speeds and the model is not 

able to simulate many of the abrupt changes in wind direction. In July, there are fewer large 

frontal systems transiting the 4 km domain and the observed winds are more affected by the 

diurnal cycle and by variability at local scales that are not well-resolved by the model. The 

observed wind direction time series therefore has many more high-frequency shifts in wind 

direction than in January and is harder for the model to simulate.

SURFACE TEMPERATURE

The observed and modeled January temperature time series are shown in the upper panels of 

Figures D.4 (2005) and D.5 (2006). In both years, the model captures the low frequency 

variability in the observed temperatures quite well, but is less successful in reproducing the 

daily maximum and minimum temperatures. In July (Figures D.8 and D.9), the daily 

temperature peaks are well-simulated in both years, but night time temperature minima are 

not low enough-this is likely related to excessive surface humidity in the model, as discussed in 

the next section. 

SURFACE HUMIDITY

The observed and modeled January water vapor concentration (humidity) time series are 

shown in the lower panels of Figures D.4 (2005) and D.5 (2006). In both years, the model 

reproduces the general trends in variability of the observed humidity, but has a high bias 

through most of the months. July is shown in Figures D.8 (2005) and D.9 (2006). In July, the 

observed humidity is higher, and there is more day-to-day humidity variation than in January. 

The model also shows an increase in overall humidity in July relative to January, but has a high 

bias in humidity throughout most of July during both 2005 and 2006. The high bias in humidity 

is most likely the result of excessive summer convective precipitation in the model (discussed 

below). The high bias in the surface humidity can also affect the surface temperature by 

causing incorrect partitioning of latent and surface heat fluxes. 
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-5

Figure D.2. Time series of observed (black) and MM5 (red) January 2005 near-surface wind 

speed (upper panel) and wind direction (lower panel) averaged over all monitoring sites in 

the 4 km grid.

Figure D.3. Time series of observed (black) and MM5 (red) January 2006 near-surface wind 

speed (upper panel) and wind direction (lower panel) averaged over all monitoring sites in 

the 4 km grid.

Observed/Predicted Windspeed

0

2

4

6

8

10

 1/ 1 1/ 2 1/ 3 1/ 4 1/ 5 1/ 6 1/ 7 1/ 8 1/ 9

 1/10 1/11 1/12 1/13 1/14 1/15 1/16 1/17 1/18 1/19 1/20 1/21 1/22 1/23 1/24 1/25 1/26 1/27 1/28 1/29 1/30 1/31

m/s

ObsWndSpd PrdWndSpd Observed/Predicted Wind Direction

0

60

120

180

240

300

360

 1/ 1 1/ 2 1/ 3 1/ 4 1/ 5 1/ 6 1/ 7 1/ 8 1/ 9

 1/10 1/11 1/12 1/13 1/14 1/15 1/16 1/17 1/18 1/19 1/20 1/21 1/22 1/23 1/24 1/25 1/26 1/27 1/28 1/29 1/30 1/31

deg

ObsWndDir PrdWndDir Observed/Predicted Windspeed

0

2

4

6

8

10

 1/ 1 1/ 2 1/ 3 1/ 4 1/ 5 1/ 6 1/ 7 1/ 8 1/ 9

 1/10 1/11 1/12 1/13 1/14 1/15 1/16 1/17 1/18 1/19 1/20 1/21 1/22 1/23 1/24 1/25 1/26 1/27 1/28 1/29 1/30 1/31

m/s

ObsWndSpd PrdWndSpd Observed/Predicted Wind Direction

0

60

120

180

240

300

360

 1/ 1 1/ 2 1/ 3 1/ 4 1/ 5 1/ 6 1/ 7 1/ 8 1/ 9

 1/10 1/11 1/12 1/13 1/14 1/15 1/16 1/17 1/18 1/19 1/20 1/21 1/22 1/23 1/24 1/25 1/26 1/27 1/28 1/29 1/30 1/31

deg

ObsWndDir PrdWndDir 
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-6

Figure D.4. Time series of observed (black) and MM5 (red) January 2005 near-surface 

temperature (upper panel) and humidity (lower panel) averaged over all monitoring sites in 

the 4 km grid.

Observed/Predicted Temperature

255

260

265

270

275

280

 1/ 1 1/ 2 1/ 3 1/ 4 1/ 5 1/ 6 1/ 7 1/ 8 1/ 9

 1/10 1/11 1/12 1/13 1/14 1/15 1/16 1/17 1/18 1/19 1/20 1/21 1/22 1/23 1/24 1/25 1/26 1/27 1/28 1/29 1/30 1/31

K

ObsTemp PrdTemp Predicted/Observed Humidity

0

1

2

3

4

5

6

 1/ 1 1/ 2 1/ 3 1/ 4 1/ 5 1/ 6 1/ 7 1/ 8 1/ 9

 1/10 1/11 1/12 1/13 1/14 1/15 1/16 1/17 1/18 1/19 1/20 1/21 1/22 1/23 1/24 1/25 1/26 1/27 1/28 1/29 1/30 1/31

g/kg

ObsHum PrdHum 
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-7

Figure D.5. Time series of observed (black) and MM5 (red) January 2006 near-surface wind 

speed (upper panel) and wind direction (lower panel) averaged over all monitoring sites in 

the 4 km grid.

Observed/Predicted Temperature

255

260

265

270

275

280

 1/ 1 1/ 2 1/ 3 1/ 4 1/ 5 1/ 6 1/ 7 1/ 8 1/ 9

 1/10 1/11 1/12 1/13 1/14 1/15 1/16 1/17 1/18 1/19 1/20 1/21 1/22 1/23 1/24 1/25 1/26 1/27 1/28 1/29 1/30 1/31

K

ObsTemp PrdTemp Predicted/Observed Humidity

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

 1/ 1 1/ 2 1/ 3 1/ 4 1/ 5 1/ 6 1/ 7 1/ 8 1/ 9

 1/10 1/11 1/12 1/13 1/14 1/15 1/16 1/17 1/18 1/19 1/20 1/21 1/22 1/23 1/24 1/25 1/26 1/27 1/28 1/29 1/30 1/31

g/kg

ObsHum PrdHum 
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-8

Figure D.6. Time series of observed (black) and MM5 (red) July 2005 near-surface wind speed 

(upper panel) and wind direction (lower panel) averaged over all monitoring sites in the 4 km 

grid.

Figure D.7. Time series of observed (black) and MM5 (red) July 2006 near-surface wind speed 

(upper panel) and wind direction (lower panel) averaged over all monitoring sites in the 4 km 

grid.

Observed/Predicted Windspeed

0

2

4

6

8

10

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

m/s

ObsWndSpd PrdWndSpd Observed/Predicted Wind Direction

0

60

120

180

240

300

360

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

deg

ObsWndDir PrdWndDir Observed/Predicted Windspeed

0

2

4

6

8

10

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

m/s

ObsWndSpd PrdWndSpd Observed/Predicted Wind Direction

0

60

120

180

240

300

360

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

deg

ObsWndDir PrdWndDir 
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-9

Figure D.8. Time series of observed (black) and MM5 (red) July 2005 near-surface 

temperature (upper panel) and humidity (lower panel) averaged over all monitoring sites in 

the 4 km grid.

Figure D.9. Time series of observed (black) and MM5 (red) July 2006 near-surface wind speed 

(upper panel) and wind direction (lower panel) averaged over all monitoring sites in the 4 km 

grid. Observed/Predicted Temperature

280

285

290

295

300

305

310

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

K

ObsTemp PrdTemp Predicted/Observed Humidity

0

2

4

6

8

10

12

14

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

g/kg

ObsHum PrdHum Observed/Predicted Temperature

280

285

290

295

300

305

310

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

K

ObsTemp PrdTemp Predicted/Observed Humidity

0

2

4

6

8

10

12

14

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

g/kg

ObsHum PrdHum 
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-10

SITE-SPECIFIC SURFACE WIND ROSE AND TIME SERIES ANALYSIS

The model performed reasonably well when performance is averaged across all monitoring 

sites in the 4 km domain; however, month-long averages taken over a large region can smooth 

over performance problems. We now turn to an examination of data for individual stations in 

Wyoming. For this phase of the evaluation, we choose sites within and outside Sublette 

County, and focus on the Wyoming state industrial site monitors in SWWY. 

Wind roses are used to summarize station near-surface wind speed and direction performance 

over the course of a year. In a wind rose, the orientation and length of spokes indicates the 

frequency with which each wind direction occurs. The spokes show the direction from which 

wind blows toward the monitor, and the colored bands indicate the percentage of time the 

winds fall in a given speed range. 

SUBLETTE COUNTY MONITORS

The 2005 wind rose for the Jonah monitor is shown in Figure D.10. The 4 km MM5 run shows 

good wind direction performance, but exhibits a low bias in simulating peak wind speed. The 4 

km MM5 run shows clear improvement in both wind speed and direction over 12 km MM5 

meteorological data used for the Moxa Arch CALMET modeling. In 2006, the Jonah wind rose 

shows that the 4 km MM5 run again captures the distribution of wind directions well, with the 

new CuP run doing a slightly better job than the old run with no CuP in simulating the highest 

wind speeds. The old run however, does a better job of simulating the frequency of winds out 

of the NNW.

The wind roses for the Daniel monitor for 2005 and 2006 Daniel 2005 are shown in Figures 

D.10 and D.11. The model correctly reproduces the dominant NW wind direction in 2005, 

although has a low bias in simulating peak wind speeds. 
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-11

Figure D.10. Wind rose for 2005 near-surface winds at the Jonah monitor.

Figure D.11 Wind rose for 2006 near-surface winds at the Jonah monitor.

NORTH

SOUTH

WEST EAST

5%

10%

15%

20%

25%

WIND SPEED

(Knots)

>= 22

17 - 21

11 - 17

7 - 11

4 - 7

1 - 4

Calms: 5.77%
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-12

The model underestimates the frequency of southeasterly winds in 2005 but does a better job 

with this feature in both the old and new 2006 runs. The new (CuP) 2006 run shows clear 

improvement in its simulation of the NW winds that dominate the wind rose for the observed 

winds. However, the old run better reproduced the fact that the observed winds are strongly 

channeled in a particular direction; albeit with a bias in the direction, while the new run has 

winds that range more broadly around the NW quadrant of the compass.

Wind roses for the Boulder monitor are shown in Figures D.14 and D.15. In 2005, the model 

underestimates the frequency of easterly winds, with wind directions that cluster too tightly 

around W-NW. There is a small westerly directional bias and the modeled NW Winds have a 

low wind speed bias; the model understates the magnitude of the peak wind speed events. In 

2006, the new (CuP) run shows some improvement in wind direction relative to the old (no 

CuP) run, with flow in the old run too strongly channeled in the NW direction. This problem is 

less pronounced in the new run. As in 2005, the frequency of NE winds is underestimated in 

2006.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-13

Figure D.12. Wind rose for 2005 near-surface winds at the Daniel monitor.

Figure D.13. Wind rose for 2006 near-surface winds at the Daniel monitor.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-14

Figure D.14. Wind rose for 2005 near-surface winds at the Boulder monitor.

Figure D.15. Wind rose for 2006 near-surface winds at the Boulder monitor.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-15

July wind speed and direction time series for the Sublette County monitors are shown in Figures 

D.16 and D.17, respectively. The wind speed time series show that the model does a 

reasonably good job of simulating the diurnal variability, but has a low wind speed bias and 

underestimates the daily peaks in wind speed. At all three of the monitors, the observed wind 

direction shows rapid shifts likely driven by local thermal and orographic circulations. This is an 

extremely challenging meteorological regime for the model to simulate, and the model misses 

many of these rapid wind shifts.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-16

Figure D.16. Time series of observed (blue) and MM5 (pink) July 2006 near-surface wind 

speed at the Sublette County monitors.

Observed/Predicted Windspeed

0

5

10

15

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

m/s

ObsWndSpd Predict ed Observed/Predicted Windspeed

0

5

10

15

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

m/s

ObsWndSpd PrdWndSpd Observed/Predicted Windspeed

0

5

10

15

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

m/s

ObsWndSpd Predict ed
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-17

Figure D.17. Time series of observed (blue) and MM5 (pink) July 2006 near-surface wind 

direction at the Sublette County monitors.

WYOMING MONITORS OUTSIDE SUBLETTE COUNTY

During the original MM5 model performance evaluation reported during the CD-C study, the 

Wamsutter monitor was incorrectly placed by ~20 miles to the southwest of the actual location 

due to incorrect location in the file. The original incorrect location and the actual monitor 

location are shown in Figure D.18. The Wamsutter monitor came online in March 2006, so no 

data are available for evaluating 2005 model performance. The wind rose for Wamsutter is 

shown in Figure D.19. The wind direction performance is good, with the southwesterly wind 

direction frequency represented with reasonable fidelity. The model has a low wind speed bias,

however. 

The Simplot monitor observed wind rose (Figure D.20) indicates that the mean flow at this 

monitor is very strongly channeled with a predominantly westerly direction. The model does a 

fairly good job of reproducing the wind direction, although the flow is not as strongly channeled 

as the observed winds. There is a low wind speed bias in the modeled wind speeds. 

Observed/Predicted Wind Direction

0

60

120

180

240

300

360

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

deg

ObsWndDir PrdWndDir Observed/Predicted Wind Direction

0

60

120

180

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300

360

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

deg

ObsWndDir PrdWndDir Observed/Predicted Wind Direction

0

60

120

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240

300

360

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

deg

ObsWndDir Predict ed
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-18

Figure D-18. Corrected Location of Wamsutter Monitor.

Figure D.19. Wind rose for 2006 near-surface winds at the Wamsutter monitor.

OBSERVED MM5 4 km Grid
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-19

At the Riverton monitor, the observed flow is more evenly distributed in direction with NW 

winds occurring most frequently. The modeled winds at Riverton are also fairly evenly 

distributed in direction, but SW winds occur most often. As with the other stations, there is a 

low bias to the modeled wind speeds. Observed winds and model performance at the OCI 

monitor (Figure D.22), Evanston (Figure D.24) and the Rock Spring Monitors (Figure D.26) are 

similar to Riverton with a fairly even distribution of directions, with a westerly peak in direction 

and low bias to the modeled wind speed. At Centennial (Figure D.23), observed and modeled 

winds generally out of the west. Unlike the other stations, the model overestimates peak wind 

speeds for the NW direction at Centennial. At Whitney Canyon (Figure 25), the model does not 

reproduce the strong westerly direction preference seen in the observed winds, but instead 

distributes the winds more evenly.

July wind speed and direction time series for the Wamsutter, Simplot, and Riverton monitors 

are shown in Figures D.27 and D.28 respectively. The diurnal variation in the observed winds is 

captured by model, but the daily wind speed peaks are too low, resulting in a low wind speed 

bias. The wind direction time series show fewer sudden wind direction shifts than the Sublette 

County monitors, and the model performance is better at these non-Sublette County monitors.

Figures D.29 and D.30 show observed and modeled humidity time series for monitors inside 

and outside Sublette County, respectively. All of these monitors show a positive humidity bias 

during most of the month of July.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-20

Figure D.20. Wind rose for 2006 near-surface winds at the Simplot monitor.

Figure D.21. Wind rose for 2006 near-surface winds at the Riverton monitor.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-21

Figure D.22. Wind rose for 2006 near-surface winds at the OCI monitor.

Figure D.23. Wind rose for 2006 near-surface winds at the Centennial monitor.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-22

Figure D.24. Wind rose for 2006 near-surface winds at the Evanston monitor.

Figure D.25. Wind rose for 2006 near-surface winds at the Whitney Canyon monitor.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-23

Figure D.26. Wind rose for 2006 near-surface winds at the Rock Springs monitor.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-24

Figure D.27. Time series of observed (blue) and MM5 (pink) July 2006 near-surface wind 

speed at monitors outside Sublette County.

Figure D.28. Time series of observed (blue) and MM5 (pink) July 2006 near-surface wind 

direction at monitors outside Sublette County.

Observed/Predicted Windspeed

0

5

10

15

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

m/s

ObsWndSpd PrdWndSpd Observed/Predicted Windspeed

0

5

10

15

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

m/s

ObsWndSpd PrdWndSpd Observed/Predicted Windspeed

0

5

10

15

20

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

m/s

ObsWndSpd PrdWndSpd Observed/Predicted Wind Direction

0

60

120

180

240

300

360

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

deg

ObsWndDir PrdWndDir Observed/Predicted Wind Direction

0

60

120

180

240

300

360

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

deg

ObsWndDir PrdWndDir Observed/Predicted Wind Direction

0

60

120

180

240

300

360

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

deg

ObsWndDir PrdWndDir 
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-25

Figure D.29. Time series of observed (blue) and MM5 (pink) 2006 near-surface humidity at 

monitors in Sublette County.

Figure D.30. Time series of observed (blue) and MM5 (pink) 2006 near-surface humidity at 

monitors outside Sublette County.

Predicted/Observed Humidity

0

2

4

6

8

10

12

14

16

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

g/kg

ObsHum Predict ed Predicted/Observed Humidity

0

2

4

6

8

10

12

14

16

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

g/kg

ObsHum PrdHum Predicted/Observed Humidity

0

2

4

6

8

10

12

14

16

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

g/kg

ObsHum PrdHum Predicted/Observed Humidity

0

2

4

6

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18

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

g/kg

ObsHum PrdHum Predicted/Observed Humidity

0

2

4

6

8

10

12

14

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18

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

g/kg

ObsHum PrdHum Predicted/Observed Humidity

0

2

4

6

8

10

12

14

16

18

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

g/kg

ObsHum PrdHum 
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-26

SUMMARY OF SURFACE PERFORMANCE

The overall model performance at monitors within southwestern Wyoming was good. The 

model does a good job of reproducing the large-scale features of the surface winds, 

temperatures and humidity at most monitors. The model has an overall low wind speed bias at 

all SW Wyoming sites, and an important part of the low wind speed bias is the model’s 

underprediction of peak wind speeds. Wind direction variability was underestimated in the 

model. This problem was particularly pronounced at the Sublette County monitors, which are 

influenced by local-scale flows due to the complex topography that surrounds them. In winter, 

MM5 often misses the daytime transition from NW winds to SW/W winds seen in observations. 

At 4 km resolution, MM5 may be expected to have difficulty resolving local-scale drainage 

flows. Outside Sublette County, the winter wind direction performance was better. In summer, 

there are more rapid changes, in wind direction outside Sublette County due to the passage of 

meso- to local-scale convective events, and the model has more difficulty simulating these. The 

model showed an overall wet bias at the surface at all Wyoming industrial site monitors. 

Overall, MM5 generally handles large-scale features of the circulation well but has more 

difficulty simulating locally-driven circulations such as small-scale convective storms and flow in 

mountainous areas.

COMPARISON WITH 2002 RPO MM5 MODELING

In order to place the performance of the 2005/2006 36/12/4 km MM5 modeling in the context 

of other annual MM5 runs, we compare the 4 km MM5 model performance to that of the 

annual MM5 simulations of 2002 that were made by the CENRAP (Johnson, 2007), VISTAS 

(Olerud, 2003a,b), and WRAP (Kemball-Cook et al., 2004) Regional Planning Organizations (RPO) 

for regional haze modeling. These annual runs were made on a 36 km grid that is identical to 

the 36 km grid used for the 2005/2006 MM5 modeling. For the purposes of comparison with 

2005/2006 MM5 modeling, only a sub-region of the 36 km MM5 run consisting of the states 

Wyoming, Montana and eastern Idaho was considered. We also compare the 2005/2006 4 km 

MM5 runs run to a 12 km 2002 annual run made by the WRAP and evaluated on the same subregion as the 36 km RPO runs. The RPO runs share a common grid and projection, but use 

different column physics options, and differ from one another in their performance (see 

Kemball-Cook et al., 2004 and Johnson et al., 2006). The RPO runs were evaluated by region 

and by month against ds472 surface meteorological data and the results were averaged over 

the Wyoming-Montana-Idaho sub-region described above (Kemball-Cook et al., 2004). The CDC results were averaged over the 4 km domain, as described in the preceding sections. 

Although the horizontal grid resolution and size of the averaging regions is different in the RPO 

and CD-C runs, we may draw a rough comparison among the annual runs to determine whether 

the CD-C run performs approximately as well as the RPO runs. 

METSTAT SURFACE STATISTICAL ANALYSIS 

In this section, we describe the benchmarks used in the comparison between the 2002 RPO and 

2005/2006 MM5 runs as well as the graphical displays used to present the data.

Emery et al. (2001) have derived a set of daily performance benchmarks for typical 

meteorological model performance. These standards were based upon the evaluation of 

approximately 30 MM5 and RAMS meteorological simulations executed in support of air quality 
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-27

applications, as reported by Tesche et al. (2001). The purpose of these benchmarks was not 

necessarily to give a passing or failing grade to any one particular meteorological model 

application, but rather to put its results into context and to allow the identification of potential 

problems in the MM5 fields. For example, expectations for meteorological model performance 

for a domain located in the Rocky Mountains might be different than for a Central U.S. domain 

with simpler topography. The statistical performance benchmarks developed by Emery and coworkers (2001) are given in Table D.1.

Table D.1 Statistical benchmarks for evaluating meteorological model performance.

Wind Speed Wind Direction Temperature Humidity

RMSE  2 m/s

Mean Bias  0.5 m/s  10  0.5 K  1 g/kg

Gross Error  30  2 K  2 g/kg

In order to summarize model performance, we will show soccer plots on which are displayed 

average performance statistics for each region over the entire episode. Definitions for the 

statistical model performance metrics are given in Table A.4 of Appendix A. Soccer plots are 

shown for wind speed root mean square error (RMSE) versus wind direction error, wind speed 

bias versus wind speed RMSE, temperature bias versus temperature error, and humidity bias 

versus humidity error. In each plot, a solid blue line indicates the benchmark. A data point that 

falls inside the box represents a model run that meets the performance benchmark. Perfect 

model performance is indicated by a data point at (0,0). The closer a data point is to the origin, 

the better the model’s performance. 

January Soccer Plots

In the soccer plot for wind direction error and wind speed RMSE for January (Figure D.31) is 

representative of winter performance during other months (not shown), the 2005 MM5 run is 

within the benchmark for wind speed RMSE but not wind direction error; the 2006 MM5 run is 

outside the benchmark for both bias and error, with performance similar to that seen in the 

CENRAP and VISTAS runs. The WRAP 36 km and 12 km runs had the best performance of all 

runs, and were within the benchmark for both RMSE and wind direction error. The 2006 new 

run wind performance was similar to the performance of the old 2006 run, and the 2006 MM5 

run performance was comparable to or better than the RPO runs, except for the WRAP 2002 12 

km run for wind direction error. The wind bias soccer plot (Figure D.32) shows that the both 

the 2005 and 2006 MM5 runs and the WRAP 2002 12 km run underestimate wind speeds; the 

2005/2006 MM5 and WRAP 2002 MM5 performance are comparable. Performance degrades

slightly going from the old to the new 2006 run. Wind bias data was not readily available for 

the 36 km RPO runs.

The January temperature soccer plot is shown in Figure D.33. The 2005 MM5 4 km run is within 

the bias benchmark, as is the VISTAS 2002 36 km run. All of the other runs are outside the bias 

benchmark, and exhibit a cold bias. The old and new 2006 MM5 runs lie outside benchmark for 

both bias and error but perform better than the WRAP and CENRAP 2002 MM5 runs for bias 

and have the best performance of any run for temperature error. For humidity (Figure D.34), 

the performance of all model runs was similar, all models falling with the benchmarks for both 

bias and error and all model runs showing a wet bias.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-28

Figure D.31. January wind speed and direction performance soccer plot.

Figure D.32. January wind speed bias and RMSE performance soccer plot. 

 January Wind Performance Comparison

0

10

20

30

40

50

60

70

0 0.5 1 1.5 2 2.5 3

Wind Speed RMSE (m/s)

Wind Direction Error (deg)

2005 CDC 4 km

2006 CDC 4 km New

2006 CDC 4 km Old

CENRAP 36 km

VISTAS 36 km

WRAP 36 km

WRAP 12 km

4 km Grid January Wind Performance Comparison

0

0.5

1

1.5

2

2.5

3

- 2 -1.5 - 1 -0.5 0 0.5 1 1.5 2

Wind Speed Bias (m/s)

Wind Speed RMSE (deg)

CDC 2005 4 km

CDC 2006 4 km New

CDC 2006 4 km Old

WRAP 12 km
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-29

Figure D.33. January temperature performance soccer plot.

Figure D.34. January humidity performance soccer plot. 

January Temperature Performance Comparison

0

0.5

1

1.5

2

2.5

3

3.5

4

- 2 -1.5 - 1 -0.5 0 0.5 1 1.5 2

Temperature Bias (K)

Temperature Error (k)

2005 CDC 4 km

2006 CDC 4km New

2006 CDC 4 km Old

36km_CENRAP

36km_VISTAS

36km_WRAP

12km_WRAP

January Humidity Performance Comparison

0

0.5

1

1.5

2

2.5

3

- 2 -1.5 - 1 -0.5 0 0.5 1 1.5 2

Humidity Bias (g/kg)

Humidity Error (g/kg)

2005 CDC 4 km

2006 CDC 4 km New

2006 CDC 4 km Old

CENRAP 36 km 

VISTAS 36 km

WRAP 36 km

WRAP 12 km
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-30

JULY SOCCER PLOTS

Figures D.35 and D.36 are the soccer plots for winds for the month of July. Results are similar 

to January, with the 2005/2006 MM5 and CENRAP and VISTAS 2002 MM5 simulations showing 

similar performance for wind speed RMSE and direction and the WRAP 36 km and 12 km MM5 

runs the only simulations to fall within the performance benchmark. Both the 2005/2006 MM5 

and WRAP 2002 12 km MM5 runs show a low bias in wind speed and have similar bias 

performance. Bias performance degrades slightly in going from the old to the new 2006 run.

For temperature (Figure D.37), the 2006 MM5 4 km runs fall within the bias benchmark and are 

close to the benchmark for error, but the 2005 MM5 run lies well outside the benchmark for 

both bias and error. The 2005 and 2006 MM5 runs performance is generally comparable to 

that of the RPO runs for error; while the 2005 MM5 run is comparable to the VISTAS run, it 

does not perform as well as the WRAP and CENRAP MM5 runs for bias.

All runs except the 2006 MM5 runs lie within the benchmarks for humidity (Figure D.38). The 

2005 MM5 4 km run lies within bias and error benchmarks, while the 2006 runs meet the 

humidity error benchmark but not the bias benchmark. All of the MM5 simulations have a wet 

bias, which is most pronounced in the 2006 MM5 simulation and is larger than in January due 

to the increased prevalence of convective rainfall during summer. Turning on the CuP in the 

new 2006 MM5 run did little to ameliorate this wet bias.

Overall, the soccer plot analysis shows that the 2005/2006 MM5 runs are comparable in 

performance to the RPO annual simulations of 2002. Low wind speed bias and wet bias were 

common to all of these MM5 simulations. 
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-31

Figure D.35. July wind speed and direction performance soccer plot.

Figure D.36. July wind speed bias and RMSE performance soccer plot. 

July Wind Performance Comparison

0

10

20

30

40

50

60

70

0 0.5 1 1.5 2 2.5 3

Wind Speed RMSE (m/s)

Wind Direction Error (deg)

CDC 2005 4 km

CDC 2006 4 km New

CDC 2006 4 km Old

CENRAP 36 km

VISTAS 36 km

WRAP 36 km

WRAP 12 km

4 km Grid July Wind Performance Comparison

0

0.5

1

1.5

2

2.5

3

- 2 -1.5 - 1 -0.5 0 0.5 1 1.5 2

Wind Speed Bias (m/s)

Wind Speed RMSE (deg)

CDC 2005 4 km

CDC 2006 4 km New

CDC 2006 4 km Old

WRAP 12 km
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-32

Figure D.37. July temperature performance soccer plot.

Figure D.38. July humidity performance soccer plot. 

July Temperature Performance Comparison

0

0.5

1

1.5

2

2.5

3

3.5

- 2 -1.5 - 1 -0.5 0 0.5 1 1.5 2

Temperature Bias (K)

Temperature Error (k)

CDC 2005 4 km

CDC 2006 4 km New

CDC 2006 4 km Old

CENRAP 36 km

VISTAS 36 km

WRAP 36 km

WRAP 12 km

July Humidity Performance Comparison

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

- 2 -1.5 - 1 -0.5 0 0.5 1 1.5 2

Humidity Bias (g/kg)

Humidity Error (g/kg)

CDC 2005 4 km

CDC 2006 4 km New

CDC 2006 4 km Old

VISTAS 36 km

CENRAP 36 km

WRAP 36 km

WRAP 12 km
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-33

PRECIPITATION EVALUATION

In this section, we evaluate the 2005 and 2006 MM5 simulation performance in simulating 

precipitation over the 12 km and 4 km grid domains. The total MM5 precipitation was 

calculated for each hour of the run. The total precipitation is equal to the sum of the resolved, 

grid-scale rainfall and the sub-grid-scale convective rainfall which is calculated by the cumulus 

parameterization. The sum of the hourly precipitation amounts in each grid cell was taken over 

a month to obtain a monthly precipitation total for each grid cell. The monthly model 

precipitation totals were then compared with monthly precipitation totals from the Climate 

Prediction Center (CPC) gridded precipitation analysis and the National Weather Service New 

Precipitation Analysis (NPA).

The CPC gridded precipitation amount dataset is available from the National Weather Service's 

Climate Prediction Center at 

http://www.cpc.ncep.noaa.gov/products/precip/realtime/retro.html. The CPC daily 

precipitation amounts are derived from rain gauge data from the River Forecast Center, and are 

gridded on a latitude-longitude mesh that covers the U.S. mainland at a resolution of 0.25°x 

0.25° (about 25 km x 25 km for Wyoming in the present modeling domain). The gridded 

precipitation fields are ramped down to zero immediately offshore of the Continental U.S. The 

CPC dataset was interpolated to the 12 km MM5 Lambert conformal grid for the analysis 

presented below. 

The advantage of the CPC precipitation data set is that it is a gridded field with reasonably high 

resolution that can be used to qualitatively evaluate model performance over land. However, 

this CPC product has a relatively coarse resolution compared to that of the 12 km or 4 km grid, 

and features such as intense localized precipitation from thunderstorms will be smoothed out 

in the CPC fields so that its maxima will be less intense and its rainfall will be distributed over a 

wider area than in the real world or on the 12/4 km MM5 grids. This CPC product can be most 

effectively used as a screening tool to determine whether there was any rainfall in a given area 

on a particular day, rather than to compare specific rainfall amounts and we use it here to 

evaluate the 12 km MM5 rainfall because its resolution is most similar to this grid. 

For evaluating the model precipitation fields on the 4 km grid, we use the National Weather 

Service New Precipitation Analysis (NPA). The NPA data set is also derived from the River 

Forecast gauge data, has a resolution of 4 km, and has been gridded to the MM5 model’s 

Lambert conformal projection. The data are available at: 

http://www.srh.noaa.gov/rfcshare/precip_analysis_new.php. The 2005/2006 MM5 

precipitation evaluation focuses on February, April, and July, which are winter, spring, and 

summer months with high ozone/nitrate over southwest Wyoming during 2005-6.

Figures D.39 and D.40 show the observed and modeled 2005 precipitation on the 12 km and 4 

km domains, respectively. On the 12 km grid, the observed large-scale features are wellsimulated by the model. Most of the rainfall during February is generated by synoptic-scale 

(~1000 km) weather systems that are well-resolved by MM5. The increased resolution of the 4 

km grid enhances the orographic rainfall. For example, precipitation totals are larger over the 

Wind River Range in Wyoming on the 4 km grid (>100 mm) than on the 12 km grid (<50 mm). 
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-34

On both grids, MM5 replicates the overall pattern well, but tends to overestimate rainfall 

maxima, especially in Northern Colorado.

In February, 2006, the overall rainfall pattern is reproduced well by the model on the 12 km grid 

(Figure D.41). On the 4 km grid (Figure D.42), rainfall is generally overpredicted on the 4 km 

grid. On the 4 km grid, there is a region of high precipitation lying along the Wind River Range 

where the maximum is greater than 160 mm, while the observed totals are lower. It is worth 

bearing in mind that mountainous regions are less well-sampled by the rain gauge network 

than lower-lying areas, which introduces a bias toward underestimating the actual precipitation 

by failing to capture the orographically enhanced precipitation in the high terrain features. The 

use of the CuP has only a minor impact on the precipitation field, since most precipitation is 

resolved at grid-scale in February.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-35

Figure D.39. February, 2005 precipitation in 12 km MM5 domain.

Figure D.40. February, 2005 precipitation in 4 km MM5 domain.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-36

Figure D.41. February, 2006 precipitation in 12 km MM5 domain.

Figure D.42. February, 2006 precipitation in 4 km MM5 domain.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-37

April marks a transition between the synoptic-scale storms of winter and the convective storms 

of summer. On the 12km grid, MM5 picks up the main features in the observed April 2005 

precipitation (Figure D.43), but shows areas of overestimated precipitation. Comparison of the 

4 km modeled precipitation with the NWS data set (Figure D.44) shows that the modeled 

maxima are much higher than the observed maxima. We may expect CAMx to overestimate 

wet deposition on the 4 km grid during April. In April, precipitation performance is better on 

the 12 km grid than on the 4 km grid. MM5 performance in 2006 is similar to 2005 (Figures 

D.45 and D.46), with better performance on the 12 km grid than the 4 km grid. Use of the CuP 

tends to exaggerate the precipitation overprediction, and does not improve performance in 

April.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-38

Figure D.43. April, 2005 precipitation in 12 km MM5 domain.

Figure D.44. April, 2005 precipitation in 4 km MM5 domain.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-39

Figure D.45. April, 2006 precipitation in 12 km MM5 domain.

Figure D.46. April, 2006 precipitation in 4 km MM5 domain.

In July, most rainfall is produced by convective storms that are not well-resolved by MM5, even at 

4 km grid size. The observed precipitation distribution is relatively smooth and is difficult to 

compare to modeled pattern, which is spottier due to localized nature of convective storms. 

Rainfall is overestimated on the 12 km grid and the modeled maxima are misplaced (Figures D.47 

and D49); the overall pattern of rainfall is not nearly as well-reproduced in July as in January. 

Summer rainfall is greatly overestimated on the 4 km grid in both 2005 (Figure D.48) and 2006 

(Figure D.50) regardless of whether or not a CuP is used. The overestimate is more pervasive in 

2006 than in 2005 despite use of cumulus parameterization in new 2006 run. This pronounced 

summer rainfall overprediction in the west was seen in the RPO 2002 annual runs, and is typical 

of MM5. Excessive rainfall will cause wet deposition of soluble species to be overestimated.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-40

Figure D.47. July, 2005 precipitation in 12 km MM5 domain.

Figure D.48. July, 2005 precipitation in 4 km MM5 domain.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-41

Figure D.49. July, 2006 precipitation in 12 km MM5 domain.

Figure D.50. July, 2006 precipitation in 4 km MM5 domain.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-42

Figure D.51. Time series of observed (black) and MM5 (red) January 2005 near-surface 

temperature (upper panel) and humidity bias (lower panel) at the Wamsutter monitor.

Predicted/Observed Humidity

0

2

4

6

8

10

12

14

16

18

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

g/kg

ObsHum PrdHum Bias Humidity

- 4

- 2

0

2

4

6

8

10

12

 7/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9

 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31

g/kg

BiasHum 
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-43

SUMMARY OF PRECIPITATION PERFORMANCE

In winter, the 2005 and 2006 MM5 runs show considerable skill in reproducing the observed 

precipitation field. In spring and summer, rainfall is overestimated over much of Wyoming on 

the 12 km and 4 km grids. The overestimate is due to excessive convective rainfall; this problem 

was noted in the RPO runs as well. Although the 2006 simulation was run both with cumulus 

parameterization turned on and off (no CuP was used in the original 2006 run), the 

overestimate of precipitation remains, and worsened in July.

OVERALL SUMMARY OF MM5 MODEL PERFORMANCE

The overall performance of the 2005/2006 MM5 simulations was generally good and was 

comparable to the RPO 2002 MM5 annual run performance. Simulation of surface winds was 

reasonably consistent with observed winds, with a persistent low wind speed bias and generally 

good wind direction except during times of rapid shifts in the observed winds. Precipitation 

performance was very good during winter, but rainfall was overestimated during spring and 

summer, which is typical of MM5 and which will likely cause CAMx to overestimate the 

deposition of soluble species. The modeled surface humidity has a corresponding wet bias, 

which grows more pronounced during the summer. 

Because of the overall good performance and the fact that the 2005/2006 MM5 run 

performance was comparable to that of similar annual modeling efforts, we conclude that the 

MM5 runs for 2005 and 2006 may be used to supply the meteorological input database for the 

CAMx air quality modeling in the CD-C impact analysis. The new 2006 run with CuP will be 

used both for consistency with 2005 and because of the slight improvement in surface wind 

performance. No significant improvement was noted in the precipitation fields due to the use 

of the CuP, however.
APPENDIX D – MODEL PERFORMANCE EVALUATION 

OF THE 2005-2006 MM5 SIMULATIONS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 D-44

REFERENCES

Dudhia, J., 1993. "A Non-hydrostatic Version of the Penn State/NCAR Mesoscale Model: 

Validation Tests and Simulation of an Atlantic Cyclone and Cold Front", Mon. Wea. Rev., 

Vol. 121. pp. 1493-1513.

ENVIRON and Alpine. 2009. Four Corners Prevention of Significant Deterioration (PSD) 

Consumption Study. ENVIRON International Corporation, Novato, CA and Alpine 

Geophysics, LLC, Arvada, CO. April 17.

ENVIRON. 2009. Air Quality Modeling Study for the Four Corners Region. ENVIRON 

International Corporation, Novato, CA. June 30.

Grell, G. A., J. Dudhia, and D. R. Stauffer, 1994. "A Description of the Fifth Generation Penn 

State/NCAR Mesoscale Model (MM5). NCAR Tech. Note, NCAR TN-398-STR, 138 pp.

Johnson, M. 2007. Meteorological Model Performance Evaluation of an Annual 2002 MM5 

(Version 3.6.3) Simulation. Iowa Department of natural Resources, Air Quality Bureau. 

November. (http://www.iowadnr.gov/air/prof/progdev/modeling.html).

Johnson, J., Y. Jia, C. Emery, R. Morris, Z. Wang and G. Tonnesen. 2006. Comparison of CENRAP 

36 km and 12 km MM5 Model Runs for 2002. Prepared for CENRAP Modeling Work 

Group. May 23. 

(http://pah.cert.ucr.edu/aqm/cenrap/ppt_files/CENRAP_2002_36km_vs_12km_MM5_

May22_2006.ppt).

Kemball-Cook, S., Y. Jia, C. Emery, R. Morris, Z. Wang and G. Tonnesen. 2004. Comparison of 

CENRAP, VISTAS and WRAP 36 km MM5 Model Runs for 2002, Task 3: Meteorological 

Gatekeeper Report. 

(http://pah.cert.ucr.edu/aqm/cenrap/ppt_files/CENRAP_VISTAS_WRAP_2002_36km_M

M5_eval.ppt). December 14.

Olerud, D. 2003a. “Evaluation Methodologies for Meteorological Modeling in Support of 

VISTAS (Visibility Improvement – State and Tribal Association): Task 1 Deliverables” 

(Draft) Baron Advanced Meteorological Systems, LLC, Research Triangle Park, NC. 

(available at: http://www.baronams.com/projects/VISTAS/#reports). April 16.

Olerud, D. 2003b. “Protocol for Annual MM5 Modeling of VISTAS (Visibility Improvement –

State and Tribal Association): Task 7c Deliverable.” Baron Advanced Meteorological 

Systems, LLC, Research Triangle Park, NC. (available at: 

http://www.baronams.com/projects/VISTAS/#reports). March 27. 
Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016

Appendix E

Diagnostic Sensitivity Test Modeling Results to Achieve Final Base Case 

Model Configuration for the Continental Divide-Creston O&G EIS
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-1

INTRODUCTION

The Continental Divide-Creston (CD-C) oil and gas (O&G) development Environmental Impact 

Statements (EISs) is using the Comprehensive Air-quality Model with extensions (CAMx; 

ENVIRON, 2009) to estimate ozone and far-field air quality (AQ) and air quality related value 

(AQRV) impacts due to the proposed project alternatives and cumulative emissions 

development throughout southwestern Wyoming (SWWY). The first step in the application of 

CAMx for an air quality analysis is to apply the model using base case year emissions and 

evaluate the model estimates against available AQ and AQRV measurements in a model 

performance evaluation (MPE). The MPE includes evaluating the CAMx model performance 

following EPA guidance metrics and goals (EPA, 1991; 1999; 2007). Once the model has been 

deemed to meet the established metrics and goals it can then be used to estimate future year 

AQ and AQRV impacts.

PRELIMINARY CAMX BASE CASE SIMULATION

CAMx has been set up on a 36/12/4 km modeling domain for the 2005 and 2006 calendar years 

with the 4 km modeling domain focused on SWWY, which includes the location of the proposed 

CD-C project. A preliminary CAMx base case simulation was performed and an initial MPE 

conducted under the Hiawatha EIS study (Kemball-Cook, et al., 2009). On August 20, 2009, the 

CD-C air quality modeling team met with the Cooperating Agencies (BLM, EPA Region 8, NPS, 

USFS and WDEQ-AQD) to discuss the preliminary CAMx model performance evaluation. The 

Cooperating Agencies raised concerns over the CAMx model performance. In particular, 

concerns were raised regarding the summer ozone performance at the SWWY industrial sites 

(e.g., Boulder, Daniel and Jonah) and the particulate nitrate (NO3) winter overprediction and 

summer underprediction tendency. The Cooperating Agencies recommended that additional 

model sensitivity tests be conducted to identify a CAMx base case model configuration with 

improved ozone and nitrate model performance, with more emphasis on improvements in the 

ozone than nitrate performance.

DIAGNOSTIC SENSITIVITY MODELING PLAN

Rarely does a photochemical grid model (PGM) meet all model performance evaluation goals in 

the first base case model simulation. As noted in EPA’s latest modeling guidance “By definition 

models are simplistic approximations of complex phenomena. The modeling analysis ... 

contains many elements that are uncertain (e.g., emission projections, meteorological inputs, 

model response)” (EPA, 2007, pg. 98). EPA recommends that diagnostic model sensitivity tests 

be performed to identify an optimally performing model and understand the model uncertainty 

to key inputs and assumptions. However, care must be taken that any changes in model 

configuration be scientifically justified and not just based on improved model performance.

Based on discussions with the Cooperating Agencies at the CD-C Air Quality Stakeholders 

meeting on August 20, 2009 in Cheyenne, the CD-C modeling team identified a set of sensitivity 

tests that could be conducted with the goal of improving model performance for ozone and 

nitrate (NO3). These tests were outlined in a Technical Memorandum to the WDEQ-AQD from 
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-2

ENVIRON and Carter Lake Consulting that was dated September 11, 2009 (Morris, KemballCook and Zapert, 2009a). The CAMx sensitivity tests were divided into three Phases:

 Already Completed Sensitivity Tests: The first set of sensitivity tests were completed 

before the August 20, 2009 Cooperating Agencies meeting and consisted of the following:

- Effects of mineral nitrate formation on NO3 model performance; and

- Updates to the ammonia emissions seasonal distribution based on more recent 

information.

 Round 1 Sensitivity Test Modeling: The first round of sensitivity tests incorporated an 

updated version of the CAMx model that includes corrections to the vertical velocity (VV) 

algorithms and evaluated the following:

- Effects of CAMx Vertical Velocity update on model performance; and

- Use of 34 vertical layers with no layer collapsing between the MM5 and CAMx vertical 

layer structure.

 Round 2 Sensitivity Tests Modeling: Round 2 sensitivity tests were performed using the 

CAMx VV modeling platform developed under Round 1 and investigated the sensitivity of 

the CAMx VV model performance to the following:

- Vertical Mixing – Alternative Kv profiles and minimum Kv;

- Dry Deposition – use of an update Zhang dry deposition scheme;

- Horizontal Resolution – use of 4 km resolution grid over portions of SWWY;

- Aggressive Plume-in-Grid (PiG) – more widespread use of PiG (e.g., compressors, drill 

rigs, etc.); 

- Horizontal Diffusion – change horizontal diffusion (Kh) coefficients by factor of 3; and

- Combinations of the above.

The initial sensitivity tests (completed August 2009) and Round 1 sensitivity modeling were 

documented in a November 19, 2009 Technical Memorandum “Continental Divide-Creston 

Modeling Preliminary (Round 1) CAMx Sensitivity Test Results for Southwestern Wyoming” 

(Morris, Kemball-Cook and Zapert, 2009b) and are summarized below. 

INITIAL MODEL SENSITIVITY TESTS

Two model sensitivity tests were completed before the August 20, 2009 Cooperating Agencies 

meeting prior to the beginning of the Round 1 sensitivity modeling:

 Update seasonal adjustments to ammonia emissions.

 Treatment of mineral nitrate formation.

SEASONAL AMMONIA EMISSIONS DISTRIBUTION

Purpose: To determine whether improved representation of the seasonal allocation of 

ammonia emissions using more recent information would reduce the wintertime NO3 

overprediction bias.
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-3

Approach: Ammonia emissions for the 2005-2006 modeling were generated using the WRAP 

Ammonia Emissions Model (Mansell, 2005) that accounts for ammonia emissions from 

livestock, fertilizer usage, domestic sources and wild animals, with livestock and fertilizer usage 

being by far the two most important source categories in SWWY. The ammonia emissions were 

updated in this sensitivity test as follows:

 Correct an error in the spatial allocation of fertilizer NH3 emissions in the 12/4 km domain.

 Incorporate new updated monthly ammonia emissions factors for livestock emissions in 

the WRAP ammonia model:

- Based on Gilliland et al., (2006).

- Amplifies seasonal cycle (higher in summer lower in winter).

- Results in ~25% reduction in livestock NH3 in February.

 Set fertilizer NH3 emissions to zero for grid cells that are covered in snow or where ground 

is frozen:

- Fertilizer is generally not applied to frozen or snow-covered ground.

- Extensive snow cover was present in SWWY during February 2006.

- Results in ~70% reduction in ammonia emissions due to fertilizer usage in February 

2006.

Results: The CAMx NH3 emissions sensitivity test was run for the February 2006 period on the 

12/4 km modeling domain. With the updates to the ammonia emissions inventory the total 

ammonia emissions in the 12/4 domain in the NH3 sensitivity test were approximately half of 

the base case emissions. Figure E-1 compares the ammonia concentrations at the Boulder site 

for February 2006 and the Base Case, corrected fertilizer NH3 emissions spatial distribution 

case (correctedNH3) and NH3 sensitivity test (revisedNH3) with the monthly observed ammonia 

concentrations in 2007. The February average predicted NH3 concentration is reduced by ~30% 

in the NH3 sensitivity test simulation at the Boulder monitoring site, but is still higher than what 

was observed in February 2007. Figure E-2 displays the NO3 fractional bias performance metric 

in February 2006 across IMPROVE monitoring sites in the 12/4 km domain for the Base Case 

and NH3 Sensitivity Test. Across all sites the NO3 overprediction bias in February 2006 is 

reduced from 131% to 126% (Figure E-2). The February 2006 NO3 results for the base case, 

corrected NH3 spatial distribution and NH3 sensitivity test at Mount Zirkel Wilderness area are 

shown in Figure E-3 that shows a very slight reduction in NO3 and very minimal improvement in 

NO3 performance for the NH3 Sensitivity Test.
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-4

Figure E-1. Comparison of predicted February 2006 ammonia concentrations with observed 

values in February 2007 for the CAMx base case, corrected NH3 spatial distribution and NH3 

sensitivity test.

Figure E-2. February 2006 NO3 Fractional Bias at IMPROVE sites in the 12/4 km modeling 

domain for the CAMx Base Case and NH3 sensitivity test.

Fractional Bias for IMPROVE Sites Within the 12 km Grid

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APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-5

Figure E-3. February 2006 predicted and observed 24-hour average NO3 concentrations at 

the Mount Zirkel IMPROVE monitoring site for the CAMx base case, corrected NH3 spatial 

distribution and NH3 sensitivity test.

Recommendation: Although the NH3 temporal allocation sensitivity test has minimal effect on 

the NO3 model performance, we recommend that the updated ammonia emissions monthly 

adjustment factors be adopted in the final CAMx base case simulation as it represents more 

current understanding of ammonia emissions than what was used previously in the WRAP 

ammonia emissions model (Mansell, 2005).

MINERAL NITRATE SENSITIVITY

Purpose: To account for the effect of the mineral component of crustal PM2.5 emissions (dust) 

to bind nitrate and convert gaseous nitric acid to particulate nitrate, and determine whether its 

effect reduces the summer NO3 underestimation bias in CAMx.

Approach: The University of Athens has implemented the capability of simulating mineral nitrate 

formation in the CAMx model Astitha et al. (2007a,b; 2009a,b). Prior to this, ammonia and 

sodium were the only basic compounds implemented in CAMx Version 4 that could neutralize 

gaseous HNO3 to form particulate NO3 [e.g., NH4NO3]. During the warmer summer months, the 

aerosol thermodynamic properties result in volatilization of particulate NH4NO3 into gaseous 

HNO3 and NH3. Mineral nitrate, such as Calcium Nitrate, on the other hand, is not volatile so will 

remain in the particulate phase even under hot conditions. Based on analysis of ambient air 

quality data, the University of Athens estimated that 6% of the crustal material in their airshed is 

Calcium and implemented the capability of forming Calcium Nitrate in CAMx assuming that 6% of 

the crustal material in the model is Calcium. We analyzed IMPROVE measurements in SWWY and 

nearby regions (e.g., Bridger, Mt. Zirkel and Yellowstone) and found the Calcium to Soil ratio was 

fairly constant with an average value of also approximately 6%. Thus, we performed a CAMx 

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APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-6

sensitivity test in which 6% of the fine and coarse crustal PM species in CAMx were assumed to be 

Calcium for treatment in the ISORROPIA aerosol thermodynamic model. 

Results: The CAMx model was run on the 12/4 km domain for August 2006 using the mineral 

nitrate algorithm assuming that 6% of the crustal material was Calcium and the modeled NO3 

predictions compared against the observed values at the IMPROVE monitoring sites. Figure E-4 

displays the NO3 fractional bias performance metric at IMPROVE monitoring sites during 

August 2006 for the CAMx Base Case and Mineral Nitrate Sensitivity Test. At most of the 

IMPROVE sites, the CAMx Base Case simulation NO3 fractional bias exhibits an underprediction 

bias of -60% to -180% during August 2006. The CAMx Mineral Nitrate Sensitivity Test reduces 

the NO3 underprediction bias slightly, but the CAMx NO3 performance is still characterized by a 

large underestimation bias (Figure E-4). The fractional bias averaged across IMPROVE 

monitoring sites in the 12/4 km domain during August 2006 is reduced from -128% in the Base 

Case to -94% in the Mineral Nitrate Sensitivity Test. Figure E-5 displays predicted and observed 

time series of 24-hour NO3 concentrations at the Bridger IMPROVE monitor that illustrate the 

small increases in particulate NO3 due to the inclusion of mineral nitrate in CAMx.

Recommendation: We recommend that mineral nitrate be adopted in the final CAMx Base 

Case simulation as it represents a real atmospheric constituent that should be accounted for in 

the modeling.

Figure E-4. Fractional bias for NO3 during August 2006 for the CAMx Base Case and Mineral 

Nitrate Sensitivity test.

Fractional Bias for IMPROVE Sites in 12 km Grid

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APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-7

Figure E-5. Time series of predicted and observed 24-hour NO3 concentrations at the Bridger 

IMPRVE monitoring site for the CAMx Base Case and Mineral Nitrate Sensitivity Test.

ROUND 1 SENSITIVITY MODELING

The Round 1 sensitivity modeling performed under the CD-C EIS focused on the update of the 

2005/2006 36/12/4 km CAMx modeling database using a new version of the CAMx model that 

has corrections to the vertical velocity (VV) algorithm (CAMx VV; Emery et al., 2009a,b)1that 

reduces excessive vertical transport over high terrain. The Western Regional Air Partnership 

(WRAP) Community Multiscale Air Quality (CMAQ) and Four Corners Air Quality Task Force 

(FCAQTF) CAMx modeling found that both models generate excessive vertical transport over 

the highest terrain features. This modeling artifact can bring high ozone concentrations of 

stratospheric origin from the very top layers of the model (top of model is ~15 km above MSL) 

to the ground-level over high terrain features, such the Rocky Mountains and the Sierra Nevada 

Mountains, Cascade Range and Wind River Range. After a focused research effort, the CAMx 

model was updated with a new vertical velocity algorithm to alleviate this modeling artifact 

(Emery et al., 2009a,b). EPA has also identified a fix of this modeling artifact (Young, Pleim and 

Mathur, 2009), but has not released an updated CMAQ code with the correction. Also during 

Round 1, we evaluated the effects of running with and without vertical layer collapsing 

between the MM5 meteorological model and the CAMx chemical transport model.

The Round 1 sensitivity modeling incorporated the following updates in the CAMx 2005/2006 

36/12/4 km modeling database:

 Use of new lateral boundary conditions (BCs) for the 36 km continental U.S. domain and 

the 2005 and 2006 modeling periods based on day-specific 2005 and 2006 GEOS-CHEM 

 

1

http://www.cmascenter.org/conference/2009/slides/emery_reducing_vertical_2009.ppt
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-8

global chemistry model output that replaced the monthly average BCs based on 2002 

GEOS-CHEM output used in the previous base case simulation2;

 Use of higher vertical resolution (22 layers) than used previously (19 layers);

 Use of zero-gradient top BC (i.e., concentrations above the top of the model are assumed 

to be the same as in the top layer of the model); and

 Use of CAMx VV model version with updated vertical velocity algorithm (Emery et al., 

2009a, b).

We also performed one additional sensitivity test with no layer collapsing between the MM5 

meteorological model and the CAMx chemical transport model: 

 Use of 34 vertical layers in CAMx with no layer collapsing between MM5 and CAMx.

Figure E-6 compares the predicted and observed daily maximum 8-hour ozone concentrations 

during April 2005 in the western portion of the 36 km domain and the 4 km SWWY domain 

using the original CAMx model (top) and CAMx VV model with updated vertical velocity 

algorithm (bottom). Both runs use the new 2005 GEOS-CHEM BCs and have 22 layers in CAMx. 

The original CAMx model estimates highest daily maximum 8-hour ozone concentrations of 80-

95 ppb that occur across the Rocky Mountains from northwest New Mexico stretching 

northward across Colorado (Figure E-6, top). The observed highest April 2005 daily maximum 

8-hour ozone concentrations at four CASTNet sites in these locations (e.g., Mesa Verde, Gothic, 

Mt. Zirkel) are 10-30 ppb lower ranging from 67 ppb to 73 ppb. In the same locations over the 

Rocky Mountains, use of the new CAMx VV code results in highest daily maximum 8-hour ozone 

concentrations during April 2005 that are comparable (65-80 ppb) to the observed values (67-

73 ppb). Time series of predicted and observed hourly ozone concentrations were evaluated at 

the Boulder and Jonah industrial sites during July 7-9, 2005 for the original CAMx base case, the 

revised CAMx VV, and the 22 and 34 vertical layer sensitivity test runs (Figure E-7). None of 

these runs reproduce the highest afternoon observed ozone concentrations at the SWWY 

industrial sites. The CAMx VV simulations run with 22 and 34 vertical layers produce nearly 

identical results.

Clearly, the overstated ozone over the high terrain produced using the original CAMx model is 

undesirable so the use of the updated CAMx VV code is recommended for the final CAMx base 

case configuration. However, it should be noted that both the original CAMx and CAMx VV 

code still underestimated the summer high afternoon ozone concentrations at the SWWY 

industrial monitoring sites at the completion of the Round 1 Sensitivity testing.

The use of 22 or 34 vertical layers in CAMx is less clear as the two layer configurations produce

essentially identical results in SWWY. However, EPA/ORD now recommends that no layer 

collapsing be utilized with their CMAQ model3. A poll of the Cooperating Agencies indicated that 

 

2

Note that day-specific 3-hour 2005/2006 GEOS-CHEM output were just available for gaseous species and May-September. 

Particulate species BCs and BCs for other time periods of the 2005/2006 year were still based on the monthly average diurnally 

varying 2002 GEOS-CHEM results.

3

http://www.cmascenter.org/conference/2009/slides/young_mass_consistency_2009.pdf
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-9

some had a preference for using a final CAMx base case configuration with no layer collapsing 

(34 vertical layers), whereas others could go with either 22 or 34 vertical layers in the CAMx 

modeling. Given this slight preference for using no layer collapsing, the recommended 

configuration for the final CAMx base case was 34 vertical layers.

Implications of Already Completed and Round 1 Sensitivity Modeling: The use of updated NH3 

emissions temporal allocations factors and the mineral nitrate algorithm in CAMx represents 

better science and has essentially no effect on the CAMx model run times so would not affect

schedules associated with the final model base case and future year simulations. Likewise, the 

original CAMx and CAMx VV codes have similar computation requirements so would also not 

affect the schedule of the CD-C modeling. Use of the CAMx VV code represents better science. 

The use of no layer collapsing (34 layers) in CAMx VV produces nearly identical concentrations 

as using 22 vertical layers with a ~50% increase in model run time for each CAMx simulation. 
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-10

36 km Grid: New BCs, 22 Layers, and Original CAMx Code

36 km Grid: New BCs, 22 Layers, and New CAMx VV Code

Figure E-6. Comparison of predicted daily maximum 8-hour ozone concentrations 

(ppb) across the western portion of the 36 km domain during April 2005 using the new 

2005 GEOS-CHEM BCs, 22 vertical layers and the original CAMx (top) and updated 

CAMx VV (bottom) models.
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-11

Figure E-7a. Predicted and observed hourly ozone concentrations during July 7-9, 

2005 at the Daniel monitoring site for the original CAMx 19 layer base case with 2002 

cropped BCs and New 2005 BCs using original CAMx with 22 layers and new CAMx VV 

with 22 and 34 vertical layers.

Figure E-7b. Predicted and observed hourly ozone concentrations during July 7-9, 

2005 at the Jonah monitoring site for the original CAMx 19 layer base case with 2002 

cropped BCs and New 2005 BCs using original CAMx with 22 layers and new CAMx VV 

with 22 and 34 vertical layers.

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APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-12

ROUND 2 SENSITIVITY MODELING

The original September 11, 2009 Technical Memorandum to the CD-C Stakeholders on the 

proposed CAMx sensitivity tests contained a list of potential additional CAMx sensitivity tests 

suggested by the Cooperating Agencies at the August 20th meeting and in follow-up 

discussions. After discussion among WDEQ-AQD and other Cooperating Agencies, the list of 

potential sensitivity tests in the September 11, 2009 Technical Memorandum (Morris, KemballCook and Zapert, 2009a ) was pared down so that it included only the tests that might lead to 

changes in the CAMx base case model configuration that would improve ozone and/or nitrate 

model performance. The following sensitivity tests were performed as part of the Round 2 

sensitivity modeling:

 Dry Deposition;

 HONO Emissions;

 Vertical Mixing;

 Horizontal Resolution;

 Aggressive Plume-in-Grid; and

 Horizontal Diffusion.

DRY DEPOSITION SENSITIVITY

Purpose: To determine whether an alternative dry deposition scheme implemented in CAMx 

would improve ozone and nitrate model performance.

Approach: Dry deposition is an important sink of ozone and its precursors as well as particulate 

matter. It is active over the entire modeling domain at all times, and the parameterization of 

dry deposition within a regional model can have a significant impact on model performance. 

The dry deposition scheme that is currently used in CAMx is based on the Wesely (1989) 

scheme, which is now rather dated, but still widely used in air quality modeling. Shortcomings 

of this scheme are that its surface resistances are defined for typical eastern U.S. vegetation 

types, density, and seasonal conditions and it has a limited representation of atypical conditions 

(e.g. drought, seasonal transitions). Recently, a new dry deposition scheme (Zhang et al., 2006; 

2003) used in the Environment Canada AURAMS air quality model has been incorporated into 

CAMx. The Zhang scheme is a state-of-the-science algorithm that incorporates recent updates 

in theory and measurements and has been adapted for use in CAMx to represent atypical 

conditions through the use of a satellite-derived leaf area index. The Zhang scheme has been 

used in daily air quality forecasting applications and has been evaluated against recent SO2 and 

ozone flux measurements. The Zhang algorithm treats deposition of both gases and particles 

and has a new cuticle and ground resistance formulation for low temperatures and snowcovered surfaces as well as an updated scheme for non-stomatal resistance that accounts for 

the effects of meteorological conditions. The Zhang scheme uses a more detailed land surface 

classification scheme than the Wesely scheme (26 land use categories in Zhang versus 13 in 

Wesely).
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-13

The CAMx alternative dry depositions scheme of Zhang and co-workers was used instead of the 

Wesely (1989) parameterization used in the preliminary and Round 1 CAMx base case 

simulations to test whether the Zhang parameterization would lead to improved CAMx summer 

ozone model performance at the SWWY industrial sites.

Results: The Round 1 CAMx 22 layer base case simulation was rerun using the CAMx model 

with the Zhang dry deposition scheme for the June 15-July 10, 2005 period and the CAMx ozone 

model performance was evaluated at ozone monitors in SWWY for the July 7-9, 2005 high 

ozone period. Figure E-8 displays the time series of the predicted and observed hourly and 

daily maximum (DM) 8-hour ozone concentrations at the Pinedale CASTNet and the Daniel, 

Jonah and Boulder WDEQ industrial sites for July 7-9. 2005 period and the CAMx model using 

the Wesely and Zhang dry deposition algorithms. CAMx using the Zhang dry deposition scheme 

estimates higher ozone concentrations that better matches the observed ozone concentrations 

at the SWWY WDEQ industrial sites during July 7-9, 2005. Results for the Pinedale CASTNet site 

are mixed and confounded by the presence of four observed hourly ozone spikes that look like 

invalid observations.

Figure E-9 displays CAMx estimated daily maximum 8-hour ozone concentrations on July 8, 

2005 for the base case (left) and the differences using the Zhang and Wesely (base case) dry 

deposition algorithms (right). Use of the Zhang dry deposition scheme generally results in daily 

maximum 8-hour ozone concentrations across SWWY that are 2-6 ppb higher than when the 

Wesely scheme is utilized. Although increases as high as 8 ppb occur in SWWY and there are 

even decreases up to -2 ppb on the lee side of the Wind River Range.

At the SWWY WDEQ monitoring sites, CAMx using the Zhang dry deposition algorithms 

estimates daily maximum 8-hour ozone concentrations that are approximately 3 ppb higher 

than the CAMx estimates using the Wesely dry deposition scheme. This results in better 

agreement with the observed daily maximum 8-hour ozone concentrations in SWWY. For 

example, average across all three WDEQ industrial sites in the Jonah-Pinedale area and the July 

7-10, 2005 period the observed average concentrations (63.6 ppb) is underestimated by 11% (-

7 ppb) using CAMx with the Wesely dry depositions algorithm (56.7 ppb), but only 

underestimated by 3% (-2 ppb) when the Zhang dry deposition algorithm is used (61.5 ppb).
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-14

Figure E-8a. Time series of observed (black) and CAMx predicted hourly ozone 

concentrations (ppb) at the Pinedale CASTNet (top) and Daniel WDEQ 

industrial (bottom) sites for CAMx using the Wesely (w_ddep; pink) and Zhang 

(z_ddep; green) dry deposition schemes. Daily maximum (DM) 8-hour ozone 

concentrations are also shown.

Time Series from Jul 07 to Jul 09 at Pinedale

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APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-15

Figure E-8b. Time series of observed (black) and CAMx predicted hourly 

ozone concentrations (ppb) at the Jonah (top) and Boulder (bottom) WDEQ 

industrial sites for CAMx using the Wesely (w_ddep; pink) and Zhang 

(z_ddep; green) dry deposition schemes. Daily maximum (DM) 8-hour 

ozone concentrations are also shown.

Time Series from Jul 07 to Jul 09 at Jonah

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APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-16

Figure E-9. CAMx estimated daily maximum 8-hour ozone concentrations (ppb) in the 

Round 1 base case on July 8, 2005 (left) and differences in estimated daily maximum 8-

hour ozone concentrations between the Zhang dry deposition sensitivity test with the base 

case that used the Wesely dry deposition scheme (right; Zhang-Wesely).

HONO EMISSIONS SENSITIVITY (S5)

Purpose: To determine whether the speciation of a small fraction of the NOx emissions into 

nitrous acid (HONO) would improve summer ozone model performance in SWWY.

Approach: The California Air Resources Board (CARB) performs their PGM modeling assuming 

that 3 percent of the emitted NOx emissions are HONO. However, when performing PGM 

modeling outside of California, the EPA and States assume that NOx is emitted as NO and NO2 

(typically split as 90% NO and 10% NO2). In this sensitivity test we assumed that all nonbiogenic NOx emissions (i.e., combustion NOx emissions including anthropogenic sources and 

wildfires) in the 12/4 km modeling domain included 3% of the NOx emitted as HONO. The NO 

and NO2 emissions were adjusted downward so that the HONO sensitivity test included the 

same amount of total NOx emissions as the original CAMx Round 1 base case simulation.

Results: Assuming that 3% of the NOx emissions are emitted as HONO results in very small 

increases in the CAMx ozone estimates. This results in a very slight improvement in the CAMx 

ozone underestimation bias. Figure E-10 displays the CAMx estimated daily maximum 8-hour 

ozone concentrations non July 8, 2005 for the base case and the differences between the 

HONO sensitivity test and the base case. The largest increase in daily maximum 8-hour ozone

concentrations due to the inclusion of 3% NOx emissions as HONO is 0.6 ppb.
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-17

Figure E-10. CAMx estimated daily maximum 8-hour ozone concentrations (ppb) in the 

Round 1 base case on July 8, 2005 (left) and differences in estimated daily maximum 8-

hour ozone concentrations between the HONO emissions sensitivity test with the base 

case that assumed no HONO emissions (right; HONO-Base).

AGGRESSIVE PLUME-IN-GRID SENSITIVITY (S6)

Purpose: To determine whether aggressive use of the Plume-in-Grid (PiG) module improves 

ozone model performance in SWWY.

Approach: CAMx includes a subgrid-scale Plume-in-Grid (PiG) module that is used to simulate 

the near-source plume chemistry and dynamics of point source plumes. Emissions from a point 

source are initially released as a concentrated point source plume, instead of instantaneously 

dispersing them across a grid cell (e.g., 4 km or 1 km in SWWY). As the plume moves downwind 

it expands and entrains concentrations from the grid and performs full chemistry on the plume 

concentrations. When the size of the PiG plume is commensurate to the size of a grid cell, the 

emissions from the point source (altered by chemical transformation) are released to the grid 

model for further simulation.

In a typical CAMx simulation, the PiG module is used to treat the largest NOx point sources. 

The NOx point sources are ranked in the area of primary interest and the top several hundred 

NOx point sources are flagged for treatment by the PiG algorithm. For example, in the 

preliminary and Round 1 CAMx base case simulations the Bridger and Naughton generating 

stations were treated by the PiG module.

In this sensitivity test we performed aggressive PiG modeling of O&G sources in SWWY. All 

O&G compressors and drill rigs in SWWY during July 2005 were flagged for treatment by the 

CAMx PiG module (139 drill rigs operating in SWWY during July 2005). The reasoning behind 

the PiG sensitivity test is that by treating the O&G NOx sources using the PiG module we may 

be able to achieve the spatial separation of the O&G VOC emissions (production) from the NOx 
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-18

emissions (drill rigs and compression) resulting in areas with higher VOC:NOx ratios and 

potentially higher ozone formation. EPA has performed multi-pollutant and multi-scale 

modeling of the Detroit area using CMAQ and CAMx and found that, for point sources, much of 

the benefit from using a high resolution 1 km grid could be realized using a 4 km grid resolution 

and the PiG module at a fraction of the computer resources. 

Results: The more aggressive use of the CAMx PiG module results in areas on ozone increases 

and decreases. Figure E-11 displays the differences in CAMx-estimated daily maximum 8-hour 

ozone concentrations between the base case and PiG sensitivity test on July 8, 2005. Ozone 

increases as high as 2.2 ppb are seen in the center of Sublette County, with more widespread 

but smaller decreases in ozone also occurring with a maximum decrease of -1.2 ppb. There is 

essentially no change in the ozone underestimation bias due to the aggressive use of the PiG 

module. There is also a computational penalty for the aggressive use of the PiG module that 

approximately doubles the computer time versus the standard PiG configuration.

Figure E-11. CAMx estimated daily maximum 8-hour ozone concentrations (ppb) in the 

Round 1 base case on July 8, 2005 (left) and differences in estimated daily maximum 8-

hour ozone concentrations between the aggressive PiG sensitivity test with the base 

case (right; PiG-Base).

VERTICAL MIXING SENSITIVITY (S7A AND S7B)

Purpose: To determine whether alternative vertical mixing parameterizations can lead to 

improved ozone and/or nitrate model performance in CAMx.

Approach: Vertical mixing in CAMx is controlled by the vertical turbulent exchange coefficients, 

which are also called vertical diffusion or eddy coefficients (referred to as Kv or Kz). The Kv 

values are defined at the interface between two vertical layers in each column of grid cells and 

are generated by the MM5CAMx processor that converts the MM5 meteorological output data 

into CAMx meteorological inputs. MM5 does not explicitly simulate Kv values, so they have to 

be deduced using the MM5 meteorological variables and a parameterization. There are three 
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-19

Kv parameterizations in MM5CAMx: (1) the O’Brien (OB70) scheme; (2) a scheme similar to the 

one used in the CMAQ MCIP processor (CMAQ-like); and (3) a scheme used with the 

Asymmetric Convective Mixing (ACM2) approach. The ACM2 approach has additional code 

internal to the CAMx model that invokes non-local vertical mixing under convective conditions 

in addition to the diffusion due to the Kv values. Thus the ACM2 Kv values represent the 

minimal level of mixing and under unstable convective conditions even more mixing can occur 

using the non-local mixing. 

After one of the three schemes listed above has been used to calculate the Kv, additional postprocessing of the MM5CAMx-generated Kv values may be performed to impose a minimal level 

of mixing in the lowest or lower layers of CAMx to account for mechanical or heat-induced 

mixing processes not included in MM5 and MM5CAMx. For example, the effects of an urban 

heat island may not be captured by MM5 so the vertical mixing over an urban area may be too 

low, trapping the urban NOx emissions in the lowest layer and inhibiting ozone formation 

within the urban area. The preliminary and Round 1 CAMx base case simulations used the 

OB70 Kv parameterization.

In this sensitivity test, we examined the sensitivity of the CAMx ozone predictions during July 

2005 to an alternative Kv parameterization and typical minimum Kv values. The Round 1 July 

2005 12/4 km 34 layer CAMx VV database was used and two vertical mixing sensitivity tests 

were performed and the resultant ozone predictions compared with the observed values during 

the July 7-9, 2005 period with high ozone at the SWWY industrial sites. The MM5CAMx 

processor was rerun to output the CMAQ-like Kv coefficients with a 1.0 m2/s minimum for 

June-July 2005 and the 12/4 km domains (s7a). A second vertical mixing sensitivity test was 

performed that ran the kv100 program on the CMAQ-like Kvs that sets the Kvs in the lowest 100 

m of the model to the maximum Kv value in that 100 m layer (s7b).

Results: Use of the CMAQ-like Kv (s7a) or CMAQ-like Kv with kv100 (s7b) results in mostly 

higher estimated ozone concentrations and improved ozone model performance at the SWWY 

ozone monitors during July 7-9, 2005. Figure E-12 displays the differences in daily maximum 8-

hour ozone concentrations on July 8, 2005 between the vertical mixing sensitivity tests and the 

Round 1 base case simulation. Use of the CMAQ-like Kvs results in mostly increases in daily 

maximum ozone concentrations on July 8th, with a maximum increase of 4.8 ppb; there are 

also smaller locations of ozone decreases with the maximum ozone decease (-5.3 ppb) 

comparable to the maximum ozone increase (Figure E-12, left). The use of the CMAQ-like KVs 

with kv100 results in even more widespread ozone increases ozone the base case with a 

maximum ozone increase of 7.3 ppb and even smaller areas of ozone deceases. Both vertical 

mixing sensitivity tests produce improved ozone bias model performance metrics.
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-20

Figure E-12. Differences in CAMx-estimated daily maximum 8-hour ozone 

concentrations on July 8, 2005 between the CMAQ-like Kv (s7a; left) and CMAQ-like Kv 

with kv100 (s7b; right) sensitivity tests and the Round 1 base case that used the OB70 

Kv parameterization.

HORIZONTAL DIFFUSION SENSITIVITY (S8A & S8B)

Purpose: To determine if increasing or decreasing horizontal diffusion in the CAMx model 

improves ozone model performance in SWWY.

Approach: Horizontal diffusion in the CAMx and CMAQ models is governed by the 3-D 

horizontal diffusion coefficients (Kh) that are calculated internally in the two models. Like 

vertical mixing, the horizontal diffusion coefficient parameterizations are uncertain, although 

modeled concentrations are believed to be less sensitive to horizontal diffusion than some 

other meteorological inputs (e.g., vertical mixing, winds, etc.). The horizontal diffusion 

coefficient sensitivity tests increase and decrease the Kh values by a factor of three and 

examined their effects on ozone performance in SWWY for July 2005. The reason for 

performing the Kh reduction sensitivity test (1/3 x Kh) is that it may sharpen the ozone peaks in 

SWWY and help separate the O&G VOC and NOx emissions resulting in higher VOC:NOx ratios 

in some locations and consequently greater ozone formation. The reason for the enhanced 

horizontal diffusion sensitivity test (3 x Kh) is that it may result in more dispersion of the O&G 

NOx emissions and lessen the NOx inhibition effect on ozone formation.

Results: Figure E-13 displays the differences in estimated daily maximum 8-hour ozone 

concentrations on July 8, 2005 between the horizontal diffusion sensitivity tests and the Round 

1 base case simulations. Again there are areas of ozone increases and decreases in the 

horizontal diffusion sensitivity tests with most of the ozone changes being within ±2 ppb.
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-21

Figure E-13. Differences in CAMx-estimated daily maximum 8-hour ozone 

concentrations on July 8, 2005 between the Kh × 3 (s8a; left) and Kh ÷ 3 (s8b; right) 

sensitivity tests and the Round 1 base case.

HIGHER HORIZONTAL RESOLUTION SENSITIVITY

Purpose: To determine whether higher horizontal grid resolution would improve ozone model 

performance in SWWY.

Approach: A 1 km “flexi-nest” grid was added to the CAMx 12/4 km modeling database that 

approximately covered Sublette County (Figure E-14). The CAMx flexi-nest feature allows the 

specification of a two-way nested-grid without having to provide all of the meteorological, 

emissions and other inputs at the higher resolution by interpolating the inputs from the coarser 

grid data (4 km in this case). The O&G emissions for SWWY are unique in that all O&G sources 

(production wells, drill rigs, compression, etc.) are specified as point sources (this is in contrast 

to O&G emissions in other locations of the western U.S. where the WRAP Phase III inventory is 

used that is based on county-level emissions data and the spatial distributions of the O&G 

sources). Thus, the use of a full 1 km flexi-nest in SWWY allows the treatment of the O&G 

emissions at a 1 km grid resolution. Note that the meteorology and other low-level emissions 

(e.g., mobile sources, area sources, biogenics, etc.) are interpolated from the 4 km modeling 

inputs to the 1 km flexi-nest.

One potential reason for the inability of the CAMx model to reproduce the high afternoon 

ozone concentrations in SWWY is inhibition of ozone formation by the fresh NOx emissions 

from the drill rigs and compressors. A more refined 1 km grid resolution may allow separation 

of the NOx (drill rigs/compressor) and VOC (production) O&G sources that would be located in 

the same grid cell at 4 km resolution. This separation of sources may allow higher VOC:NOx 

ratios in some regions resulting in higher ozone concentrations and greater horizontal 

variability in the ozone concentrations.
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-22

Figure E-14. Location of the 1 km resolution grid used in the s9 high grid resolution 

sensitivity test.

Results: Figure E-15 displays the CAMx estimated daily maximum 8-hour ozone concentrations 

ion July 8, 2005 using a 4 km (base case; left) and 1 km flexi-nest (s9; left) grid resolution. As 

expected, use of the 1 km grid tightens up the peaks and valleys in the modeled ozone 

concentrations, but doesn’t alter their basic features. The overall highest daily maximum 8-

hour ozone concentrations on July 8th is the same using either grid resolution (67 ppb). 

However, as shown in the next section, the use of the 1 km grid resolution actually degrades 

the ozone model performance measures by increasing the ozone underprediction bias. This is 

because the 1 km resolution grid not only tightens up the ozone peaks, but also tightens up the 

ozone valleys as well. There appears to be an area in the central Sublette County where ozone 

is depressed that is likely due to local NOx emissions. The use of the 1 km grid enhances this 

ozone depression, which affects ozone at the nearby WDEQ industrial monitoring sites. The use 
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-23

of the 120 by 108 1 km flexi-nest grid has takes over 3 times longer to run than the 4 km base 

case, which is a significant computational penalty

Figure E-15. CAMx estimated daily maximum 8-hour ozone concentrations (ppb) in 

Sublette County using a 4 km (left) and 1 km (right) grid resolution.

DISCUSSION OF ROUND 2 SENSITIVITY MODELING EFFECTS ON OZONE MODEL 

PERFORMANCE

EPA has model performance goals for mean normalized bias and gross error of ≤±15% and 

≤35%, respectively (EPA, 1991). EPA’s original modeling guidance recommended that these 

performance metrics be calculated for all predicted and observed hourly ozone pairs in which 

the observed value is greater than 60 ppb (i.e., 60 ppb cutoff). However, EPA’s guidance was 

developed to address the 124 ppb 1-hour ozone NAAQS in urban areas almost two decades ago 

(EPA, 1991). There have been significant reductions in ozone concentrations over the last 20 

years and ozone levels in rural SWWY are usually lower than urban areas. Thus, the mean 

normalized bias and gross error performance statistics are calculated using a 60, 50 and 40 ppb 

ozone cutoff concentration. The lower threshold ozone cutoffs are used so that more predicted 

/observed pairs can be used in the statistical comparisons. Figure E-16 displays these ozone 

bias and error performance statistics for the July 7-10, 2005 period and SWWY using the three 

ozone cutoff concentrations and the following CAMx scenarios:

Base – Round 1 base case;

S5 – HONO emissions sensitivity test;

S6 – Aggressive PiG sensitivity test;

S7a – CMAQ like Kv sensitivity test;
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

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CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-24

S7b – CMAQ-like and kv100 Kvs sensitivity test;

S8a – Kh × 3 horizontal diffusion sensitivity test;

S8b – Kh ÷ 3 sensitivity test; and

S9 – Higher horizontal grid resolution sensitivity test.

All of the sensitivity tests achieve EPA’s ≤35% gross error performance goal. Using a 60 ppb 

ozone cutoff, the CAMx Round 1 base case exhibits a bias of between -16% and -17% so does 

not achieve EPA’s ≤±15% bias performance goal (Figure E-16, top left). The HONO emissions 

and aggressive PiG sensitivity tests result in small improvements in the bias, but it is still in the -

16% to -17% range so still does not achieve EPA’s performance goal when a 60 ppb cutoff is 

used. Similarly, the horizontal diffusion coefficient sensitivity tests (s8a and s8b) also show 

marginal improvements and degradation in the ozone bias measure with values again in the 

approximate -16% to -17% range so does not achieve EPA’s performance goals. And the higher 

grid resolution sensitivity test results in a degradation in ozone model performance from the 

base case with bias metrics using a 60 ppb cutoff in the -17% to -18% range. Only the vertical 

mixing sensitivity tests (s7a and s7b) result in marked improvements in ozone model 

performance with the CMAQ-like KVs with kv100 (s7b) producing bias values in the -12% to -

13% using a 60 ppb cutoff that achieves EPA’s bias performance goal.

Similar improved ozone bias performance statistics for the s7b vertical mixing sensitivity test 

are seen using 50 and 40 ppb ozone cutoff concentrations. Using a 50 ppb ozone cutoff (Figure 

E-16, middle left), there is no discernable difference in the bias between the base case (-6.5%) 

and sensitivity tests except for the s7b (vertical mixing) and s9 (grid resolution) sensitivity tests. 

The s7b vertical mixing sensitivity test exhibits better bias (-2.5%) than the base case (-6.5%), 

whereas the s9 grid resolution sensitivity test exhibits degraded ozone bias statistics (-10.6%).

Similarly, using a 40 ppb ozone cutoff concentration (Figure E-16, bottom left) all the sensitivity 

tests exhibit similar bias values in the -8% to -9.5% range except for the s7b vertical mixing 

sensitivity test that exhibits much improved bias (-2.6%) and the s9 grid resolution sensitivity 

test that exhibits degraded bias values (-14.2%).
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-25

Figure E-16. Ozone model performance mean normalized bias (left) and gross error (right) 

in SWWY during July 7-10, 2005 using a 60 (top), 50 (middle) and 40 (bottom) ppb ozone 

cutoff concentrations.

60cut

-18

-17

-16

-15

-14

-13

-12

-11

-10

base s5 s6 s7a s7b s8a s8b s9

AllDay

Mean_Norm_Bias(%)

60cut

60cut

10

11

12

13

14

15

16

17

18

19

20

base s5 s6 s7a s7b s8a s8b s9

AllDay

Mean_Norm_GErr(%)

60cut

50cut

-12

-11

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

base s5 s6 s7a s7b s8a s8b s9

AllDay

Mean_Norm_Bias(%)

50cut

50cut

6

7

8

9

10

11

12

13

14

base s5 s6 s7a s7b s8a s8b s9

AllDay

Mean_Norm_GErr(%)

50cut

40cut

-12

-11

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

base s5 s6 s7a s7b s8a s8b s9

AllDay

Mean_Norm_Bias(%)

40cut

40cut

8

9

10

11

12

13

14

15

16

17

18

base s5 s6 s7a s7b s8a s8b s9

AllDay

Mean_Norm_GErr(%)

40cut
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-26

The time series of predicted and observed hourly ozone concentrations during July 7-9, 2005 

for the various sensitivity tests are shown in Figure E-17. The time series confirm what the 

performance statistics indicated in Figure E-16 that the s7b vertical mixing sensitivity test is the 

best performing with the others not very different from the base case simulation.

Figure E-17a. Time series of predicted and observed hourly ozone 

concentrations during July 7-9, 2005 at the Pinedale CASTNet (top) and Jonah 

WDEQ (bottom) sites for the various CAMx sensitivity tests.

Jul 07 to Jul 09 Ozone at Pinedale

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

Jul 7 0:00Jul 7 3:00Jul 7 6:00Jul 7 9:00

Jul 7 12:00Jul 7 15:00Jul 7 18:00Jul 7 21:00

Jul 8 0:00Jul 8 3:00Jul 8 6:00Jul 8 9:00

Jul 8 12:00Jul 8 15:00Jul 8 18:00Jul 8 21:00

Jul 9 0:00Jul 9 3:00Jul 9 6:00Jul 9 9:00

Jul 9 12:00Jul 9 15:00Jul 9 18:00Jul 9 21:00Jul 10 0:00

1-hour average ozone [ppb]

MX7x7 base MN7x7 base Obs s5 s6 s7a

s7b s8a s8b s9 base

LST

Jul 07 to Jul 09 Ozone at Jonah

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

Jul 7 0:00Jul 7 3:00Jul 7 6:00Jul 7 9:00

Jul 7 12:00Jul 7 15:00Jul 7 18:00Jul 7 21:00

Jul 8 0:00Jul 8 3:00Jul 8 6:00Jul 8 9:00

Jul 8 12:00Jul 8 15:00Jul 8 18:00Jul 8 21:00

Jul 9 0:00Jul 9 3:00Jul 9 6:00Jul 9 9:00

Jul 9 12:00Jul 9 15:00Jul 9 18:00Jul 9 21:00Jul 10 0:00

1-hour average ozone [ppb]

MX7x7 base MN7x7 base Obs s5 s6 s7a

s7b s8a s8b s9 base

LST
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-27

Figure E-17b. Time series of predicted and observed hourly ozone 

concentrations during July 7-9, 2005 at the Boulder (top) and Daniel (bottom) 

sites for the various CAMx sensitivity tests.

Jul 07 to Jul 09 Ozone at Boulder

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

Jul 7 0:00Jul 7 3:00Jul 7 6:00Jul 7 9:00

Jul 7 12:00Jul 7 15:00Jul 7 18:00Jul 7 21:00

Jul 8 0:00Jul 8 3:00Jul 8 6:00Jul 8 9:00

Jul 8 12:00Jul 8 15:00Jul 8 18:00Jul 8 21:00

Jul 9 0:00Jul 9 3:00Jul 9 6:00Jul 9 9:00

Jul 9 12:00Jul 9 15:00Jul 9 18:00Jul 9 21:00Jul 10 0:00

1-hour average ozone [ppb]

MX7x7 base MN7x7 base Obs s5 s6 s7a

s7b s8a s8b s9 base

LST

Jul 07 to Jul 09 Ozone at Daniel

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

Jul 7 0:00Jul 7 3:00Jul 7 6:00Jul 7 9:00

Jul 7 12:00Jul 7 15:00Jul 7 18:00Jul 7 21:00

Jul 8 0:00Jul 8 3:00Jul 8 6:00Jul 8 9:00

Jul 8 12:00Jul 8 15:00Jul 8 18:00Jul 8 21:00

Jul 9 0:00Jul 9 3:00Jul 9 6:00Jul 9 9:00

Jul 9 12:00Jul 9 15:00Jul 9 18:00Jul 9 21:00Jul 10 0:00

1-hour average ozone [ppb]

MX7x7 base MN7x7 base Obs s5 s6 s7a

s7b s8a s8b s9 base

LST
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-28

NITRATE PERFORMANCE EVALUATION

The Round 2 sensitivity tests were focused on improving summer ozone performance in SWWY. 

The observed and modeled nitrate concentrations are extremely low during the Round 2 July 

2005 modeling period so little can be ascertained regarding the sensitivity effects on nitrate 

performance. The focus on ozone performance in the Round 2 sensitivity modeling was based 

in part on the conservative nature of the CAMx nitrate predictions for AQRVs in the original 

(June 2009) CAMx base case simulation. This is shown in Table E-1 that displays the number of 

predicted and observed days that the visibility impairment due to nitrate exceeds the 0.5 and 

1.0 deciview (dv) thresholds at the Bridger and Mount Zirkel IMPROVE monitoring sites during 

2005 and 2006 using the 1:3 day sampling frequency. The model is estimating significantly 

more days in which nitrate visibility exceeds the 0.5 and 1.0 dv thresholds than observed.

The conservative nature of the CAMx nitrate AQRV predictions is also shown in the time series 

of predicted and observed 24-hour visibility impairment at the Bridger (Figure E-18) and Mount 

Zirkel (Figure E-19) IMPROVE monitoring sites. Although the modeled nitrate visibility 

impairment is below the observed value during some summer days, this is when the observed 

nitrate visibility is extremely low. In the winter when the observed nitrate visibility is more 

significant the model has an overestimation bias so is conservative.

Table E-1a. Comparison of number days during 2005 that observed and predicted visibility 

impairment due to NO3 (FLAG Method 6) exceeds the 0.5 and 1.0 deciview thresholds using the 

1:3 day sampling frequency and the preliminary CAMx base case simulation (Kemball-Cook et 

al., 2009).

Site Observed Modeled Observed Modeled

Bridger 43 90 11 78

Mount Zirkel 49 77 21 63

# Days > 0.5 DV # Days > 1.0 DV
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

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CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-29

Table E-1b. Comparison of number days during 2006 that observed and predicted visibility 

impairment due to NO3 (FLAG Method 6) exceeds the 0.5 and 1.0 deciview thresholds using the 

1:3 day sampling frequency and the preliminary CAMx base case simulation (Kemball-Cook et 

al., 2009).

Figure E-18a. Comparison of predicted and observed 24-hour NO3 

concentrations at the Bridger IMPROVE monitoring site during 2005 

for the preliminary CAMx base case simulation (Kemball-Cook et al., 

2009).

Site Observed Modeled Observed Modeled

Bridger 53 86 24 76

Mount Zirkel 52 67 17 58

# Days > 0.5 DV # Days > 1.0 DV Nitrate Contribution to Haze: BRID 2005

0.000

1.000

2.000

3.000

4.000

5.000

6.000

7.000

8.000

101122212305326416507528618709730820910

10011022111212031224

Date (Month and Day)

Haze Index (dv)

observed

modeled
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-30

Figure E-18b. Comparison of predicted and observed 24-hour NO3 

concentrations at the Bridger IMPROVE monitoring site during 2006 for the 

preliminary CAMx base case simulation (Kemball-Cook et al., 2009).
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-31

Figure E-19a. Comparison of predicted and observed 24-hour NO3 

concentrations at the Mt. Zirkel IMPROVE monitoring site during 2005 for 

the preliminary CAMx base case simulation (Kemball-Cook et al., 2009).

Figure E-19b. Comparison of predicted and observed 24-hour NO3 

concentrations at the Mt. Zirkel IMPROVE monitoring site during 2006 for 

the preliminary CAMx base case simulation (Kemball-Cook et al., 2009).

Nitrate Contribution to Haze: MOZI 2005

0.000

1.000

2.000

3.000

4.000

5.000

6.000

7.000

8.000

101122212305326416507528618709730820910

10011022111212031224

date

Haze Index (dv)

observed

modeled
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-32

FINAL BASE CASE MODEL CONFIGURATION

The results of the Round 2 sensitivity tests were presented to the Cooperating Agencies in a 

meeting January 7, 2010 at WDEQ’s office in Cheyenne. The Cooperating Agencies selected the 

following CAMx model configuration for the revised CD-C 2005/2006 base case simulations:

 CAMx VV model version and Round 1 database updates;

 34 vertical layers;

 Updated ammonia emission seasonal allocations;

 Include mineral nitrate processes;

 Zhang dry deposition algorithm; and

 CMAQ-like Kvs with Kv100 vertical diffusion.
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-33

REFERENCES

Astitha M., 2007a. Characteristic scales of transport and transformation of air pollutants -

Impacts on climate. Ph.D. Thesis. University of Athens, School of Physics, Department 

of Environmental Physics-Meteorology.

Astitha M., Kallos G., Katsafados P., Mavromatidis E., 2007b. Heterogeneous chemical 

processes and their role on particulate matter formation in the Mediterranean region. 

29th NATO/SPS ITM on Air Pollution Modeling and its Applications, September 2007, 

Aveiro, Portugal.

Astitha and Kallos, 2009a: Gas-phase and aerosol chemistry interactions in South Europe and 

the Mediterranean Region. Environmental Fluid Mechanics, Vol. 9, Number 1, February 

2009.

Astitha M., Spyrou C., Kallos G., Denier Van der Gon HAC, Visschedijk AJH and J. Lelieveld, 

2009b: Chemical composition change of aerosols along long-range transport paths. 30th 

NATO/SPS ITM on Air Pollution Modeling and its Applications, May 2009, San Francisco, 

USA.

Emery, C., E. Tai, R. Morris and G. Yarwood. 2009a. Reducing Vertical Transport over Complex 

Terrain in Photochemical Grid Models. Presented at the 8th Annual CMAS Conference, 

October 19-21, 2009, Chapel Hill, NC. 

(http://www.cmascenter.org/conference/2009/abstracts/emery_reducing_vertical_2009.p

df)

Emery, C.E., E. Tai, R. Morris and G. Yarwood. 2009b. Reducing Vertical Transport over Complex 

Terrain in Photochemical Grid Models. AWMA Guideline on Air Quality Models: Next 

Generation of Models. Raleigh, NC. October 28.

ENVIRON. 2008. “User’s Guide Comprehensive Air Quality Model with Extensions (CAMx) 

Version 4.50.” ENVIRON International Corporation, Novato, California. 

(www.camx.com). September.

ENVIRON and Carter Lake. 2010. Southwest Wyoming Round 2 CAMx Sensitivity Tests. 

ENVIRON International Corporation, Novato, CA and Carter Lake Consultants, Laramie, 

WY. PowerPoint presentation to Continental Divide-Creston Cooperating Agencies, 

Cheyenne, Wyoming. January 7.

EPA. 1991. Guidance for Regulatory Application of the Urban Airshed Model (UAM), Office of 

Air Quality Planning and Standards, Research Triangle Park, North Carolina. 

EPA. 1999. Guidance on the Use of Models and Other Analyses for Demonstrating Attainment 

of Air Quality Goals for 8-Hour Ozone NAAQS. Draft. U.S. Environmental Protection 

Agency, Office of Air Quality and Planning Standards, Research Triangle Park, North 

Carolina.

EPA. 2007. Guidance on the Use of Models and Other Analyses for Demonstrating Attainment

of Air Quality Goals for Ozone, PM2.5, and Regional Haze. U.S. Environmental 
APPENDIX E – DIAGNOSTIC SENSITIVITY TEST MODELING RESULTS TO 

ACHIEVE FINAL BASE CASE MODEL CONFIGURATION FOR THE 

CONTINENTAL DIVIDE-CRESTON O&G EIS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 E-34

Protection Agency, Office of Air Quality and Planning Standards, Research Triangle Park, 

North Carolina. (EPE-454/B-07-002). April.

Gilliland, A., K., K. Appel, R.W. Pinder, and R.L. Dennis, 2006. Seasonal NH3 emissions for the 

continental United States: inverse model estimation and evaluation. Atmospheric 

Environment, 40, pp. 4986-4998.

Kemball-Cook, S., R. Morris, J. Johnson, B. Koo, T. Sakulyanontvittaya, L. Parker, T. Shah, U. 

Nopmongcol, and P. Piyachaturawat, 2009. Draft Report: Hiawatha CAMx 2005-2006 

Base Case Model Performance Evaluation, Prepared for SWCA Environmental 

Consultants, Broomfield, CO. June 26.

Mansell, G. 2005. An Improved Ammonia Inventory for the WRAP Domain. Final Report, 

Volume I. ENVIRON International, Novato, California. 

http://pah.cert.ucr.edu/aqm/308/ppt_files/emissions/nh3/Volume_I_FinalReport.3-

07.pdf. March 7.

Morris, Ralph, S. Kemball-Cook and J. Zapert, 2009a. Preliminary list of Proposed Sensitivity 

Tests for the Continental Divide-Creston O&G Development EIS CAMx Base Case, 

Technical Memorandum. ENVIRON International Corporation, Novato, CA and Carter 

Lake Consultants, Laramie, WY. Prepared for David Finley, WDEQ/AQD, Cheyenne, 

Wyoming. September 11.

Morris, Ralph, S. Kemball-Cook and J. Zapert, 2009b. Potential CAMx Sensitivity Tests to 

Improve Ozone and Nitrate Model Performance under the Continental Divide-Creston 

Oil and Gas Project, Technical Memorandum. ENVIRON International Corporation, 

Novato, CA and Carter Lake Consultants, Laramie, WY. Prepared for David Finley, 

WDEQ-AQD, Cheyenne, Wyoming. September 30.

Wesely, M.L. 1989. Parameterization of Surface Resistances to Gaseous Dry Deposition in 

Regional-Scale Numerical Models. Atmos. Environ., 23, 1293-1304. 

Young, J., J. Pleim and R. Mathur. 2009. Mass Consistency Improvements in CMAQ Advection. 

Presented at the 8th Annual CMAS Conference, October 19-21, 2009, Chapel Hill, NC. 

(http://www.cmascenter.org/conference/2009/slides/young_mass_consistency_2009.p

df).

Zhang, L., J. R. Brook, and R. Vet, 2003. A revised parameterization for gaseous dry deposition 

in air-quality models. Atmos. Chem. Phys., 3, 2067–2082.

Zhang, L., Vet, R., Brook, J.R., Legge, A.H. 2006. Factors affecting stomatal uptake of ozone by 

different canopies and a comparison between dose and exposure. Science of the Total 

Environment, 370 (1), pp. 117-132.
Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016

Appendix F

Development of the 2008 Baseline Emission Inventory
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-1

INTRODUCTION 

The air quality impact assessment for the Continental Divide-Creston (CD-C) EIS is being 

performed using the photochemical grid model (PGM) CAMx (Comprehensive Air quality Model 

with Extensions; ENVIRON, 2009; www.camx.com). The basic modeling strategy used in any EIS 

that employs a PGM such as CAMx is to first simulate a current year base case using a 

comprehensive regional emission inventory of actual emissions from all sources (including 

motor vehicles, power plants, oil and gas exploration and production sources, biogenic sources, 

etc.). It is preferable to run the model for more than one year so that as many different 

meteorological regimes as possible are simulated. Pollutants emitted from Project sources may 

only influence a particular sensitive receptor under certain conditions (wind direction, 

atmospheric stability) and a conservative estimate of AQ and AQRV impacts requires that those 

conditions be simulated. While it is not possible to ensure that all possible meteorological 

conditions that might lead to transport of pollutants from Project sources to sensitive receptors 

are simulated, modeling two full years increases the likelihood that the relevant conditions will 

occur. 

The base case simulation is evaluated with respect to ambient air quality measurements. If the 

base case simulation reproduces concentrations of observed species with reasonable fidelity, 

then the model can be used in the future year impact assessment. The future year modeling 

involves development of a future year Project emission inventory as well as a future year 

regional emission inventory. In the future year regional emission inventory, the emissions from 

human activities are projected from the base year to the future year and changes such as 

population growth and planned emissions controls (such as controls on motor vehicle 

emissions) are accounted for. Emissions that are not controllable, such as biogenics and 

wildfire emissions, are held fixed. The Project emissions are included in the future year 

emission inventory. The model is run using the future year regional emission inventory with 

the rest of the model (meteorological fields, boundary conditions, model settings, etc.) in the 

same configuration as in the base case. If multiple years were simulated in the base case, then 

the meteorological conditions for those same years are used together with the future year 

emissions scenario in the future year modeling. Project AQ and AQRV impacts are determined 

from the future year simulations.

For the CD-C EIS, a base case simulation has been completed. CAMx was applied for the 

calendar years 2005 and 2006 using a nested-grid modeling domain with horizontal spatial 

resolution 36/12/4 km (Figure F1). The 2005 and 2006 base case model runs used actual 

emissions of NOx, SO2, PM10, PM2.5, VOC and CO from all sources for those years and included a 

comprehensive inventory of oil and gas (O&G) emissions sources within Southwest Wyoming 

developed by Carter Lake and BP as well as the WRAP Phase III O&G emissions for the DenverJulesburg, Piceance, and Uinta Basins. The model used 2005-6 MM5 meteorology. The CAMx 

gas phase and particle phase model estimates were compared against observed ambient values 

for those two years and a model performance evaluation was conducted (Appendix A). The 

base case modeling was approved by the CD-C stakeholders. The next step in the CD-C analysis 

is to apply CAMx for a baseline emissions scenario and then for future year scenarios for each 

of the Project Alternatives individually to estimate its AQ and AQRV impacts. The future years 

to be modeled for each Alternative are to be determined after analysis of the proposed CD-C
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-2

Project Alternative emissions; it may be necessary to run two future years corresponding to the 

maximum VOC and maximum NOx emissions year for each CD-C Project Alternative. 

In early 2010, the CD-C stakeholders determined that the baseline year to be used in 

performing future year modeling and impact analyses would be 2008. Originally, 2006 was to 

have been the baseline year, but extensive development of oil and gas resources in southwest 

Wyoming occurred during the 2006-2008 period and emissions of criteria pollutants and ozone 

precursors from this source category were significantly larger in 2008 than in 2006. The 

economic slowdown in 2008-9 led to a reduction in the pace of development such that 2009 

emissions are expected to be smaller than 2008 emissions. 2008 is a National Emission 

Inventory Year, in which states submit emission inventories to the EPA. Because emission 

inventories for 2008 for the state of Wyoming are now available, and 2008 is the year of peak 

emissions from the energy sector in Wyoming as well as the year of peak measured southwest 

Wyoming wintertime ozone concentrations, the CD-C stakeholders selected 2008 as the 

baseline year for the impact analysis modeling. Another important factor is that more ambient 

monitoring was available in 2008 than in 2006. Carter Lake Consulting and ENVIRON have 

developed a regional emission inventory for the year 2008 for use in CAMx baseline modeling, 

and the 2008 inventory is described in this Appendix.

ACTUAL VERSUS TYPICAL EMISSION INVENTORIES

The 2005-6 base case inventory uses actual measured electric generating unit (EGU) emissions 

and monthly drill rig emissions because the base case model is evaluated against observations 

to determine whether the model provides a realistic simulation of the atmospheric processes 

related to ozone and PM formation, transport, and removal. The purpose of the 2008 baseline 

model, on the other hand, is to serve as the base year from which future year projections are 

made and against which future year project alternative and cumulative emissions impacts will 

be evaluated. The 2008 inventory, therefore, uses typical rather than actual emissions for some 

source categories in order to be consistent with the future year emission inventories. For 

example, baseline EGU emissions represent typical conditions (no shutdowns for maintenance, 

for example) in order to be consistent with the future year emissions, which also represent 

typical conditions and would have no maintenance shutdowns. The base case emission 

inventory would have a period of zero emissions during a maintenance shutdown. If base case 

EGU emissions were used rather than typical emissions, a period when a plant was shut down 

for maintenance would show up as an impact due to an apparent emissions increase in the 

future year, which would use a typical inventory and would not contain the period of zero 

emissions from the shutdown. The two source categories for which 2008 typical emissions will 

be developed are EGUs and drilling rigs. The method for calculating emissions from these 

source categories is described below.

2008 CAMX BASELINE MODEL CONFIGURATION

The 2008 baseline run will consist of two annual CAMx runs. Both annual simulations will be 

performed with the 2008 emission inventory; one year will be run with 2005 meteorology and 

the other year will be run with 2006 meteorology. The 2005-6 meteorological data to be used 

in the 2008 baseline modeling are the same data used in the 2005-6 base case CAMx modeling. 

All other CAMx inputs (e.g. photolysis rates, land use files, etc.) and the CAMx model 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-3

configuration (dry deposition scheme, PiG model, etc.) are the same as those used in the 2005-

6 base case modeling.

2008 EMISSION INVENTORY DEVELOPMENT METHOD

The overall strategy for developing the 2008 inventory was to update the 2006 inventory to 

2008 for anthropogenic emissions. For the 2008 baseline simulations using 2005 and 2006 

meteorology, the corresponding 2005 and 2006 emission inventories for wildfires, wind-blown 

dust, biogenics, and ammonia were used.

The Sparse Matrix Operating Kernel Emissions (SMOKE; Coats, 1996) emissions modeling 

system (available from www.cmascenter.org) was used to generate the hourly, gridded, 

speciated model-ready 2008 emissions inputs for CAMx. The most recent version of SMOKE is 

version 2.6, which was used in the processing of the 2008 baseline inventory. SMOKE was 

applied for the area, off-road mobile, onroad mobile source categories and for point sources. 

Non-O&G area sources and off-road mobile were linearly interpolated from the latest WRAP 

2002 and WRAP 2018 emission inventories. The most recent WRAP emission databases 

currently available are the “2002 Plan D” and “2018 PRP18b” emissions databases. The 2018 

PRP18b database recently developed for Preliminary Reasonable Progress was built from the 

WRAP 2002 inventory by projecting the impacts of activity growth and emission controls. The 

methodology for projecting emissions is described in the WRAP PRP Technical Memorandum 

(Fields and Wolf, 2007), and information on the WRAP 2002 emission inventory can be found in 

Tonnesen et al. (2006). SMOKE ancillary files from 2005-6 emissions modeling were used for 

speciation, spatial & temporal allocation.

The MOBILE6 module of SMOKE was used to develop the on-road mobile source emissions. 

The MOBILE6 parameters, vehicle fleet descriptions, and vehicle miles of travel (VMT) estimates 

were combined with gridded, episode-specific temperature data to obtain the gridded, 

temporally allocated emission estimates for weekday, Saturday, and Sunday. 2008 Vehicle 

Miles Travelled (VMT) were developed by linear interpolation of 2006 VMT developed for the 

2006 base case modeling and VISTAS 2009 VMT. VISTA 2009 MOBILE6 inputs were used to 

specify average speed, fuel parameters, and control programs. 2005 and 2006 MM5 

meteorological data were then used with the SMOKE-MOBILE6 processor to generate the 

gridded speciated day-of-week emissions required as input to CAMx. For each month, 

emissions were generated for a representative weekday, Saturday and Sunday in 2008. 

Holidays were treated as Sundays.

ENVIRON and Carter Lake have developed a detailed inventory of point source emissions for 

the 2008 year for Wyoming based on point source data for major (i.e. Title V) and minor point 

sources supplied by the WDEQ. 2008 is a national emissions inventory reporting year and 

emission inventories for Wyoming major and minor point sources have recently been made 

available by the State of Wyoming. Note that these are draft emission inventories that were 

under review by the WDEQ at the time of the emissions processing. These inventories were 

quality-assured by ENVIRON and Carter Lake and prepared for processing through SMOKE to 

create CAMx-ready emissions inputs. For several sources, modifications to the emissions were 

made. Emissions for the Black Thunder and Cordero Rojo Mines were double counted and this 

error was corrected. A haul truck at the Cordero Rojo Mine had NOx emissions of 51,000 tpy. 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-4

ENVIRON used the inventory data describing the haul truck as inputs to a run of EPA’s 

NONROAD model in order to estimate emissions for this source. The NONROAD run produced 

NOx emissions of ~2,000 tpy, which is consistent with the NOx emissions in the 2005-6 

inventory for this source; the emissions were adjusted to reflect the results of the NONROAD 

run. Another outlier was high NOx (~46,000 tpy) emissions from the Pioneer Asphalt plant. 

These emissions were from a heater having 800,000 MMBTU/hr capacity. Carter Lake 

investigated this facility and found that it holds a permit waiver and has only one 250 hp/ 0.636 

MMBTU/hr heater on-site. Emissions were recalculated using the actual heater capacity and 

corrected to 0.04 tpy NOx emissions. VOC emissions for the Bairoil Plant were listed as 162,949 

tpy (~93% of Wyoming total) VOC emissions. This appears to be the result of expressing in tpy 

emissions that were actually reported in lbs/hr. When the conversion to tpy was made, this 

source had VOC emissions of 81.5 tpy, which is consistent with the 2005-6 inventory. Emissions 

in tpy for the Evans Construction Yard were also recalculated based on their lbs/hr values, as 

NOx emissions for this source were 17,000 tpy and a units error was suspected. The revised 

NOx emissions are a more reasonable 60 tpy.

Where SCC information was missing from the inventory, ENVIRON assigned an SCC based on 

the SCC assigned to the source in the 2005-6 base case inventory or on the description of the 

source provided in the inventory. Sources missing location information were identified by 

comparison with the 2005-6 inventory or through an internet search. Locations were assigned 

to all sources except portable nitrogen vaporizers; these are very small portable source 

emissions for which no information on where and when they operated was provided in the 

inventory. These sources were removed from the inventory, but this should not have any 

measurable effect on the CD-C analysis, given the small size (for all vaporizers combined, ~10 

tpy NOx, ~1 tpy VOC) and distributed nature of these sources. For other states within the 12 

km domain, non-EGU point emissions were generated by linear interpolation of 2006 and 

WRAP 2018 (PRP18b) point source emission inventories.

During the initial quality assurance of the 2008 emission inventory, ENVIRON noted sharp 

declines in non-EGU point source emissions in 2008 relative to 2005 and 2006. Further 

inspection of the inventory showed that several major point sources that were operational in 

2005 were not present in the 2008 inventory (e.g. Kemmerer Mine). ENVIRON prepared a list 

of these sources and the WDEQ reviewed these sources to determine whether they were 

operational in 2008. After careful source-by-source review, WDEQ provided a list of sources 

missing from the 2008 inventory that were still in operation in 2008. For these sources, the 

WDEQ recommended including them in the 2008 EI and keeping their emissions constant at 

2006 levels. 

For Wyoming and other states, Continuous Emissions Monitor (CEM) data from the U.S. EPA’s 

Clean Air Markets Division (CAMD) were used to supply actual 2008 hourly emissions for 

electric generating utilities (EGUs). The hourly emissions were then used to form quarterly 

averages for each of the 24 hours in a day. These quarterly averages constitute typical 

emissions for a particular EGU; they are averages that retain information about the typical 

temporal profile of emissions for that facility during a given season. Use of typical EGU 

emissions is one important difference between the base case and baseline inventories. 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-5

SUMMARY OF PROCESSING OF OIL AND GAS EMISSION INVENTORY

Carter Lake and BP have prepared a detailed emission inventory for oil and gas sources in the 5-

county area of southwest Wyoming that is similar in nature and scope to the 2005-6 southwest 

Wyoming oil and gas inventory used in the base case modeling. The 2008 5-county southwest 

Wyoming inventory was developed using the oil and gas emissions information available from 

the state of Wyoming and from operator-provided emissions assumptions. In order to be 

consistent with future year emission inventories, drill rig emissions were annualized rather than 

reported by month, as was done for the 2005-6 base case emission inventory. For oil and gas 

sources in Wyoming outside the 5-county area of southwest Wyoming, emissions were 

developed from the Wyoming 2008 point source inventory supplied by the Wyoming 

Department of Environmental Quality Air Quality Division. Well VOC emissions outside the 5-

County area were developed by Carter Lake. Emissions for oil and gas sources within the 12 km 

domain but outside Wyoming were estimated through interpolation of the 2006 and 2010 

(Denver-Julesberg) and 2012 (Piceance, Uinta) WRAP Phase III inventories in the basins covered 

by this inventory and through interpolation of the 2005 and 2018 WRAP Phase II inventories 

elsewhere.

In this summary, we focus on the oil and gas emission inventory used in the 4 km domain, 

which contains the sources and receptors of interest in the CD-C impact analysis. We give a 

brief description of the emission inventories used and then discuss the spatial and temporal 

allocation of those emissions. A more detailed discussion of the inventories and their 

processing may be found in Section 4 of the CD-C Modeling Protocol (Carter Lake and ENVIRON, 

2010).

Overview of Emission Inventories Used in 4 km Domain

Several different oil and gas emission inventories are used in the 4 km domain. As discussed 

above, Carter Lake and BP have compiled a detailed and comprehensive emission inventory of 

O&G sources in Southwest Wyoming for 2008. Based on field data and well data from the 

Wyoming Oil and Gas Conservation Commission, this inventory includes emissions from drill 

rigs, well venting, flashing, fugitives, construction and production truck traffic, and well site 

production equipment such as dehydrators, heaters, and pumps. The Carter Lake/BP inventory 

covers five Southwest Wyoming counties that have extensive oil and gas exploration and 

production. These counties are Carbon, Lincoln, Sublette, Sweetwater, and Uinta. The 

development of the Carter Lake/BP Southwest Wyoming oil and gas emission inventory has 

been documented in Section 4 of the CD-C Modeling Protocol (Carter Lake and ENVIRON, 2010). 

The WRAP Phase III oil and gas inventory (Bar-Ilan et al. 2008; Bar-Ilan et al., 2009) was used for 

the Denver-Julesberg, Uinta, and Piceance Basins. This inventory is used for regions of 

Colorado and Utah that fall within the 4 km domain. The WRAP Phase III work expands on the 

work done under WRAP Phase II, and addresses the limitations of its VOC inventory. The Phase 

III inventory is being assembled by combining data on permitted sources from states’ permit 

databases, and data on unpermitted sources obtained from industry surveys. These surveys 

request information on typical equipment types, counts, configurations, annual activity levels, 

controls, and emissions factors. The IHS database is used to determine oil and gas production 

statistics, which are used to combine these two groups of source categories to generate a 

complete basin-wide emissions inventory. To develop 2008 emissions, a linear interpolation 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-6

was performed between 2006 and 2012 for the Uinta and Piceance Basins and between 2006 

and 2010 for the Denver-Julesberg Basin. The WRAP Phase III emission inventory for the Wind 

River Basin was finished just as the CD-C 2008 emission inventory was being completed and so 

is not included in this 2008 inventory. 

Oil and gas area source emissions from the remaining areas were obtained from the WRAP 

Phase II emission inventory (Bar-Ilan et al., 2007). The WRAP Phase II O&G emissions inventory, 

which is being used in the Regional Haze SIP modeling, is available for all basins in the western 

U.S. Therefore, the WRAP Phase II inventory was used for all regions within the CD-C modeling 

domain that are not covered by the Carter Lake/BP or WRAP Phase III (discussed below) 

inventories. To obtain 2008 emissions, an interpolation was performed between the 2005 and 

2018 WRAP Phase II inventories. Because the emphasis of the WRAP Phase II O&G emissions 

inventory development was on visibility impairment precursors, the inventory was focused on 

SOx, NOx and PM emissions and is known to underestimate VOC emissions. 

Spatial Allocation of Oil and Gas Emissions within the 4 km Domain

Carter Lake/BP Southwest Wyoming Inventory 

Spatial surrogates were not required to process the Carter Lake/BP Southwest Wyoming 

emissions since the wells were modeled as point sources and the latitude and longitudes of the 

wells were compiled as part of the inventory development. Emissions from drill rigs, 

completion, and traffic as well as production emissions were all modeled as point sources sited 

at the well location. 

Wrap Phase III Inventory 

The allocation of the WRAP Phase III emissions in the 2008 inventory followed the same 

procedure that was used for the 2005-6 base case emission inventories. The WRAP Phase III 

O&G inventory for the Denver-Julesburg, Piceance, and Uinta Basins was assembled for both 

point (permitted) and area (unpermitted) source categories. All the permitted sources were 

modeled as point sources and unpermitted sources were modeled as area sources. The WRAP 

Phase III area source emissions were calculated on a basin-wide basis by SCC (Source 

Classification Code). The next step in the emission inventory development process was to 

distribute the emissions among the model grid cells within each basin using a spatial surrogate 

that serves as a proxy for the location of the actual emitting processes. Area sources are often 

estimated at the county level, and are then allocated to the grid cells within each county based 

on such spatial surrogates as population or economic activity. Through this process, the spatial 

resolution of the emissions is matched to the CAMx grid(s). The EPA default spatial allocation 

surrogates were not detailed enough for the area source oil and gas production emissions, and 

were based on data from the year 2000. ENVIRON therefore developed a new set of spatial 

allocation surrogates for 2005-6 base case modeling using the locations of wells within these 

basins to allocate the county-level area source emissions to the appropriate oil and gas fields. 

The updated spatial allocation surrogates were developed using the 2006 IHS database for the 

WRAP Phase III basins. The oil and gas production surrogates were based on production data at 

known well locations, while the drilling surrogate was based solely on the number and location 

of wells drilled. For each individual well, the oil, gas and water production values were divided 

by the total oil, gas and water production values corresponding to the county in which the well 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-7

was located. This division resulted in determination of the fraction of a county’s total 

production taking place at each well. In the case of the drilling surrogate, the number of drilling 

events, rather than the production values, was used. For each grid cell (intersecting a county) 

and county combination, well production fraction were summed for wells inside the given grid 

cell to obtain the surrogate value. A detailed description of the spatial surrogate development 

is given in Appendix C of the CD-C Modeling Protocol. 

WRAP Phase II Inventory

WRAP Phase II emissions were allocated using spatial surrogates developed from 2002 well and 

spud data obtained from the Wyoming Oil and Gas Conservation Commission (WOGCC), as was 

done for the 2005-6 base case inventory.

O&G Point Source Emissions

All Wyoming oil and gas sources were modeled as point sources; this includes compressor 

engines, production sites, drill rigs, and gas plant and compressor station sources. In Colorado 

(i.e. Piceance & DJ Basins) - small compressor engines, compressor station and gas plants were 

included in the point source inventory (and therefore modeled as point sources) because of 

Colorado’s requirement that sources with NOx emissions greater than 2 tpy report emissions to 

the state. In Utah (Uinta Basin), compressor station and gas plants were included in the point 

inventory. The rest were included in the area inventory and were modeled as area sources. 

Temporal Allocation of Oil and Gas Emissions within the 4 km Domain

Carter Lake/BP Southwest Wyoming Inventory 

The Carter Lake/BP inventory provided drill rig and construction traffic in Southwest Wyoming 

as annualized emissions, unlike the 2005-6 base case inventories, which used actual monthly 

emissions. Heater emissions were provided and processed as actual monthly emissions. It was 

expected that monthly distribution of heater emissions will remain the same for the future 

years. Heater emissions were allocated across all hours in the month during which the activity 

took place according to the default SMOKE temporal profile for oil and gas sources. This profile 

assumes that the source operates constantly throughout a given time period. Construction 

traffic emissions were allocated in time using the SMOKE default profile for Heavy Duty Diesel 

Vehicles (HDDV), which has both weekly and diurnal variation. 

Production traffic emissions were temporally allocated using the SMOKE default profile for 

Heavy Duty Diesel Vehicles. No temporal variation was applied to the rest of the O&G sources, 

i.e. emissions from well production sources were assumed to be equally distributed across 

every hour within the calendar year according to the default SMOKE temporal profile for oil and 

gas sources. 

WRAP Phase II and Phase III Inventories

Emissions from the WRAP Phase II and Phase III inventories are given in terms of tons of 

pollutant per year. No temporal variation was applied to these O&G sources, i.e. emissions 

from all sources were assumed to be equally distributed across every hour within the calendar 

year. 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-8

Summary of Oil and Gas Emission Inventory QA Procedures

Once the oil and gas emission inventory processing for the 4 km grid was completed, several 

quality assurance (QA) steps were taken to determine whether the emissions had been 

properly processed through SMOKE. First, for each source category and county, the SMOKE 

inputs were compared to SMOKE outputs. The SMOKE inputs consist of the data files that 

contain the original inventory data. For example, the SMOKE inputs for the drill rig emission 

inventory are comprised of data for individual rigs provided by Carter Lake/BP. The SMOKE 

outputs include diagnostic files provided by SMOKE after processing for QA purposes. These 

diagnostic (“Carter Lake”) files can then be compared with the input data spreadsheets to 

determine whether the emission amounts for each species match and the data have been 

processed correctly. Once the SMOKE output netCDF files containing the gridded, pre-merged, 

model-ready emissions had been prepared, these files were checked by applying QA utilities 

that add up the emissions through the depth of the model by county for each file. These 

emissions totals were then compared with the emissions from the original SMOKE input files to 

ensure that the speciation and temporal and spatial allocation of emissions had been 

performed correctly and that no emissions had been lost or gained during the emissions 

processing.

Next, emissions tables were prepared that summarize emissions by source category and county 

for within the 4 km grid and by source category and state within the 12 km grid. Additional 4 

km emissions summaries are provided in Table F4 of this Memorandum. In addition to the 

tables, emissions tile plots were prepared for the 4 km domain for each source category and 

pollutant. Examples are shown in Figures F11-F13. These plots were used to check that the 

amount of emissions and their spatial allocation were correct. For example, plots of 2008 

mobile source NOx within the 4 km domain were prepared to ensure that the location of the 

emissions matched the locations where mobile source emissions occurred in 2008. 

ADDITIONAL DOCUMENTATION OF SMOKE MODEL INPUTS

There are two types of model-ready emissions inputs files required to run CAMx:

(1) 2-D emissions Fortran binary file with all sources other than point sources 

(2) Elevated-point-source Fortran binary file. 

These Fortran binary files cannot be opened using a text editor. The model-ready binary files 

are generated using the SMOKE emissions processor. Emission inventories are generally text or 

spreadsheet files (The Carter Lake/BP oil and gas emissions inventory provided to WDEQ AQD is 

an example) that are then converted to text files in fixed format known as IDA format. The IDA 

files are input to SMOKE. Along with diagnostic Carter Lake files (which can be viewed in a text 

editor), SMOKE produces two-dimensional surface layer emissions files (area + off-road + onroad + off-shore area + O&G area + biogenic) in I/O API NetCDF format. NetCDF is a selfdescribing data file format. These surface layer emissions files for the above source categories 

were then merged together in NetCDF format using a script and then finally converted into 

UAM-based FORTRAN binary format that is readable by CAMx. 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-9

To obtain the elevated-point source Fortran binary file, an ASCII elevated-point-source file was 

created using the SMOKE program, and was then converted to the required binary format using 

a standard CAMx preprocessing tool.

The table below provides list of individual emissions components that were merged together to 

create 2008 12 km model-ready emissions. 

Table F1. Pre-merged emissions files for the 2008 12-km domain.

Major 

Category

Sub Category File Name

Area Generic Area 

excluding 

dust&fire

argts_l.{date}.1.12k.cdc08.cmaq.cb05p25.ncf

Road dust rdgts_s.{date}.1.12k.cdc08.cmaq.cb05p25.ncf

Fugitive dust fdgts_s.{date}.1.12k.cdc08.cmaq.cb05p25.ncf

Wind-blown dust wb_dust_ii_cmaq_cdc12k_{date}_agadj_tf_b.ncf

Non-WRAP 

monthly ammonia

nh3mgts_l.{date}.1.cdc12k.bpcdc06.cmaq.cb05p25.ncf

WRAP ammonia 

(fertilizer, 

domestics, wild 

animals, 

livestocks)

nh3all.bp12k.{date}.CMAQ.ncf

Off-road Annual nonroad nrygts_l.{date}.1.12k.cdc08.cmaq.cb05p25.ncf

Monthly nonroad nrmgts_l.{date}.1.12k.cdc08.cmaq.cb05p25.ncf

Onroad 

Mobile

US onroad mobile 

with 2005 

meteorological 

data

mgts_l.{date}.1.cdc12km.cdc08_08.ncf

US onroad mobile 

with 2006 

meteorological 

data

mgts_l.{date}.1.cdc12km.cdc08_08.ncf

Point EGUs elevegu_l.{date}.1.12k.cdc08.txt

Non-EGUs elevnegu_l.{date}.1.12k.cdc08.txt

Trona elevtrn_l.{date}.1.12k.cdc08.txt

O&G Point - Wyoming elevpt_comp_l.{date}.1.CDC12km.Wyoming2008.txt

elevpt_prod_l.{date}.1.CDC12km.Wyoming2008.txt

elevpt_spud_l.{date}.1.CDC12km.Wyoming2008.txt

WRAP Phase III 

area

ar_compgts_l.{date}.1.CDC12km.phaseIII2008.cmaq.cb05p25.ncf

ar_prodgts_l.{date}.1.CDC12km.phaseIII2008.cmaq.cb05p25.ncf

spudgts_l.{date}.1.CDC12km.phaseIII2008.cmaq.cb05p25.ncf

WRAP Phase III 

point

elevpt_comp_l.{date}.1.CDC12km.phaseIII2008.txt

elevpt_prod_l.{date}.1.CDC12km.phaseIII2008.txt

'WRAP Phase II 

area

ar_compgts_l.{date}.1.CDC12km.phaseII2008.cmaq.cb05p25.ncf

ar_prodgts_l.{date}.1.CDC12km.phaseII2008.cmaq.cb05p25.ncf

spudgts_l.{date}.1.CDC12km.phaseII2008.cmaq.cb05p25.ncf

WRAP Phase II 

point

elevpt_comp_l.{date}.1.CDC12km.phaseII2008.txt

elevpt_prod_l.{date}.1.CDC12km.phaseII2008.txt

Fire Low-level fire emiss.area.ncarfires.soa.cdc_12km.{date}

Elevated fire ptsrce.ncarfires.soa.cdc_12km.{date}.bin

Biogenic Biogenic emiss_MEGAN_CDC12km_CB05X_{date}.camx
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-10

The output files from the SMOKE processor are primarily I/O API NetCDF files. The I/O API files 

cannot be viewed with a text editor because they are binary files. These binary files use less 

disk space than ASCII files containing the same data. These I/O API files can be viewed by the 

Package for Analysis and Visualization of Environmental data

[http://www.cep.unc.edu/empd/EDSS/pave_doc/] (PAVE). Files with extension .txt however, 

are text files that may be viewed with a text editor or in a spreadsheet.

SOURCES MODELED WITH CAMx PLUME-IN-GRID MODEL

Large stationary NOx sources within the 12 km domain were modeled with the CAMx Plume-inGrid (PiG) model. For each simulated day, PiG sources were identified in the following way:

(1) Identified sources (i.e. individual stacks) emitting more than 1 ton/day NOx emissions 

(2) Identified sources co-located with those sources found in (1);

 i.e. sources that are within 100 m distance AND have NOx emissions greater than or equal 

to 0.1 ton/day were identified

The sources identified in this manner for all 366 days of 2008 were appended together to 

compile a list of distinct sources within the 12 km domain for each year. Sources on this list 

were selected for PiG treatment in emissions processing. Maps of sources selected for PiG 

treatment within the 12 km domain are shown in Figures F4-F7. Point sources were broken out 

by source category into EGU, oil and gas, trona, and non-EGU sources that do not fit under 

either oil and gas or trona source categories. This was done to configure the inventory for use 

in potential CAMx source apportionment analyses. PiGged sources are displayed in separate 

figures by source category and year in Figures F4-F7. Table F3 lists the sources selected for PiG 

treatment in 2008 along with their locations, source identification information, and NOx, SO2, 

CO, NH3, and PM emissions.

VOC SPECIATION PROFILES

The Carter Lake/BP Southwest Wyoming O&G inventory includes detailed VOC gas composition 

analyses for the 5-County area. Speciation profiles were developed for the main VOC-emitting 

processes from oil and gas production activities for each county in the region. Where 

additional spatial resolution was needed, counties were further subdivided; the Jonah and 

Pinedale fields were separated out from the rest of Sublette County, and Sweetwater County 

was divided into East Sweetwater and West Sweetwater. Separate speciation profiles were 

developed for the following processes: flashing, well venting, pneumatic pumps, and fugitive 

emissions, which were further broken down into emissions from sales gas, produced gas and 

condensate. Profile codes and descriptions are shown in Table F5. Since gas analyses for the 

Southwest Wyoming basin were available for both 2005 and 2006, two-year average profiles 

were used for those years and the same profiles were used for the 2008 inventory. The 

Speciation Tool was used to convert these gas composition analyses to CB05 speciation profiles 

ready for use in SMOKE. 

The SMOKE emission model includes default speciation profiles indexed by SCC codes. These 

profiles are based on EPA default data as well as on various updates and improvements 

incorporated to account for such things as variations in fuels, solvent composition, and 

chemical mechanisms used in air quality models. For the CD-C Southwest Wyoming O&G 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-11

processing, instead of using generic EPA default profiles, region-specific VOC speciation profiles 

derived from the gas composition analysis for each basin were used.

Speciation profiles used for modeling of VOC emissions from O&G sources in SW Wyoming are 

shown in Table F7 and the cross reference between speciation profiles and SCCs that shows 

which profile was used for a given source category is shown in Table F8. Table F6 provides a 

key to the abbreviations for the CB05 species. For comparison, EPA default speciation profiles 

and cross references are shown in Tables F9-F11.

SW WYOMING O&G VOC EMISSION INVENTORY

Table F4 shows the emissions of total organic gases (TOG) in SW Wyoming. For ease of 

comparison with other WDEQ inventories, we also present the TOG emissions broken down 

into methane, ethane and VOC. Table F12 shows the SW Wyoming emission inventory in terms 

of the relevant species used in the Carbon Bond 05 (CB05; Yarwood et al., 2005) chemical 

mechanism for methane (CH4), ethane (ETHA), and VOC (CB05 VOC). Ethane is treated as 

explicit species in the CB05 mechanism, whereas methane is assumed to have a constant 

background of 1.7 ppm in the CB05 chemical mechanism as implemented in CAMx and CMAQ. 

Table F12a shows the input NOx, PM2.5, SO2, and VOC for 2008 for each source category of the 

SW Wyoming inventory. Table F12b shows the 2008 SMOKE output species once the speciation 

into CB05 species has been performed. 

Inspection of Table F12 shows that the output VOC mass emissions after speciation are close 

but do not exactly match the input VOC mass emissions. The output VOC mass emissions after 

speciation are not expected to match the input VOC mass emissions; an explanation for this is 

provided below.

O&G VOC emission estimates for Southwest Wyoming for each region and source category 

were provided by the Carter Lake/BP emission inventory. These emission estimates for total 

VOC were converted to the more detailed chemical speciation used by the CB05 chemical 

mechanism in CAMx. For each VOC emissions source, a speciation profile code based on the 

emissions source category determines the "split factors" for that particular profile. The split 

factors are multiplicative factors for converting grams of criteria pollutant (e.g. VOC) emissions 

into moles of CB05 species. For example, in Table F7, the JON06 profile gives the split factors 

required to take VOC emissions from well venting in the Jonah field and speciate the emissions 

into moles of CB05 species that can then be used by the chemical mechanism in CAMx. Note 

that the speciation of VOC to CB05 species conserves moles of material. An example of how 

split factors are derived from data specifying the composition of a hydrocarbon mixture (e.g. a 

gas composition analysis) is given below. 

A given organic compound is assigned to CB05 model species based on its carbon bond 

structure. This is in contrast to a lumped species approach (e.g., SAPRC99) whereby VOC 

species with similar characteristics and reactivities are assigned to the same lumped species. In 

the Carbon Bond approach, a VOC species is decomposed based on its reactive carbon bonds. 

One advantage of the Carbon Bond approach is that it conserves Carbon atoms, however, 

information on other atoms that may be attached to the Carbon (e.g., hydrogen and oxygen) is 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-12

lost. For example, propene contains 3 carbon atoms with one carbon-carbon double bond 

(olefin bond) and one carbon-carbon single bond (paraffinic bond) and six hydrogen atoms:

1 mole of propene is therefore assigned to 1 mole of PAR (paraffin) and 1 mole of OLE (olefin). 

Consider a hypothetical mixture of several non-methane organic compounds (NMOCs; Table 

F2). The first column shows the gases that comprise the mixture, and the second column shows 

the mole fraction for each gas. The third column shows the CB05 mapping for each compound; 

this mapping is done according to the carbon structure as in the propene example above. The 

CB05 mappings are weighted by mole fraction (shown in the second column) and then summed 

to obtain the total CB05 model species per mole of the NMOC mixture emitted (i.e. 0.2 ETHA + 

1 PAR + 0.05 ETH + 0.1 OLE + 0.1 FORM + 0.15 TOL + 0.05 XYL). 

Table F2. Example calculation to assign a hypothetical non-methane organic compound 

(NMOC) mixture to CB05 model species. 

NMOC

Mixture

Mole 

Fraction

CB05 Mapping (mol/mol 

specie)

CB05 Mixture

(mol/mol NMOC)

Ethane 0.2 1 ETHA 0.2 ETHA

Butane 0.15 4 PAR 0.6 PAR

Ethene 0.05 1 ETH 0.05 ETH

Propene 0.10 1 PAR + 1 OLE 0.1 PAR + 0.1 OLE

Formaldehyde 0.10 1 FORM 0.1 FORM

Acetaldehyde 0.15 1 ALD2 0.15 ALD2

Toluene 0.10 1 TOL 0.1 TOL

Ethylbenzene 0.05 1 PAR + 1 TOL 0.05 PAR + 0.05 TOL

Diethylbenzene 0.05 2 PAR + 1 XYL 0.1 PAR + 0.05 XYL

Acetone 0.05 3 PAR 0.15 PAR

Total 1.0 0.2 ETHA + 1 PAR + 0.05 ETH + 0.1 OLE 

+ 0.1 FORM + 0.15 TOL + 0.05 XYL

In order to create the SMOKE output CB05 emissions summary tables shown in Table F12, the 

CB05 VOC species in moles must be converted back to units of weight (i.e. tons). This is done 

for reporting purposes only and has nothing to do with the CB05 chemical mechanism that is 

conserving moles of VOC. The default molecular weight for reporting the mass of CB05 species 

derived from hydrocarbons is the carbon number multiplied by the molecular weight of methane 

(16 gm/mole), which assumes that there are four hydrogen atoms associated with each carbon 

atom. Note that the while the number of carbon atoms in the original VOC emissions estimate 

is preserved throughout the speciation process, the number of atoms of other species 

(hydrogen, oxygen, etc.) is not, so that the VOC emissions input to SMOKE will not match the 

VOC emissions tallied after speciation has occurred. Also note that alternative molecular 

weights than that for methane could also be used for converting the CB05 species from moles 

to mass units for reporting purposes. For example, in the propene example given above, if we 

started with 42 gm of propene it would first be converted into one mole of propene (molecular 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-13

weight of 42 gm/mole) and then speciated into one mole of PAR and one mole of OLE. To 

convert back to mass for reporting purposes we assume the molecular weight of methane (16 

gm/mole) for each carbon and get the following CB05 VOC mass back for 42 gm of propene:

 16 x (1 mole PAR) + 2 x 16 x (1 mole of OLE) = 48 gm

So in this case, the CB05 VOC mass for propene coming out of the speciation when reported as 

mass is 14% higher than the mass of propene going into the speciation. This is solely a 

reporting convention; as far as the CB05 speciation is concerned carbon, is preserved as three 

moles of carbon going in the speciation (propene) and three moles of carbon coming out of the 

speciation (one PAR and one OLE). For hydrocarbon species, the CB05 VOC mass will be the 

same or higher than the mass of hydrocarbons going into the speciation because the maximum 

number of hydrogen atoms that can be associated with a carbon atom is 4 (i.e., methane, CH4). 

DESCRIPTION OF EMISSIONS TABLES

Emission summary tables appear in the following section, Figures and Tables. Below is an 

explanation of the information in each table and how the emissions totals were calculated.

Table F4 shows emissions of CO, NOx, TOG, PM and SO2 within the 4 km domain. The 4 km 

domain encompasses portions of Colorado, Idaho, Utah, and Wyoming. Wyoming is broken out 

into two regions: the 5-County area (Sublette, Carbon, Lincoln, Uinta, and Sweetwater) and the 

rest of Wyoming. The data for the point source categories in Table F4 (Oil and Gas, EGU, NEGU, 

trona and fires) are totals for the 4 km grid that were extracted from the CAMx-ready binary 

emissions files. This was necessary because the point source data was processed on the 12 km 

grid, so emissions information specific to the 4 km grid was not available from the SMOKE 

processing outputs. The county and state lines for doing the emissions extraction are defined 

at 4 km resolution and match the true county boundaries only as well as the spatial resolution 

of the model allows. Therefore, these totals do not match exactly with SMOKE inputs because 

of inconsistencies in definition of county boundaries introduced by the discretization of the 

model. The emission totals for the area, onroad, and off-road categories were developed from 

SMOKE reports from the processing of the 4 km grid emissions. 

Emissions estimates shown in Table F12 are drawn from the SMOKE input and output QA 

reports as discussed above. Tables F13-F17 give a summary of point source emissions within 

the 12 km domain and were generated from SMOKE input emissions QA reports. Point source 

emissions are broken down by category into EGU, non-EGU, and trona emissions. Sources are 

classified within SMOKE as EGU (electricity generating unit) or non-EGU based on SCC code. 

SCCs considered to be EGUs begin with the digits 101 or 201. The SMOKE EGU/non-EGU 

convention causes small sources such as hospital emergency generators to be classified as EGUs 

along with power plants. In the emissions summary tables, all EGU sources are grouped 

together, but in Figures F2-F3, we have divided EGUs into two categories: EGUs that appear in 

the EPA Acid Rain Program Database and those that do not. 

For regions outside Wyoming, the emissions totals in Tables F13-F17 do not include oil and gas 

sources. The point source emission inventory for Wyoming was prepared using a different 

method than the other states. Emissions sources are classified by their SCC and SIC (Standard 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-14

Industrial Classification) codes. In the 2005-6 inventory, SCCs were available for Wyoming point 

sources, but SIC codes were not; therefore, it was difficult to determine whether a given source 

should be classified as an O&G source. Special efforts were made to identify O&G sources 

inside the 5-County area of SW Wyoming. Outside the 5-County area, all Wyoming point 

sources that were not classified as either EGU or trona sources were included in the non-EGU 

category for 2005-6. For 2008, point source emissions for oil and gas sources were broken out 

separately from other sources for all of Wyoming.

Emissions for the 5-County area of Southwest Wyoming appear in multiple tables in this memo; 

we have compiled emissions estimates that were derived using different techniques or from 

different model grids into a single table for comparison. Table F18 compares emissions for each 

pollutant for the 5-County Area of Southwest Wyoming from Tables F4, F12 and F13-17 for the 

year 2008. Comparable emissions totals for the 5-County area are highlighted. For example, 

2008 EGU NOx emission totals from Table F14 may be compared with the EGU totals from 

Table F4a, and these two cells are highlighted in purple in Table F18a.

WYOMING EMISSIONS SUMMARY PLOTS

The upper panel of Figure F9 shows the changes in point source emissions (taken to be the sum 

of trona processing emissions, EGU emissions and emissions from all non-O&G non-EGU 

sources) from 2005 and 2006 to 2008 for NOx, VOC, CO and SO2. For all four pollutants, 

emissions are similar in 2005-6 and decline in 2008. The lower panel of Figure F9, on the other 

hand, shows O&G point source emissions increasing from 2006 to 2008, with NOx showing the 

sharpest rise. NOx and TOG emissions from on-road and off-road sources in Wyoming decrease 

from 2005 through 2008 (Figure F10) but emissions from non-O&G area sources rise going from 

2005 to 2008. The non-O&G area source emissions were calculated through interpolation of 

the 2002 and 2018 WRAP inventories and the increase in the area source emissions with each 

successive year is due to population growth expected between 2002 and 2018. Figure F11 

shows tile plots of the changes in Wyoming onroad and off-road mobile source emissions and 

area source emissions, respectively. Figure F11 shows reductions in emissions on the roadways 

going from 2006 to 2008 expected from fleet turnover to cleaner vehicles. Figure F12 shows the 

increase in non-O&G area emissions, which are concentrated in population centers. Figure F13 

shows an increase in O&G emissions in 2008 relative to 2006 in Wyoming. Note that the 2008 

emission inventory includes O&G sources outside the SWWY 5–county area that were not 

included in the O&G source category in the 2006 emission inventory. These sources were 

included in the non-EGU source category in the 2006 inventory. 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-15

REFERENCES

Bar-Ilan, A., R. Friesen, A. Pollack, and A. Hoats, 2007. “WRAP Area Source Emissions Inventory 

Projections and Control Strategy Evaluation, Phase II”. Prepared for the Western 

Governors’ Association, Denver, CO. September.

Bar-Ilan, A., Grant, J., Friesen, R., Pollack, A., Henderer, D., Pring, D., Sgamma, K., 2008. 

“Development of Baseline 2006 Emissions from Oil and Gas Activity in the DenverJulesburg Basin”; Prepared for Western Governor’s Association by ENVIRON 

International Corp., Novato CA. 

http://www.wrapair.org/forums/ogwg/documents/2008-

04_%2706_Baseline_Emissions_DJ_Basin_Technical_Memo_(04-30).pdf

Bar-Ilan, A., Grant, J., R. Parikh, Pollack, A., Henderer, D., Pring, D., Sgamma, K., 2009. 

“Development of Baseline 2006 Emissions from Oil and Gas Activity in the Piceance 

Basin”; Prepared for Western Governor’s Association by ENVIRON International Corp., 

Novato CA. www.wrapair.org/forums/ssjf/documents/eictts/oilgas.html.

Carter Lake Consulting and ENVIRON, 2010. Revised Draft Air Quality Impact Assessment 

Protocol for the Continental Divide-Creston Project Environmental Impact Statement. 

Prepared for Bureau of Land Management Rawlins Field Office and Bureau of Land 

Management Wyoming State Office. March.

Coats, C.J. Jr. 1996. High-performance algorithms in the Sparse Matrix Operator Kernel 

Emissions (SMOKE) modeling system. Proc. Ninth AMS Joint Conference on Applications 

of Air Pollution Meteorology with AWMA. Amer. Meteor. Soc., Atlanta, GA, 584-588.

ENVIRON. 2008. “User’s Guide Comprehensive Air Quality Model With Extensions (CAMx) 

Version 4.50.” ENVIRON International Corporation, Novato, California. 

(www.camx.com). September.

ENVIRON and Carter Lake Consulting, 2010. “Model Performance Evaluation of the

CAMx 2005 and 2006 Base Case Simulation Performed Under the Continental Divide-Creston 

Environmental Impact Statement Study”. Prepared for Wyoming Department of 

Environmental Quality Air Quality Division, Cheyenne, Wyoming, Bureau of Land 

Management Rawlins Field Office Rawlins, Wyoming, Bureau of Land Management, 

Wyoming State Office, Cheyenne, Wyoming. March.

Yarwood, G., S. Rao, M. Yocke and G. Whitten. 2005. Updates to the Carbon Bond Chemical 

Mechanism: CB05. ENVIRON International Corporation, Novato, California. December 

8.
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-16

FIGURES AND TABLES

Figure F1. CD-C 12/4 km modeling domain with corrected monitor labels.
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-17

Figure F2. 2008 point sources within the 12 km domain excluding O&G sources for all of 

Wyoming, and not only within the 5-county area. Sources are classified within SMOKE as EGU 

(electricity generating unit) or non-EGU based on SCC code. SCCs considered to be EGUs 

begin with the digits 101 or 201. Because the SMOKE EGU/non-EGU convention causes small 

sources such as hospital emergency generators to be classified as EGUs along with power 

plants, we have divided EGUs into two categories: EGUs that appear in the EPA Acid Rain 

Program Database and those that do not. Only large power plants appear in the Acid Rain 

Program Database. These EGUs are labeled and indicated by a square icon. Sources in the 

Denver area are shown separately in Figure F3.

For Wyoming point sources, SCCs were available, but SIC codes were not; therefore, it was 

difficult to determine whether a given source should be classified as an O&G source. Special 

efforts were made to identify O&G sources inside the 5-County area of SW Wyoming. 

Outside the 5-County area, all Wyoming point sources that were not classified as either EGU 

or trona sources were included in the non-EGU category. 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-18

Figure F3. 2008 ARD point sources in the Denver area within the 12 km domain. Sources are 

classified within SMOKE as EGU (electricity generating unit) or non-EGU based on SCC code. 

SCCs considered to be EGUs begin with the digits 101 or 201. Because the SMOKE EGU/nonEGU convention causes small sources such as hospital emergency generators to be classified 

as EGUs along with power plants, we have divided EGUs into two categories: EGUs that 

appear in the EPA Acid Rain Program Database and those that do not. Only large power 

plants appear in the Acid Rain Program Database. These EGUs are labeled and indicated in by 

a square icon. 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-19

Figure F4. 2008 EGU sources treated with the CAMx Plume-in-Grid (PiG) Model within the 12 

km domain. 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-20

Figure F5. 2008 non-EGU sources treated with the CAMx Plume-in-Grid (PiG) Model within 

the 12 km domain. 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-21

Figure F6. 2008 oil and gas sources treated with the CAMx Plume-in-Grid (PiG) Model within 

the 12 km domain. 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-22

Figure F7. 2008 trona sources treated with the CAMx Plume-in-Grid (PiG) Model within the 

12 km domain. 
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-23

Table F3a. 2008 EGU Sources within the 12/4 km grid modeled with the CAMx Plume-in-Grid. Sources are ranked by their NOx 

emissions.

Rank NOx (tpd) PT # X (m) Y (m) Plant ID Stack ID ORISID FIPS Plant NOx VOC CO SO2 PM10 PM2.5 NH3

1 78.1 517 -1322699 59547 EGU1222 202 6481 49027 Intermountain Generation Station 28532.9 0.0 0.0 5980.3 0.0 0.0 71.5

2 73.6 401 -743950 714784 EGU0727 226 6076 30087 COLSTRIP STEAM ELECTRIC STATION 26215.4 0.0 0.0 13888.6 0.0 0.0 0.0

3 48.2 284 -891863 107264 EGU0175 222 6021 8081 TRI STATE GENERATION CRAIG 17137.5 0.0 0.0 4060.1 0.0 0.0 64.0

4 39.1 506 -1198213 -1559 EGU1220 212 6165 49015 Hunter Power Plant 14179.1 0.0 0.0 5085.5 0.0 0.0 0.0

5 28.8 508 -1198431 24452 EGU1221 212 8069 49015 Huntington Power Plant 10409.2 0.0 0.0 3458.0 0.0 0.0 0.0

6 23.9 859 -971185 255585 5603701002 2163 806 56037 Jim Bridger Power Plant 8594.3 79.4 680.6 5547.3 754.2 754.2 0.0

7 22.5 45 -689997 9568 EGU0163 222 469 8001 PUBLIC SERVICE CO CHEROKEE PLT 8070.9 0.0 0.0 6027.6 0.0 0.0 16.3

8 20.5 843 -646788 261579 5603100001 1350 620 56031 Laramie River Station 7300.1 78.3 652.1 4466.7 581.4 581.4 0.0

9 19.5 736 -1036751 80250 EGU1224 202 7790 49047 BONANZA POWER PLANT 7126.8 52.4 437.0 994.2 568.9 470.2 26.2

10 19.1 842 -646788 261579 5603100001 1349 620 56031 Laramie River Station 6786.9 81.8 681.3 3278.6 223.0 223.0 0.0

11 18.3 841 -646788 261579 5603100001 1338 620 56031 Laramie River Station 6596.6 83.6 696.4 3837.2 245.5 245.5 0.0

12 17.8 505 -1198213 -1559 EGU1220 202 6165 49015 Hunter Power Plant 6441.6 0.0 0.0 1049.6 0.0 0.0 0.0

13 17.6 834 -1119667 277408 5602300004 210 416 56023 Naughton Plant 6249.6 46.5 332.4 5975.6 2860.5 2860.5 0.0

14 14.9 862 -971185 255585 5603701002 2166 806 56037 Jim Bridger Power Plant 5384.4 80.2 687.4 3010.0 752.5 752.5 0.0

15 14.8 818 -712133 348563 5600900001 2193 415 56009 Dave Johnston 5316.1 37.2 309.7 7496.7 0.0 0.0 0.0

16 14.1 804 -665539 505681 5600500046 1317 610 56005 Wyodak Plant 5025.6 62.0 517.3 8196.0 1684.6 1684.6 0.0

17 13.4 307 -563976 46860 EGU0179 222 6248 8087 PUBLIC SERVICE CO PAWNEE PLT 4818.2 0.0 0.0 13980.8 0.0 0.0 27.3

18 13.2 860 -971185 255585 5603701002 2164 806 56037 Jim Bridger Power Plant 4735.9 79.1 677.6 5912.1 755.9 755.9 0.0

19 12.6 861 -971185 255585 5603701002 2165 806 56037 Jim Bridger Power Plant 4561.4 82.3 705.8 6227.2 767.2 767.2 0.0

20 12.4 46 -689997 9568 EGU0163 226 469 8001 PUBLIC SERVICE CO CHEROKEE PLT 4426.1 0.0 0.0 1768.7 0.0 0.0 13.2

21 12.2 833 -1119667 277408 5602300004 209 416 56023 Naughton Plant 4477.3 29.9 213.4 9225.6 2045.2 2045.2 0.0

22 11.7 513 -1322699 59547 10327 202 6481 49027 Intermountain Generation Station 4286.7 0.0 0.0 597.9 0.0 0.0 13.6

23 10.5 344 -856301 102086 EGU0183 226 525 8107 PUBLIC SERVICE CO HAYDEN PLT 3738.5 0.0 0.0 1477.5 0.0 0.0 14.6

24 10.3 343 -856301 102086 EGU0183 222 525 8107 PUBLIC SERVICE CO HAYDEN PLT 3659.6 0.0 0.0 1222.9 0.0 0.0 9.5

25 10.1 466 -1174662 59571 EGU1218 212 3644 49007 Carbon Power Plant 3689.5 0.0 0.0 5596.0 0.0 0.0 0.0

26 10 832 -1119667 277408 5602300004 208 416 56023 Naughton Plant 3605.9 22.7 162.1 7308.1 1621.0 1621.0 0.0

27 9.5 819 -712178 348612 5600900001 2194 415 56009 Dave Johnston 3412.4 52.1 434.5 5405.6 0.0 0.0 0.0

28 9.4 158 -680287 -6529 EGU0165 222 465 8031 PUBLIC SERVICE CO - ARAPAHOE 3401.0 0.0 0.0 3154.8 0.0 0.0 9.9

29 7.9 273 -891863 107264 18 222 6021 8081 TRI STATE GENERATION CRAIG 2799.9 0.0 0.0 656.7 0.0 0.0 12.5

30 7.5 80 -693836 34254 EGU0164 226 477 8013 PUBLIC SERVICE CO - VALMONT 2675.7 0.0 0.0 873.1 0.0 0.0 8.1

31 6.1 817 -712112 348527 5600900001 2192 415 56009 Dave Johnston 2204.1 18.0 150.1 3705.2 0.0 0.0 0.0

32 6.1 813 -712075 348491 5600900001 2179 415 56009 Dave Johnston 2199.7 17.9 149.0 3818.6 0.0 0.0 0.0

33 5.4 418 -889488 696596 EGU0728 226 2187 30111 PPL MONTANA - JE CORETTE PLANT 1926.8 0.0 0.0 3304.8 0.0 0.0 10.5

34 5.4 236 -671031 123737 EGU0173 226 6761 8069 PLATTE RIVER POWER AUTHORITY - RAWHIDE 1951.3 0.0 0.0 979.0 0.0 0.0 16.8

35 4.7 496 -1198213 -1559 10237 212 6165 49015 Hunter Power Plant 1721.2 0.0 0.0 794.3 0.0 0.0 0.0

36 4.2 806 -665582 505394 5600500063 2335 750 56005 Neil Simpson Two 1549.8 4.2 211.0 786.1 84.5 84.5 0.0

37 4 410 -743950 714784 087-0008 226 6076 30087 COLSTRIP STEAM ELECTRIC STATION 1441.6 0.0 0.0 1554.8 0.0 0.0 0.0

38 3.9 501 -1198431 24452 10238 212 8069 49015 Huntington Power Plant 1422.3 0.0 0.0 658.8 0.0 0.0 0.0

39 2.8 11 -689997 9568 1 222 469 8001 PUBLIC SERVICE CO CHEROKEE PLT 999.6 0.0 0.0 869.0 0.0 0.0 3.3

40 2.8 495 -1198213 -1559 10237 202 6165 49015 Hunter Power Plant 1024.5 0.0 0.0 263.5 0.0 0.0 0.0

41 2.8 868 -591155 463494 5604500005 64 0 56045 Osage 964.9 0.0 586.5 2381.3 571.9 571.9 0.0

42 2.4 810 -665255 506078 5600590001 0 5631 56005 WYGEN II 269.7 4.0 301.5 221.1 51.6 0.0 0.0

42 2.6 433 -498985 470013 28.0801-02 1 0 46103 Black Hill Power & Light Company (Ben Fr 887.2 3.4 131.2 759.9 30.2 0.0 0.0

43 2.2 397 -821441 687100 ORIS55749 STKDEF 55749 30003 HARDIN 754.2 71.5 595.9 517.9 38540.2 10054.0 35.8

44 2 12 -689997 9568 1 226 469 8001 PUBLIC SERVICE CO CHEROKEE PLT 379.8 0.0 0.0 146.5 0.0 0.0 1.4

45 1.9 291 -563976 46860 11 222 6248 8087 PUBLIC SERVICE CO PAWNEE PLT 657.0 0.0 0.0 370.8 0.0 0.0 6.0

46 1.8 227 -671031 123737 53 226 6761 8069 PLATTE RIVER POWER AUTHORITY - RAWHIDE 651.9 0.0 0.0 154.5 0.0 0.0 3.0

47 1.8 331 -856301 102086 1 222 469 8107 PUBLIC SERVICE CO CHEROKEE PLT 999.6 0.0 0.0 869.0 0.0 0.0 3.3

48 1.7 160 -680930 986 EGU0166 601 478 8031 Zuni 367.4 0.0 0.0 0.9 0.0 0.0 77.7

49 1.7 265 -968076 -34362 EGU0174 202 468 8077 PUBLIC SERVICE CO CAMEO PLT 626.9 0.0 0.0 1909.8 0.0 0.0 2.7

50 1.6 332 -856301 102086 1 226 469 8107 PUBLIC SERVICE CO CHEROKEE PLT 379.8 0.0 0.0 146.5 0.0 0.0 1.4

51 1.5 459 -1174662 59571 10081 212 3644 49007 Carbon Power Plant 560.9 0.0 0.0 1137.3 0.0 0.0 0.0

52 1.5 809 -665575 505472 5600500146 2759 5547 56005 WYGEN Station I 597.8 8.3 344.5 659.7 82.9 82.9 0.0

53 1.1 512 -1368566 20475 10327 1 6481 49027 Intermountain Generation Station 412.6 15.9 884.2 530.5 70.7 18.5 0.0

54 1.1 306 -564179 47790 EGU0178 201 55127 8087 MANCHIEF POWER COMPANY LLC 219.9 25.1 977.7 2.3 80.1 80.1 76.5

55 1.1 68 -693836 34254 1 226 469 8013 PUBLIC SERVICE CO CHEROKEE PLT 379.8 0.0 0.0 146.5 0.0 0.0 1.4

56 1 403 -743950 714784 EGU0727 801 6076 30087 COLSTRIP STEAM ELECTRIC STATION 416.8 0.0 0.0 2377.2 0.0 0.0 0.0

56 1 431 -470333 696581 NEW-ND1 1 0 38011 Future Coal EGU (Gascoyne/Westmoreland P 338.7 6.9 443.7 254.0 37.2 0.0 0.0

57 0.8 423 -889488 696596 111-0015 226 2187 30111 PPL MONTANA - JE CORETTE PLANT 299.3 0.0 0.0 545.8 0.0 0.0 2.1

58 0.7 47 -689997 9568 EGU0163 601 469 8001 PUBLIC SERVICE CO CHEROKEE PLT 278.9 0.0 0.0 0.9 0.0 0.0 3.1

59 0.6 98 -680930 986 7 601 478 8031 Zuni 229.7 0.0 0.0 0.6 0.0 0.0 9.3

60 0.4 235 -671031 123737 EGU0173 201 6761 8069 PLATTE RIVER POWER AUTHORITY - RAWHIDE 98.3 0.0 0.0 1.9 0.0 0.0 28.4

61 0.2 48 -689997 9568 EGU0163 604 469 8001 PUBLIC SERVICE CO CHEROKEE PLT 69.7 0.0 0.0 0.1 0.0 0.0 1.2

62 0.1 159 -680287 -6529 EGU0165 601 465 8031 PUBLIC SERVICE CO - ARAPAHOE 42.0 0.0 0.0 1.0 0.0 0.0 2.3

63 0.1 305 -564179 47790 72 201 55127 8087 MANCHIEF POWER COMPANY LLC 39.1 1.5 59.0 0.4 0.2 0.1 4.6

64 0.1 13 -689997 9568 1 601 469 8001 PUBLIC SERVICE CO CHEROKEE PLT 34.7 0.0 0.0 0.1 0.0 0.0 0.7

Source Parameters Emissions (TPY)
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-24

Table F3b. 2008 non-EGU Sources within the 12/4 km grid modeled with the CAMx Plume-in-Grid. Sources are ranked by their 

NOx emissions.

Rank NOx (tpd) PT # X (m) Y (m) Plant ID Stack ID ORISID FIPS Plant NOx VOC CO SO2 PM10 PM2.5 NH3

1 8.4 16600 -1267843 164918 10571 927593 0 49035 Mine & Copperton Concentrator 3124.6 1303.4 286.1 37.8 255.6 255.6 0.0

2 8 23261 -1057458 253150 5603799999 0 56037 FMC Westvaco 2961.2 574.8 281.3 3636.9 1569.1 487.4 0.0

3 4.8 2636 -694677 53910 3 7 0 8013 CEMEX, INC. - LYONS CEMENT PLANT 1801.7 113.3 2.5 15.0 111.6 0.0 0.0

4 4.2 21233 -714531 174056 5600100002 1285 0 56001 Laramie Cement Plant 1565.0 680.2 57.5 79.2 116.5 0.0 0.0

5 4.1 14512 -1289629 59699 10303 1616 0 49023 Leamington Cement Plant 1496.1 17319.2 57.6 0.7 50.9 50.9 3.7

6 3.8 14837 -1207603 213047 10007 16758 0 49029 Devil's Slide Plant 1369.1 892.2 50.8 204.3 16.2 5.1 3.5

7 3.7 10401 -1183016 392330 2900001 10 0 16029 P4 Production LLC 1704.3 213.8 0.0 7293.2 40.2 31.5 0.0

8 3.3 11144 -499781 470177 28.1121-02 9 9 46103 GCC Dacotah 2086.9 1860.5 56.628 221.49 4.283 0 0

9 3 14920 -1207603 213047 10007 948011 0 49029 Devil's Slide Plant 1078.1 640.7 39.0 190.5 12.2 3.8 4.4

10 3 14945 -1207603 213047 10007 952430 0 49029 Devil's Slide Plant 1078.1 640.7 39.0 190.5 12.2 3.8 3.5

11 2.5 14648 -1354245 1417 10313 17059 0 49027 Cricket Mountain Plant 926.4 420.1 45.3 38.1 33.0 26.4 20.7

12 2.3 6650 -697446 5119 820 6 10003 8059 TRIGEN - COLORADO ENERGY CORPORATION 950.4 43.5 5.2 1938.1 16.9 0.0 0.0

13 1.8 22615 -658781 149654 56-021-00002 6979 0 56021 Fertilizer Plant 659.3 53.3 16.3 0.0 0.0 0.0 0.0

14 1.8 22599 -659258 149940 56-021-00002 0 56021 Fertilizer Plant 648.0 169.1 76.4 0.2 44.0 44.0 0.0

15 1.5 16630 -1262021 182635 10572 1312 0 49035 Power Plt/ Lab/ Tailings Impoundment 556.4 27.5 2.2 654.8 7.7 4.2 0.1

16 1.5 16634 -1262021 182635 10572 1316 0 49035 Power Plt/ Lab/ Tailings Impoundment 553.1 31.7 3.9 871.9 21.7 10.2 0.1

17 1.4 10627 -1414379 416258 8300001 10 0 16083 TASCO, Twin Falls 558.1 178.2 4.4 653.4 43.0 22.0 0.0

18 1.3 16628 -1262021 182635 10572 1310 0 49035 Power Plt/ Lab/ Tailings Impoundment 489.1 27.4 2.2 636.6 2.8 1.5 0.1

19 1.3 16631 -1262021 182635 10572 1313 0 49035 Power Plt/ Lab/ Tailings Impoundment 478.3 24.2 1.9 593.1 6.9 3.7 0.1

20 1.3 11168 -499542 470162 28.1121-02 41 0 46103 GCC Dacotah 467.81 417.06 12.7 79.52 7.61 0 0

21 1.3 16632 -1262021 182635 10572 1314 0 49035 Power Plt/ Lab/ Tailings Impoundment 462.4 28.3 2.2 663.5 3.5 2.0 0.1

22 1.2 11138 -499781 470177 28.1121-02 3 0 46103 GCC Dacotah 788.4 101.87 16.24 29.323 151.5 0 0

23 1.2 6648 -697446 5119 820 4 10003 8059 TRIGEN - COLORADO ENERGY CORPORATION 535.7 21.1 2.6 670.2 7.6 0.0 0.0

24 1.2 21228 -714531 174056 5600100002 1278 0 56001 Laramie Cement Plant 455.1 4.9 22.2 118.8 56.8 0.0 0.0

25 1.2 16635 -1262021 182635 10572 1317 0 49035 Power Plt/ Lab/ Tailings Impoundment 439.05 25.058 3.1095 751.91 12.83 5.588 0.1

26 1.2 10628 -1414379 416258 8300001 20 0 16083 TASCO, Twin Falls 509.7 19.8 2.4 746.1 85.6 44.3 0.0

27 1.1 16629 -1262021 182635 10572 1311 0 49035 Power Plt/ Lab/ Tailings Impoundment 410.9 23.8 1.9 568.5 2.4 1.3 0.1

28 1.1 23185 -1009594 238534 560379324 0 56037 "P4 Production, L.L.C." 399.3 10.6 2.3 714.6 75.8 75.2 0.0

29 1.1 12023 -1137841 33914 10096 3236 50951 49007 Sunnyside Cogeneration Facility 396.5 108.1 13.0 893.8 35.2 33.7 0.2

30 1.1 14647 -1354245 1417 10313 73 0 49027 Cricket Mountain Plant 397.1 268.5 25.4 27.9 21.4 17.1 13.2

31 1.1 10572 -1358824 414676 6700001 20 0 16067 TASCO, Paul 446.8 156.6 1.7 165.5 103.7 51.9 0.0

32 1.1 10571 -1358824 414676 6700001 10 0 16067 TASCO, Paul 484.0 21.0 3.1 128.4 94.2 48.4 0.0

33 1.1 16633 -1262021 182635 10572 1315 0 49035 Power Plt/ Lab/ Tailings Impoundment 392.5 24.6 1.9 594.0 2.4 1.3 0.1

34 1 23187 -1009636 236437 5603700003 2021 0 56037 Rock Springs - Rotary Coking 394.25 0.5 2.29 705.56 56.54 0 0

35 1 10398 -1183016 392330 2900001 10 0 16029 P4 Production LLC 1704.3 213.8 0.0 7293.2 40.2 31.5 0.0

36 1 10056 -1234508 412961 500004 90 0 16005 Ash Grove Cement 496.9 622.8 13.4 4.5 21.1 5.4 4.9

37 0.9 14645 -1354245 1417 10313 71 0 49027 Cricket Mountain Plant 312.7 151.2 8.0 4.8 58.2 46.5 7.5

38 0.7 11139 -499781 470177 28.1121-02 4 0 46103 GCC Dacotah 432.71 222.13 17.645 480.74 50.38 0 0

39 0.6 14646 -1354245 1417 10313 72 0 49027 Cricket Mountain Plant 221.2 160.4 14.8 19.8 24.7 19.7 7.9

40 0.4 6647 -697446 5119 820 3 10003 8059 TRIGEN - COLORADO ENERGY CORPORATION 180.9 85.2 0.9 234.7 2.2 0.0 0.0

41 0.8 10055 -1234508 412961 500004 80 0 16005 Ash Grove Cement 409.1 592.6 9.4 14.2 28.6 6.0 1.8

42 0.4 11146 -499781 470177 28.1121-02 11 0 46103 GCC Dacotah 147.94 139.2 4.2397 26.54 7.611 0 0

43 0.4 2610 -694677 53910 3 7 0 8013 CEMEX, INC. - LYONS CEMENT PLANT 1801.7 113.3 2.5 15.0 111.6 0.0 0.0

44 0.3 6639 -697446 5119 820 6 10003 8059 TRIGEN - COLORADO ENERGY CORPORATION 950.4 43.5 5.2 1938.1 16.9 0.0 0.0

45 0.3 10574 -1358824 414676 6700001 40 0 16067 TASCO, Paul 131.4 573.3 6.4 46.3 70.8 35.3 0.0

46 0.2 10565 -1358824 414676 6700001 10 0 16067 TASCO, Paul 484.0 21.0 3.1 128.4 94.2 48.4 0.0

47 0.2 10573 -1358824 414676 6700001 30 0 16067 TASCO, Paul 109.8 422.1 4.6 34.8 86.0 43.1 0.0

48 0.2 10622 -1414379 416258 8300001 20 0 16083 TASCO, Twin Falls 509.7 19.8 2.4 746.1 85.6 44.3 0.0

49 0.2 6637 -697446 5119 820 4 0 8059 TRIGEN - COLORADO ENERGY CORPORATION 535.7 21.1 2.6 670.2 7.6 0.0 0.0

50 0.2 10629 -1414379 416258 8300001 30 0 16083 TASCO, Twin Falls 80.8 285.6 6.2 27.3 33.0 16.4 0.0

51 0.1 10621 -1414379 416258 8300001 10 0 16083 TASCO, Twin Falls 558.1 178.2 4.4 653.4 43.0 22.0 0.0

52 0.2 10054 -1234508 412961 500004 90 0 16005 Ash Grove Cement 496.9 622.8 13.4 4.5 21.1 5.4 4.9

53 0.1 10566 -1358824 414676 6700001 20 0 16067 TASCO, Paul 446.8 156.6 1.7 165.5 103.7 51.9 0.0

54 0.2 10053 -1234508 412961 500004 80 0 16005 Ash Grove Cement 409.1 592.6 9.4 14.2 28.6 6.0 1.8

55 0.1 14516 -1289629 59699 10303 17008 0 49023 Leamington Cement Plant 43.7 43.7 3.1 0.1 4.2 4.2 0.0

56 0.1 10568 -1358824 414676 6700001 40 0 16067 TASCO, Paul 131.4 573.3 6.4 46.3 70.8 35.3 0.0

Source Parameters Emissions (TPY)
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-25

Table F3c. 2008 oil and gas sources within the 12/4 km grid modeled with the CAMx Plume-in-Grid. Sources are ranked by their 

NOx emissions.

Table F3d. 2008 trona sources within the 12/4 km grid modeled with the CAMx Plume-in-Grid. Sources are ranked by their NOx 

emissions.

Rank NOx (tpd) PT # X (m) Y (m) Plant ID Stack ID ORISID FIPS Plant NOx VOC CO SO2 PM10 PM2.5 NH3

1 3.8 410 -645330 40222 123-0048 1 - 8123 KERR-MCGEE GATHERING LLC - HUDSON 1381.4 69.9 232.0 0.3 18.6 18.6 -

2 3.6 1070 -936219 562955 5602900012 0 - 56029 Elk Basin Gas Plant 1319.1 38.6 420.5 0.0 0.0 0.0 -

3 3.1 1263 -972850 215796 5603700008 0 - 56037 Brady Gas Plant 1131.1 30.2 43.0 0.0 0.0 0.0 -

4 2.7 427 -667935 455811 56-005-000 0 - 56005 Hilight Gas Plant 973.2 38.8 316.8 0.0 0.0 0.0 -

5 2.6 455 -828947 240288 5600700019 0 - 56007 Rawlins Plant 956.1 101.4 161.0 0.0 0.0 0.0 -

6 2.5 2 -653900 -531 001-0036 1 - 8001 COLORADO INTERSTATE GAS CO WATKINS STA 920.3 88.4 243.7 0.5 7.3 7.3 -

7 2.3 1306 -866388 509639 5604300007 0 - 56043 Worland Compressor Station 840.7 20.8 225.2 0.0 0.0 0.0 -

8 2.2 1 -740374 195338 5600100006 0 - 56001 Laramie Compressor Station 812.6 39.3 152.8 0.8 8.5 8.5 -

9 2 412 -651163 133423 123-0051 1 - 8123 COLORADO INTERSTATE GAS CO CHEYENNE STN 740.1 327.0 375.9 4.1 11.7 11.7 -

10 2 123 -1269939 421949 R10T5-ID-0 1 - 905001 Pocatello Compressor Station 715.5 23.6 81.2 1.4 1.8 0.0 -

11 1.8 1 -652350 -363 001-0025 1 - 8001 BP AMERICA PRODUCTION CO. WATTENBERG PLT 640.3 50.8 129.4 0.1 1.8 1.8 -

12 1.7 909 -1132624 287706 5602300005 0 - 56023 Kemmerer Compressor Station 620.0 15.5 39.8 0.0 0.0 0.0 -

13 1.5 60 -610754 -19271 005-0055 1 - 8005 COLORADO INTERSTATE GAS CO LATIGO C & S 554.9 14.9 153.3 0.1 1.4 1.4 -

14 1.3 1268 -1051284 216732 5603700027 0 - 56037 Green River Compressor Station 469.8 8.8 18.3 0.0 0.0 0.0 -

15 1.2 477 -680866 340637 56009482 0 - 56009 Douglas Gas Plant 438.9 23.7 157.5 0.0 0.0 0.0 -

16 1.2 445 -666557 35213 123-0184 1 - 8123 KERR-MCGEE FREDERICK COMPRESSOR STATION 434.8 108.9 224.4 0.0 12.4 12.4 -

17 1.2 18 -1172147 374572 700008 40 - 16007 Northwest Pipeline Soda Springs 431.1 15.7 94.1 0.1 0.0 0.0 -

18 1.1 407 -666403 38741 123-0015 1 - 8123 "DCP MIDSTREAM, LP - SPINDLE" 401.3 114.2 411.8 0.3 9.0 9.0 -

19 1.1 294 -993845 68874 103-0021 1 - 8103 NORTHWEST PIPELINE CORP RANGELY STA 388.5 14.7 47.3 0.1 4.7 4.7 -

20 1.1 275 -575438 42396 087-0003 1 - 8087 COLORADO INTERSTATE GAS CO FORT MORGAN 382.7 71.4 280.5 114.4 1.0 1.0 -

21 1 413 -654667 43901 123-0057 1 - 8123 KERR-MCGEE FT LUPTON COMPRESSOR STATION 372.8 100.6 231.1 0.2 14.5 14.5 -

22 0.4 16 -1172147 374572 700008 20 - 16007 Northwest Pipeline Soda Springs 148.3 3.7 11.5 0.0 0.0 0.0 -

23 0.4 15 -1172147 374572 700008 10 - 16007 Northwest Pipeline Soda Springs 146.8 3.7 10.0 0.0 0.0 0.0 -

24 0.4 14 -1172147 374572 700008 40 - 16007 Northwest Pipeline Soda Springs 146.3 13.7 82.3 0.1 0.0 0.0 -

25 0.4 17 -1172147 374572 700008 30 - 16007 Northwest Pipeline Soda Springs 140.6 3.5 10.9 0.0 0.0 0.0 -

26 0.1 12 -1172147 374572 700008 20 - 16007 Northwest Pipeline Soda Springs 50.4 3.2 10.1 0.0 0.0 0.0 -

27 0.1 11 -1172147 374572 700008 10 - 16007 Northwest Pipeline Soda Springs 49.8 3.2 8.7 0.0 0.0 0.0 -

28 0.1 13 -1172147 374572 700008 30 - 16007 Northwest Pipeline Soda Springs 47.7 3.1 9.5 0.0 0.0 0.0 -

Source Parameters Emissions (TPY)

Rank NOx (tpd) PT # X (m) Y (m) Plant ID Stack ID ORISID FIPS Plant NOx VOC CO SO2 PM10 PM2.5 NH3

1 4.5 90 -1051622 249014 5603700002 4457 0 56037 Green River Trona Plant 1642.6 11.4 97.5 3285.2 345.5 0 0

2 3 89 -1051622 249014 5603700002 4456 1 56037 Green River Trona Plant 1099.1 7.2 61.6 2096.4 214.8 0 0

3 1.5 154 -1062820 260555 5603700010 4318 2 56037 Soda Ash Facility - Granger 531.3 2.9 153.6 138.6 145 0 0

4 1.4 155 -1062820 260555 5603700010 4319 3 56037 Soda Ash Facility - Granger 525.5 2.7 207 168.2 145.6 0 0

5 1.3 114 -1054153 240283 5603700005 40714 4 56037 Green River Soda Ash Plant 482.5 2 48.2 19.3 21.1 0 0

6 1.3 113 -1054023 240254 5603700005 40713 5 56037 Green River Soda Ash Plant 482.4 2 49.2 19.7 22 0 0

7 0.2 66 -1051622 249014 5603700002 4428 6 56037 Green River Trona Plant 70.7 107.1 1274.8 0 159.2 0 0

8 0.1 67 -1051622 249014 5603700002 4429 7 56037 Green River Trona Plant 52.1 102.5 2472.7 0 159.1 0 0

Source Parameters Emissions (TPY)
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-26

Table F4a. 2008 CD-C 4 km Domain Emission Summary using 2005 meteorology (tpy).

Compressor Drilling Production Area Onroad Offroad EGU NEGU Trona Biogenic Fire

Colorado 777 0 45 2,448 18,082 7,931 1,356 58 0 10,053 2,224

Idaho 263 0 0 487 2,563 4,545 0 10,909 0 6,777 16,701

Utah 1,747 0 4 1,974 19,482 12,212 426 645 0 2,504 17,793

Wyoming (5 counties) 4,403 2,600 3,509 6,186 37,451 15,649 3,323 3,466 12,492 8,667 6,157

Wyoming (rest) 975 286 540 7,656 34,112 20,696 15 1,416 0 9,532 2,434

Colorado 1,311 0 51 152 1,730 1,245 28,689 86 0 566 66

Idaho 1,282 0 0 340 300 675 0 1,932 0 352 575

Utah 3,175 0 4 214 1,920 1,771 7,209 1,130 0 140 515

Wyoming (5 counties) 8,660 5,800 4,206 3,167 4,556 14,154 38,501 7,042 6,330 443 210

Wyoming (rest) 1,957 638 375 3,967 4,004 4,941 27 1,441 0 490 85

Colorado 1,097 0 18,299 1,608 1,390 1,703 137 267 0 53,008 116

Idaho 547 0 0 3,895 207 1,458 0 10 0 32,183 704

Utah 24,092 0 151 2,015 1,430 3,533 64 2,057 0 13,009 945

Wyoming (5 counties) 21,955 1,449 891,377 8,823 2,917 3,193 1,072 3,958 16,162 38,617 273

Wyoming (rest) 7,204 148 205,272 9,740 2,838 2,623 6 2,615 0 42,181 102

Colorado 10 0 8 371 48 135 410 3,852 0 320

Idaho 0 0 0 129 9 96 0 469 0 1,950

Utah 31 0 0 79 55 203 570 225 0 2,602

Wyoming (5 counties) 126 179 120 875 128 667 9,591 10,529 3,610 751

Wyoming (rest) 34 42 23 1,142 113 312 7 600 0 282

Colorado 0 0 9 80 11 33 7,794 4 0 20

Idaho 1 0 0 15 2 18 0 8,918 0 125

Utah 5 0 0 144 12 44 973 6 0 159

Wyoming (5 counties) 168 342 1,599 2,430 27 295 43,977 7,960 5,763 48

Wyoming (rest) 5 89 3,298 3,988 25 111 1 1,848 0 18

STATE

Oil and Gas Sources Source Category

CO

NOx

TOG

P M

SO2
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-27

Table F4b. 2008 CD-C 4 km Domain Emission Summary using 2006 meteorology (tpy).

Compressor Drilling Production Area Onroad Offroad EGU NEGU Trona Biogenic Fire

Colorado 777 0 45 2,448 18,362 7,931 1,356 58 0 10,462 2,073

Idaho 263 0 0 487 2,580 4,545 0 10,909 0 6,916 13,597

Utah 1,747 0 4 1,974 19,598 12,212 426 645 0 2,597 6,011

Wyoming (5 counties) 4,403 2,600 3,509 6,186 38,037 15,649 3,323 3,466 12,492 9,391 15,119

Wyoming (rest) 975 286 540 7,656 34,631 20,696 15 1,416 0 10,071 48,047

Colorado 1,311 0 51 152 1,735 1,245 28,689 86 0 607 70

Idaho 1,282 0 0 340 301 675 0 1,932 0 373 491

Utah 3,175 0 4 214 1,924 1,771 7,209 1,130 0 150 197

Wyoming (5 counties) 8,660 5,800 4,206 3,167 4,570 14,154 38,501 7,042 6,330 492 443

Wyoming (rest) 1,957 638 375 3,967 4,018 4,941 27 1,441 0 530 1,446

Colorado 1,097 0 18,299 1,608 1,403 1,703 137 267 0 54,105 94

Idaho 547 0 0 3,895 208 1,458 0 10 0 31,941 545

Utah 24,092 0 151 2,015 1,436 3,533 64 2,057 0 13,133 274

Wyoming (5 counties) 21,955 1,449 891,377 8,823 2,938 3,193 1,072 3,958 16,162 42,058 800

Wyoming (rest) 7,204 148 205,272 9,740 2,858 2,623 6 2,615 0 44,609 2,510

Colorado 10 0 8 371 48 135 410 3,852 0 261

Idaho 0 0 0 129 9 96 0 469 0 1,513

Utah 31 0 0 79 55 203 570 225 0 756

Wyoming (5 counties) 126 179 120 875 128 667 9,591 10,529 3,610 2,203

Wyoming (rest) 34 42 23 1,142 113 312 7 600 0 6,936

Colorado 0 0 9 80 11 33 7,794 4 0 16

Idaho 1 0 0 15 2 18 0 8,918 0 97

Utah 5 0 0 144 12 44 973 6 0 48

Wyoming (5 counties) 168 342 1,599 2,430 27 295 43,977 7,960 5,763 134

Wyoming (rest) 5 89 3,298 3,988 25 111 1 1,848 0 422

STATE

Oil and Gas Sources Source Category

CO

NOx

TOG

P M

SO2
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-28

Figure F8a. Comparison of 2005 and 2006 PM2.5 fire emissions within the 12/4 km domain. Note that the 2008 baseline simulation 

using 2005 meteorology will use the 2005 fire emissions, and the 2008 baseline simulation using 2006 meteorology will use the 

2006 fire emissions.
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-29

Figure F8b. Comparison of 2005 and 2006 NOx fire emissions within the 12/4 km domain. Note that the 2008 baseline simulation 

using 2005 meteorology will use the 2005 fire emissions, and the 2008 baseline simulation using 2006 meteorology will use the 

2006 fire emissions.
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-30

Table F5. Southwest Wyoming Speciation Profile Code by Process by County.

Basin O&G Field / County O&G production –Processes Profile Code

SW Wyoming Carbon flash CBN01

SW Wyoming Carbon fugitive - sales CBN02

SW Wyoming Carbon fugitive - produced CBN03

SW Wyoming Carbon fugitive - condensate CBN04

SW Wyoming Carbon pneumatic pumps CBN05

SW Wyoming Carbon well venting CBN06

SW Wyoming Jonah flash JON01

SW Wyoming Jonah fugitives JON02

SW Wyoming Jonah pneumatic pumps JON05

SW Wyoming Jonah well venting JON06

SW Wyoming Lincoln flash LNC01

SW Wyoming Lincoln fugitive - sales LNC02

SW Wyoming Lincoln fugitive - produced LNC03

SW Wyoming Lincoln fugitive - condensate LNC04

SW Wyoming Lincoln pneumatic pumps LNC05

SW Wyoming Lincoln well venting LNC06

SW Wyoming Pinedale flash PND01

SW Wyoming Pinedale fugitives PND02

SW Wyoming Pinedale pneumatic pumps PND05

SW Wyoming Pinedale well venting PND06

SW Wyoming Sublette flash SBL01

SW Wyoming Sublette fugitive - sales SBL02

SW Wyoming Sublette fugitive - produced SBL03

SW Wyoming Sublette fugitive - condensate SBL04

SW Wyoming Sublette pneumatic pumps SBL05

SW Wyoming Sublette well venting SBL06

SW Wyoming Sweetwater - East flash SWE01

SW Wyoming Sweetwater - East fugitive - sales SWE02

SW Wyoming Sweetwater - East fugitive - produced SWE03

SW Wyoming Sweetwater - East fugitive - condensate SWE04

SW Wyoming Sweetwater - East pneumatic pumps SWE05

SW Wyoming Sweetwater - East well venting SWE06

SW Wyoming Sweetwater - West flash SWW01

SW Wyoming Sweetwater - West fugitive - sales SWW02

SW Wyoming Sweetwater - West fugitive - produced SWW03

SW Wyoming Sweetwater - West fugitive - condensate SWW04
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-31

Basin O&G Field / County O&G production –Processes Profile Code

SW Wyoming Sweetwater - West pneumatic pumps SWW05

SW Wyoming Sweetwater - West well venting SWW06

SW Wyoming Uinta flash UNT01

SW Wyoming Uinta fugitive - sales UNT02

SW Wyoming Uinta fugitive - produced UNT03

SW Wyoming Uinta fugitive - condensate UNT04

SW Wyoming Uinta pneumatic pumps UNT05

SW Wyoming Uinta well venting UNT06

Table F6. CB-05 Species Names and Abbreviations Used in Table F5.

Species Name Description

MEOH Methanol

ETHA Ethane

PAR Paraffin carbon bond (C-C)

TOL Toluene and other monoalkyl aromatics

XYL Xylene and other polyalkyl aromatics

UNR Unreactive
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-32

Table F7. SMOKE speciation profiles used in SW Wyoming O&G emissions modeling.

Sum of splitFactor modelSpecies

Data source Profile CH4 ETHA PAR TOL UNR XYL FORM OLE ETH ALD2 ALDX IOLE UNK

Gas profiles provided by Sage CBN01 0.1397 0.1025 0.6374 0.0090 0.1066 0.0048

Gas profiles provided by Sage CBN02 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

Gas profiles provided by Sage CBN03 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

Gas profiles provided by Sage CBN04 0.1400 0.1015 0.6393 0.0090 0.1055 0.0047

Gas profiles provided by Sage CBN05 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

Gas profiles provided by Sage CBN06 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

Gas profiles provided by Sage JON01 0.2372 0.1141 0.5530 0.0037 0.0842 0.0078

Gas profiles provided by Sage JON02 0.5389 0.0583 0.3373 0.0180 0.0189 0.0287

Gas profiles provided by Sage JON05 0.8146 0.0878 0.0744 0.0012 0.0215 0.0006

Gas profiles provided by Sage JON06 0.8146 0.0878 0.0744 0.0012 0.0215 0.0006

Gas profiles provided by Sage LNC01 0.1545 0.1512 0.5528 0.0146 0.1198 0.0071

Gas profiles provided by Sage LNC02 0.8045 0.0902 0.0812 0.0241

Gas profiles provided by Sage LNC03 0.8045 0.0902 0.0812 0.0241

Gas profiles provided by Sage LNC04 0.1400 0.1015 0.6393 0.0090 0.1055 0.0047

Gas profiles provided by Sage LNC05 0.8045 0.0902 0.0812 0.0241

Gas profiles provided by Sage LNC06 0.8045 0.0902 0.0812 0.0241

Gas profiles provided by Sage PND01 0.2527 0.1272 0.5170 0.0116 0.0854 0.0061

Gas profiles provided by Sage PND02 0.5517 0.1076 0.2759 0.0035 0.0594 0.0019

Gas profiles provided by Sage PND05 0.8146 0.0878 0.0744 0.0012 0.0215 0.0006

Gas profiles provided by Sage PND06 0.7743 0.0990 0.0953 0.0010 0.0298 0.0005

Gas profiles provided by Sage SBL01 0.1545 0.1512 0.5528 0.0146 0.1198 0.0071

Gas profiles provided by Sage SBL02 0.8045 0.0902 0.0812 0.0241

Gas profiles provided by Sage SBL03 0.8045 0.0902 0.0812 0.0241

Gas profiles provided by Sage SBL04 0.1555 0.1127 0.6547 0.0100 0.0618 0.0053

Gas profiles provided by Sage SBL05 0.8045 0.0902 0.0812 0.0241

Gas profiles provided by Sage SBL06 0.8045 0.0902 0.0812 0.0241

Gas profiles provided by Sage SWE01 0.1397 0.1025 0.6374 0.0090 0.1066 0.0048

Gas profiles provided by Sage SWE02 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

Gas profiles provided by Sage SWE03 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

Gas profiles provided by Sage SWE04 0.1400 0.1015 0.6393 0.0090 0.1055 0.0047

Gas profiles provided by Sage SWE05 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

Gas profiles provided by Sage SWE06 0.7339 0.1103 0.1162 0.0009 0.0382 0.0005

Gas profiles provided by Sage SWW01 0.1545 0.1512 0.5528 0.0146 0.1198 0.0071

Gas profiles provided by Sage SWW02 0.8045 0.0902 0.0812 0.0241

Gas profiles provided by Sage SWW03 0.8045 0.0902 0.0812 0.0241

Gas profiles provided by Sage SWW04 0.1400 0.1015 0.6393 0.0090 0.1055 0.0047

Gas profiles provided by Sage SWW05 0.8045 0.0902 0.0812 0.0241

Gas profiles provided by Sage SWW06 0.8045 0.0902 0.0812 0.0241

Gas profiles provided by Sage UNT01 0.1545 0.1512 0.5528 0.0146 0.1198 0.0071

Gas profiles provided by Sage UNT02 0.8045 0.0902 0.0812 0.0241

Gas profiles provided by Sage UNT03 0.8045 0.0902 0.0812 0.0241

Gas profiles provided by Sage UNT04 0.1400 0.1015 0.6393 0.0090 0.1055 0.0047

Gas profiles provided by Sage UNT05 0.8045 0.0902 0.0812 0.0241

Gas profiles provided by Sage UNT06 0.8045 0.0902 0.0812 0.0241

SPECIATE4.1 profile 1 0.1100 0.4700 0.4200

SPECIATE4.1 profile 2 0.5034 0.0096 0.4870

SPECIATE4.1 profile 3 0.5600 0.2864 0.0200 0.0536 0.0800

SPECIATE4.1 profile 4 0.0760 0.2090 0.4278 0.0945 0.0760 0.1167

SPECIATE4.1 profile 7 0.7000 0.3000

SPECIATE4.1 profile 9 0.1160 0.0280 0.1943 0.1223 0.2523 0.2870

SPECIATE4.1 profile 51 0.2000 0.3000 0.1500 0.1500 0.2000

SPECIATE4.1 profile 297 0.0880 0.0270 0.7676 0.0140 0.1034

SPECIATE4.1 profile 1001 0.7669 0.1400 0.0443 0.0006 0.0171 0.0010 0.0082 0.0121 0.0063 0.0003 0.0001 0.0031

SPECIATE4.1 profile 1010 0.4630 0.0699 0.4115 0.0556

SPECIATE4.1 profile 1011 0.3760 0.0640 0.4996 0.0604

SPECIATE4.1 profile 1012 0.6130 0.0790 0.2674 0.0406

SPECIATE4.1 profile 1201 0.0580 0.4537 0.0055 0.0060 0.0861 0.0602 0.1996 0.0291 0.0171 0.0847
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-33

Table F8. SMOKE speciation cross reference for SW Wyoming O&G emissions modeling.

SCC Source Category Profile_Name Profile Description County County_Code

2310030300 Industrial Processes, Oil and Gas Production, Natural Gas Liquids, Tanks - Flashing & Standing/Working/Breathing CBN01 flash Carbon 56007

2310020700 Industrial Processes, Oil and Gas Production, Natural Gas, Fugitives CBN03 fugitive - produced Carbon 56007

2310020900 Industrial Processes, Oil and Gas Production, Natural Gas, Pneumatic Pumps CBN05 pneumatic pumps Carbon 56007

2310020100 Industrial Processes, Oil and Gas Production, Natural Gas, Dehydrators CBN03 fugitive - produced Carbon 56007

2310020400 Industrial Processes, Oil and Gas Production, Natural Gas, Venting - Blowdowns CBN06 well venting Carbon 56007

2310030300 Industrial Processes, Oil and Gas Production, Natural Gas Liquids, Tanks - Flashing & Standing/Working/Breathing JON01 flash Jonah 56034

2310020700 Industrial Processes, Oil and Gas Production, Natural Gas, Fugitives JON02 fugitives Jonah 56034

2310020900 Industrial Processes, Oil and Gas Production, Natural Gas, Pneumatic Pumps JON05 pneumatic pumps Jonah 56034

2310020100 Industrial Processes, Oil and Gas Production, Natural Gas, Dehydrators JON02 fugitives Jonah 56034

2310020400 Industrial Processes, Oil and Gas Production, Natural Gas, Venting - Blowdowns JON06 well venting Jonah 56034

2310030300 Industrial Processes, Oil and Gas Production, Natural Gas Liquids, Tanks - Flashing & Standing/Working/Breathing LNC01 flash Lincoln 56023

2310020700 Industrial Processes, Oil and Gas Production, Natural Gas, Fugitives LNC03 fugitive - produced Lincoln 56023

2310020900 Industrial Processes, Oil and Gas Production, Natural Gas, Pneumatic Pumps LNC05 pneumatic pumps Lincoln 56023

2310020100 Industrial Processes, Oil and Gas Production, Natural Gas, Dehydrators LNC03 fugitive - produced Lincoln 56023

2310020400 Industrial Processes, Oil and Gas Production, Natural Gas, Venting - Blowdowns LNC06 well venting Lincoln 56023

2310030300 Industrial Processes, Oil and Gas Production, Natural Gas Liquids, Tanks - Flashing & Standing/Working/Breathing PND01 flash Pinedale 56036

2310020700 Industrial Processes, Oil and Gas Production, Natural Gas, Fugitives PND02 fugitives Pinedale 56036

2310020900 Industrial Processes, Oil and Gas Production, Natural Gas, Pneumatic Pumps PND05 pneumatic pumps Pinedale 56036

2310020100 Industrial Processes, Oil and Gas Production, Natural Gas, Dehydrators PND02 fugitives Pinedale 56036

2310020400 Industrial Processes, Oil and Gas Production, Natural Gas, Venting - Blowdowns PND06 well venting Pinedale 56036

2310030300 Industrial Processes, Oil and Gas Production, Natural Gas Liquids, Tanks - Flashing & Standing/Working/Breathing SBL01 flash Sublette 56035

2310020700 Industrial Processes, Oil and Gas Production, Natural Gas, Fugitives SBL03 fugitive - produced Sublette 56035

2310020900 Industrial Processes, Oil and Gas Production, Natural Gas, Pneumatic Pumps SBL05 pneumatic pumps Sublette 56035

2310020100 Industrial Processes, Oil and Gas Production, Natural Gas, Dehydrators SBL03 fugitive - produced Sublette 56035

2310020400 Industrial Processes, Oil and Gas Production, Natural Gas, Venting - Blowdowns SBL06 well venting Sublette 56035

2310030300 Industrial Processes, Oil and Gas Production, Natural Gas Liquids, Tanks - Flashing & Standing/Working/Breathing SWE01 flash Sweetwater - East 56038

2310020700 Industrial Processes, Oil and Gas Production, Natural Gas, Fugitives SWE03 fugitive - produced Sweetwater - East 56038

2310020900 Industrial Processes, Oil and Gas Production, Natural Gas, Pneumatic Pumps SWE05 pneumatic pumps Sweetwater - East 56038

2310020100 Industrial Processes, Oil and Gas Production, Natural Gas, Dehydrators SWE03 fugitive - produced Sweetwater - East 56038

2310020400 Industrial Processes, Oil and Gas Production, Natural Gas, Venting - Blowdowns SWE06 well venting Sweetwater - East 56038

2310030300 Industrial Processes, Oil and Gas Production, Natural Gas Liquids, Tanks - Flashing & Standing/Working/BreathingSWW01 flash Sweetwater - West 56037

2310020700 Industrial Processes, Oil and Gas Production, Natural Gas, Fugitives SWW03 fugitive - produced Sweetwater - West 56037

2310020900 Industrial Processes, Oil and Gas Production, Natural Gas, Pneumatic Pumps SWW05 pneumatic pumps Sweetwater - West 56037

2310020100 Industrial Processes, Oil and Gas Production, Natural Gas, Dehydrators SWW03 fugitive - produced Sweetwater - West 56037

2310020400 Industrial Processes, Oil and Gas Production, Natural Gas, Venting - Blowdowns SWW06 well venting Sweetwater - West 56037

2310030300 Industrial Processes, Oil and Gas Production, Natural Gas Liquids, Tanks - Flashing & Standing/Working/Breathing UNT01 flash Uinta 56041

2310020700 Industrial Processes, Oil and Gas Production, Natural Gas, Fugitives UNT03 fugitive - produced Uinta 56041

2310020900 Industrial Processes, Oil and Gas Production, Natural Gas, Pneumatic Pumps UNT05 pneumatic pumps Uinta 56041

2310020100 Industrial Processes, Oil and Gas Production, Natural Gas, Dehydrators UNT03 fugitive - produced Uinta 56041

2310020400 Industrial Processes, Oil and Gas Production, Natural Gas, Venting - Blowdowns UNT06 well venting Uinta 56041

2310000110 Industrial Processes, Oil and Gas Production, All Processes, Drill Rigs 9 Reciprocating Distillate Oil Engine

2310024100 Industrial Processes, Oil and Gas Production, Natural Gas, Heaters 3 External Combustion Boiler - Natural Gas

2230070000 Mobile Sources; Highway Vehicles - Diesel; All HDDV including Buses (use subdivisions -071 thru -075 if possible); Total: All Road Types 1201 Light-Duty Diesel Vehicles
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-34

Table F8. SMOKE speciation cross reference for SW Wyoming O&G emissions modeling (continued).

SCC Source Cat Profile_Name Profile Description County County_Code

20200201 Internal Combustion Engines; Industrial; Natural Gas; Turbine 7 Natural Gas Turbine

20200202 Internal Combustion Engines; Industrial; Natural Gas; Reciprocating 1001 Internal Combustion Engine - Natural Gas

20200203 Internal Combustion Engines; Industrial; Natural Gas; Turbine: Cogeneration 7 Natural Gas Turbine

20200204 Internal Combustion Engines; Industrial; Natural Gas; Reciprocating: Cogeneration 1001 Internal Combustion Engine - Natural Gas

20200209 Internal Combustion Engines; Industrial; Natural Gas; Turbine: Exhaust 7 Natural Gas Turbine

20200252 Internal Combustion Engines; Industrial; Natural Gas; 2-cycle Lean Burn 1001 Internal Combustion Engine - Natural Gas

20200253 Internal Combustion Engines; Industrial; Natural Gas; 4-cycle Rich Burn 1001 Internal Combustion Engine - Natural Gas

20200254 Internal Combustion Engines; Industrial; Natural Gas; 4-cycle Lean Burn 1001 Internal Combustion Engine - Natural Gas

20200256 Internal Combustion Engines; Industrial; Natural Gas; 4-cycle Clean Burn 1001 Internal Combustion Engine - Natural Gas

31000101 Industrial Processes; Oil and Gas Production; Crude Oil Production; Complete Well: Fugitive Emissions SWE03 fugitive - produced Sweetwater - East

31000102 Industrial Processes; Oil and Gas Production; Crude Oil Production; Miscellaneous Well: General 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000103 Industrial Processes; Oil and Gas Production; Crude Oil Production; Wells: Rod Pumps 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000104 Industrial Processes; Oil and Gas Production; Crude Oil Production; Crude Oil Sumps 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000105 Industrial Processes; Oil and Gas Production; Crude Oil Production; Crude Oil Pits 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000107 Industrial Processes; Oil and Gas Production; Crude Oil Production; Oil/Gas/Water/Separation 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000108 Industrial Processes; Oil and Gas Production; Crude Oil Production; Evaporation from Liquid Leaks into Oil Well Cellars1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000123 Industrial Processes; Oil and Gas Production; Crude Oil Production; Well Casing Vents 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000124 Industrial Processes; Oil and Gas Production; Crude Oil Production; Valves: General SWE03 fugitive - produced Sweetwater - East

31000125 Industrial Processes; Oil and Gas Production; Crude Oil Production; Relief Valves SWE03 fugitive - produced Sweetwater - East

31000126 Industrial Processes; Oil and Gas Production; Crude Oil Production; Pump Seals SWE03 fugitive - produced Sweetwater - East

31000127 Industrial Processes; Oil and Gas Production; Crude Oil Production; Ranges and Connections SWE03 fugitive - produced Sweetwater - East

31000128 Industrial Processes; Oil and Gas Production; Crude Oil Production; Oil Heating 2 External Combustion Boiler - Distillate Oil

31000129 Industrial Processes; Oil and Gas Production; Crude Oil Production; Gas/Liquid Separation 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000130 Industrial Processes; Oil and Gas Production; Crude Oil Production; Fugitives: Compressor Seals SWE03 fugitive - produced Sweetwater - East

31000132 Industrial Processes; Oil and Gas Production; Crude Oil Production; Atmospheric Wash Tank (2nd Stage of Gas-Oil Separation): Flashing Loss 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000160 Industrial Processes; Oil and Gas Production; Crude Oil Production; Flares 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000199 Industrial Processes; Oil and Gas Production; Crude Oil Production; Processing Operations: Not Classified 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000201 Industrial Processes; Oil and Gas Production; Natural Gas Production; Gas Sweetening: Amine Process SWE03 fugitive - produced Sweetwater - East

31000202 Industrial Processes; Oil and Gas Production; Natural Gas Production; Gas Stripping Operations 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000203 Industrial Processes; Oil and Gas Production; Natural Gas Production; Compressors 1001 Internal Combustion Engine - Natural Gas

31000204 Industrial Processes; Oil and Gas Production; Natural Gas Production; Wells 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000205 Industrial Processes; Oil and Gas Production; Natural Gas Production; Flares 51 Flares - Natural Gas

31000206 Industrial Processes; Oil and Gas Production; Natural Gas Production; Gas Lift 1001 Internal Combustion Engine - Natural Gas

31000207 Industrial Processes; Oil and Gas Production; Natural Gas Production; Valves: Fugitive Emissions SWE03 fugitive - produced Sweetwater - East

31000208 Industrial Processes; Oil and Gas Production; Natural Gas Production; Sulfur Recovery Unit 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000209 Industrial Processes; Oil and Gas Production; Natural Gas Production; Incinerators Burning Waste Gas or Augmented Waste Gas 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000215 Industrial Processes; Oil and Gas Production; Natural Gas Production; Flares Combusting Gases >1000 BTU/scf 51 Flares - Natural Gas

31000216 Industrial Processes; Oil and Gas Production; Natural Gas Production; Flares Combusting Gases <1000 BTU/scf 51 Flares - Natural Gas

31000220 Industrial Processes; Oil and Gas Production; Natural Gas Production; All Equipt Leak Fugitives (Valves, Flanges, Connections, Seals, Drains SWE03 fugitive - produced Sweetwater - East

31000222 Industrial Processes; Oil and Gas Production; Natural Gas Production; Drilling and Well Completion SWE03 fugitive - produced Sweetwater - East

31000223 Industrial Processes; Oil and Gas Production; Natural Gas Production; Relief Valves SWE03 fugitive - produced Sweetwater - East

31000224 Industrial Processes; Oil and Gas Production; Natural Gas Production; Pump Seals SWE03 fugitive - produced Sweetwater - East

31000225 Industrial Processes; Oil and Gas Production; Natural Gas Production; Compressor Seals SWE03 fugitive - produced Sweetwater - East

31000226 Industrial Processes; Oil and Gas Production; Natural Gas Production; Flanges and Connections SWE03 fugitive - produced Sweetwater - East

31000227 Industrial Processes; Oil and Gas Production; Natural Gas Production; Glycol Dehydrator Reboiler Still Stack SWE03 fugitive - produced Sweetwater - East

31000228 Industrial Processes; Oil and Gas Production; Natural Gas Production; Glycol Dehydrator Reboiler Burner 3 External Combustion Boiler - Natural Gas

31000229 Industrial Processes; Oil and Gas Production; Natural Gas Production; Gathering Lines 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000231 Industrial Processes; Oil and Gas Production; Natural Gas Production; Fugitives: Drains 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000299 Industrial Processes; Oil and Gas Production; Natural Gas Production; Other Not Classified 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-35

Table F8 SMOKE speciation cross reference for SW Wyoming O&G emissions modeling (concluded).

SCC Source Cat Profile_Name Profile Description County County_Code

31000301 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Glycol Dehydrators: Reboiler Still Vent: Triethylene Glycol SWE03 fugitive - produced Sweetwater - East

31000302 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Glycol Dehydrators: Reboiler Burner Stack: Triethylene Glycol SWE03 fugitive - produced Sweetwater - East

31000303 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Glycol Dehydrators: Phase Separator Vent: Triethylene Glycol SWE03 fugitive - produced Sweetwater - East

31000304 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Glycol Dehydrators: Ethylene Glycol: General SWE03 fugitive - produced Sweetwater - East

31000305 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Gas Sweeting: Amine Process SWE03 fugitive - produced Sweetwater - East

31000306 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Process Valves SWE03 fugitive - produced Sweetwater - East

31000307 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Relief Valves SWE03 fugitive - produced Sweetwater - East

31000310 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Pump Seals SWE03 fugitive - produced Sweetwater - East

31000311 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Flanges and Connections SWE03 fugitive - produced Sweetwater - East

31000401 Industrial Processes; Oil and Gas Production; Process Heaters; Distillate Oil (No. 2) 2 External Combustion Boiler - Distillate Oil

31000403 Industrial Processes; Oil and Gas Production; Process Heaters; Crude Oil 1 External Combustion Boiler - Residual Oil

31000404 Industrial Processes; Oil and Gas Production; Process Heaters; Natural Gas 3 External Combustion Boiler - Natural Gas

31000405 Industrial Processes; Oil and Gas Production; Process Heaters; Process Gas 4 External Combustion Boiler - Refinery Gas

31000413 Industrial Processes; Oil and Gas Production; Process Heaters; Crude Oil: Steam Generators 1 External Combustion Boiler - Residual Oil

31000414 Industrial Processes; Oil and Gas Production; Process Heaters; Natural Gas: Steam Generators 3 External Combustion Boiler - Natural Gas

31000415 Industrial Processes; Oil and Gas Production; Process Heaters; Process Gas: Steam Generators 4 External Combustion Boiler - Refinery Gas

31000501 Industrial Processes; Oil and Gas Production; Liquid Waste Treatment; Floatation Units 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000502 Industrial Processes; Oil and Gas Production; Liquid Waste Treatment; Liquid - Liquid Separator 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000506 Industrial Processes; Oil and Gas Production; Liquid Waste Treatment; Oil-Water Separation Wastewater Holding Tanks 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31088801 Industrial Processes; Oil and Gas Production; Fugitive Emissions; Specify in Comments Field SWE03 fugitive - produced Sweetwater - East

31088804 Industrial Processes; Oil and Gas Production; Fugitive Emissions; Specify in Comments Field SWE03 fugitive - produced Sweetwater - East

31088811 Industrial Processes; Oil and Gas Production; Fugitive Emissions; Fugitive Emissions SWE03 fugitive - produced Sweetwater - East

40400301 Petroleum and Solvent Evaporation; Petroleum Liquids Storage (non-Refinery); Oil and Gas Field Storage and Working Tanks; Fixed Roof Tank: Breathing Loss SWE01 flash Sweetwater - East

40400302 Petroleum and Solvent Evaporation; Petroleum Liquids Storage (non-Refinery); Oil and Gas Field Storage and Working Tanks; Fixed Roof Tank: Working Loss SWE01 flash Sweetwater - East

40400304 Petroleum and Solvent Evaporation; Petroleum Liquids Storage (non-Refinery); Oil and Gas Field Storage and Working Tanks; External Floating Roof Tank with Secondary Seals: Standing Loss SWE01 flash Sweetwater - East

40400305 Petroleum and Solvent Evaporation; Petroleum Liquids Storage (non-Refinery); Oil and Gas Field Storage and Working Tanks; Internal Floating Roof Tank: Standing Loss SWE01 flash Sweetwater - East

40400306 Petroleum and Solvent Evaporation; Petroleum Liquids Storage (non-Refinery); Oil and Gas Field Storage and Working Tanks; External Floating Roof Tank: Withdrawal Loss SWE01 flash Sweetwater - East

40400307 Petroleum and Solvent Evaporation; Petroleum Liquids Storage (non-Refinery); Oil and Gas Field Storage and Working Tanks; Internal Floating Roof Tank: Withdrawal Loss SWE01 flash Sweetwater - East

40400311 Petroleum and Solvent Evaporation; Petroleum Liquids Storage (non-Refinery); Oil and Gas Field Storage and Working Tanks; Fixed Roof Tank, Condensate, working+breathing+flashing losses SWE01 flash Sweetwater - East

40400312 Petroleum and Solvent Evaporation; Petroleum Liquids Storage (non-Refinery); Oil and Gas Field Storage and Working Tanks; Fixed Roof Tank, Crude Oil, working+breathing+flashing losses SWE01 flash Sweetwater - East

40400313 Petroleum and Solvent Evaporation; Petroleum Liquids Storage (non-Refinery); Oil and Gas Field Storage and Working Tanks; Fixed Roof Tank, Lube Oil, working+breathing+flashing losses SWE01 flash Sweetwater - East

40400314 Petroleum and Solvent Evaporation; Petroleum Liquids Storage (non-Refinery); Oil and Gas Field Storage and Working Tanks; Fixed Roof Tank, Specialty Chem-working+breathing+flashing SWE01 flash Sweetwater - East

40400315 Petroleum and Solvent Evaporation; Petroleum Liquids Storage (non-Refinery); Oil and Gas Field Storage and Working Tanks; Fixed Roof Tank, Produced Water, working+breathing+flashing SWE01 flash Sweetwater - East

40400322 Petroleum and Solvent Evaporation; Petroleum Liquids Storage (non-Refinery); Oil and Gas Field Storage and Working Tanks; External Floating Roof Tank, Crude Oil, working+breathing+flashing SWE01 flash Sweetwater - East

40400332 Petroleum and Solvent Evaporation; Petroleum Liquids Storage (non-Refinery); Oil and Gas Field Storage and Working Tanks; Internal Floating Roof Tank, Crude Oil, working+breathing+flashing SWE01 flash Sweetwater - East

31000000 Compressor Stations 1001 Internal Combustion Engine - Natural Gas
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-36

Table F9. EPA default SMOKE speciation profiles for O&G

Profile ALD2 ALDX CH4 ETH ETHA FORM OLE PAR TOL UNK UNR ETOH IOLE ISOP MEOH NVOL TERP XYL

0 0.0177 0.0208 0.0732 0.0369 0.0138 0.0156 0.0554 0.4239 0.0620 0.0002 0.1849 0.0138 0.0066 0.0040 0.0139 0.0039 0.0068 0.0467

1 0.1100 0.4200 0.4700

2 0.4870 0.5034 0.0096

3 0.5600 0.0800 0.2864 0.0200 0.0536

4 0.0760 0.2090 0.0760 0.1167 0.4278 0.0945

51 0.2000 0.3000 0.2000 0.1500 0.1500

1010 0.4630 0.0699 0.4115 0.0556

1011 0.3760 0.0640 0.4996 0.0604

1012 0.6130 0.0790 0.2674 0.0406

1201 0.0291 0.0171 0.0580 0.1996 0.0861 0.0602 0.4537 0.0055 0.0847 0.0060

9012 0.1301 0.0605 0.0888 0.0124 0.5983 0.0048 0.1037 0.0014

9015 0.5381 0.0744 0.3394 0.0481
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-37

Table F10. EPA default SMOKE speciation cross reference for O&G.

SCC Source Category Description Profile Profile Description

31000101 Industrial Processes; Oil and Gas Production; Crude Oil Production; Complete Well: Fugitive Emissions 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000102 Industrial Processes; Oil and Gas Production; Crude Oil Production; Miscellaneous Well: General 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000103 Industrial Processes; Oil and Gas Production; Crude Oil Production; Wells: Rod Pumps 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000104 Industrial Processes; Oil and Gas Production; Crude Oil Production; Crude Oil Sumps 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000105 Industrial Processes; Oil and Gas Production; Crude Oil Production; Crude Oil Pits 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000106 Industrial Processes; Oil and Gas Production; Crude Oil Production; Enhanced Wells, Water Reinjection 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000107 Industrial Processes; Oil and Gas Production; Crude Oil Production; Oil/Gas/Water/Separation 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000108 Industrial Processes; Oil and Gas Production; Crude Oil Production; Evaporation from Liquid Leaks into Oil Well Cellars 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000121 Industrial Processes; Oil and Gas Production; Crude Oil Production; Site Preparation 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000122 Industrial Processes; Oil and Gas Production; Crude Oil Production; Drilling and Well Completion 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000123 Industrial Processes; Oil and Gas Production; Crude Oil Production; Well Casing Vents 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000124 Industrial Processes; Oil and Gas Production; Crude Oil Production; Valves: General 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000125 Industrial Processes; Oil and Gas Production; Crude Oil Production; Relief Valves 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000126 Industrial Processes; Oil and Gas Production; Crude Oil Production; Pump Seals 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000127 Industrial Processes; Oil and Gas Production; Crude Oil Production; Ranges and Connections 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000128 Industrial Processes; Oil and Gas Production; Crude Oil Production; Oil Heating 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000129 Industrial Processes; Oil and Gas Production; Crude Oil Production; Gas/Liquid Separation 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000130 Industrial Processes; Oil and Gas Production; Crude Oil Production; Fugitives: Compressor Seals 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000131 Industrial Processes; Oil and Gas Production; Crude Oil Production; Fugitives: Drains 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000132 Industrial Processes; Oil and Gas Production; Crude Oil Production; Atmospheric Wash Tank (2nd Stage of Gas-Oil Separation): Flashing Loss 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000140 Industrial Processes; Oil and Gas Production; Crude Oil Production; Waste Sumps: Primary Light Crude 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000141 Industrial Processes; Oil and Gas Production; Crude Oil Production; Waste Sumps: Primary Heavy Crude 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000142 Industrial Processes; Oil and Gas Production; Crude Oil Production; Waste Sumps: Secondary Light Crude 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000143 Industrial Processes; Oil and Gas Production; Crude Oil Production; Waste Sumps: Secondary Heavy Crude 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000144 Industrial Processes; Oil and Gas Production; Crude Oil Production; Waste Sumps: Tertiary Light Crude 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000145 Industrial Processes; Oil and Gas Production; Crude Oil Production; Waste Sumps: Tertiary Heavy Crude 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000146 Industrial Processes; Oil and Gas Production; Crude Oil Production; Gathering Lines 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000160 Industrial Processes; Oil and Gas Production; Crude Oil Production; Flares 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000199 Industrial Processes; Oil and Gas Production; Crude Oil Production; Processing Operations: Not Classified 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000201 Industrial Processes; Oil and Gas Production; Natural Gas Production; Gas Sweetening: Amine Process 0

31000202 Industrial Processes; Oil and Gas Production; Natural Gas Production; Gas Stripping Operations 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000203 Industrial Processes; Oil and Gas Production; Natural Gas Production; Compressors 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000204 Industrial Processes; Oil and Gas Production; Natural Gas Production; Wells 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000205 Industrial Processes; Oil and Gas Production; Natural Gas Production; Flares 51 Flares - Natural Gas

31000206 Industrial Processes; Oil and Gas Production; Natural Gas Production; Gas Lift 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000207 Industrial Processes; Oil and Gas Production; Natural Gas Production; Valves: Fugitive Emissions 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000208 Industrial Processes; Oil and Gas Production; Natural Gas Production; Sulfur Recovery Unit 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000209 Industrial Processes; Oil and Gas Production; Natural Gas Production; Incinerators Burning Waste Gas or Augmented Waste Gas 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000211 Industrial Processes; Oil and Gas Production; Natural Gas Production; Pipeline Pigging (releases during pig removal) 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-38

Table F10. EPA default SMOKE speciation cross reference for O&G (continued).

SCC Source Category Description Profile Profile Description

31000215 Industrial Processes; Oil and Gas Production; Natural Gas Production; Flares Combusting Gases >1000 BTU/scf 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000216 Industrial Processes; Oil and Gas Production; Natural Gas Production; Flares Combusting Gases <1000 BTU/scf 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000220 Industrial Processes; Oil and Gas Production; Natural Gas Production; All Equipt Leak Fugitives (Valves, Flanges, Connections, Seals, Drains 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000221 Industrial Processes; Oil and Gas Production; Natural Gas Production; Site Preparation 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000222 Industrial Processes; Oil and Gas Production; Natural Gas Production; Drilling and Well Completion 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000223 Industrial Processes; Oil and Gas Production; Natural Gas Production; Relief Valves 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000224 Industrial Processes; Oil and Gas Production; Natural Gas Production; Pump Seals 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000225 Industrial Processes; Oil and Gas Production; Natural Gas Production; Compressor Seals 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000226 Industrial Processes; Oil and Gas Production; Natural Gas Production; Flanges and Connections 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000227 Industrial Processes; Oil and Gas Production; Natural Gas Production; Glycol Dehydrator Reboiler Still Stack 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000228 Industrial Processes; Oil and Gas Production; Natural Gas Production; Glycol Dehydrator Reboiler Burner 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000229 Industrial Processes; Oil and Gas Production; Natural Gas Production; Gathering Lines 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000230 Industrial Processes; Oil and Gas Production; Natural Gas Production; Hydrocarbon Skimmer 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000231 Industrial Processes; Oil and Gas Production; Natural Gas Production; Fugitives: Drains 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000299 Industrial Processes; Oil and Gas Production; Natural Gas Production; Other Not Classified 1012 Oil and Gas Production - Fugitives - Valves and Fittings - Gas Service

31000301 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Glycol Dehydrators: Reboiler Still Vent: Triethylene Glycol 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000302 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Glycol Dehydrators: Reboiler Burner Stack: Triethylene Glycol 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000303 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Glycol Dehydrators: Phase Separator Vent: Triethylene Glycol 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000304 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Glycol Dehydrators: Ethylene Glycol: General 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000305 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Gas Sweeting: Amine Process1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000306 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Process Valves 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000307 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Relief Valves 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000308 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Open-ended Lines 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000309 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Compressor Seals 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000310 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Pump Seals 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000311 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Flanges and Connections 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000321 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Glycol Dehydrators: Niagaran Formation (Mich.) 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000322 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Glycol Dehydrators: Prairie du Chien Formation (Mich.) 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000323 Industrial Processes; Oil and Gas Production; Natural Gas Processing Facilities; Glycol Dehydrators: Antrim Formation (Mich.) 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000401 Industrial Processes; Oil and Gas Production; Process Heaters; Distillate Oil (No. 2) 2 External Combustion Boiler - Distillate Oil

31000402 Industrial Processes; Oil and Gas Production; Process Heaters; Residual Oil 1 External Combustion Boiler - Residual Oil

31000403 Industrial Processes; Oil and Gas Production; Process Heaters; Crude Oil 1 External Combustion Boiler - Residual Oil

31000404 Industrial Processes; Oil and Gas Production; Process Heaters; Natural Gas 3 External Combustion Boiler - Natural Gas

31000405 Industrial Processes; Oil and Gas Production; Process Heaters; Process Gas 4 External Combustion Boiler - Refinery Gas

31000406 Industrial Processes; Oil and Gas Production; Process Heaters; Propane/Butane 1 External Combustion Boiler - Residual Oil

31000411 Industrial Processes; Oil and Gas Production; Process Heaters; Distillate Oil (No. 2): Steam Generators 2 External Combustion Boiler - Distillate Oil

31000412 Industrial Processes; Oil and Gas Production; Process Heaters; Residual Oil: Steam Generators 1 External Combustion Boiler - Residual Oil

31000413 Industrial Processes; Oil and Gas Production; Process Heaters; Crude Oil: Steam Generators 1 External Combustion Boiler - Residual Oil

31000414 Industrial Processes; Oil and Gas Production; Process Heaters; Natural Gas: Steam Generators 3 External Combustion Boiler - Natural Gas

31000415 Industrial Processes; Oil and Gas Production; Process Heaters; Process Gas: Steam Generators 4 External Combustion Boiler - Refinery Gas

31000501 Industrial Processes; Oil and Gas Production; Liquid Waste Treatment; Floatation Units 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000502 Industrial Processes; Oil and Gas Production; Liquid Waste Treatment; Liquid - Liquid Separator 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000503 Industrial Processes; Oil and Gas Production; Liquid Waste Treatment; Oil-Water Separator 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000504 Industrial Processes; Oil and Gas Production; Liquid Waste Treatment; Oil-Sludge-Waste Water Pit 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000505 Industrial Processes; Oil and Gas Production; Liquid Waste Treatment; Sand Filter Operation 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31000506 Industrial Processes; Oil and Gas Production; Liquid Waste Treatment; Oil-Water Separation Wastewater Holding Tanks 1011 Oil and Gas Production - Fugitives - Valves and Fittings - Liquid Service

31088801 Industrial Processes; Oil and Gas Production; Fugitive Emissions; Specify in Comments Field 1010 Oil and Gas Production - Fugitives - Unclassified
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-39

Table F11. EPA default SMOKE speciation cross reference for O&G .

SCC Source Category Description Profile Profile Description

31088802 Industrial Processes; Oil and Gas Production; Fugitive Emissions; Specify in Comments Field 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

31088803 Industrial Processes; Oil and Gas Production; Fugitive Emissions; Specify in Comments Field 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

31088804 Industrial Processes; Oil and Gas Production; Fugitive Emissions; Specify in Comments Field 9012 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

31088805 Industrial Processes; Oil and Gas Production; Fugitive Emissions; Specify in Comments Field 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

31088811 Industrial Processes; Oil and Gas Production; Fugitive Emissions; Fugitive Emissions 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

2310000000 Industrial Processes; Oil and Gas Production: SIC 13; All Processes; Total: All Processes 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

2310001000 Industrial Processes; Oil and Gas Production: SIC 13; All Processes : On-shore; Total: All Processes 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

2310002000 Industrial Processes; Oil and Gas Production: SIC 13; All Processes : Off-shore; Total: All Processes 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

2310010000 Industrial Processes; Oil and Gas Production: SIC 13; Crude Petroleum; Total: All Processes 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

2310011000 Industrial Processes; Oil and Gas Production: SIC 13; Crude Petroleum : On-shore; Total: All Processes 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

2310012000 Industrial Processes; Oil and Gas Production: SIC 13; Crude Petroleum : Off-shore; Total: All Processes 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

2310020000 Industrial Processes; Oil and Gas Production: SIC 13; Natural Gas; Total: All Processes 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

2310021000 Industrial Processes; Oil and Gas Production: SIC 13; Natural Gas : On-shore; Total: All Processes 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

2310022000 Industrial Processes; Oil and Gas Production: SIC 13; Natural Gas : Off-shore; Total: All Processes 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

2310030000 Industrial Processes; Oil and Gas Production: SIC 13; Natural Gas Liquids; Total: All Processes 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

2310031000 Industrial Processes; Oil and Gas Production: SIC 13; Natural Gas Liquids : On-shore; Total: All Processes 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

2310032000 Industrial Processes; Oil and Gas Production: SIC 13; Natural Gas Liquids : Off-shore; Total: All Processes 9015 Not a SPECIATE4 Profile. It used to be in SPECIATE3, but EPA dropped average TOG profiles (9000+) in SPECIATE 4 

2270002033 Mobile Sources; Off-highway Vehicle Diesel; Construction and Mining Equipment; Bore/Drill Rigs 1201 Light-Duty Diesel Vehicles
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-40

Table F12a. 2008 SMOKE Inputs.

Table F12b. 2008 SMOKE Outputs.

Source

Category CO NOX PM2.5 SO2 VOC

Carbon County Compression 323 1,292 49 0 231

Production 403 539 13 12 30,463

Spud 387 802 40 48 83

Lincoln County Compression 577 1,567 59 166 99

Production 491 605 18 1,378 25,787

Spud 59 131 4 2 94

Sublette County Compression 1,458 1,989 10 1 1,096

Production 1,363 1,872 75 15 26,496

Spud 1,579 3,699 67 120 462

Sweetwater County Compression 1,774 3,276 7 0 560

Production 790 1,021 15 103 74,435

Spud 565 1,117 66 167 357

Uinta County Compression 258 516 0 0 156

Production 316 232 2 95 6,305

Spud 10 42 2 4 90

Grand Total 10,352 18,699 427 2,112 166,713

County

Emissions (Tons/Year) Source

Category CO NOx PM2.5 SO2 CB05 VOC CH4 ETHA

Carbon County Compression 324 1,295 49 0 240 1,822 349

Production 461 521 12 12 34,142 105,081 16,681

Spud 387 799 40 48 96 11 3

Lincoln County Compression 579 1,570 59 167 84 568 92

Production 506 567 17 1,378 28,487 122,283 16,699

Spud 59 131 4 2 110 13 3

Sublette County Compression 1,461 1,994 10 2 1,129 8,548 1,627

Production 1,387 1,906 74 15 28,570 126,428 16,956

Spud 1,580 3,711 67 120 540 63 16

Sweetwater County Compression 1,780 3,283 7 0 580 4,392 840

Production 834 979 15 101 75,736 237,477 42,313

Spud 564 1,117 67 168 414 48 13

Uinta County Compression 259 517 0 0 166 1,274 247

Production 321 234 2 95 6,963 29,492 4,072

Spud 10 42 2 4 105 12 3

Grand Total 10,512 18,666 425 2,110 177,359 637,510 99,911

Emissions (Tons/Year)

County
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-41

Table F13. 2008 CD-C 12km Domain Point Source CO Emissions Summary (tpy).

State County EGU Non-EGU Trona

Colorado Adams Co 650.0 1,252.3

Arapahoe Co 91.2 328.7

Boulder Co 173.6 413.4

Broomfield Co 4.1 3.0

Clear Creek Co 0.0 74.5

Delta Co 0.9 0.0

Denver Co 306.0 878.8

Douglas Co 0.6 199.5

Eagle Co 41.6 48.9

El Paso Co 89.8 28.8

Elbert Co 14.0

Garfield Co 32.7 406.9

Gilpin Co 0.0

Grand Co 28.5

Gunnison Co 2.6

Jackson Co 0.0

Jefferson Co 63.1 1,047.6

Kit Carson Co 0.8 18.8

Lake Co 0.9

Larimer Co 251.7 426.5

Lincoln Co 110.7 28.1

Logan Co 2.5 44.8

Mesa Co 106.7 226.9

Moffat Co 1,270.6 25.9

Morgan Co 13,379.5 461.0

Park Co 0.0

Phillips Co 0.2 2.6

Pitkin Co 0.0

Rio Blanco Co 84.7 442.0

Routt Co 76.3 6.3

Sedgwick Co 0.0

Summit Co 3.3

Teller Co 0.0

Washington Co 0.0

Weld Co 1,111.3 1,175.0

Yuma Co 0.0 5.1
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-42

Table F13 (cont.). 2008 CD-C 12km Domain Point Source CO Emissions Summary (tpy).

State County EGU Non-EGU Trona

Idaho Bannock Co 1,215.5

Bingham Co 302.8

Bonneville Co 0.0

Butte Co 25.8

Caribou Co 10,890.0

Cassia Co 0.0

Clark Co 14.6

Jefferson Co 13.9

Madison Co 224.1

Minidoka Co 2,305.7

Power Co 104.7

Twin Falls Co 1,387.3

Montana Beaverhead Co 1.6

Big Horn Co 885.1 522.6

Carbon Co 3.8

Fallon Co 0.2

Gallatin Co 57.0

Madison Co 48.9

Park Co 7.4

Rosebud Co 585.0 143.4

Stillwater Co 47.6

Sweet Grass Co 22.8

Yellowstone Co 151.4 698.2

Nebraska Arthur Co 0.0

Banner Co 0.0

Box Butte Co 9.1

Chase Co 0.0

Cheyenne Co 55.8

Dawes Co 14.1

Deuel Co 0.1 29.5

Dundy Co 0.0 0.0

Garden Co 0.0

Keith Co 1.7

Kimball Co 4.7

Morrill Co 0.8

Perkins Co 0.9

Scotts Bluff Co 32.3 62.5

Sheridan Co 0.0

Sioux Co 0.0

South Dakota Harding Co 40.4

Lawrence Co 821.5

Pennington Co 146.2 3,070.3
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-43

Table F13 (cont.). 2008 CD-C 12km Domain Point Source CO Emissions Summary (tpy).

State County EGU Non-EGU Trona

Utah Beaver Co 1.5 9.5

Box Elder Co 2.8 1,245.7

Cache Co 6.4 72.5

Carbon Co 167.5 182.3

Daggett Co 0.0 55.0

Davis Co 25.0 1,400.8

Duchesne Co 0.4 521.6

Emery Co 1,862.7 11.0

Grand Co 52.7

Juab Co 0.1 17,422.1

Millard Co 2,301.4 1,109.3

Morgan Co 1.3 2,189.8

Rich Co 0.5

Salt Lake Co 159.9 3,567.9

Sanpete Co 1.3 16.4

Sevier Co 198.4 21.4

Summit Co 1.6 69.2

Tooele Co 53.0 484.9

Uintah Co 437.9 89.3

Utah Co 43.9 776.9

Wasatch Co 0.8 7.5

Washington Co 0.0

Weber Co 76.6 1,471.6
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-44

Table F13 (cont.). 2008 CD-C 12km Domain Point Source CO Emissions Summary (tpy).

State County EGU Non-EGU Trona

 Wyoming Albany Co 743.9

Big Horn Co 2.9 278.6

Campbell Co 1,451.5 9,133.4

Carbon Co 0.0 648.5

Converse Co 1,046.5 337.2

Crook Co 44.4 539.5

Fremont Co 6.0 178.9

Goshen Co 17.7

Hot Springs Co 232.6

Johnson Co 6.5 510.3

Laramie Co 5.8 795.0

Lincoln Co 707.9 327.7

Natrona Co 5.9 707.6

Niobrara Co 116.1

Park Co 348.5

Platte Co 2,029.7 0.1

Sheridan Co 40.7 4,036.3

Sublette Co 19.7 83.7

Sweetwater Co 2,757.6 2,298.7 12,451.1

Teton Co 0.0 42.9

Uinta Co 102.5

Washakie Co 2.9 107.1

Weston Co 586.5 179.5

 Wind Rivers Reserv Wind Rivers Reserv 0.0 0.0
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-45

Table F14. 2008 CD-C 12km Domain Point Source NOx Emissions Summary (tpy).

State County EGU Non-EGU Trona

Colorado Adams Co 14,742.9 1,433.8

Arapahoe Co 56.4 204.6

Boulder Co 3,128.3 2,349.2

Broomfield Co 11.2 0.9

Clear Creek Co 4.0 53.6

Delta Co 6.5 0.1

Denver Co 4,205.9 872.5

Douglas Co 1.9 90.3

Eagle Co 96.3 76.3

El Paso Co 56.2 49.3

Elbert Co 42.3

Garfield Co 31.0 217.0

Gilpin Co 0.0

Grand Co 42.9

Gunnison Co 11.5

Jackson Co 0.0

Jefferson Co 28.1 2,777.1

Kit Carson Co 16.9 5.1

Lake Co 3.0

Larimer Co 2,784.7 544.7

Lincoln Co 80.5 5.4

Logan Co 8.8 57.2

Mesa Co 657.2 246.8

Moffat Co 19,995.0 21.2

Morgan Co 5,808.6 465.3

Park Co 0.0

Phillips Co 0.2 8.8

Pitkin Co 0.0

Rio Blanco Co 89.2 605.6

Routt Co 8,626.9 22.3

Sedgwick Co 0.0

Summit Co 0.3

Teller Co 0.0

Washington Co 0.0

Weld Co 1,124.4 1,656.1

Yuma Co 0.0 19.3
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-46

Table F14 (cont.). 2008 CD-C 12km Domain Point Source NOx Emissions Summary (tpy).

State County EGU Non-EGU Trona

Idaho Bannock Co 906.0

Bingham Co 268.4

Bonneville Co 21.0

Butte Co 141.4

Caribou Co 1,927.2

Cassia Co 0.0

Clark Co 125.7

Jefferson Co 42.8

Madison Co 80.1

Minidoka Co 1,174.6

Power Co 113.4

Twin Falls Co 1,156.0

Montana Beaverhead Co 10.1

Big Horn Co 914.6 506.4

Carbon Co 15.5

Fallon Co 0.5

Gallatin Co 26.8

Madison Co 41.7

Park Co 31.5

Rosebud Co 28,201.5 11.3

Stillwater Co 93.7

Sweet Grass Co 14.4

Yellowstone Co 2,398.5 1,169.8

Nebraska Arthur Co 0.1

Banner Co 0.0

Box Butte Co 4.5

Chase Co 0.0

Cheyenne Co 90.7

Dawes Co 2.0

Deuel Co 0.6 48.2

Dundy Co 0.0 0.0

Garden Co 0.0

Keith Co 0.0

Kimball Co 27.4

Morrill Co 0.2

Perkins Co 0.0

Scotts Bluff Co 22.7 78.3

Sheridan Co 0.0

Sioux Co 0.0

South Dakota Harding Co 21.7

Lawrence Co 39.7

Pennington Co 974.5 4,368.5
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-47

Table F14 (cont.). 2008 CD-C 12km Domain Point Source NOx Emissions Summary (tpy).

State County EGU Non-EGU Trona

Utah Beaver Co 2.9 25.3

Box Elder Co 6.6 515.4

Cache Co 30.4 83.8

Carbon Co 4,254.3 553.5

Daggett Co 0.1 621.5

Davis Co 54.3 2,258.3

Duchesne Co 0.5 421.3

Emery Co 35,245.6 64.6

Grand Co 57.5

Juab Co 101.1 1,836.2

Millard Co 33,249.0 1,994.6

Morgan Co 6.0 3,569.7

Rich Co 0.0

Salt Lake Co 604.1 9,576.5

Sanpete Co 1.6 24.1

Sevier Co 196.1 19.0

Summit Co 6.0 375.3

Tooele Co 185.3 1,350.1

Uintah Co 7,132.2 77.4

Utah Co 137.8 813.5

Wasatch Co 3.8 48.0

Washington Co 0.0

Weber Co 212.6 304.4
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-48

Table F14 (cont.). 2008 CD-C 12km Domain Point Source NOx Emissions Summary (tpy).

State County EGU Non-EGU Trona

 Wyoming Albany Co 2,146.6

Big Horn Co 2.9 579.3

Campbell Co 7,807.7 14,913.4

Carbon Co 0.2 619.9

Converse Co 13,136.8 444.2

Crook Co 56.8 664.7

Fremont Co 17.5 194.9

Goshen Co 149.9

Hot Springs Co 70.3

Johnson Co 9.1 492.0

Laramie Co 5.8 1,923.4

Lincoln Co 14,333.6 1,411.6

Natrona Co 6.0 729.9

Niobrara Co 118.0

Park Co 608.4

Platte Co 20,684.0 0.4

Sheridan Co 35.9 1,322.9

Sublette Co 203.6 104.4

Sweetwater Co 23,291.6 4,845.4 6,309.7

Teton Co 0.0 59.8

Uinta Co 45.7

Washakie Co 2.9 159.2

Weston Co 964.9 260.6

 Wind Rivers Reserv Wind Rivers Reserv 0.6 8.2
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-49

Table F15. 2008 CD-C 12km Domain Point Source VOC Emissions Summary (tpy).

State County EGU Non-EGU Trona

Colorado Adams Co 91.2 4,418.1

Arapahoe Co 11.5 2,272.0

Boulder Co 30.7 1,706.4

Broomfield Co 0.4 351.8

Clear Creek Co 0.0 56.1

Delta Co 0.2 96.0

Denver Co 29.0 3,313.9

Douglas Co 0.1 708.4

Eagle Co 0.8 172.6

El Paso Co 0.9 147.7

Elbert Co 32.4

Garfield Co 28.5 387.4

Gilpin Co 8.3

Grand Co 47.0

Gunnison Co 4.2

Jackson Co 22.1

Jefferson Co 27.5 3,170.7

Kit Carson Co 0.3 60.5

Lake Co 39.7

Larimer Co 35.2 1,471.0

Lincoln Co 0.0 56.2

Logan Co 0.1 142.7

Mesa Co 11.1 847.0

Moffat Co 15.9 88.3

Morgan Co 2,199.6 150.7

Park Co 24.5

Phillips Co 0.0 25.0

Pitkin Co 36.5

Rio Blanco Co 40.3 395.0

Routt Co 54.3 31.2

Sedgwick Co 8.0

Summit Co 136.0

Teller Co 79.7

Washington Co 25.4

Weld Co 199.3 2,599.7

Yuma Co 2.6 51.0
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-50

Table F15 (cont.). 2008 CD-C 12km Domain Point Source VOC Emissions Summary (tpy).

State County EGU Non-EGU Trona

Idaho Bannock Co 22.9

Bingham Co 15.3

Bonneville Co 0.9

Butte Co 4.0

Caribou Co 6.0

Cassia Co 214.4

Clark Co 3.2

Jefferson Co 1.5

Madison Co 27.0

Minidoka Co 55.3

Power Co 3.5

Twin Falls Co 34.0

Montana Beaverhead Co 0.1

Big Horn Co 77.0 30.6

Carbon Co 2.5

Fallon Co 10.2

Gallatin Co 48.2

Madison Co 3.3

Park Co 14.8

Rosebud Co 104.5 1.8

Stillwater Co 4.9

Sweet Grass Co 1.7

Yellowstone Co 10.9 1,064.6

Nebraska Arthur Co 0.0

Banner Co 289.4

Box Butte Co 390.8

Chase Co 889.4

Cheyenne Co 267.4

Dawes Co 1.6

Deuel Co 0.0 82.5

Dundy Co 0.0 0.0

Garden Co 148.8

Keith Co 174.2

Kimball Co 45.8

Morrill Co 306.2

Perkins Co 51.0

Scotts Bluff Co 0.3 738.3

Sheridan Co 0.0

Sioux Co 156.1

South Dakota Harding Co 56.8

Lawrence Co 75.5

Pennington Co 4.6 198.8
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-51

Table F15 (cont.). 2008 CD-C 12km Domain Point Source VOC Emissions Summary (tpy).

State County EGU Non-EGU Trona

Utah Beaver Co 0.2 2.1

Box Elder Co 0.4 651.4

Cache Co 2.1 234.1

Carbon Co 20.3 61.5

Daggett Co 0.0 43.9

Davis Co 2.1 1,867.4

Duchesne Co 0.0 298.4

Emery Co 223.2 5.3

Grand Co 28.7

Juab Co 0.0 93.5

Millard Co 28.2 320.1

Morgan Co 0.5 132.4

Rich Co 0.2

Salt Lake Co 28.8 2,501.2

Sanpete Co 0.1 3.2

Sevier Co 3.7 3.6

Summit Co 0.2 267.6

Tooele Co 4.8 516.4

Uintah Co 52.7 140.0

Utah Co 9.0 1,608.9

Wasatch Co 0.3 2.9

Washington Co 0.0

Weber Co 3.1 252.3
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-52

Table F15 (cont.). 2008 CD-C 12km Domain Point Source VOC Emissions Summary (tpy).

State County EGU Non-EGU Trona

 Wyoming Albany Co 84.6

Big Horn Co 0.7 90.8

Campbell Co 106.9 2,209.0

Carbon Co 0.0 1,031.9

Converse Co 125.9 261.1

Crook Co 12.4 132.9

Fremont Co 1.9 194.3

Goshen Co 44.0

Hot Springs Co 33.4

Johnson Co 1.7 224.4

Laramie Co 1.4 239.9

Lincoln Co 99.1 39.0

Natrona Co 1.5 1,176.1

Niobrara Co 27.8

Park Co 351.0

Platte Co 243.7 27.5

Sheridan Co 11.3 623.6

Sublette Co 19.1 32.4

Sweetwater Co 321.8 1,167.9 7,464.1

Teton Co 0.0 9.8

Uinta Co 116.9

Washakie Co 0.7 142.2

Weston Co 0.0 178.4

 Wind Rivers Reserv Wind Rivers Reserv 0.4 2.2
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-53

Table F16. 2008 CD-C 12km Domain Point Source SO2 Emissions Summary (tpy).

State County EGU Non-EGU Trona

Colorado Adams Co 9,008.5 1,979.1

Arapahoe Co 28.4 56.1

Boulder Co 1,020.3 88.0

Broomfield Co 0.0 0.0

Clear Creek Co 0.0 1.9

Delta Co 0.0 0.2

Denver Co 3,165.8 340.4

Douglas Co 0.0 78.1

Eagle Co 1.1 0.9

El Paso Co 0.1 3.9

Elbert Co 0.1

Garfield Co 0.2 11.2

Gilpin Co 0.0

Grand Co 35.5

Gunnison Co 0.0

Jackson Co 0.0

Jefferson Co 2.3 3,370.7

Kit Carson Co 2.8 0.1

Lake Co 3.7

Larimer Co 1,137.0 156.1

Lincoln Co 5.5 0.3

Logan Co 6.1 14.0

Mesa Co 1,911.7 29.6

Moffat Co 4,719.5 2.0

Morgan Co 14,356.6 135.3

Park Co 0.0

Phillips Co 0.0 2.6

Pitkin Co 0.0

Rio Blanco Co 1.0 3.7

Routt Co 3,185.3 2.6

Sedgwick Co 0.0

Summit Co 0.2

Teller Co 0.0

Washington Co 0.0

Weld Co 50.7 240.5

Yuma Co 0.0 0.2
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-54

Table F16 (cont.). 2008 CD-C 12km Domain Point Source SO2 Emissions Summary (tpy).

State County EGU Non-EGU Trona

Idaho Bannock Co 18.6

Bingham Co 364.7

Bonneville Co 58.9

Butte Co 26.0

Caribou Co 8,895.1

Cassia Co 0.0

Clark Co 170.9

Jefferson Co 124.7

Madison Co 13.6

Minidoka Co 385.3

Power Co 1,759.0

Twin Falls Co 1,434.7

Montana Beaverhead Co 0.5

Big Horn Co 669.4 42.2

Carbon Co 2.2

Fallon Co 0.2

Gallatin Co 1.2

Madison Co 4.0

Park Co 16.0

Rosebud Co 18,287.9 0.6

Stillwater Co 10.8

Sweet Grass Co 1.3

Yellowstone Co 4,903.3 3,608.0

Nebraska Arthur Co 0.5

Banner Co 19.2

Box Butte Co 28.5

Chase Co 23.2

Cheyenne Co 15.9

Dawes Co 0.3

Deuel Co 0.0 4.6

Dundy Co 0.0 0.0

Garden Co 9.9

Keith Co 11.6

Kimball Co 3.3

Morrill Co 21.2

Perkins Co 17.1

Scotts Bluff Co 5.4 78.0

Sheridan Co 0.0

Sioux Co 8.5

South Dakota Harding Co 0.1

Lawrence Co 4.5

Pennington Co 761.0 849.7
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-55

Table F16 (cont.). 2008 CD-C 12km Domain Point Source SO2 Emissions Summary (tpy).

State County EGU Non-EGU Trona

Utah Beaver Co 0.1 2.3

Box Elder Co 0.2 86.8

Cache Co 3.4 25.6

Carbon Co 6,734.6 915.1

Daggett Co 0.0 1.1

Davis Co 3.5 3,004.1

Duchesne Co 0.0 3.7

Emery Co 11,313.1 6.9

Grand Co 7.3

Juab Co 5.8 33.3

Millard Co 7,109.8 127.5

Morgan Co 0.4 589.9

Rich Co 0.0

Salt Lake Co 10.2 7,501.6

Sanpete Co 0.0 4.4

Sevier Co 38.6 1.4

Summit Co 0.1 213.9

Tooele Co 2.4 202.2

Uintah Co 994.4 1.1

Utah Co 7.8 315.1

Wasatch Co 0.3 0.1

Washington Co 0.0

Weber Co 3.2 55.6
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-56

Table F16 (cont.). 2008 CD-C 12km Domain Point Source SO2 Emissions Summary (tpy).

State County EGU Non-EGU Trona

 Wyoming Albany Co 278.2

Big Horn Co 0.0 42.8

Campbell Co 10,804.5 899.1

Carbon Co 0.0 1,098.7

Converse Co 20,425.6 29.4

Crook Co 0.0 199.9

Fremont Co 1.0 0.9

Goshen Co 183.6

Hot Springs Co 23.2

Johnson Co 0.2 62.9

Laramie Co 0.0 45.3

Lincoln Co 22,509.1 193.8

Natrona Co 0.0 719.1

Niobrara Co 0.0

Park Co 96.7

Platte Co 11,583.0 0.0

Sheridan Co 0.0 207.0

Sublette Co 0.0 15.8

Sweetwater Co 20,700.8 6,618.0 5,748.1

Teton Co 0.0 13.8

Uinta Co 14.6

Washakie Co 0.0 47.4

Weston Co 2,381.3 716.9

 Wind Rivers Reserv Wind Rivers Reserv 0.0 1,057.1
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-57

Table F17. 2008 CD-C 12km Domain Point Source PM10 Emissions Summary (tpy).

State County EGU Non-EGU Trona

Colorado Adams Co 238.5 2,380.8

Arapahoe Co 0.8 1,004.4

Boulder Co 47.3 826.4

Broomfield Co 0.3 9.3

Clear Creek Co 0.0 85.8

Delta Co 0.0 592.9

Denver Co 111.7 473.0

Douglas Co 0.1 146.5

Eagle Co 0.8 177.4

El Paso Co 0.3 36.7

Elbert Co 52.1

Garfield Co 0.6 206.8

Gilpin Co 0.0

Grand Co 99.5

Gunnison Co 277.3

Jackson Co 24.7

Jefferson Co 2.3 622.7

Kit Carson Co 1.1 43.7

Lake Co 1,231.7

Larimer Co 95.7 760.9

Lincoln Co 26.4 16.8

Logan Co 0.9 26.9

Mesa Co 62.8 551.9

Moffat Co 230.5 2,157.3

Morgan Co 740.4 214.9

Park Co 64.3

Phillips Co 0.0 14.2

Pitkin Co 45.4

Rio Blanco Co 0.9 981.1

Routt Co 178.8 897.2

Sedgwick Co 3.5

Summit Co 88.7

Teller Co 0.0

Washington Co 81.0

Weld Co 216.2 1,852.8

Yuma Co 0.0 28.7
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-58

Table F17 (cont.). 2008 CD-C 12km Domain Point Source PM10 Emissions Summary (tpy).

State County EGU Non-EGU Trona

Idaho Bannock Co 49.6

Bingham Co 238.0

Bonneville Co 1.3

Butte Co 4.4

Caribou Co 467.5

Cassia Co 0.0

Clark Co 62.2

Jefferson Co 27.7

Madison Co 99.3

Minidoka Co 357.5

Power Co 194.5

Twin Falls Co 203.9

Montana Beaverhead Co 22.0

Big Horn Co 38,572.3 408.6

Carbon Co 19.3

Fallon Co 0.7

Gallatin Co 18.1

Madison Co 78.7

Park Co 39.0

Rosebud Co 342.1 21.5

Stillwater Co 37.5

Sweet Grass Co 5.5

Yellowstone Co 163.7 447.0

Nebraska Arthur Co 0.4

Banner Co 27.6

Box Butte Co 52.8

Chase Co 33.3

Cheyenne Co 30.0

Dawes Co 10.2

Deuel Co 0.0 9.2

Dundy Co 0.0 0.0

Garden Co 14.2

Keith Co 16.6

Kimball Co 6.5

Morrill Co 30.0

Perkins Co 14.3

Scotts Bluff Co 5.6 88.0

Sheridan Co 2.8

Sioux Co 12.2

South Dakota Harding Co 1.1

Lawrence Co 84.9

Pennington Co 35.7 370.0
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-59

Table F17 (cont.). 2008 CD-C 12km Domain Point Source PM10 Emissions Summary (tpy).

State County EGU Non-EGU Trona

Utah Beaver Co 42.2 29.8

Box Elder Co 0.2 953.7

Cache Co 1.8 35.1

Carbon Co 237.7 285.2

Daggett Co 0.0 3.8

Davis Co 1.5 500.6

Duchesne Co 0.0 5.5

Emery Co 1,721.5 462.0

Grand Co 21.3

Juab Co 10.1 207.1

Millard Co 275.7 662.2

Morgan Co 0.4 188.2

Rich Co 0.3

Salt Lake Co 25.8 4,929.4

Sanpete Co 0.1 53.2

Sevier Co 27.8 73.8

Summit Co 0.1 98.6

Tooele Co 3.2 1,868.6

Uintah Co 569.1 182.2

Utah Co 3.0 476.7

Wasatch Co 0.3 7.8

Washington Co 0.0

Weber Co 5.6 625.0
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-60

Table F17 (cont.). 2008 CD-C 12km Domain Point Source PM10 Emissions Summary (tpy).

State County EGU Non-EGU Trona

 Wyoming Albany Co 435.8

Big Horn Co 1.4 395.2

Campbell Co 2,225.0 14,203.6

Carbon Co 0.0 267.7

Converse Co 1.4 1,272.2

Crook Co 6.2 922.1

Fremont Co 2.5 4.5

Goshen Co 494.1

Hot Springs Co 9.0

Johnson Co 3.1 176.6

Laramie Co 2.9 664.3

Lincoln Co 6,526.7 1,344.9

Natrona Co 2.9 390.1

Niobrara Co 0.3

Park Co 135.8

Platte Co 1,049.9 262.1

Sheridan Co 6.8 182.3

Sublette Co 3.0 33.9

Sweetwater Co 3,039.0 8,809.0 3,598.4

Teton Co 0.0 5.3

Uinta Co 53.5

Washakie Co 1.4 358.5

Weston Co 571.9 458.6

 Wind Rivers Reserv Wind Rivers Reserv 0.0 12.7
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-61

Table F18a. Comparison of 2008 NOx emissions from Tables F4, F12, and F13-F17.

Table F18b. Comparison of 2008 VOC/TOG emissions from Tables F4, F12, and F13-F17.

Compressor Drilling Production EGU nEGU Trona

Carbon 0 620

Lincoln 14,334 1,412

Sublette 204 104

Sweetwater 23,292 4,845 6,310

Uinta 46

5-county Total 37,829 7,027 6,310

Table 4 5-county Total 8,660 5,800 4,206 38,501 7,042 6,330

Carbon 1,292 802 539

Lincoln 1,567 131 605

Sublette 1,989 3,699 1,872

Sweetwater 3,276 1,117 1,021

Uinta 516 42 232

5-county Total 8,640 5,791 4,269

Carbon 1,295 799 521

Lincoln 1,570 131 567

Sublette 1,994 3,711 1,906

Sweetwater 3,283 1,117 979

Uinta 517 42 234

5-county Total 8,659 5,800 4,207

NOx

Tables 13-22

Table 12 Inputs

Table 12 Outputs

Compressor Drilling Production EGU nEGU Trona VOC/TOG

Carbon 0 1,032 VOC

Lincoln 99 39 VOC

Sublette 19 32 VOC

Sweetwater 322 1,168 7,464 VOC

Uinta 117 VOC

5-county Total 440 2,388 7,464 VOC

Table 4 5-county Total 21,955 1,449 891,377 1,072 3,958 16,162 TOG

Carbon 231 83 30,463 VOC

Lincoln 99 94 25,787 VOC

Sublette 1,096 462 26,496 VOC

Sweetwater 560 357 74,435 VOC

Uinta 156 90 6,305 VOC

5-county Total 2,142 1,086 163,486 VOC

Carbon 240 96 34,142 VOC

Lincoln 84 110 28,487 VOC

Sublette 1,129 540 28,570 VOC

Sweetwater 580 414 75,736 VOC

Uinta 166 105 6,963 VOC

5-county Total 2,199 1,265 173,897 VOC

Table 12 Inputs

Table 12 Outputs

Tables 13-22

VOC/TOG
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-62

Table F18c. Comparison of 2008 CO emissions from Tables F4, F12, and F13-F17.

Table F18d. Comparison of 2008 SO2 emissions from Tables F4, F12, and F13-F17.

Compressor Drilling Production EGU nEGU Trona

Carbon 0 649

Lincoln 708 328

Sublette 20 84

Sweetwater 2,758 2,299 12,451

Uinta 102

5-county Total 3,485 3,461 12,451

Table 4 5-county Total 4,403 2,600 3,509 3,323 3,466 12,492

Carbon 323 387 403

Lincoln 577 59 491

Sublette 1,458 1,579 1,363

Sweetwater 1,774 565 790

Uinta 258 10 316

5-county Total 4,390 2,600 3,362

Carbon 324 387 461

Lincoln 579 59 506

Sublette 1,461 1,580 1,387

Sweetwater 1,780 564 834

Uinta 259 10 321

5-county Total 4,403 2,600 3,509

Table 12 Inputs

Table 12 Outputs

CO

Tables 13-22

Compressor Drilling Production EGU nEGU Trona

Carbon 0 1,099

Lincoln 22,509 194

Sublette 0 16

Sweetwater 20,701 6,618 5,748

Uinta 0 15

5-county Total 43,210 7,941 5,748

Table 4 5-county Total 168 342 1,599 43,977 7,960 5,763

Carbon 0 48 12

Lincoln 166 2 1,378

Sublette 1 120 15

Sweetwater 0 167 103

Uinta 0 4 95

5-county Total 167 341 1,603

Carbon 0 48 12

Lincoln 167 2 1,378

Sublette 2 120 15

Sweetwater 0 168 101

Uinta 0 4 95

5-county Total 169 342 1,601

Table 12 Inputs

Table 12 Outputs

SO2

Tables 13-22
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-63

Figure F9. Wyoming Emissions Trends. Top panel: Wyoming point source (not including O&G 

points) emission trends. Lower panel: Wyoming oil and gas emissions trends.

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

2005 2006 2008

Emissions (tons/yr)

Point Source (EGU+Non-EGU+Trona) Emissions

NOx

VOC

CO

SO2

0

5,000

10,000

15,000

20,000

25,000

2005 2006 2008

Emissions (tons/yr)

Oil and Gas Point Source Emissions

NOx

VOC

CO

SO2
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-64

Figure F10. Wyoming Emissions Trends. Top panel: Wyoming NOx emission trends. Lower 

panel: Wyoming TOG emissions trends.

0

5,000

10,000

15,000

20,000

25,000

2005 2006 2008

NOx Emissions (tpy)

Wyoming NOx Emissions Trends

O n-Road Mobile

Off-Road Mobile

Area

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

2005 2006 2008

TOG Emissions (tpy)

Wyoming TOG Emissions Trends

O n-Road Mobile

Off-Road Mobile

Area
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-65

Figure F11. Wyoming Emissions Trends. Top panel: Wyoming onroad mobile NOx emission 

trends. Lower panel: Wyoming nonroad mobile NOx emissions trends.

2008 2008 - 2006 2008 2008 - 2006
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-66

Figure F12. Wyoming Emissions Trends. Top panel: Wyoming non-O&G area source NOx 

emission trends. 

2008 2008 - 2006
APPENDIX F – DEVELOPMENT OF THE 2008 BASELINE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 F-67

Figure F13. Wyoming O&G Emissions Trends. Top panel: Wyoming O&G source category 

NOx emission trends. Lower panel: Wyoming O&G source category CB05 VOC emissions 

trends.
Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016

Appendix G

Development of the 2005-2006 Base-Case Emission Inventory
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-1

INTRODUCTION 

For the Continental Divide-Creston (CD-C) EIS, a base case simulation has been completed. 

CAMx was applied for the calendar years 2005 and 2006 using a nested-grid modeling domain 

with horizontal spatial resolution 36/12/4 km. The 2005 and 2006 base case model runs used 

actual emissions of NOx, SO2, PM10, PM2.5, VOC and CO from all sources for those years and 

included a comprehensive inventory of oil and gas (O&G) emissions sources within Southwest 

Wyoming developed by Carter Lake and BP as well as the WRAP Phase III O&G emissions for the 

Denver-Julesburg, Piceance, and Uinta Basins. The2005-6 base case emission inventory was 

reviewed by the Wyoming Department of Environmental Quality and approved for use in the 

2005-6 base case modeling on February 11, 2010. In this Appendix, we describe the 

development of each source category of the 2005-6 emission inventory. 

SMOKE POINT SOURCE EMISSIONS MODELING

Carter Lake has developed a detailed point source emissions inventory for 2005 and 2006 for 

the region covered by the 12 km grid. The data included annual emissions for all point sources 

and hourly CEM data for points in the CAMD database. Point source emissions were separated 

into EGU, non-EGU, trona, and O&G exploration and production categories to be processed 

separately to facilitate source apportionment. The O&G emissions were further subdivided into 

the Southwest Wyoming, Denver-Julesburg, Uinta, Piceance and other basins for processing. 

The details of O&G emissions processing are discussed in the next section. 

The detailed 2005 and 2006 point inventory developed by Carter Lake was quality assured and 

adjustments were made as follows: 

 The inventory did not include point emissions within Tribal lands, thus, ENVIRON projected 

the Tribal point emissions from the WRAP 2002 emissions inventory and incorporated 

these projected emissions into the 2005-2006 point inventory;

 ENVIRON moved O&G emissions from small compressor engines out of the point source 

inventory to the O&G inventory for the purpose of source apportionment; 

 The State of Wyoming does not inventory PM.2.5 emissions. Therefore, the Wyoming point 

source emissions inventory for 2005-2006 did not contain PM2.5, although PM10 emissions 

were included. ENVIRON determined the ratio of PM2.5/PM10 by SCC by state from the 

WRAP 2002 inventory and applied these ratios to point sources within Wyoming. Analysis 

of the WRAP inventory showed:

- 56% of PM10 comes from mineral products (mining [especially coal mining], and 

transfer of materials). These sources contribute to minimal PM2.5.

- 20% of PM10 comes from EGUs. 99% of PM10 emissions are PM2.5 for these sources.

- 8% of PM10 comes from Chemical Manufacturing (sodium carbonate, fertilizer 

facilities). No PM2.5 is reported from these sources.

- 7% of PM10 comes from the cooling tower at the Dave Johnston coal-fired plant. No 

PM2.5 is reported for this category.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-2

Based on this analysis, ENVIRON determined that 30% of the PM10 emissions will be allocated 

to PM2.5;

 Where CEM data were missing or flagged as suspect, ENVIRON checked the CAMD reports 

and determined appropriate corrections;

 CEM sources that were unmatched with the Carter Lake’s point inventory were identified 

and were added to the point inventory;

 CEM sources that were matched with multiple records in the Carter Lake’s point inventory 

were weighted allocated among those records based on their emissions.

Point source emissions from non-EGU sectors were not based on day- or hour-specific 

emissions (i.e., are not included in CAMD). Emissions from these sources were temporally 

allocated to month, day, and hour using annual emissions and source category code (SCC) 

based allocation factors available in the WRAP SMOKE setup which incorporated any relevant 

data that has been developed by other RPOs. 

To temporally allocate the EGU point source emissions for species in the emissions inventory 

other than NOx and SO2, specifically CO, VOC, NH3, and PM, heat input data from the 2005 and 

2006 CEM datasets were used to develop facility-level temporal distributions. The day-specific 

and facility-specific temporal profiles were used in conjunction with the supplied emissions 

data to calculate hourly EGU emissions by facility. 

The Acid Rain data does not contain hourly emissions of VOC or CO, so this information was 

calculated by ENVIRON based on the hourly heat input reported in the Acid Rain database and 

the daily VOC and CO emissions data from the WRAP database. For each source, an average 

diurnal cycle of hourly heat input was calculated by averaging all heat inputs for a given hour 

across all days in that quarter. For each hour, the daily value of the VOC and CO emissions for 

that source was multiplied by the ratio of the measured heat input for that hour from the Acid 

Rain data base to the quarterly average heat input. An example calculation is shown below:

 

( 2)

(2 , 21)

2 , 21) ( 21)

Heat Input Quarter

Heat Input pm May VOC pm May VOC May

acidrain

acidrain

 WRAP 

Table G-1 lists EGU sources in Wyoming that report hourly CEM data to CAMD. These sources’ 

hourly emissions data were used for SMOKE EGU emissions processing. 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-3

Table G-1 Wyoming EGU Sources in 2005&2006 CAMD CEM Database.

Facility ORIS ID 

NOx (tpy) SO2 (tpy)

2005 2006 2005 2006

Dave Johnston 4158 14,721 16,457 19,751 22,351

Jim Bridger 8066 32,171 28,054 21,651 20,055

Laramie River 6204 19,951 19,781 13,098 11,539

Naughton 4162 14,736 14,168 23,229 20,664

Neil Simpson II 7504 634 824 498 633

Neil Simpson II (CT2) 55477 10 12 0 0

Wygen I 55479 561 587 538 647

Wyodak 6101 4,946 3,855 7,732 6,514

All non-O&G point sources were spatially allocated in the domain based on their geographic 

coordinates.

Stack parameters are often more important to the reliability of the air quality modeling results 

than the emissions rates themselves. Stack parameter data are frequently incorrect, especially 

in some of the current regional modeling inventories, and careful QA is required to assure that 

the point source emissions are properly located both horizontally and vertically within the 

modeling domain. To screen for simple, but potentially serious inventory errors, the modeling 

team modified procedures originally developed by EPA to quality assure, augment, and where 

necessary, revise, stack parameters to ensure the accuracy of the point source emissions, as 

well as standardize procedures to identify and correct stack data errors. SMOKE has a number 

of built-in QA procedures designed to catch missing or out-of-range stack parameters. These 

procedures were also invoked in the processing of the point source data.

Figures G-1 and G-2 show 2005 and 2006 point sources within the 12 km domain, excluding 

O&G sources within the 5-county area. For clarity, the Denver area, which has many point 

sources within a small area, is shown separately in Figure G-3. Sources are classified within 

SMOKE as EGU (electricity generating unit) or non-EGU based on SCC code. SCCs considered to 

be EGUs begin with the digits 101 or 201. Because the SMOKE EGU/non-EGU convention 

causes small sources such as hospital emergency generators to be classified as EGUs along with 

power plants, we have divided EGUs into two categories in Figures G-1-G-3: EGUs that appear 

in the EPA Acid Rain Program Database and those that do not. Only large power plants appear 

in the Acid Rain Program Database. These EGUs are labeled and indicated in Figure G-1-G-3 by 

a square icon. 

For Wyoming point sources, SCCs were available, but SIC codes were not; therefore, it was 

difficult to determine whether a given source should be classified as an O&G source. Special 

efforts were made to identify O&G sources inside the 5-County area of SW Wyoming. Outside 

the 5-County area, all Wyoming point sources that were not classified as either EGU or trona 

sources were included in the non-EGU category. 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-4

Figure G-1 2005 point sources within the 12 km domain, excluding O&G sources within the 5-

county area. 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-5

Figure G-2 2006 point sources within the 12 km domain excluding O&G sources within the 5-

county area. 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-6

Figure G-3 2005 and 2006 ARD point sources in the Denver area within the 12 km domain. 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-7

Sources Modeled With CAMx Plume-In-Grid Model

Large stationary NOx sources within the 12 km domain were modeled with the CAMx Plume-inGrid (PiG) model. For each simulated day, PiG sources were identified in the following way:

1. Identified sources (i.e. individual stacks) emitting more than 1 ton/day NOx emissions 

2. Identified sources co-located with those sources found in (1);

i.e. sources that are within 100 m distance AND have NOx emissions greater than or 

equal to 0.1 ton/day were identified

The sources identified in this manner for all 365 days of 2005 and 2006 were appended 

together to compile a list of distinct sources within the 12 km domain for each year. Sources on 

this list were selected for PiG treatment in emissions processing. Maps of sources selected for 

PiG treatment within the 12 km domain are shown in Figures G-1-G-3. Point sources were 

broken out by source category into EGU, oil and gas, trona, and non-EGU sources that do not fit 

under either oil and gas or trona source categories. This was done to configure the inventory 

for use in potential CAMx source apportionment analyses. PiGged sources are displayed in 

separate figures by source category and year in Figures G-4 through G-11. Tables G-2 through 

G-9 list the sources selected for PiG treatment along with their locations, source identification 

information, and NOx, SO2, CO, NH3, and PM emissions.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-8

Figure G-4 2005 EGU sources treated with the CAMx Plume-in-Grid (PiG) Model within the 12 

km domain. 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-9

Figure G-5 2005 non-EGU sources treated with the CAMx Plume-in-Grid (PiG) Model within 

the 12 km domain. 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-10

Figure G-6 2005 oil and gas sources treated with the CAMx Plume-in-Grid (PiG) Model within 

the 12 km domain. 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-11

Figure G-7 2005 trona sources treated with the CAMx Plume-in-Grid (PiG) Model within the 

12 km domain. 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-12

Figure G-8 2006 EGU sources treated with the CAMx Plume-in-Grid (PiG) Model within the 12 

km domain. 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-13

Figure G-9 2006 non-EGU sources treated with the CAMx Plume-in-Grid (PiG) Model within 

the 12 km domain. 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-14

Figure G-10 2006 oil and gas sources treated with the CAMx Plume-in-Grid (PiG) Model 

within the 12 km domain. 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-15

Figure G-11 2006 trona sources treated with the CAMx Plume-in-Grid (PiG) Model within the 

12 km domain. 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-16

Table G-2 2005 EGU Sources within the 12/4 km grid modeled with the CAMx Plume-in-Grid. Sources are ranked by their NOx 

emissions.

Rank NOx (TPD) PT X Y PlantID StackID ORISID FIPS PLANT NOx VOC CO SO2 PM10 PM25 NH3

1 104.6 203 -743950. 714784. EGU0727 0226 6076 30087 COLSTRIP STEAM ELECTRIC STATION 36,393.6 13,279.7

2 80.5 299 -1322699. 59547. EGU1222 202 6481 49027 Intermountain Generation Station 25,062.7 0.0 0.0 3,593.9 0.0 0.0 81.5

3 48.3 142 -891863. 107264. EGU0175 0222 6021 08081 TRI STATE GENERATION CRAIG 17,683.1 4,075.6 74.5

4 38.6 292 -1198213. -1559. EGU1220 212 6165 49015 Hunter Power Plant 12,156.4 0.0 0.0 5,033.8 0.0 0.0 0.0

5 32.1 294 -1198431. 24452. EGU1221 212 8069 49015 Huntington Power Plant 10,167.2 0.0 0.0 17,362.8 0.0 0.0 0.0

6 31.2 655 -970515. 255230. 5603701002 2085 8066 56037 Jim Bridger Plant 9,743.3 77.3 662.3 6,383.0 477.7 477.7 31.3

7 25.4 653 -970515. 255230. 5603701002 2062 8066 56037 Jim Bridger Plant 8,894.3 76.6 657.0 6,700.8 165.0 165.0 31.3

8 23.8 515 -1036751. 80250. EGU1224 202 7790 49047 BONANZA POWER PLANT 7,398.3 62.8 523.0 1,229.7 680.8 562.7 31.4

9 21.2 654 -970515. 255230. 5603701002 2076 8066 56037 Jim Bridger Plant 4,822.1 64.1 549.4 5,100.6 137.1 137.1 31.3

10 21.1 633 -646798. 261361. 5603100001 213 6204 56031 Laramie River Station 6,922.2 81.9 682.3 4,475.5 98.8 98.8 39.5

11 20.5 635 -646798. 261361. 5603100001 225 6204 56031 Laramie River Station 6,009.7 70.7 588.4 4,142.7 138.0 138.0 39.5

12 19.8 634 -646798. 261361. 5603100001 224 6204 56031 Laramie River Station 7,019.2 87.2 726.8 4,479.6 161.9 161.9 39.5

13 19.5 626 -1118665. 278236. 5602300004 2107 4162 56023 Naughton Plant 5,560.0 42.9 368.1 6,103.2 232.1 232.1 13.5

14 17.1 21 -689997. 9568. EGU0163 0222 469 08001 PUBLIC SERVICE CO CHEROKEE PLT 6,415.5 5,310.4 16.8

15 15.8 622 -712198. 348399. 5600900001 2040 4158 56009 Dave Johnston 5,583.5 48.7 405.6 5,382.4 841.5 841.5 14.4

16 15 656 -970515. 255230. 5603701002 2086 8066 56037 Jim Bridger Plant 8,711.3 73.8 633.0 3,466.4 118.0 118.0 31.3

17 14 154 -563976. 46860. EGU0179 0222 6248 08087 PUBLIC SERVICE CO PAWNEE PLT 3,646.4 11,247.8 31.0

18 14 574 -665551. 505468. 5600500046 2122 6101 56005 Wyodak Plant 4,946.3 58.2 485.3 7,732.1 1,642.9 1,642.9 0.5

19 13.9 625 -1118665. 278236. 5602300004 2106 4162 56023 Naughton Plant 4,988.1 29.2 250.0 9,464.3 201.5 201.5 13.5

20 13.8 621 -712154. 348344. 5600900001 2039 4158 56009 Dave Johnston 4,602.6 33.0 275.0 7,685.2 176.4 176.4 14.4

21 13.8 22 -689997. 9568. EGU0163 0226 469 08001 PUBLIC SERVICE CO CHEROKEE PLT 4,093.2 1,749.7 14.9

22 13 171 -856301. 102086. EGU0183 0222 525 08107 PUBLIC SERVICE CO HAYDEN PLT 4,090.0 1,297.4 11.3

23 12.4 624 -1118665. 278236. 5602300004 2095 4162 56023 Naughton Plant 4,188.2 22.9 196.1 7,661.8 32.9 32.9 13.5

24 11.7 119 -671031. 123737. EGU0173 0226 6761 08069 PLATTE RIVER POWER AUTHORITY - RAWHIDE 3,726.3 875.4 18.0

24 11.7 119 -671031. 123737. EGU0173 0226 6761 08069 RAWHIDE ENERGY STATION 0.6 0.0 0.2 0.0 0.0 0.0 0.0

25 11.6 172 -856301. 102086. EGU0183 0226 525 08107 PUBLIC SERVICE CO HAYDEN PLT 3,979.5 1,592.8 15.8

26 6.7 216 -889488. 696596. EGU0728 0226 2187 30111 PPL MONTANA - JE CORETTE PLANT 1,655.5 2,874.5 10.8

27 6.5 79 -680287. -6529. EGU0165 0222 465 08031 PUBLIC SERVICE CO - ARAPAHOE 2,307.9 2,410.8 9.8

28 6.5 620 -712125. 348311. 5600900001 2038 4158 56009 Dave Johnston 2,289.6 16.9 141.1 3,395.4 40.6 40.6 14.4

29 6.5 615 -712096. 348278. 5600900001 2025 4158 56009 Dave Johnston 2,245.4 17.2 143.6 3,287.7 256.6 256.6 14.4

30 6.2 40 -693836. 34254. EGU0164 0226 477 08013 PUBLIC SERVICE CO - VALMONT 2,510.8 878.6 8.3

31 5.6 259 -1174662. 59571. EGU1218 212 3644 49007 Carbon Power Plant 3,402.3 0.0 0.0 5,410.1 0.0 0.0 0.0

32 5 291 -1198213. -1559. EGU1220 202 6165 49015 Hunter Power Plant 6,082.1 0.0 0.0 1,243.0 0.0 0.0 0.0

33 2.7 25 -652300. -778. ORIS55645 STKDEF 55645 08001 BLUE SPRUCE ENERGY CENTER 50.9 0.3 13.1 4.0 0.3 0.3 1.0

33 4.6 603 -665477. 505749. 5600590001 3149 0 56005 WYGEN 2 1,578.0 225.0 3,381.0 2,254.0 270.0 270.0 0.0

34 3.2 664 -591164. 463283. 5604500005 398 0 56045 Osage 1,105.4 7.3 61.1 2,051.3 609.8 609.8 0.0

35 3.2 605 -658592. 434661. 5600590002 3639 0 56005 Two Elk Facility 1,166.8 175.6 1,750.2 1,711.4 233.5 0.0 0.0

36 2.7 228 -498985. 470013. 28.0801-02 1 46103 Black Hill Power & Light Company (Ben Fr 907.7 3.3 126.9 785.0 30.4

37 2 133 -968076. -34362. EGU0174 0202 468 08077 PUBLIC SERVICE CO CAMEO PLT 724.5 2,108.0 3.1

38 1.9 578 -665602. 505182. 5600500063 385 7504 56005 Neil Simpson Two 628.4 3.9 194.9 498.4 78.4 78.4 12.1

39 1.6 602 -665586. 505259. 5600500146 3156 55479 56005 WYGEN Station 1 561.5 8.2 340.2 538.4 81.9 81.9 0.0

40 1.4 199 -834061. 655046. 003-0018 0 30003 HARDIN GENERATOR PROJECT 0.5 0.4

41 1.3 205 -743950. 714784. EGU0727 0801 6076 30087 COLSTRIP STEAM ELECTRIC STATION 459.6 2,226.4

42 1 194 -663958. 55844. EGU0186 0201 6112 08123 PUBLIC SERVICE CO FORT SAINT VRAIN PLT 386.2 9.8 121.3

42 1.2 573 -665857. 505353. 5600500002 380 0 56005 Neil Simpson One 419.0 6.2 18.9 949.8 342.0 342.0 0.0

42 1.3 81 -680930. 986. EGU0166 0601 478 08031 Zuni 52.7 0.2 3.5

42 1.4 153 -564179. 47790. EGU0178 0201 55127 08087 MANCHIEF POWER COMPANY LLC 27.2 9.1 354.0 0.3 29.0 29.0 27.7

43 0.6 23 -689997. 9568. EGU0163 0601 469 08001 PUBLIC SERVICE CO CHEROKEE PLT 227.8 0.8 3.2

44 0.1 80 -680287. -6529. EGU0165 0601 465 08031 PUBLIC SERVICE CO - ARAPAHOE 28.6 0.8 2.3

44 0.2 24 -689997. 9568. EGU0163 0604 469 08001 PUBLIC SERVICE CO CHEROKEE PLT 64.5 0.1 1.4

45 0.1 295 -1198431. 24452. EGU1221 501 8069 49015 Huntington Power Plant 25.4 0.0 0.0 2.0 0.0 0.0 0.0

46 0.1 118 -671031. 123737. EGU0173 0201 6761 08069 PLATTE RIVER POWER AUTHORITY - RAWHIDE 3.6 0.1 1.1

47 0.1 155 -563976. 46860. EGU0179 0601 6248 08087 PUBLIC SERVICE CO PAWNEE PLT 21.7 0.3 0.8

Source Parameters Emissions (tons/year)
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-17

Table G-3 2005 non-EGU Sources within the 12/4 km grid modeled with the CAMx Plume-in-Grid. Sources are ranked by their

NOx emissions.

Rank NOx (TPD) PT X Y PlantID StackID ORISID FIPS PLANT NOx VOC CO SO2 PM10 PM25 NH3

1 10.1 11167 -1267843. 164918. 10571 927593 49035 Mine & Copperton Concentrator 3,749.5 343.4 1,564.0 45.4 306.7 306.7

2 5.7 1334 -694677. 53910. 0003 007 08013 CEMEX, INC. - LYONS CEMENT PLANT 2,162.0 3.0 136.0 18.0 134.0

3 4.4 5410 -1183016. 392330. 02900001 010 16029 P4 Production LLC 1,625.5 110.2 8,551.8 48.2 37.9

4 3.7 9191 -1289629. 59699. 10303 1616 0 49023 Leamington Cement Plant 1,340.7 52.7 8,626.3 0.3 44.6 44.6 4.4

5 3.5 9516 -1207603. 213047. 10007 16758 0 49029 Devil's Slide Plant 1,293.7 46.8 768.8 228.5 14.7 4.6 4.1

6 3.5 9599 -1207603. 213047. 10007 948011 0 49029 Devil's Slide Plant 1,293.7 46.8 768.8 228.5 14.7 4.6 4.1

7 3.5 9624 -1207603. 213047. 10007 952430 0 49029 Devil's Slide Plant 1,293.7 46.8 768.8 228.5 14.7 4.6 4.1

8 3 5949 -499781. 470177.28.1121-02 9 46103 GCC Dacotah 1,871.0 50.8 1,668.0 198.6 3.8

9 2.8 3390 -697446. 5119. 0820 006 10003 08059 TRIGEN - COLORADO ENERGY CORPORATION 1,005.1 5.2 43.0 1,947.5 17.4

10 2.5 9327 -1354245. 1417. 10313 17059 0 49027 Cricket Mountain Plant 908.8 17.6 440.8 3.1 24.5 19.6 21.7

11 2.4 15696 -714543. 173840.5600100002 1863 0 56001 Laramie Cement Plant 920.2 30.6 660.3 85.5 20.1 0.0 28.6

12 1.7 5565 -1414379. 416258. 08300001 010 16083 TASCO, Twin Falls 606.1 2.4 173.0 717.0 44.8 22.3

13 1.6 11197 -1262021. 182635. 10572 1312 0 49035 Power Plt/ Lab/ Tailings Impoundment 573.8 2.3 28.9 711.7 8.3 4.4 0.1

14 1.6 11198 -1262021. 182635. 10572 1313 0 49035 Power Plt/ Lab/ Tailings Impoundment 573.8 2.3 28.9 711.7 8.3 4.4 0.1

15 1.5 3388 -697446. 5119. 0820 004 10003 08059 TRIGEN - COLORADO ENERGY CORPORATION 541.3 2.5 20.9 657.7 7.8

16 1.4 11201 -1262021. 182635. 10572 1316 0 49035 Power Plt/ Lab/ Tailings Impoundment 526.9 3.7 30.0 902.3 15.4 6.7 0.2

17 1.4 11202 -1262021. 182635. 10572 1317 0 49035 Power Plt/ Lab/ Tailings Impoundment 526.9 3.7 30.0 902.3 15.4 6.7 0.2

18 1.4 15690 -714543. 173840.5600100002 1856 0 56001 Laramie Cement Plant 531.1 12.1 177.7 53.8 8.6 0.0 0.9

19 1.4 5566 -1414379. 416258. 08300001 020 16083 TASCO, Twin Falls 508.4 2.3 19.0 827.0 85.6 42.9

20 1.4 11195 -1262021. 182635. 10572 1310 0 49035 Power Plt/ Lab/ Tailings Impoundment 492.9 2.2 28.3 682.2 2.9 1.5 0.1

21 1.3 11196 -1262021. 182635. 10572 1311 0 49035 Power Plt/ Lab/ Tailings Impoundment 492.9 2.2 28.3 682.2 2.9 1.5 0.1

22 1.3 21022 -658369. 149577.5602100002 668 0 56021 Cheyenne Nitrogenous Fertilizer Facility 481.7 56.1 59.6 0.0 0.0 0.0 0.0

23 1.3 5537 -1358824. 414676. 06700001 020 16067 TASCO, Paul 473.0 1.7 169.0 189.0 119.5 59.4

24 1.3 5536 -1358824. 414676. 06700001 010 16067 TASCO, Paul 471.4 2.0 19.3 139.8 95.6 47.8

25 1.3 11199 -1262021. 182635. 10572 1314 0 49035 Power Plt/ Lab/ Tailings Impoundment 471.0 2.3 29.3 712.8 2.9 1.6 0.1

26 1.3 11200 -1262021. 182635. 10572 1315 0 49035 Power Plt/ Lab/ Tailings Impoundment 471.0 2.3 29.3 712.8 2.9 1.6 0.1

27 1.3 5973 -499542. 470162.28.1121-02 41 46103 GCC Dacotah 467.8 12.7 417.1 79.5 8.0

28 1.1 21023 -658369. 149577.5602100002 669 0 56021 Cheyenne Nitrogenous Fertilizer Facility 410.8 48.2 59.5 0.0 0.0 0.0 0.0

29 1.1 5943 -499781. 470177.28.1121-02 3 46103 GCC Dacotah 706.8 14.6 91.3 26.3 135.8

30 1.2 5126 -1234508. 412961. 00500004 090 16005 Ash Grove Cement 496.2 14.8 529.0 2.2 25.3 6.5 4.4

31 1.1 6817 -1137841. 33914. 10096 3236 50951 49007 Sunnyside Cogeneration Facility 387.3 12.2 116.1 931.7 38.7 38.7 0.2

32 1.1 33 -674199. 7746. 0003 025 08001 SUNCOR ENERGY - DENVER REFINERY 389.9 409.8 422.2 315.7

33 1.1 4841 -656837. 39181. 0250 001 08123 THERMO COGEN PARTNERSHIP FT LUPTON 350.0 36.9 371.1 5.5 54.5

34 1 9326 -1354245. 1417. 10313 73 0 49027 Cricket Mountain Plant 372.6 11.6 289.7 10.6 19.4 15.5 14.3

35 1.2 9269 -1262203. 86989. 12524 965416 56102 49023 Pacificorp Currant Creek Power Plant 88.8 0.9 21.5 0.3 3.8 3.8 6.6

36 1 12441 -1245947. 167466. 12096 954511 0 49035 I-15 CORRIDOR RECONSTRUCTION 370.3 17.1 159.5 40.4 22.8 22.8 0.0

37 1 9324 -1354245. 1417. 10313 71 0 49027 Cricket Mountain Plant 366.1 7.1 177.0 1.3 66.7 53.4 8.7

38 0.6 5944 -499781. 470177.28.1121-02 4 46103 GCC Dacotah 388.0 15.8 199.2 431.0 45.2

39 0.6 9325 -1354245. 1417. 10313 72 0 49027 Cricket Mountain Plant 206.1 7.0 173.9 1.7 23.2 18.5 8.6

40 0.5 3387 -697446. 5119. 0820 003 10003 08059 TRIGEN - COLORADO ENERGY CORPORATION 185.3 0.8 84.2 247.6 2.2

41 0.9 5125 -1234508. 412961. 00500004 080 16005 Ash Grove Cement 396.6 10.2 515.0 11.2 34.3 7.3 1.5

42 0.4 5951 -499781. 470177.28.1121-02 11 46103 GCC Dacotah 140.3 3.8 125.1 23.9 6.8

43 0.4 12437 -1245947. 167466. 12096 954507 0 49035 I-15 CORRIDOR RECONSTRUCTION 140.0 12.6 55.9 11.8 11.5 11.5 0.0

44 0.4 12450 -1245947. 167466. 12096 954520 0 49035 I-15 CORRIDOR RECONSTRUCTION 138.3 11.2 29.8 9.1 9.8 9.8 0.0

45 0.4 12479 -1245947. 167466. 12096 954552 0 49035 I-15 CORRIDOR RECONSTRUCTION 134.8 10.9 29.1 8.9 9.6 9.6 0.0

46 0.3 21028 -658369. 149577.5602100002 675 0 56021 Cheyenne Nitrogenous Fertilizer Facility 119.9 0.0 0.0 0.0 0.0 0.0 0.0

47 0.3 5539 -1358824. 414676. 06700001 040 16067 TASCO, Paul 115.1 6.1 544.0 43.8 72.2 36.1

48 0.3 5538 -1358824. 414676. 06700001 030 16067 TASCO, Paul 102.8 4.6 401.7 33.1 90.8 44.6

49 0.3 12435 -1245947. 167466. 12096 954505 0 49035 I-15 CORRIDOR RECONSTRUCTION 99.1 4.6 42.7 10.8 6.1 6.1 0.0

50 0.2 5567 -1414379. 416258. 08300001 030 16083 TASCO, Twin Falls 74.0 5.7 260.0 25.0 30.0 15.0

51 0.2 12433 -1245947. 167466. 12096 954503 0 49035 I-15 CORRIDOR RECONSTRUCTION 68.4 9.0 20.7 6.6 6.2 6.2 0.0

52 0.1 21040 -658369. 149577.5602100002 687 0 56021 Cheyenne Nitrogenous Fertilizer Facility 52.8 2.6 1.9 3.0 0.9 0.0 0.0

53 0.1 21039 -658369. 149577.5602100002 686 0 56021 Cheyenne Nitrogenous Fertilizer Facility 48.2 3.1 2.6 3.0 1.1 0.0 0.0

54 0.1 21038 -658369. 149577.5602100002 685 0 56021 Cheyenne Nitrogenous Fertilizer Facility 45.7 1.9 0.5 0.2 0.7 0.0 0.0

55 0.2 9270 -1262203. 86989. 12524 965417 56102 49023 Pacificorp Currant Creek Power Plant 13.1 0.7 27.2 0.2 5.1 5.1 5.0

56 0.1 9195 -1289629. 59699. 10303 17008 0 49023 Leamington Cement Plant 38.1 2.8 38.1 0.1 3.6 3.6 0.0

57 0.1 21021 -658369. 149577.5602100002 667 0 56021 Cheyenne Nitrogenous Fertilizer Facility 35.4 3.8 58.3 0.4 1.3 0.0 0.0

Source Parameters Emissions (tons/year)
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-18

Table G-4 2005 oil and gas sources within the 12/4 km grid modeled with the CAMx Plume-in-Grid. Sources are ranked by their 

NOx emissions.

Table G-5 2005 trona sources within the 12/4 km grid modeled with the CAMx Plume-in-Grid. Sources are ranked by their NOx 

emissions.

Rank NOx (TPD) PT X Y PlantID StackID ORISID FIPS PLANT NOx VOC CO SO2 PM10 PM25 NH3

1 3.4 411 -645321 40225 123-0048 1 8123 KERR-MCGEE GATHERING LLC - HUDSON 1,247.1 64.6 209.4 0.2 17.1 17.1

2 2.9 2 -653901 -533 001-0036 1 8001 COLORADO INTERSTATE GAS CO WATKINS STA 1,062.5 102.1 281.3 0.5 8.4 8.4

3 2.2 631 -1269939. 421949. R10T5-ID-01-01 1 5001 Pocatello Compressor Station 785.1 21.9 115.2 1.3 1.7 0.0 0.0

4 2 1 -652351 -366 001-0025 1 8001 BP AMERICA PRODUCTION CO. WATTENBERG PLT 739.2 58.6 149.4 0.1 2.1 2.1

5 1.8 60 -610746 -19277 005-0055 1 8005 COLORADO INTERSTATE GAS CO LATIGO C & S 640.7 17.2 177.0 0.1 1.6 1.6

6 1.8 413 -651163 133421 123-0051 1 8123 COLORADO INTERSTATE GAS CO CHEYENNE STN 668.1 295.2 339.3 3.7 10.6 10.6

7 1.5 18 -1172147. 374572. 00700008 040 16007 Northwest Pipeline Soda Springs 560.4 20.4 122.3 0.1 0.0 0.0 0.0

8 1.3 145 -1083213 3451095603500004 2887 0 56035 Big Piney Compressor Station 481.8 19.0 34.6 0.0 0.0 0.0 0.0

9 1.2 275 -575438 42400 087-0003 1 8087 COLORADO INTERSTATE GAS CO FORT MORGAN 441.8 82.5 323.8 132.0 1.2 1.2

10 1.1 294 -993845 68874 103-0021 1 8103 NORTHWEST PIPELINE CORP RANGELY STA 383.4 14.5 46.7 0.1 4.6 4.6

11 1.1 446 -666557 35211 123-0184 1 8123 KERR-MCGEE FREDERICK COMPRESSOR STATION 392.6 98.3 202.6 0.2 11.2 11.2

12 1.1 436 -1166696 2082775604100006 1632 0 56041 Anschutz Ranch East 400.2 17.9 62.5 0.0 0.0 0.0 0.0

13 1.1 437 -1166668 2082905604100006 1641 0 56041 Anschutz Ranch East 390.4 18.3 126.2 0.0 0.0 0.0 0.0

14 1 171 -535652 95785 075-0029 1 8075 STERLING ENERGY CO. - YENTER C.S. & G.P. 376.5 27.6 89.3 0.1 1.2 1.2

15 0.5 15 -1172147. 374572. 00700008 010 16007 Northwest Pipeline Soda Springs 190.9 4.8 13.0 0.0 0.0 0.0 0.0

16 0.5 16 -1172147. 374572. 00700008 020 16007 Northwest Pipeline Soda Springs 192.8 4.8 15.0 0.0 0.0 0.0 0.0

17 0.5 17 -1172147. 374572. 00700008 030 16007 Northwest Pipeline Soda Springs 182.8 4.6 14.2 0.0 0.0 0.0 0.0

18 0.2 14 -1172147. 374572. 00700008 40 16007 Northwest Pipeline Soda Springs 73.2 6.9 41.2 0.0 0.0 0.0 0.0

Source Parameters Emissions (tons/year)

Rank NOx (TPD) PT X Y PlantID StackID ORISID FIPS PLANT NOx VOC CO SO2 PM10 PM25 NH3

1 5.7 304 -1056349 253483 5603700048 974 0 56037 Sodium Products 2,088.8 0.1 2.2 2,541.4 0.3 0.0 0.0

2 5.7 303 -1056349 253483 5603700048 973 0 56037 Sodium Products 2,087.1 0.1 2.1 2,463.4 0.4 0.0 0.0

3 4.5 126 -1052567 249905 5603700002 1201 0 56037 Green River Trona Plant 1,648.9 11.0 94.5 3,202.7 0.6 0.0 0.0

4 3 105 -1052567 249905 5603700002 1180 0 56037 Green River Trona Plant 1,096.6 6.9 59.4 2,013.7 0.3 0.0 0.0

5 1.5 139 -1053989 239839 5603700005 2434 0 56037 Green River Soda Ash Plant 547.1 2.1 52.6 42.1 0.0 0.0 0.0

6 1.5 140 -1053991 239827 5603700005 2435 0 56037 Green River Soda Ash Plant 535.4 2.1 52.2 25.0 0.0 0.0 0.0

7 0.2 111 -1052567 249905 5603700002 1186 0 56037 Green River Trona Plant 82.2 105.3 1,261.8 0.0 0.4 0.0 0.0

8 0.2 112 -1052567 249905 5603700002 1187 0 56037 Green River Trona Plant 81.0 103.8 2,439.8 0.0 0.2 0.0 0.0

9 0.2 324 -1056349 253483 5603700048 995 0 56037 Sodium Products 58.5 0.5 1.6 0.0 0.1 0.0 0.0

Source Parameters Emissions (tons/year)
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-19

Table G-6 2006 EGU Sources within the 12/4 km grid modeled with the CAMx Plume-in-Grid. Sources are ranked by their NOx 

emissions.

Rank NOx (TPD) PT X Y PlantID StackID ORISID FIPS PLANT NOx VOC CO SO2 PM10 PM25 NH3

1 86 201 -743950. 714784. EGU0727 0226 6076 30087 COLSTRIP STEAM ELECTRIC STATION 32,472.5 12,232.7

2 79.7 297 -1322699. 59547. EGU1222 202 6481 49027 Intermountain Generation Station 28,896.9 0.0 0.0 4,238.3 0.0 0.0 81.5

3 49.7 140 -891863. 107264. EGU0175 0222 6021 08081 TRI STATE GENERATION CRAIG 17,058.2 3,585.8 74.5

4 31.6 292 -1198431. 24452. EGU1221 212 8069 49015 Huntington Power Plant 11,130.4 0.0 0.0 17,395.4 0.0 0.0 0.0

5 31 290 -1198213. -1559. EGU1220 212 6165 49015 Hunter Power Plant 12,882.8 0.0 0.0 5,832.9 0.0 0.0 0.0

6 24.7 653 -970515. 255230.5603701002 2085 8066 56037 Jim Bridger Plant 8,073.1 79.3 685.0 5,950.3 647.8 647.8

7 21.4 651 -970515. 255230.5603701002 2062 8066 56037 Jim Bridger Plant 7,480.0 78.5 679.5 5,062.0 223.8 223.8

8 20.8 633 -646798. 261361.5603100001 225 6204 56031 Laramie River Station 6,900.2 71.0 591.6 4,481.6 198.7 198.7 35.6

9 19.8 632 -646798. 261361.5603100001 224 6204 56031 Laramie River Station 7,084.2 87.7 730.8 3,867.4 233.2 233.2 44.0

10 18.7 631 -646798. 261361.5603100001 213 6204 56031 Laramie River Station 5,796.8 82.4 686.1 3,190.1 142.3 142.3 41.3

11 17.5 21 -689997. 9568. EGU0163 0222 469 08001 PUBLIC SERVICE CO CHEROKEE PLT 5,900.0 4,806.2 16.8

12 17.4 654 -970515. 255230.5603701002 2086 8066 56037 Jim Bridger Plant 7,969.3 75.7 654.7 3,308.1 160.0 160.0

13 17 513 -1036751. 80250. EGU1224 202 7790 49047 BONANZA POWER PLANT 7,348.1 62.8 523.0 864.2 680.8 562.7 31.4

14 15.1 289 -1198213. -1559. EGU1220 202 6165 49015 Hunter Power Plant 5,946.1 0.0 0.0 1,505.4 0.0 0.0 0.0

15 15 620 -712198. 348399.5600900001 2040 4158 56009 Dave Johnston 6,277.6 50.8 423.4 5,457.1 949.8 949.8

16 13.2 624 -1118665. 278236.5602300004 2107 4162 56023 Naughton Plant 6,604.0 41.2 353.6 6,098.9 340.4 340.4

17 13.1 572 -665551. 505468.5600500046 2122 6101 56005 Wyodak Plant 3,854.6 51.0 425.7 6,513.9 1,403.2 1,403.2 0.5

18 12.8 22 -689997. 9568. EGU0163 0226 469 08001 PUBLIC SERVICE CO CHEROKEE PLT 4,033.1 2,308.9 14.9

19 11.7 652 -970515. 255230.5603701002 2076 8066 56037 Jim Bridger Plant 4,531.4 65.7 568.2 5,734.4 185.9 185.9

20 11 619 -712154. 348344.5600900001 2039 4158 56009 Dave Johnston 5,346.6 34.5 287.1 9,060.8 199.1 199.1

21 11 152 -563976. 46860. EGU0179 0222 6248 08087 PUBLIC SERVICE CO PAWNEE PLT 4,575.5 13,072.2 31.0

22 10.4 169 -856301. 102086. EGU0183 0222 525 08107 PUBLIC SERVICE CO HAYDEN PLT 3,531.5 1,056.5 11.3

23 10.1 623 -1118665. 278236.5602300004 2106 4162 56023 Naughton Plant 4,101.8 28.1 240.2 7,726.6 295.5 295.5

24 10 257 -1174662. 59571. EGU1218 212 3644 49007 Carbon Power Plant 3,703.1 0.0 0.0 6,778.6 0.0 0.0 0.0

25 9.4 622 -1118665. 278236.5602300004 2095 4162 56023 Naughton Plant 3,462.3 22.0 188.4 6,838.3 48.3 48.3

26 9.2 170 -856301. 102086. EGU0183 0226 525 08107 PUBLIC SERVICE CO HAYDEN PLT 4,154.2 1,599.1 15.8

27 7.7 39 -693836. 34254. EGU0164 0226 477 08013 PUBLIC SERVICE CO - VALMONT 2,300.9 748.0 8.3

28 6.8 613 -712096. 348278.5600900001 2025 4158 56009 Dave Johnston 2,428.1 18.0 149.9 3,895.1 289.6 289.6

29 6.4 618 -712125. 348311.5600900001 2038 4158 56009 Dave Johnston 2,404.8 17.6 147.3 3,937.8 45.8 45.8

30 5.9 214 -889488. 696596. EGU0728 0226 2187 30111 PPL MONTANA - JE CORETTE PLANT 1,918.3 3,473.3 10.8

31 5.5 117 -671031. 123737. EGU0173 0226 6761 08069 PLATTE RIVER POWER AUTHORITY - RAWHIDE 1,988.7 942.6 18.0

32 5.1 77 -680287. -6529. EGU0165 0222 465 08031 PUBLIC SERVICE CO - ARAPAHOE 2,827.6 2,493.5 9.8

33 4.5 601 -665477. 505749.5600590001 3149 0 56005 WYGEN 2 1,578.0 225.0 3,381.0 2,254.0 270.0 270.0 0.0

34 3.1 603 -658592. 434661.5600590002 3639 0 56005 Two Elk Facility 1,166.8 175.6 1,750.2 1,711.4 233.5 0.0 0.0

35 2.9 662 -591164. 463283.5604500005 398 0 56045 Osage 1,023.7 7.6 63.1 2,870.5 629.4 629.4

33 2.8 79 -680930. 986. EGU0166 0601 478 08031 Zuni 68.1 1.8 3.5

36 2.7 197 -821441. 687100.ORIS55749 STKDEF 55749 30003 HARDIN 3,293.0 67.5 562.7 315.5 36,392.0 9,493.6 33.8

37 2.6 226 -498985. 470013.28.0801-02 1 46103 Black Hill Power & Light Company (Ben Fr 907.7 3.3 126.9 785.0 30.4

38 2.1 576 -665602. 505182.5600500063 385 7504 56005 Neil Simpson Two 815.2 4.6 215.3 633.0 86.1 86.1 12.1

39 1.7 600 -665586. 505259.5600500146 3156 55479 56005 WYGEN Station 1 587.0 8.2 176.9 625.6 82.0 82.0 0.0

41 1.6 151 -564179. 47790. EGU0178 0201 55127 08087 MANCHIEF POWER COMPANY LLC 34.9 9.1 354.0 0.4 29.0 29.0 27.7

40 1.4 196 -834061. 655046. 003-0018 0 30003 HARDIN GENERATOR PROJECT 0.5 0.4

42 1.4 120 -573494. -66662. 0036 002 55504 08073 TRI-STATE GENERATION & TRANS - LIMON 4.4 4.1 0.6 1.0

42 1.3 468 -1245283. 187343. EGU1223 601 3648 49035 Gadsby Power Plant 43.7 0.0 0.0 0.3 0.0 0.0 0.0

41 1.1 131 -968076. -34362. EGU0174 0202 468 08077 PUBLIC SERVICE CO CAMEO PLT 650.7 1,899.1 3.1

41 1.1 192 -663958. 55844. EGU0186 0201 6112 08123 PUBLIC SERVICE CO FORT SAINT VRAIN PLT 391.6 9.7 121.3

42 0.7 203 -743950. 714784. EGU0727 0801 6076 30087 COLSTRIP STEAM ELECTRIC STATION 359.0 2,062.3

45 0.7 469 -1245283. 187343. EGU1223 604 3648 49035 Gadsby Power Plant 42.6 0.0 0.0 0.3 0.0 0.0 0.0

43 0.6 23 -689997. 9568. EGU0163 0601 469 08001 PUBLIC SERVICE CO CHEROKEE PLT 206.7 0.7 3.2

39 0.2 116 -671031. 123737. EGU0173 0201 6761 08069 PLATTE RIVER POWER AUTHORITY - RAWHIDE 7.4 0.1 1.1

44 0.2 24 -689997. 9568. EGU0163 0604 469 08001 PUBLIC SERVICE CO CHEROKEE PLT 63.5 0.2 1.4

41 0.1 153 -563976. 46860. EGU0179 0601 6248 08087 PUBLIC SERVICE CO PAWNEE PLT 27.2 0.3 0.8

43 0.1 78 -680287. -6529. EGU0165 0601 465 08031 PUBLIC SERVICE CO - ARAPAHOE 35.5 0.8 2.3

46 0.1 293 -1198431. 24452. EGU1221 501 8069 49015 Huntington Power Plant 25.4 0.0 0.0 2.0 0.0 0.0 0.0

Source Parameters Emissions (tons/year)
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-20

Table G-7 2006 non-EGU Sources within the 12/4 km grid modeled with the CAMx Plume-in-Grid. Sources are ranked by their 

NOx emissions.

Rank NOx (TPD) PT X Y PlantID StackID ORISID FIPS PLANT NOx VOC CO SO2 PM10 PM25 NH3

1 10.1 11167 -1267843. 164918. 10571 927593 49035 Mine & Copperton Concentrator 3,749.5 343.4 1,564.0 45.4 306.7 306.7

2 5.7 1334 -694677. 53910. 0003 007 08013 CEMEX, INC. - LYONS CEMENT PLANT 2,162.0 3.0 136.0 18.0 134.0

3 4.4 5410 -1183016. 392330. 02900001 010 16029 P4 Production LLC 1,625.5 110.2 8,551.8 48.2 37.9

4 3.7 9191 -1289629. 59699. 10303 1616 0 49023 Leamington Cement Plant 1,340.7 52.7 8,626.3 0.3 44.6 44.6 4.4

5 3.5 9516 -1207603. 213047. 10007 16758 0 49029 Devil's Slide Plant 1,293.7 46.8 768.8 228.5 14.7 4.6 4.1

6 3.5 9599 -1207603. 213047. 10007 948011 0 49029 Devil's Slide Plant 1,293.7 46.8 768.8 228.5 14.7 4.6 4.1

7 3.5 9624 -1207603. 213047. 10007 952430 0 49029 Devil's Slide Plant 1,293.7 46.8 768.8 228.5 14.7 4.6 4.1

8 3.4 15696 -714543. 173840.5600100002 1863 0 56001 Laramie Cement Plant 1,276.7 56.5 666.2 56.4 48.5 0.0 30.1

9 3 5949 -499781. 470177.28.1121-02 9 46103 GCC Dacotah 1,871.0 50.8 1,668.0 198.6 3.8

10 2.8 3390 -697446. 5119. 0820 006 10003 08059 TRIGEN - COLORADO ENERGY CORPORATION 1,005.1 5.2 43.0 1,947.5 17.4

11 2.8 9269 -1262203. 86989. 12524 965416 56102 49023 Pacificorp Currant Creek Power Plant 218.2 0.9 21.5 2.1 3.8 3.8 6.6

12 2.5 9327 -1354245. 1417. 10313 17059 0 49027 Cricket Mountain Plant 908.8 17.6 440.8 3.1 24.5 19.6 21.7

13 2.1 20996 -658369. 149577.5602100002 668 0 56021 Cheyenne Nitrogenous Fertilizer Facility 753.9 41.3 72.5 0.0 0.0 0.0 0.0

14 2 15690 -714543. 173840.5600100002 1856 0 56001 Laramie Cement Plant 736.9 22.2 179.3 35.5 20.8 0.0 0.9

15 1.8 20997 -658369. 149577.5602100002 669 0 56021 Cheyenne Nitrogenous Fertilizer Facility 643.0 35.4 72.4 0.0 0.0 0.0 0.0

16 1.7 5565 -1414379. 416258. 08300001 010 16083 TASCO, Twin Falls 606.1 2.4 173.0 717.0 44.8 22.3

17 1.6 11197 -1262021. 182635. 10572 1312 0 49035 Power Plt/ Lab/ Tailings Impoundment 573.8 2.3 28.9 711.7 8.3 4.4 0.1

18 1.6 11198 -1262021. 182635. 10572 1313 0 49035 Power Plt/ Lab/ Tailings Impoundment 573.8 2.3 28.9 711.7 8.3 4.4 0.1

19 1.5 3388 -697446. 5119. 0820 004 10003 08059 TRIGEN - COLORADO ENERGY CORPORATION 541.3 2.5 20.9 657.7 7.8

20 1.4 11201 -1262021. 182635. 10572 1316 0 49035 Power Plt/ Lab/ Tailings Impoundment 526.9 3.7 30.0 902.3 15.4 6.7 0.2

21 1.4 11202 -1262021. 182635. 10572 1317 0 49035 Power Plt/ Lab/ Tailings Impoundment 526.9 3.7 30.0 902.3 15.4 6.7 0.2

22 1.4 5566 -1414379. 416258. 08300001 020 16083 TASCO, Twin Falls 508.4 2.3 19.0 827.0 85.6 42.9

23 1.4 11195 -1262021. 182635. 10572 1310 0 49035 Power Plt/ Lab/ Tailings Impoundment 492.9 2.2 28.3 682.2 2.9 1.5 0.1

24 1.3 11196 -1262021. 182635. 10572 1311 0 49035 Power Plt/ Lab/ Tailings Impoundment 492.9 2.2 28.3 682.2 2.9 1.5 0.1

25 1.3 5537 -1358824. 414676. 06700001 020 16067 TASCO, Paul 473.0 1.7 169.0 189.0 119.5 59.4

26 1.3 5536 -1358824. 414676. 06700001 010 16067 TASCO, Paul 471.4 2.0 19.3 139.8 95.6 47.8

27 1.3 11199 -1262021. 182635. 10572 1314 0 49035 Power Plt/ Lab/ Tailings Impoundment 471.0 2.3 29.3 712.8 2.9 1.6 0.1

28 1.3 11200 -1262021. 182635. 10572 1315 0 49035 Power Plt/ Lab/ Tailings Impoundment 471.0 2.3 29.3 712.8 2.9 1.6 0.1

29 1.3 5973 -499542. 470162.28.1121-02 41 46103 GCC Dacotah 467.8 12.7 417.1 79.5 8.0

30 1.1 5943 -499781. 470177.28.1121-02 3 46103 GCC Dacotah 706.8 14.6 91.3 26.3 135.8

31 1.1 6817 -1137841. 33914. 10096 3236 50951 49007 Sunnyside Cogeneration Facility 387.3 12.2 116.1 931.7 38.7 38.7 0.2

32 1.3 9270 -1262203. 86989. 12524 965417 56102 49023 Pacificorp Currant Creek Power Plant 83.7 0.7 27.2 1.9 5.1 5.1 5.0

33 1.1 33 -674199. 7746. 0003 025 08001 SUNCOR ENERGY - DENVER REFINERY 389.9 409.8 422.2 315.7

34 1 9326 -1354245. 1417. 10313 73 0 49027 Cricket Mountain Plant 372.6 11.6 289.7 10.6 19.4 15.5 14.3

35 1.2 5126 -1234508. 412961. 00500004 090 16005 Ash Grove Cement 496.2 14.8 529.0 2.2 25.3 6.5 4.4

36 1 12441 -1245947. 167466. 12096 954511 0 49035 I-15 CORRIDOR RECONSTRUCTION 370.3 17.1 159.5 40.4 22.8 22.8 0.0

37 1.1 4841 -656837. 39181. 0250 001 08123 THERMO COGEN PARTNERSHIP FT LUPTON 350.0 36.9 371.1 5.5 54.5

38 1 22795 -1009636. 236437.5603700003 2021 0 56037 Rock Springs - Rotary Coking 394.3 2.3 10.5 705.6 56.5 0.0

39 1 9324 -1354245. 1417. 10313 71 0 49027 Cricket Mountain Plant 366.1 7.1 177.0 1.3 66.7 53.4 8.7

40 0.6 5944 -499781. 470177.28.1121-02 4 46103 GCC Dacotah 388.0 15.8 199.2 431.0 45.2

41 0.6 9325 -1354245. 1417. 10313 72 0 49027 Cricket Mountain Plant 206.1 7.0 173.9 1.7 23.2 18.5 8.6

42 0.5 21002 -658369. 149577.5602100002 675 0 56021 Cheyenne Nitrogenous Fertilizer Facility 187.7 0.0 0.0 0.0 0.0 0.0 0.0

43 0.5 3387 -697446. 5119. 0820 003 10003 08059 TRIGEN - COLORADO ENERGY CORPORATION 185.3 0.8 84.2 247.6 2.2

44 0.4 5951 -499781. 470177.28.1121-02 11 46103 GCC Dacotah 140.3 3.8 125.1 23.9 6.8

45 0.9 5125 -1234508. 412961. 00500004 080 16005 Ash Grove Cement 396.6 10.2 515.0 11.2 34.3 7.3 1.5

46 0.4 12437 -1245947. 167466. 12096 954507 0 49035 I-15 CORRIDOR RECONSTRUCTION 140.0 12.6 55.9 11.8 11.5 11.5 0.0

47 0.4 12450 -1245947. 167466. 12096 954520 0 49035 I-15 CORRIDOR RECONSTRUCTION 138.3 11.2 29.8 9.1 9.8 9.8 0.0

48 0.4 12479 -1245947. 167466. 12096 954552 0 49035 I-15 CORRIDOR RECONSTRUCTION 134.8 10.9 29.1 8.9 9.6 9.6 0.0

49 0.3 5539 -1358824. 414676. 06700001 040 16067 TASCO, Paul 115.1 6.1 544.0 43.8 72.2 36.1

50 0.3 5538 -1358824. 414676. 06700001 030 16067 TASCO, Paul 102.8 4.6 401.7 33.1 90.8 44.6

51 0.3 12435 -1245947. 167466. 12096 954505 0 49035 I-15 CORRIDOR RECONSTRUCTION 99.1 4.6 42.7 10.8 6.1 6.1 0.0

52 0.2 5567 -1414379. 416258. 08300001 030 16083 TASCO, Twin Falls 74.0 5.7 260.0 25.0 30.0 15.0

53 0.2 12433 -1245947. 167466. 12096 954503 0 49035 I-15 CORRIDOR RECONSTRUCTION 68.4 9.0 20.7 6.6 6.2 6.2 0.0

54 0.2 20995 -658369. 149577.5602100002 667 0 56021 Cheyenne Nitrogenous Fertilizer Facility 55.4 2.8 70.9 0.5 1.6 0.0 0.0

55 0.1 9195 -1289629. 59699. 10303 17008 0 49023 Leamington Cement Plant 38.1 2.8 38.1 0.1 3.6 3.6 0.0

Source Parameters Emissions (tons/year)
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-21

Table G-8 2006 oil and gas sources within the 12/4 km grid modeled with the CAMx Plume-in-Grid. Sources are ranked by their 

NOx emissions.

Table G-9 2006 trona sources within the 12/4 km grid modeled with the CAMx Plume-in-Grid. Sources are ranked by their NOx 

emissions.

Rank NOx (TPD) PT X Y PlantID StackID ORISID FIPS PLANT NOx VOC CO SO2 PM10 PM25 NH3

1 3.4 411 -645321 40225 123-0048 1 8123 KERR-MCGEE GATHERING LLC - HUDSON 64.6 1,247.1 209.4 0.2 17.1 17.1

2 2.9 2 -653901 -533 001-0036 1 8001 COLORADO INTERSTATE GAS CO WATKINS STA 102.1 1,062.5 281.3 0.5 8.4 8.4

3 2.2 631 -1269939 421949 R10T5-ID-01-01 1 5001 Pocatello Compressor Station 21.9 785.1 115.2 1.3 1.7 0.0 0.0

4 2 1 -652351 -366 001-0025 1 8001 BP AMERICA PRODUCTION CO. WATTENBERG PLT 58.6 739.2 149.4 0.1 2.1 2.1

5 2 222 -1083213 345109 5603500004 2887 0 56035 Big Piney Compressor Station 18.6 720.4 41.6 0.0

6 1.8 60 -610746 -19277 005-0055 1 8005 COLORADO INTERSTATE GAS CO LATIGO C & S 17.2 640.7 177.0 0.1 1.6 1.6

7 1.8 413 -651163 133421 123-0051 1 8123 COLORADO INTERSTATE GAS CO CHEYENNE STN 295.2 668.1 339.3 3.7 10.6 10.6

8 1.5 18 -1172147 374572 00700008 40 16007 Northwest Pipeline Soda Springs 6.9 73.2 41.2 0.0 0.0 0.0 0.0

9 1.2 275 -575438 42400 087-0003 1 8087 COLORADO INTERSTATE GAS CO FORT MORGAN 82.5 441.8 323.8 132.0 1.2 1.2

10 1.1 294 -993845 68874 103-0021 1 8103 NORTHWEST PIPELINE CORP RANGELY STA 14.5 383.4 46.7 0.1 4.6 4.6

11 1.1 446 -666557 35211 123-0184 1 8123 KERR-MCGEE FREDERICK COMPRESSOR STATION 98.3 392.6 202.6 0.2 11.2 11.2

12 1.1 394 -972459 216166 5603700008 163 0 56037 Brady Gas Plant 4.6 404.1 4.4 0.0 0.0

13 1 171 -535652 95785 075-0029 1 8075 STERLING ENERGY CO. - YENTER C.S. & G.P. 27.6 376.5 89.3 0.1 1.2 1.2

14 0.5 15 -1172147 374572 00700008 10 16007 Northwest Pipeline Soda Springs 1.6 24.9 4.4 0.0 0.0 0.0 0.0

15 0.5 16 -1172147 374572 00700008 20 16007 Northwest Pipeline Soda Springs 1.6 25.2 5.0 0.0 0.0 0.0 0.0

16 0.5 17 -1172147 374572 00700008 30 16007 Northwest Pipeline Soda Springs 1.5 23.9 4.8 0.0 0.0 0.0 0.0

17 0.2 14 -1172147 374572 00700008 40 16007 Northwest Pipeline Soda Springs 6.9 73.2 41.2 0.0 0.0 0.0 0.0

18 0.2 393 -972457 216175 5603700008 159 0 56037 Brady Gas Plant 3.9 87.9 12.0 0.0 0.0

Source Parameters Emissions (tons/year)

Rank NOx (TPD) PT X Y PlantID StackID ORISID FIPS PLANT NOx VOC CO SO2 PM10 PM25 NH3

1 5.4 305 -1056349 2534835603700048 974 0 56037 Sodium Products 1,985.5 0.1 126.8 2,475.9 0.4 0.0

2 5.4 304 -1056349 2534835603700048 973 0 56037 Sodium Products 1,983.9 0.1 121.1 2,399.9 0.4 0.0

3 4.4 126 -1052567 2499055603700002 1201 0 56037 Green River Trona Plant 1,617.8 11.0 95.1 3,349.3 0.1 0.0

4 2.9 105 -1052567 2499055603700002 1180 0 56037 Green River Trona Plant 1,075.9 6.9 59.8 2,105.9 0.5 0.0

5 2 252 -1062920 2604985603700010 1004 0 56037 Soda Ash Facility - Granger 713.1 3.4 965.1 156.7 3.0 0.0

6 1.4 139 -1053989 2398395603700005 2434 0 56037 Green River Soda Ash Plant 508.6 2.1 49.2 39.6 0.0 0.0 0.0

7 1.4 140 -1053991 2398275603700005 2435 0 56037 Green River Soda Ash Plant 497.7 2.1 48.8 23.5 0.0 0.0 0.0

8 0.2 111 -1052567 2499055603700002 1186 0 56037 Green River Trona Plant 80.7 105.6 1,270.3 0.0 0.3 0.0

9 0.2 112 -1052567 2499055603700002 1187 0 56037 Green River Trona Plant 79.5 104.1 2,456.2 0.0 0.2 0.0

10 0.2 325 -1056349 2534835603700048 995 0 56037 Sodium Products 55.6 0.0 92.2 0.0 2.3 0.0

Source Parameters Emissions (tons/year)
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-22

SMOKE AREA AND NON-ROAD MOBILE SOURCE EMISSIONS MODELING

This category comprises stationary sources that are not identified as individual points and so 

are treated as being spread over a spatial extent (usually a county). Examples of stationary area 

sources include (but are not limited to) residential emissions, fugitive dust, and road dust. 

Although oil and gas exploration and production sources are often included as part of an area 

source inventory, they are treated as a separate source category in this study. The 2005 and 

2006 base year emissions were projected from the 2002 WRAP Plan D inventory. The 2008 

baseline emissions were interpolated from the 2002 WRAP Plan D and 2018 WRAP PRP18b 

inventories. The emissions team considered updating 2006 Colorado emissions with the 

Colorado Department of Public Health and Environment (CDPHE) Air Pollution Control Division 

(APCD) emissions inventory used in the Denver 8-hour ozone SIP Modeling. However, the 

purpose of the database was mainly to serve ozone modeling in summer period, thus wintertime sources and particulate matter emissions were not well characterized. Thus, the 

CDPHE/APCD data were not used in this study.

All area (except oil and gas production) source emissions were temporally allocated to a specific 

month, day, and hour using their annual emissions and allocation factors based on their source 

category code (SCC). These factors were based on the cross-reference and profile data supplied 

with the WRAP SMOKE setup. Area sources were spatially allocated in the domain using SCCbased spatial allocation factor files. If an area source SCC did not have an existing crossreference profile assigned to it, the county-level emissions were allocated by population density 

in that county.

A crustal PM transport factor has been applied to fugitive dust emission sources that have been 

identified in U.S. EPA modeling to have only a portion of their mass transported from the 

source of the emission generation. The EPA’s studies (Pace, 2003; 2005) indicate that 60 to 90 

percent of PM emissions from fugitive dust sources do not reach an elevated level necessary for 

transport and are deposited near the source. For this reason, the county-specific fugitive dust 

emissions transport factors have been applied to these sources to adjust PM emissions prior to 

the SMOKE modeling. This procedure is consistent with the WRAP fugitive dust inventory. 

Off-road mobile sources include, for example, railroad locomotives, aircraft, commercial marine 

vessels, farm equipment, recreational boating, and lawn and garden equipment. The 2005 and 

2006 base year emissions were projected from the WRAP 2002. The off-road mobile source 

emissions were temporally and spatially allocated in the same manner as the area source 

emissions. 

The marine shipping emissions were held constant from WRAP 2002 inventory, which was 

estimated using the Waterway Network Ship Traffic, Energy and Environment Model (STEEM) 

to characterize ship traffic, estimate energy use and assess the environmental impacts of 

shipping (Corbett et al., 2006). 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-23

SMOKE ON-ROAD MOBILE SOURCE EMISSIONS MODELING

This category comprises vehicular sources that operate on roadways such as light-duty gasoline 

vehicles and heavy-duty diesel vehicles. The MOBILE6 module of SMOKE was used to develop 

the on-road mobile source emissions. The MOBILE6 parameters, vehicle fleet descriptions, and 

vehicle miles of travel (VMT) estimates were combined with gridded, episode-specific 

temperature data to obtain the gridded, temporally allocated emission estimates for weekday, 

Saturday, and Sunday for the 2005 and 2006 base years. For the 2008 baseline year, 2005 and 

2006 meteorology were used to develop two years of on-road mobile inputs for the 2008 

emissions year.

The MOBILE6 emissions factors were based on episode-specific monthly average temperatures 

for each hour predicted by the MM5 meteorological model. Further, the MOBILE6 emissions 

factor model accounts for the following:

 Hourly and daily minimum/maximum temperatures;

 Vehicle speeds;

 Locale-specific inspection/maintenance (I/M) control programs, if any;

 Adjustments for running losses;

 Splitting of evaporative and exhaust emissions into separate source categories; 

 VMT, fleet turnover, and changes in fuel composition and Reid vapor pressure (RVP).

The MOBILE6 input file identifies the various options (e.g. type of inspection and maintenance 

program in effect, type of oxygenated fuel program in effect, alternative vehicle mix profiles, 

RVP of in-use fuel, operating mode) that direct the calculation of the MOBILE6 emissions 

factors for each county. Within Colorado, the MOBILE6 inputs for Colorado were obtained from 

the mobile source inventory of the Denver 2006 8-hour ozone SIP modeling. The data set was 

based on the CDPHE estimates of VMT for 2006, divided by county, vehicle type and roadway 

type. Also provided by CDPHE were average speeds estimated by county and roadway, and 

fleet information parameters (such as I/M and fuel programs) required as input into MOBILE6. 

To model the states outside of Colorado, the VISTAS/WRAP 2002 and 2009 inventories were 

used as a basis for VMT and activity data estimates. The 2005, 2006, and 2008 county VMT 

totals were interpolated from the 2002 and 2009 VMT estimates, and the MOBILE6 inputs were 

adjusted to reflect 2005, 2006 and 2008 conditions. 

BIOGENIC SOURCE EMISSIONS MODELING

Biogenic emissions were modeled using the Model of Emissions of Gases and Aerosols from 

Nature (MEGAN) version 2.03 with modifications made by ENVIRON (Guenther et al, 2006; 

Guenther and Wiedinmyer, 2007; Mansell et al, 2007). MEGAN was used to prepare gridded 

hourly biogenic emissions inventories suitable for input to CAMx. MEGAN is the latest biogenic 

emissions model developed by researchers from the National Center for Atmospheric Research 

(NCAR) and incorporates the full range of ozone and PM precursor species. MEGAN accounts 

for the spatial variability of biogenic emissions through the use of high resolution estimates of 

vegetation type and quantity. MEGAN requires as input weather data, Leaf Area Index (LAI), 

plant functional type (PFT) cover and compound-specific emission factors that are based on 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-24

plant species composition. All of these variables are provided in a geo-referenced gridded 

database in several formats (e.g., netcdf, ESRI GRID). The inputs to MEGAN model are:

 Landcover: The land cover available in MEGAN database has global coverage at 30 sec (~ 

1km) spatial resolution (Guenther et al, 2006). 

 Surface Temperature Data: Gridded, hourly temperature fields were extracted from MM5 

predictions for each day for each grid cell.

 Photosynthetically active radiation (PAR): The PAR data represents the intensity of solar 

radiation in the spectral range that is used by plants for the photosynthesis process. The 

PAR data were downloaded from the University of Maryland (UMD; 2006) and a FORTRAN 

program was used to reformat the data. Some of the PAR data were missing. As part of 

the QA process, the PAR data were inspected, and the missing data were replaced by 

interpolating the missing data between hours with available data. 

Day-specific hourly biogenic emissions were generated for all grid domains for the 2005 and 

2006 base years. The 2005 and 2006 biogenic emissions will be used for the 2008 baseline 

modeling for the 2005 and 2006 meteorological years, respectively.

SMOKE WILDFIRES AND PRESCRIBED BURNS EMISSIONS MODELING

Wildfire and prescribed burn emissions were handled separately from the standard area source 

input files. For the 2005 and 2006 calendar years, ENVIRON has received estimates of fire 

emissions from the National Center for Atmospheric Research (NCAR). These emission 

estimates are derived from analysis of fire locations determined by satellite-borne detectors. 

The MODerate-resolution Imaging Spectroradiometer (MODIS) instruments fly aboard two 

polar-orbiting satellites, Terra, and Aqua. These two satellites orbit the Earth, traveling from 

pole to pole while the earth rotates beneath them; a given area of the Earth will have an 

overpass from Terra and Aqua approximately twice a day. MODIS instruments detect fires as 

thermal anomalies (i.e. hot spots seen against a cooler background) at a spatial resolution of 

about 1 kilometer. Fire emissions derived from the MODIS data include NOx, CO, VOC and PM 

species, along with other compounds (e.g., Hg). The NCAR fire emissions inventory 

development is described by Wiedinmyer and co-workers (2006) and Friedli and Wiedinmyer 

(2008). 

The NCAR satellite-derived fire emissions data for 2005 and 2006 contain daily emissions 

location, acreage burned, and fuel loading at a resolution of 1 km2, representing the size of 

each satellite pixel. SMOKE does not have the capability to handle this type of inventory; 

therefore, the fire inventory was processed using the Emissions Processing System version 3 

(EPS3). Similar to SMOKE, the EPS model can perform the intensive data manipulations 

required to incorporate spatial, temporal, and chemical resolution into an emissions inventory 

used for photochemical modeling. Two new EPS modules, PREFIR and PSTFIR, were recently 

developed specifically to handle point source fire emissions. These new modules allow EPS to 

treat fire emissions from many data sources including satellite-derived fire emissions and fire 

inventories from RPO databases. ENVIRON recently conducted fire emissions modeling for the 

Texas Commission on Environmental Quality (TCEQ) (Tai et al., 2008). The EPS configuration 

from the TCEQ modeling was used for fire processing in this study. 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-25

Each fire record was treated as a point source and emissions were distributed vertically into 

multiple model layers to better represent each fire plume. A plume profile was calculated for 

each point in order to distribute the emissions vertically using the methodology outlined in the 

WRAP 2002 Phase II report (WRAP, 2005). In the WRAP algorithm, fires are assigned to one of 

five fire size classes. Three plume parameters – the top and bottom of the plume and the 

fraction of emissions in layer 1 – are computed from tables of buoyancy efficiencies and 

maximum top and bottom plume heights, which are functions of the fire size class and/or hour 

of the day. 

The diurnal profiles, parameters, and equations needed to compute the plume attributes were 

obtained from the WRAP report and were incorporated into the PSTFIR routine in EPS3. The 

only variable not directly available from the NCAR dataset and required by EPS3 was the fire 

size.

In the WRAP report, fire sizes were classed in terms of virtual acres, which are estimated using 

the equation below:

Acreagevirtual = Acreageactual * 

FuelLoading / Normalizer

WRAP normalized wildfires to 13.8 tons per acre (tpa) and prescribed fires to 5.0 tpa. The five 

fire classes are shown in Table G-10. Because it is not possible to determine from the NCAR 

satellite data whether a particular fire is a wildfire or a prescribed burn, all points were 

conservatively treated as wildfires. Any point within 5 km of another point was assumed to be 

part of the same fire event. The virtual area for each fire event was set to the sum of the virtual 

areas from the cluster of points defining the fire event. 

Table G-10 Fire Classes used by WRAP.

Fire Class MinVirtual Area [acres] Max Virtual Area [acres]

1 >= 0 <10

2 10 100

3 100 1000

4 1000 5000

5 5000

The chemical speciation profile used in this task (shown in Table G-11) was derived from a 

recent study on tropical biomass burning (Karl et al., 2007). The study integrated laboratory 

experiments and field measurements conducted as part of the TROFFEE (Tropical Fire and 

Forest Emissions Experiment) campaign. The combination of laboratory and field 

measurements makes it possible to report many compounds previously not quantified in the 

field and therefore not included in previous studies
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-26

Table G-11 Chemical Speciation Profile used to Convert TOG to CB05 Species for Fire 

Emissions.

Criteria Pollutant CB05 Species Split Factor Divisor [mol/g] # Carbons

TOG ALD2 0.1519 43.5932 2

TOG ALDX 0.0622 37.1144 2

TOG FORM 0.0619 29.2445 1

TOG ISOP 0.024 68.117 5

TOG MEOH 0.1766 32.0419 1

TOG OLE 0.0383 36.9936 2

TOG PAR 0.2334 22.0391 1

TOG TOL 0.0285 92.2464 7

TOG UNR 0.2091 22.8743 1

TOG XYL 0.014 106.165 8

The NCAR fire emissions were reformatted into the EPS3 input format for point source fires and 

CAMx-ready hourly fire emissions were generated for each simulation day.

Fire emission totals for 2005 and 2006 for the 12 km domain for PM2.5 and NOx are shown in 

Figures G-12 and G-13. The Figures are derived directly from the raw NCAR fire emissions 

dataset. There were more emissions from fires in 2006 than in 2005, and this is reflected in the 

fire emissions totals for the two years in Tables G-12 through G-15 below. The 2005 and 2006 

fire emissions will be used for the 2008 baseline modeling for the 2005 and 2006 

meteorological years, respectively.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-27

Figure G-12 Comparison of 2005 and 2006 PM2.5 fire emissions within the 12/4 km domain.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-28

Figure G-13 Comparison of 2005 and 2006 NOx fire emissions within the 12/4 km domain.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-29

SMOKE OIL AND GAS EMISSIONS MODELING

Oil and gas sources are a critical part of the CD-C regional emissions inventory. In this section, 

we discuss the three O&G emissions inventories that were used across different regions in the 

modeling domain. These are the Carter Lake/BP 2005-6 inventory for southwest Wyoming, the 

Carter Lake 2008 inventory for southwest Wyoming and the WRAP Phase II and Phase III oil and 

gas inventories. 

Carter Lake/BP 2005-6 Emission Inventory for Southwest Wyoming

Carter Lake and BP have compiled a detailed and comprehensive emissions inventory of O&G 

sources in Southwest Wyoming for the years 2005 and 2006. Based on field data and well data 

from the WYOGCC, this inventory includes emissions from drill rigs, well venting, flashing, 

fugitives, construction and production truck traffic, and well site production equipment such as 

dehydrators, heaters, and pumps. Carter Lake/BP provided the following description of the 

drill rig and truck traffic emission inventory methods to CD-C stakeholders on June 27, 2008:

Monthly drill rig emissions (NOx, CO, VOC, SO2, and PM10) were developed for all drill rigs that 

operated during 2005 and 2006 in Carbon, Lincoln, Sublette, Sweetwater and Uinta Counties. 

Monthly drill rig emissions were computed from hourly emissions and well drilling durations. 

Emissions were allocated to the corresponding latitude and longitude coordinates of each drill 

rig that operated for at least one hour during the month.

Well spud date and well depth data were obtained from the WOGCC for all wells drilled in 

Carbon, Lincoln, Sublette, Sweetwater and Uinta Counties beginning in November 2004 though 

December 2006.

BP drill rig summary data for BP rigs in the CDC field during 2005 and 2006 were used for drill 

rig emissions and drilling durations for all BP drill rigs within the CDC field. BP data for well 

completion/well fracing emissions were added to each drilling event. The well completion 

events were assumed to last 24 hours. Monthly emissions were developed for each drill rig 

that operated during the month. Average drilling rates (ft/hour) and emissions (lbs/hour) were 

determined from the BP CDC drill rig summary data.

For other operators within the CDC project area, Carbon County, Sweetwater County, Lincoln 

County, Uinta County, and all of Sublette County with the exception of Jonah Field and the 

Pinedale Anticline Project Area, the basis for calculating the rig emissions is BP’s CDC drill rig 

summary data. Well depth data and well spud date data from the WOGCC combined with BP 

average drilling rate information were used to estimate a drilling duration for each well. 

Average hourly emissions were applied to each hour over the drilling duration. 24 hours of well 

completion emissions were added to each drilling event. Monthly emissions were developed 

for each drill rig that operated during the month.

For Jonah Field, well depth data and well spud data from the WOGCC combined with BP 

average drilling rate information for wells in the Jonah Field were used to estimate a drilling 

duration for each well. WDEQ provided individual well drilling emissions for 2005 and 2006 

were applied to each well for all hours over each drilling event. Data for well completion 

emissions obtained from the WDEQ 2007 Ozone Study - Upper Green River Basin emissions 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-30

inventory were added to each drilling event. The well completion events were assumed to last 

96 hours. Monthly emissions were developed for each drill rig that operated during the month.

For the Pinedale Anticline Field, WDEQ provided individual well drilling emissions for 2005 and 

2006 were used in combination with WOGCC well spud date data and an assumed 45 day well 

drilling duration to develop hourly well drilling emission events. Data for well completion 

emissions obtained from the WDEQ 2007 Ozone Study - Upper Green River Basin emission 

inventory were added to each drilling event. The well completion events were assumed to last 

96 hours. Monthly emissions were developed for each drill rig that operated during the month.

WDEQ requested revisions to the original Carter Lake/BP well VOC emissions inventory that 

increased the field-wide VOC emissions for both fields by approximately 3%. The additional 

VOC emissions are due to adjustments to working/breathing losses from well site tanks and 

dehydration. Carter Lake/BP has revised the VOC emissions and has submitted the updated 

emissions inventories to WDEQ for review. 

Truck traffic emissions (NOx, CO, VOC, SO2, and PM10) associated with 2005 and 2006 well 

production activities were developed for each production well in Carbon, Lincoln, Sublette, 

Sweetwater, and Uinta Counties. Per well annual production truck traffic emissions were 

computed using the 2005 Pinedale Anticline emissions inventory obtained from the Pinedale 

Revised Draft Supplemental EIS.

Monthly truck traffic emissions (NOx, CO, VOC, SO2, and PM10) were developed for all wells that 

were constructed during 2005 and 2006 in Carbon, Lincoln, Sublette, Sweetwater and Uinta 

Counties. The methodology used for computing drill rig emissions was applied to estimate 

construction traffic emissions. Monthly construction traffic emissions were computed from 

hourly emissions that were based on well pad construction, well drilling duration, and well 

completion assumptions. Emissions were allocated to the latitude and longitude coordinates of 

the drill rigs.

Well spud date data obtained from the WOGCC, for all wells drilled in Carbon, Lincoln, Sublette, 

Sweetwater and Uinta Counties beginning in November 2004 though December 2006, and used 

for computing drill rig emissions were used as a basis for calculating construction traffic 

emissions.

Per well, construction traffic emissions data were obtained from the Pinedale Anticline SDEIS 

and Jonah EIS emissions inventories. Hourly emissions were calculated and assigned to drill rig 

locations. 

There are three phases of well construction traffic emissions; 1) Well pad and access road 

construction, 2) drilling traffic, and 3) rig move and completion traffic. 

1. For wells in the Pinedale Anticline, well pad and access road construction was estimated 

to occur for 16 days. Well pad and access road construction for wells in the Jonah Field 

was estimated to occur for 4 days. Well pad and access road construction hourly 

emissions for wells in the Pinedale Anticline were assigned to corresponding drill rig 

locations for the 16 days prior to the well spud date. For Jonah Field wells, well pad and 

access road construction hourly emissions were applied for the 4 days prior to the well 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-31

spud date. The Jonah Field emissions assumption was used for all other wells in 

Sublette County, and for all wells in Carbon, Lincoln, Sweetwater and Uinta Counties.

2. For all counties, hourly emissions for drilling haul trucks were applied for all hours when 

drilling occurs.

3. For all counties, rig move and completion traffic emissions were added for 10 days after 

drilling was completed.

Spatial surrogates were not required to process the Carter Lake/BP southwest Wyoming 

emissions, as the wells were modeled as point sources and the latitude and longitudes of the 

wells were compiled as part of the inventory development. Emissions from drill rigs, 

completion, and traffic as well as production emissions were all modeled as point sources sited 

at the well location. Maps of production well and drill rig locations are shown in 2005 and 2006 

are shown in Figures G-14-G-17.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-32

Figure G-14 2005 drill rig locations in Southwest Wyoming.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-33

Figure G-15 2006 drill rig locations in Southwest Wyoming.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-34

Figure G-16 Map of 2005 production well locations within Southwest Wyoming.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-35

Figure G-17 Map of 2006 production well locations within Southwest Wyoming.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-36

WRAP Phase II Emissions Inventory

Beginning in 2005, the Western States Regional Air Partnership initiated a series of projects to 

develop a regionally consistent emissions inventory of oil and gas exploration and production 

activities for all of the western U.S. states. The first of these projects, the Phase I inventory, 

completed in 2005, represented the first regional oil and gas emissions inventory for the 

western U.S (Russell and Pollack, 2005). This was followed by the Phase II inventory (Bar-Ilan et 

al., 2007), which focused on improving emissions estimates of drilling rigs and compressors 

from those in the Phase I work. Both the Phase I and Phase II inventories were focused on 

estimating oil and gas NOx and SOx emissions for regional haze modeling purposes. Final 

reports of the Phase I and Phase II inventories are available on the WRAP web page at 

http://www.wrapair.org/forums/ssjf/documents/eictts/oilgas.html. 

The WRAP Phase II O&G emissions inventory, which is being used in the Regional Haze SIP 

modeling, is available for all basins in the western U.S. Because the emphasis of the WRAP 

Phase II O&G emissions inventory development was on visibility impairment precursors the 

inventory was focused on SOx, NOx and PM emissions. The WRAP Phase II O&G emissions 

inventory is known to be deficient in VOC emissions as O&G VOC emissions are not significant 

contributors to visibility impairment, but are critically important contributors to ozone 

formation. The understated VOCs in the WRAP Phase II inventory could potentially cause CAMx 

to underestimate ozone concentrations. The WRAP Phase II emissions are, however the best 

source of O&G emissions information away from the Carter Lake/BP Southwest Wyoming and 

WRAP Phase III inventory regions, and the WRAP Phase III inventory will not be completed in 

time for the CD-C modeling for regions outside the Piceance, Uinta and Denver-Julesburg 

Basins. ENVIRON suspects that using the WRAP Phase II inventory in areas of Wyoming that are 

predominately downwind of the Wind River Range will not significantly affect ozone upwind in 

Southwest Wyoming. For the 2008 baseline modeling, oil and gas emissions data were 

available as part of the Wyoming 2008 point source emission inventory, and the use of the 

WRAP Phase II inventory was not required within Wyoming.

WRAP Phase III Emissions Inventory

The WRAP Phase III work, which is currently in progress, will expand on the work done under 

WRAP Phase II, and will address the limitations of its VOC inventory. A comprehensive 2006 

inventory of emissions from oil and gas sources is under development for the following basins 

(Figure G-18):

 Denver-Julesburg Basin

 Uinta Basin

 San Juan Basin (North and South)

 Piceance Basin 

 Southwest Wyoming Basin (Green River Basin)

 Powder River Basin

 Paradox Basin

 Williston Basin

 Wind River Basin

 North-Central Montana Basin (Great Plains Basin)
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-37

This list includes all of the major basins of significant oil and gas activity in New Mexico, Utah, 

Colorado, Wyoming, Montana and North Dakota. Note that the Big Horn Basin was originally 

slated for inventory development, but was removed from the list because of lack of producer 

response to the WRAP Phase III survey and the fact that the Basin has relatively little 

production compared to surrounding basins.

Figure G-18 Basins to be covered by the WRAP Phase III O&G Emissions Inventory.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-38

The Phase III inventory is being assembled by combining data on permitted sources from states’ 

permit databases, and data on unpermitted sources obtained from industry surveys. These 

surveys request information on typical equipment types, counts, configurations, annual activity 

levels, controls, and emissions factors. The IHS database is used to determine oil and gas 

production statistics, which are used to combine these two groups of source categories to 

generate a complete basin-wide emissions inventory. The IHS database (also known as the P.I. 

Dwight database) is a high-quality commercially available database of oil and gas statistics for 

all of the United States and is maintained by IHS Corporation.

To date, the 2006 WRAP Phase III emissions inventories for the Denver-Julesburg, Uinta, and 

Piceance Basins are complete, and this data was incorporated into the CD-C O&G emissions 

inventory. The 2006 Phase III data were used for the year 2005.

Processing of Oil and Gas Emissions within SMOKE

The SMOKE emissions model has been used to model the NOx, VOC, CO and PM emissions for 

Oil and Gas sources. O&G productions emissions were modeled as either point or area sources 

depending on how they are provided in the base emission inventories. All Wyoming oil and gas 

sources were modeled as point sources; this includes compressor engines, production sites, 

drill rigs, and gas plant and compressor station sources. In Colorado (i.e. Piceance & DJ Basins) -

small compressor engines, compressor station and gas plants were included in the point source 

inventory (and therefore modeled as point sources) because of Colorado’s requirement that 

sources with NOx emissions greater than 2 tons/year report emissions to the state. In Utah 

(Uinta Basin), compressor station and gas plants were included in the point inventory. The rest 

were included in the area inventory and were modeled as area sources. 

Basin- and process-specific VOC speciation profiles derived from gas composition analyses from 

each basin were, rather than the SMOKE default VOC speciation that is cross-referenced by SCC 

category. No spatial surrogate is required to process the Carter Lake/BP southwest Wyoming 

emissions, as the wells are modeled as point sources and the latitude and longitudes of the 

wells were compiled as part of the inventory development. For Colorado and Utah, the WRAP 

Phase III emissions for the Uinta, Denver-Julesburg, and Piceance Basins were used. These 

emissions are calculated on a basin-wide basis, and were treated as area sources. The locations 

of wells within these three basins were used to develop a surrogate for the spatial allocation of 

emissions. For all other basins, the WRAP Phase II O&G emissions inventory was used. 

Tables G-12 through G-15 show the SW Wyoming emission inventory in terms of the relevant 

species used in the Carbon Bond 05 (CB05; Yarwood et al., 2005) chemical mechanism for 

methane (CH4), ethane (ETHA), and VOC (CB05 VOC). Ethane is treated as explicit species in 

the CB05 mechanism, whereas methane is assumed to have a constant background of 1.7 ppm 

in the CB05 chemical mechanism as implemented in CAMx and CMAQ. Tables G-12 and G-14 

show the input NOx, PM2.5, SO2, and VOC for 2005 and 2006 respectively for each source 

category of the southwest Wyoming oil and gas emission inventory. Tables G-13 and G-15 

show the 2005 and 2006 SMOKE output species once the speciation into CB05 species has been 

performed. Inspection of Tables G-12 through G-15 shows that the output VOC mass emissions 

after speciation are close but do not exactly match the input VOC mass emissions. The output 

VOC mass emissions after speciation are not expected to match the input VOC mass emissions; 

an explanation for this is provided below.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-39

Table G-12 2005 SMOKE Inputs.

Table G-13 2005 SMOKE Outputs.

Source 

County Category CO NOx PM2.5 SO2 VOC

Carbon County Compression 574 1,111 1 0 218

Production 160 423 31 6 20,982

Spud 63 447 42 7 24

Lincoln County Compression 880 2,047 13 135 208

Production 3,433 657 32 2,169 22,087

Spud 47 361 35 5 16

Sublette County Compression 812 1,564 0 0 784

Production 421 758 67 8 27,079

Spud 2,035 4,163 137 369 261

Sweetwater County Compression 2,126 2,712 0 0 672

Production 364 889 63 185 46,726

Spud 112 787 77 11 31

Uinta County Compression 705 1,414 0 0 205

Production 1,076 314 15 4,736 6,532

Spud 17 51 5 2 2

Grand Total 12,826 17,699 517 7,632 125,826

Emissions (Tons/Year) Source 

County Category CO NOx PM2.5 SO2 CB05 VOC CH4 ETHA

Carbon County Compression 574 1,110 1 0 216 1,609 300

Production 158 413 31 6 22,969 75,787 12,559

Spud 62 446 38 7 28 3 1

Lincoln County Compression 880 2,047 12 135 182 1,269 213

Production 3,403 640 31 2,168 24,095 108,675 14,787

Spud 48 361 32 5 18 2 0

Sublette County Compression 812 1,561 0 0 836 6,439 1,256

Production 410 761 64 7 29,596 122,723 16,054

Spud 2,036 4,165 124 369 304 35 9

Sweetwater County Compression 2,124 2,707 0 0 712 5,477 1,061

Production 355 879 62 184 52,999 196,162 29,193

Spud 111 786 70 11 36 4 1

Uinta County Compression 705 1,414 0 0 193 1,396 250

Production 1,069 311 13 4,735 7,182 30,640 4,282

Spud 8 61 5 1 3 0 0

Grand Total 12,754 17,662 483 7,629 139,369 550,222 79,965

Emissions (Tons/Year)
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-40

Table G-14 2006 SMOKE Inputs.

Table G-15 2006 SMOKE Outputs.

Source 

County Category CO NOx PM2.5 SO2 VOC

Carbon County Compression 1,128 2,092 1 0 559

Production 192 485 35 7 23,562

Spud 73 612 56 9 34

Lincoln County Compression 682 2,010 46 129 148

Production 701 691 43 2,080 23,185

Spud 44 331 32 5 14

Sublette County Compression 1,094 2,300 0 2 725

Production 484 912 79 11 26,413

Spud 1,946 4,036 133 250 253

Sweetwater County Compression 2,620 4,361 0 0 819

Production 396 1,084 67 122 49,240

Spud 106 820 81 12 32

Uinta County Compression 519 702 0 0 175

Production 1,152 417 14 2,470 6,529

Spud 11 82 8 1 4

Grand Total 11,149 20,935 595 5,099 131,692

Emissions (Tons/Year) Source 

County Category CO NOx PM2.5 SO2 CB05 VOC CH4 ETHA

Carbon County Compression 1,129 2,094 1 0 574 4,345 827

Production 184 473 35 7 26,028 84,877 13,680

Spud 73 614 51 9 40 5 1

Lincoln County Compression 683 2,010 41 130 148 1,110 207

Production 677 673 39 2,080 25,348 113,693 15,450

Spud 44 332 29 5 17 2 0

Sublette County Compression 1,092 2,299 0 2 773 5,952 1,161

Production 469 908 76 10 28,890 127,490 16,514

Spud 1,945 4,035 121 250 294 34 9

Sweetwater County Compression 2,620 4,356 0 0 871 6,682 1,300

Production 388 1,073 64 121 56,251 210,547 31,474

Spud 107 820 73 12 37 4 1

Uinta County Compression 519 701 0 0 180 1,365 260

Production 1,144 413 13 2,469 7,186 30,902 4,304

Spud 11 81 7 1 4 0 0

Grand Total 11,084 20,882 550 5,096 146,642 587,007 85,189

Emissions (Tons/Year)
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-41

O&G VOC emission estimates for southwest Wyoming for each region and source category 

were provided by the Carter Lake/BP emission inventory. These emission estimates for total 

VOC were converted to the more detailed chemical speciation used by the CB05 chemical 

mechanism in CAMx. For each VOC emissions source, a speciation profile code based on the 

emissions source category determines the "split factors" for that particular profile. The split 

factors are multiplicative factors for converting grams of criteria pollutant (e.g. VOC) emissions 

into moles of CB05 species. For example, in Appendix C, Table C.3, the JON06 profile gives the 

split factors required to take VOC emissions from well venting in the Jonah field and speciate 

the emissions into moles of CB05 species that can then be used by the chemical mechanism in 

CAMx. Note that the speciation of VOC to CB05 species conserves moles of material. An 

example of how split factors are derived from data specifying the composition of a hydrocarbon 

mixture (e.g. a gas composition analysis) is given below. 

A given organic compound is assigned to CB05 model species based on its carbon bond 

structure. This is in contrast to a lumped species approach (e.g., SAPRC99) whereby VOC 

species with similar characteristics and reactivities are assigned to the same lumped species. In 

the Carbon Bond approach, a VOC species is decomposed based on its reactive carbon bonds. 

One advantage of the Carbon Bond approach is that it conserves Carbon atoms, however, 

information on other atoms that may be attached to the Carbon (e.g., hydrogen and oxygen) is 

lost. For example, propene contains 3 carbon atoms with one carbon-carbon double bond 

(olefin bond) and one carbon-carbon single bond (paraffinic bond) and six hydrogen atoms:

1 mole of propene is therefore assigned to 1 mole of PAR (paraffin) and 1 mole of OLE (olefin). 

Consider a hypothetical mixture of several non-methane organic compounds (NMOCs; Table G16). The first column shows the gases that comprise the mixture, and the second column 

shows the mole fraction for each gas. The third column shows the CB05 mapping for each 

compound; this mapping is done according to the carbon structure as in the propene example 

above. The CB05 mappings are weighted by mole fraction (shown in the second column) and 

then summed to obtain the total CB05 model species per mole of the NMOC mixture emitted 

(i.e. 0.2 ETHA + 1 PAR + 0.05 ETH + 0.1 OLE + 0.1 FORM + 0.15 TOL + 0.05 XYL). 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-42

Table G-16 Example calculation to assign a hypothetical non-methane organic compound 

(NMOC) mixture to CB05 model species. 

NMOC

Mixture

Mole 

Fraction

CB05 Mapping 

(mol/mol specie)

CB05 Mixture

(mol/mol NMOC)

Ethane 0.2 1 ETHA 0.2 ETHA

Butane 0.15 4 PAR 0.6 PAR

Ethene 0.05 1 ETH 0.05 ETH

Propene 0.10 1 PAR + 1 OLE 0.1 PAR + 0.1 OLE

Formaldehyde 0.10 1 FORM 0.1 FORM

Acetaldehyde 0.15 1 ALD2 0.15 ALD2

Toluene 0.10 1 TOL 0.1 TOL

Ethylbenzene 0.05 1 PAR + 1 TOL 0.05 PAR + 0.05 TOL

Diethylbenzene 0.05 2 PAR + 1 XYL 0.1 PAR + 0.05 XYL

Acetone 0.05 3 PAR 0.15 PAR

Total 1.0 0.2 ETHA + 1 PAR + 0.05 ETH + 0.1 OLE + 0.1 

FORM + 0.15 TOL + 0.05 XYL

In order to create the SMOKE output CB05 emissions summary tables shown in Table G-12 

through G-15, the CB05 VOC species in moles must be converted back to units of weight (i.e. 

tons). This is done for reporting purposes only and has nothing to do with the CB05 chemical 

mechanism that is conserving moles of VOC. The default molecular weight for reporting the 

mass of CB05 species derived from hydrocarbons is the carbon number multiplied by the 

molecular weight of methane (16 gm/mole), which assumes that there are four hydrogen atoms 

associated with each carbon atom. Note that the while the number of carbon atoms in the 

original VOC emissions estimate is preserved throughout the speciation process, the number of 

atoms of other species (hydrogen, oxygen, etc.) is not, so that the VOC emissions input to 

SMOKE will not match the VOC emissions tallied after speciation has occurred. Also note that 

alternative molecular weights than that for methane could also be used for converting the CB05 

species from moles to mass units for reporting purposes. For example, in the propene example 

given above, if we started with 42 gm of propene it would first be converted into one mole of 

propene (molecular weight of 42 gm/mole) and then speciated into one mole of PAR and one 

mole of OLE. To convert back to mass for reporting purposes we assume the molecular weight 

of methane (16 gm/mole) for each carbon and get the following CB05 VOC mass back for 42 gm 

of propene:

 16 x (1 mole PAR) + 2 x 16 x (1 mole of OLE) = 48 gm

So in this case, the CB05 VOC mass for propene coming out of the speciation when reported as 

mass is 14% higher than the mass of propene going into the speciation. This is solely a 

reporting convention; as far as the CB05 speciation is concerned carbon, is preserved as three 

moles of carbon going in the speciation (propene) and three moles of carbon coming out of the 

speciation (one PAR and one OLE). For hydrocarbon species, the CB05 VOC mass will be the 

same or higher than the mass of hydrocarbons going into the speciation because the maximum 

number of hydrogen atoms that can be associated with a carbon atom is 4 (i.e., methane, CH4). 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-43

O&G Categories 

O&G production categories by basin were processed separately into three source categories to 

facilitate source apportionment. The three source categories include:

1. Drill Rigs;

2. Compressor Engines (including compressor station);

3. Production sources including:

a. Heaters

b. Gas processing plants

c. Flashing

d. Venting

e. Fugitives

f. Dehydrators

g. Pneumatic pumps

h. Traffic Construction & Production (only available for SW Wyoming basin)

i. Workover Rigs (used to restore or increase well production) 

In SW Wyoming, all O&G emissions were modeled as point source. In Colorado (i.e. Piceance & 

Denver-Julesburg Basins) - small compressor engines, compressor station and gas plants were 

included in the point inventory (and hence modeled as point sources) because of Colorado’s 

requirement that sources with NOx emissions greater than 2 tons/year report emissions to the 

state. In Utah (Uinta Basin), compressor station and gas plants were included in the point 

inventory. The rest of the oil and gas sources were modeled as area sources

O&G Spatial Surrogates

The WRAP Phase III O&G inventory for the Denver-Julesburg, Piceance, and Uinta Basins was 

assembled for both point (permitted) and area (unpermitted) source categories. All the 

permitted sources were modeled as point sources and unpermitted sources were modeled as 

area sources. WRAP Phase III emissions for the Denver-Julesburg, Piceance, and Uinta Basins 

were calculated on a basin-wide basis by SCCs (listed in Table G-17), and were treated as area 

sources. The next step in the emission inventory development process was to distribute the 

emissions among the model grid cells within each basin using a spatial surrogate that serves as 

a proxy for the location of the actual emitting processes. Area sources are often estimated at 

the county level, and are then allocated to the grid cells within each county based on such 

spatial surrogates as population or economic activity. Through this process, the spatial 

resolution of the emissions is matched to the CAMx grid(s). 

The updated spatial allocation surrogates were developed using the 2006 IHS database for the 

WRAP Phase III basins. The oil and gas production surrogates were based on production data at 

known well locations, while the drilling surrogate was based solely on the number and location 

of wells drilled. For each individual well, the oil, gas and water production values were divided 

by the total oil, gas and water production values corresponding to the county in which the well 

was located. This division resulted in determination of the fraction of a county’s total 

production taking place at each well. In the case of the drilling surrogate, the number of drilling 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-44

events, rather than the production values, was used. For each grid cell (intersecting a county) 

and county combination, well production fraction were summed for wells inside the given grid 

cell to obtain the surrogate value. A detailed description of the spatial surrogate development 

is given in Appendix B. 

SW Wyoming emissions were prepared by Carter Lake/BP. In addition to WRAP Phase III source 

categories, the SW Wyoming inventory included traffic production and traffic construction 

source category emissions. These emissions were assigned to SCC - 2230070000 (Mobile 

Sources, Highway Vehicles - Diesel, All HDDV including Buses (use subdivisions -071 thru -075 if 

possible), Total: All Road Types). Spatial surrogates were not required to process the Carter 

Lake/BP southwest Wyoming emissions, as the wells were modeled as point sources and the 

latitude and longitudes of the wells were compiled as part of the inventory development. For 

all other basins, the WRAP Phase II O&G emissions inventory was used along with the WRAP 

Phase II spatial surrogates, developed using 2002 well and spud data obtained from the 

Wyoming Oil and Gas Conservation Commission (WOGCC).

Table G-17 WRAP Phase III O&G SCC List.

SCC SCC Description

2310000110 Industrial Processes, Oil and Gas Production, All Processes, Drill Rigs

2310000120 Industrial Processes, Oil and Gas Production, All Processes, Workover Rigs

2310010100 Industrial Processes, Oil and Gas Production, Crude Petroleum, Truck Loading

2310010200

Industrial Processes, Oil and Gas Production, Crude Petroleum, Tanks - Flashing & 

Standing/Working/Breathing

2310010300 Industrial Processes, Oil and Gas Production, Crude Petroleum, Pneumatic devices

2310010400 Industrial Processes, Oil and Gas Production, Crude Petroleum, Fugitives

2310020100 Industrial Processes, Oil and Gas Production, Natural Gas, Dehydrators

2310020200 Industrial Processes, Oil and Gas Production, Natural Gas, Venting - Initial Completions

2310020300 Industrial Processes, Oil and Gas Production, Natural Gas, Venting – Recompletions

2310020400 Industrial Processes, Oil and Gas Production, Natural Gas, Venting - Blowdowns

2310020500 Industrial Processes, Oil and Gas Production, Natural Gas, Venting - Compressor Startup 

2310020600 Industrial Processes, Oil and Gas Production, Natural Gas, Venting - Compressor Shutdown

2310020700 Industrial Processes, Oil and Gas Production, Natural Gas, Fugitives

2310020800 Industrial Processes, Oil and Gas Production, Natural Gas, Pneumatic Devices

2310020900 Industrial Processes, Oil and Gas Production, Natural Gas, Pneumatic Pumps

2310020110 Industrial Processes, Oil and Gas Production, Natural Gas, Amine Units

2310023100 Industrial Processes, Oil and Gas Production, CBM, Dehydrators

2310023200 Industrial Processes, Oil and Gas Production, CBM, Venting - Initial Completions

2310023300 Industrial Processes, Oil and Gas Production, CBM, Venting - Recompletions

2310023400 Industrial Processes, Oil and Gas Production, CBM, Venting - Blowdowns

2310023500 Industrial Processes, Oil and Gas Production, CBM, Venting - Compressor Startup 

2310023600 Industrial Processes, Oil and Gas Production, CBM, Venting - Compressor Shutdown

2310023700 Industrial Processes, Oil and Gas Production, CBM, Fugitives

2310023800 Industrial Processes, Oil and Gas Production, CBM, Pneumatic Devices

2310023900 Industrial Processes, Oil and Gas Production, CBM, Pneumatic Pumps

2310023110 Industrial Processes, Oil and Gas Production, CBM, Amine Units
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-45

SCC SCC Description

2310030100 Industrial Processes, Oil and Gas Production, Natural Gas Liquids, Gas Plant Truck Loading

2310030200 Industrial Processes, Oil and Gas Production, Natural Gas Liquids, Truck Loading

2310030300

Industrial Processes, Oil and Gas Production, Natural Gas Liquids, Tanks - Flashing & 

Standing/Working/Breathing

2310030400 Industrial Processes, Oil and Gas Production, Natural Gas Liquids, Water Tank Losses

2310024100 Industrial Processes, Oil and Gas Production, Natural Gas, Heaters

2310024200 Industrial Processes, Oil and Gas Production, Natural Gas, Initial Completion Flaring

2310024300 Industrial Processes, Oil and Gas Production, Natural Gas, Condensate Tank Flaring

2310024400 Industrial Processes, Oil and Gas Production, Natural Gas, Dehydrator Flaring

2310025100 Industrial Processes, Oil and Gas Production, Natural Gas, Compressor Engines

2310025200 Industrial Processes, Oil and Gas Production, Natural Gas, Miscellaneous Engines

2310025300 Industrial Processes, Oil and Gas Production, Natural Gas, Artificial Lift

O&G VOC Speciation

Basin-specific VOC composition profiles were used to the fullest extent possible, rather than the 

SMOKE default VOC speciation that is cross-referenced by SCC category. Specifically, for WRAP 

Phase III, those source categories that relied on estimates of volume of gas vented or leaked 

(i.e. blowdowns, completions, and fugitive emissions), gas composition analyses were compiled 

from data collected through surveys of producers. These composition analyses were averaged 

to derive a single basin-wide produced gas composition analysis for CBM, conventional gas and 

oil wells. 

The Carter Lake/BP southwest Wyoming O&G inventory includes detailed VOC gas composition 

analyses for the 5-County area. Speciation profiles were developed for the main VOC-emitting 

processes from oil and gas production activities for each county in the region. Where 

additional spatial resolution was needed, counties were further subdivided; the Jonah and 

Pinedale fields were separated out from the rest of Sublette County, and Sweetwater County 

was divided into East Sweetwater and West Sweetwater. Separate speciation profiles were 

developed for the following processes: flashing, well venting, pneumatic pumps, and fugitive 

emissions, which were further broken down into emissions from sales gas, produced gas and 

condensate. Profile codes and descriptions are shown in Table C.3 of Appendix C. Since gas 

analyses for the Southwest Wyoming basin were available for both 2005 and 2006, two-year 

average profiles were used. The Speciation Tool (ENVIRON, 2007) was used to convert these 

gas composition analyses to CB05 speciation profiles ready for use in SMOKE. 

The SMOKE emission model includes default speciation profiles indexed by SCC codes. These 

profiles are based on EPA default data as well as on various updates and improvements 

incorporated to account for such things as variations in fuels, solvent composition, and 

chemical mechanisms used in air quality models. For the CD-C southwest Wyoming O&G 

processing, instead of using generic EPA default profiles, region-specific VOC speciation profiles 

derived from the gas composition analysis for each basin were used.

Speciation profiles used for modeling of VOC emissions from O&G sources in SW Wyoming are 

shown in Table C.4, and the cross reference between speciation profiles and SCCs that shows 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-46

which profile was used for a given source category is shown in Table C.5. Table C.6 provides a 

key to the abbreviations for the CB05 species. For comparison, EPA default speciation profiles 

and cross references are shown in Tables C.7-C.9.

O&G Temporal Allocation

The Carter Lake/BP inventory provided drill rig, construction traffic and heater emissions in 

southwest Wyoming as monthly emissions. In the emission inventory used for the Hiawatha 

modeling, the monthly heater emissions were allocated across all hours in the month during 

which the activity took place according to the default SMOKE temporal profile for oil and gas 

sources. This profile assumes that the source operates constantly throughout a given time 

period. Monthly construction traffic emissions were allocated in time using the SMOKE default 

profile for Heavy Duty Diesel Vehicles (HDDV), which has both weekly and diurnal variation. 

However, the drill rig emissions were incorrectly allocated evenly across the entire year in 

which a particular drilling event occurred, rather than only during the months when drilling 

actually took place. The 2005-6 drill rig emission inventory has been reprocessed so that the 

monthly emissions are allocated by month to hourly emissions using the default SMOKE 

temporal profile for oil and gas sources, as was done for the heater emissions. 

Production traffic emissions were temporally allocated using the SMOKE default profile for 

Heavy Duty Diesel Vehicles. No temporal variation was applied to the rest of the O&G sources, 

i.e. emissions from well production sources were assumed to be equally distributed across 

every hour within the calendar year according to the default SMOKE temporal profile for oil and 

gas sources. 

Other Source Categories 

Other emission categories such as agricultural source ammonia and the wind-blown dust were 

processed outside of SMOKE and were obtained from the original data sources, described 

below. 

Ammonia emissions from sources including livestock, fertilizer usage, domestic sources, and 

wild animals within WRAP states were generated from a GIS-based ammonia emissions model 

(Mansell, 2005) using day-specific meteorology for temporal distribution processing. 

The windblown fugitive dust PM emission inventory was developed using the estimation 

methodology developed for WRAP by a team of contractors led by ENVIRON (ENVIRON, 2004) 

and subsequently revised by Mansell and others (Mansell, 2003a; 2003b; Mansell, et al. 2004). 

The methodology is based on the results of wind tunnel studies and a detailed characterization

of vacant lands. The model generates estimates of PM10 dust emissions. The fine fraction of 

dust is obtained by using a nominal PM2.5 of 0.10, as used in the implementation of the model 

for the WRAP. Windblown dust emissions are estimated hourly on a gridded modeling domain 

using hourly averaged wind speeds and other meteorological parameters. Estimates were 

developed for every hour of the 2005 and 2006 base year and these emissions will also be used 

the 2008 baseline modeling. 

Merging Products of Emissions Processing into Model-Ready Files

Emissions for different major source groups (e.g., mobile, off-road mobile, area, point and 

biogenic) were processed separately and merged together prior to CAMx modeling. Table G-18 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-47

lists all of the pre-merged emissions files needed for the 36 km domain, and Table G-19 lists the 

pre-merged files required for the 12 km domain for 2006.

Table G-18 Pre-merged emissions files for the 36 km domain.

Major 

Category Sub Category File Name

Area

Generic Area 

excluding 

dust&fire 1. argts_l.{date}.1.RPO36km.{CASE}.cmaq.cb05p25.ncf

Road dust 2. rdgts_s.{date}.1.RPO36km.{CASE}.cmaq.cb05p25.ncf

Fugitive dust 3. fdgts_s.{date}.1.RPO36km.{CASE}.cmaq.cb05p25.ncf

Wind-blown 

dust 4. wb_dust_ii_cmaq_{case}_{date}_agadj_tf_b.ncf

Non-WRAP 

monthly 

ammonia 5. nh3mgts_l.{date}.1.RPO36km.{CASE}.cmaq.cb05p25.ncf

Non-WRAP 

annual 

ammonia 6. nh3ygts_l.{date}.1.RPO36km.{CASE}.cmaq.cb05p25.ncf

WRAP 

ammonia 

(fertilizer, 

domestics, 

wild animals, 

livestocks)

7. nh3frt.{CASE}.36k.{date}.CMAQ.ncf"

8. nh3domest.{CASE}.36k.{date}.CMAQ.ncf"

9. nh3wild.{CASE}.36k.{date}.CMAQ.ncf"

10. nh3lvstck.{CASE}.36k.{date}.CMAQ.ncf

Off-road

Annual 

nonroad 11. nrygts_l.{date}.1.RPO36km.{CASE}.cmaq.cb05p25.ncf

Monthly 

nonroad 12. nrmgts_l.{date}.1.RPO36km.{CASE}.cmaq.cb05p25.ncf

Onroad 

Mobile

US onroad 

mobile 13. mbvgts_l.{date}.1.RPO36km.{CASE}.ncf

Non-US 

onroad 

mobile 14. nusmgts_l.{date}.1.RPO36km.{CASE}.ncf

Point EGUs 15. egugts3d_l.{date}.1.RPO36km.15L.{CASE}.cmaq.cb05p25

Non-EGUs 16. negugts3d_l.{date}.1.RPO36km.15L.{CASE}.cmaq.cb05p25

Trona 17. trngts3d_l.{date}.1.RPO36km.15L.{CASE}.cmaq.cb05p25

Off-shore

Offshore area 

facilities 18. ofsargts_l.{date}.1.RPO_US36. plan02d.cmaq.cb4p25.ncf

Offshore 

point facilities 19. ofsgts3d_l.${date}.1.RPO_US36.15L.Base02a.cmaq.cb4p25

Atlantic 

shipping 

emissions 20. ofsshgts_l.{date}.1.vista36.baseg_2002.shipping_NoPacific.ncf

Pacific 

shipping 

emissions 21. offshore_marine_RPO36_{date}_pacific_Plan02a.ncf

O&G

Area - Uinta, 

DJ and 

Piceance 22. woggts_l.{date}.1.RPO36km.ubaqs2005.cmaq.cb05p25.ncf

Point - Uinta, 

DJ and 

Piceance 23. poggts3d_l.{date}.1.RPO36km.15L.ubaqs2005.cmaq.cb05p25.ncf

Point - SWWY 24. poggts3d_l.{date}.1.RPO36km.15L.SW_Wyoming_2005.cmaq.cb05p25.ncf
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-48

Major 

Category Sub Category File Name

Point – SWWY 

(monthly 

inputs) 25. poggts3d_l.{date}.1.RPO36km.15L.SW_Wyoming_Monthly_2005.cmaq.cb05p25.ncf

WRAP Phase 

II area 26. woggts_l.{date}.1.RPO36km.phaseII_2005.cmaq.cb05p25.ncf

WRAP Phase 

II point 27. poggts3d_l.{date}.1.RPO36km.15L.phaseII_2005.cmaq.cb05p25.ncf

Fire Low-level fire 28. emiss.area.ncarfires.soa.rpo36km.{date}

Elevated fire 29. ptsrce.ncarfires.soa.rpo36km.{date}.bin

Biogenic Biogenic 30. emiss_MEGAN_CB05X_36km_{date}
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-49

Table G-19 Pre-merged emissions files for the 2006 12-km domain

Major 

Category Sub Category File Name

Area

Generic Area 

excluding 

dust&fire 1 argts_l.{date}.1.cdc12k.bpcdc06.cmaq.cb05p25.ncf

Road dust 2 rdgts_s.{date}.1.cdc12k.bpcdc06.cmaq.cb05p25.ncf

Fugitive dust 3. fdgts_s.{date}.1.cdc12k.bpcdc06.cmaq.cb05p25.ncf

Wind-blown 

dust 4. wb_dust_ii_cmaq_cdc12k_{date}_agadj_tf_b.ncf

Non-WRAP 

monthly 

ammonia 5. nh3mgts_l.{date}.1.cdc12k.bpcdc06.cmaq.cb05p25.ncf

WRAP ammonia 

(fertilizer, 

domestics, wild 

animals, 

livestocks) 6. nh3all.bp12k.{date}.CMAQ.ncf

Off-road Annual nonroad 7. nrygts_l.{date}.1.cdc12k.bpcdc06.cmaq.cb05p25.ncf

Monthly 

nonroad 8. nrmgts_l.{date}.1.cdc12k.bpcdc06.cmaq.cb05p25.ncf

Onroad 

Mobile

US onroad 

mobile 9. mbvgts_l.{date}.1.cdc12k.bpcdc06.ncf

Point EGUs 10. elevegu_l.{date}.1.cdc12k.bpcdc06_camx.txt

Non-EGUs 11. elevnegu_l.{date}.1.cdc12k.bpcdc06_camx.txt

Trona 12. elevtrn_l.{date}.1.cdc12k.bpcdc06_camx.txt

O&G

Area - Uinta, DJ 

and Piceance

13. ar_compgts_l.{date}.1.CDC12km.cdc_eis2006.cmaq.cb05p25.ncf

14. ar_prodgts_l.{date}.1.CDC12km.cdc_eis2006.cmaq.cb05p25.ncf

15. spudgts_l.{date}.1.CDC12km.cdc_eis2006.cmaq.cb05p25.ncf

Point - Uinta, DJ 

and Piceance

16. elevpt_comp_l.{date}.1.CDC12km.cdc_eis2006.txt

17. elevpt_prod_l.{date}.1.CDC12km.cdc_eis2006.txt

Point - SWWY

18. elevpt_comp_l.{date}.1.CDC12km.SW_Wyoming2006.txt

19. elevpt_prod_l.{date}.1.CDC12km.SW_Wyoming2006.txt

20. elevpt_spud_l.{date}.1.CDC12km.SW_Wyoming2006.txt

Point – SWWY 

(monthly inputs) 21. elevpt_prod_l.{date}.1.CDC12km.SW_Wyoming_revised_2006.txt

WRAP Phase II 

area

22. ar_compgts_l.{date}.1.CDC12km.phaseII2006.cmaq.cb05p25.ncf

23. ar_prodgts_l.{date}.1.CDC12km.phaseII2006.cmaq.cb05p25.ncf

24. spudgts_l.{date}.1.CDC12km.phaseII2006.cmaq.cb05p25.ncf

WRAP Phase II 

point

25. elevpt_comp_l.{date}.1.CDC12km.phaseII2006.txt

26. elevpt_prod_l.{date}.1.CDC12km.phaseII2006.txt

Fire Low-level fire 27. emiss.area.ncarfires.soa.cdc_12km.$Y2$M2$D2

Elevated fire 28. ptsrce.ncarfires.soa.cdc_12km.$Y2$M2$D2.bin

Biogenic Biogenic 29. emiss_MEGAN_CDC12km_CB05X_{date}.camx
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-50

EMISSIONS SUMMARY

Annual O&G emissions by county in southwest Wyoming region and O&G emissions by state in 

the 12 km domain for both calendar years are summarized in Tables G-20 and G-21, 

respectively. The spatial distribution of the annual O&G emissions by category within the 12 

km domain is shown in Figure G-19. Note that PM emissions from compressors are minimal in 

southwest Wyoming due to the usage of natural gas fuel. In addition, there are no PM 

emissions from O&G sources in Northeastern Wyoming due to the lack of a PM inventory in the 

WRAP Phase II O&G database. 

Annual emissions of non-O&G categories by state within the 12 km domain for both calendar 

years are summarized in Tables G-22 and G-23, respectively. Spatial distributions of the annual 

2005 and 2006 emissions of the surface emissions (area, onroad, non-road and biogenics) at 

the 12 km resolution are shown in Figures G-20 and G-21, respectively. 

For both base years, CO emissions in Wyoming are dominated by mobile sources, with on-road 

mobile sources contributing about half of the anthropogenic CO emissions and non-road mobile 

contributing most of the rest. 

Several source categories contribute significantly to NOx emissions in Wyoming with EGU point 

sources being the largest contributor, followed by non-road mobile. NOx emissions from nonEGU point sources are comparable to those from O&G sources.

TOG emissions from anthropogenic sources in Wyoming are dominated by O&G sources, 

specifically, from production sources. Non-EGU point sources are the second largest 

contributor, followed by area sources. 

PM emissions in Wyoming are primarily from wind-blown dust (part of the area source 

category) emissions. Non-EGU emissions also contribute to PM emissions due largely from 

mineral production processes such as coal mining. O&G sources do not significantly contribute 

to PM emissions in Wyoming. 
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-51

Table G-20 2005 and 2006 Southwest Wyoming O&G emissions by county.

County

2005 2006

Compressor Drilling Production Compressor Drilling Production

NOx

Carbon Co 1,111 448 1,010 2092 554 1214

Lincoln Co 2,047 343 1,016 2010 314 1029

Sublette Co 1,564 4,169 2,433 2300 3155 2975

Sweetwater Co 2,712 806 1,682 4361 819 1940

Uinta Co 1,414 62 373 702 75 486

Grand Total 8,848 5,829 6,513 11465 4917 7644

VOC

Carbon Co 218 23 20,613 559 30 23356

Lincoln Co 208 14 21,702 148 13 21997

Sublette Co 784 257 27,230 725 184 26500

Sweetwater Co 672 30 45,754 819 29 48156

Uinta Co 205 3 6,228 175 3 6225

Grand Total 2,087 326 121,528 2427 259 126234

CO

Carbon Co 574 48 451 1128 50 558

Lincoln Co 880 37 3,614 682 34 874

Sublette Co 812 2,025 2,064 1094 1412 2356

Sweetwater Co 2,126 95 765 2620 86 827

Uinta Co 705 7 1,104 519 8 1189

Grand Total 5,097 2,213 7,999 6044 1590 5804

PM10

Carbon Co 1 44 86 1 53 103

Lincoln Co 13 35 65 46 32 74

Sublette Co 0 138 185 0 102 232

Sweetwater Co 0 81 137 0 84 147

Uinta Co 0 6 20 0 8 21

Grand Total 14 304 494 46 279 577
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-52

Table G-21 2005 and 2006 O&G Emissions by state within the 12 km domain.

State

2005 2006

Compressor Drilling Production Compressor Drilling Production

NOx

Colorado 17,155 10,525 5,416 17,155 10,525 5,416

Idaho 1,394 0 0 1,394 0 0

Montana 1,092 304 759 1,092 304 759

Nevada 0 0 0 0 0 0

North Dakota 501 1,424 136 501 1,424 136

South Dakota 305 182 58 305 182 58

Utah 5,916 4,819 3,806 5,916 4,819 3,806

Wyoming 11,308 9,914 15,694 13,925 9,003 16,825

Tribes 838 0 1 838 0 1

Grand Total 38,509 27,168 25,869 41,126 26,257 27,000

VOC

Colorado 3,893 600 104,004 3,893 600 104,004

Idaho 47 0 0 47 0 0

Montana 104 3 1,473 104 3 1,473

Nevada 0 0 0 0 0 0

North Dakota 3 0 3,374 3 0 3,374

South Dakota 0 0 369 0 0 369

Utah 1,891 417 71,534 1,891 417 71,534

Wyoming 2,799 503 165,372 3,139 436 170,078

Tribes 37 0 77 37 0 77

Grand Total 8,776 1,523 346,204 9,116 1,456 350,910

CO

Colorado 11,172 4,819 4,768 11,172 4,819 4,768

Idaho 243 0 0 243 0 0

Montana 587 2 171 587 2 171

Nevada 0 0 0 0 0 0

North Dakota 86 0 70 86 0 70

South Dakota 0 1 12 0 1 12

Utah 3,635 1,815 3,686 3,635 1,815 3,686

Wyoming 6,408 3,528 9,658 7,354 2,905 7,464

Tribes 125 0 0 125 0 0

Grand Total 22,256 10,164 18,365 23,203 9,541 16,170

PM

Colorado 238 1,178 222 238 1,178 222

Idaho 0 0 0 0 0 0

Montana 0 0 0 0 0 0

Nevada 0 0 0 0 0 0

North Dakota 0 0 0 0 0 0

South Dakota 0 0 0 0 0 0

Utah 63 354 207 63 354 207

Wyoming 14 304 498 47 279 581

Tribes 2 0 0 2 0 0

Grand Total 317 1,835 927 350 1,810 1,010
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-53

Table G-22 2005 Non-O&G Emissions by state within the 12 km domain. 

State

Source Category

Area On-Road Non-Road EGU NEGU Trona Biogenic Fire

CO

Colorado 46,962 701,674 322,522 4,833 7,258 46,958 21,012

Idaho 14,057 130,655 69,006 0 14,622 27,081 316,859

Kansas 166 5,647 1,125 0 0 1,863 516

Montana 9,604 66,418 26,599 800 908 28,770 23,776

Nebraska 1,609 46,711 19,555 39 85 18,170 3,318

Nevada 58 5,695 491 0 0 1,048 0

North Dakota 579 2,673 2,612 0 0 2,963 449

South Dakota 5,605 40,381 16,838 139 3,573 22,407 37,015

Utah 36,481 445,281 190,599 4,336 21,790 32,538 59,242

Wyoming 28,281 194,920 77,532 13,241 42,421 14,029 55,886 51,284

NOx

Colorado 9,787 80,652 42,969 77,845 11,692 3,390 753

Idaho 10,828 16,072 12,729 0 5,852 2,073 9,513

Kansas 50 706 408 0 0 183 26

Montana 1,387 8,314 9,266 46,421 1,367 2,109 781

Nebraska 550 5,956 28,812 28 87 1,735 157

Nevada 4 755 1,031 0 0 52

North Dakota 89 360 1,388 0 0 397 28

South Dakota 624 5,412 5,121 977 4,021 1,928 1,086

Utah 5,899 50,922 40,360 118,724 25,888 2,058 1,857

Wyoming 15,516 24,649 69,321 92,711 43,878 10,209 3,207 1,708

TOG

Colorado 84,810 65,098 28,730 2,655 25,184 240,257 979

Idaho 75,325 11,275 14,487 0 423 113,543 15,473

Kansas 455 528 124 9,826 17

Montana 16,107 5,799 3,261 91 718 134,355 1,097

Nebraska 5,741 4,240 4,619 0 2,950 43,856 128

Nevada 133 421 150 4,489

North Dakota 1,864 249 579 0 0 6,932 17

South Dakota 6,380 3,696 2,841 7 304 71,833 1,863

Utah 58,848 39,771 26,734 585 13,830 158,436 2,812

Wyoming 39,496 16,642 16,290 1,710 50,966 16,546 259,276 2,379

PM

Colorado 121,465 2,087 3,625 1,404 15,622 0 2,773

Idaho 79,187 427 1,503 0 1,859 0 44,426

Kansas 15,927 16 47 0 54

Montana 255,810 222 616 216 814 0 3,171

Nebraska 84,172 137 1,389 7 1,604 0 349

Nevada 9,238 20 38 0

North Dakota 14,654 10 140 0 0 0 55

South Dakota 154,780 147 448 37 420 0 5,371

Utah 178,883 1,355 3,379 3,005 11,679 0 8,111

Wyoming 129,112 659 3,084 6,390 33,478 3,731 0 6,912
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-54

Table G-23 2006 Non-O&G Emissions by state within the 12 km domain. 

State

Source Category

Area On-Road Non-Road EGU NEGU Trona Biogenic Fire

CO

Colorado 47,171 773,316 326,993 4,791 7,257 49,164 19,757

Idaho 14,201 114,720 70,573 0 14,622 29,984 397,803

Kansas 165 5,094 1,124 0 0 2,035

Montana 9,670 57,974 27,177 1,362 908 31,756 412,343

Nebraska 1,594 41,936 19,495 39 85 19,983 76,911

Nevada 59 4,955 511 0 0 1,134 3,778

North Dakota 577 2,340 2,635 0 0 3,472 893

South Dakota 5,625 35,494 17,261 139 3,573 24,224 19,703

Utah 36,572 396,907 193,786 4,335 21,790 34,407 63,472

Wyoming 28,432 173,081 79,247 13,187 37,292 15,058 59,252 227,945

NOx

Colorado 10,013 88,859 41,720 75,536 11,694 3,718 646

Idaho 11,063 14,409 12,490 0 5,852 2,361 12,107

Kansas 51 647 395 0 0 205

Montana 1,411 7,445 8,975 45,930 1,367 2,408 13,216

Nebraska 554 5,449 27,602 28 87 1,972 2,526

Nevada 4 676 992 0 0 57 142

North Dakota 90 324 1,362 0 0 489 46

South Dakota 638 4,856 4,988 977 4,021 2,180 837

Utah 6,034 45,527 39,005 124,433 26,088 2,256 2,146

Wyoming 15,767 22,138 66,878 88,487 41,449 9,785 3,513 7,138

TOG

Colorado 86,797 69,589 27,698 2,652 25,184 244,317 929

Idaho 77,749 10,210 14,739 0 423 127,746 18,866

Kansas 462 500 120 0 0 10,946 0

Montana 16,378 5,236 3,287 172 718 150,232 19,764

Nebraska 5,790 3,985 4,490 0 2,950 48,660 3,785

Nevada 139 384 156 0 0 4,895 110

North Dakota 1,872 224 583 0 0 8,207 43

South Dakota 6,480 3,325 2,909 7 304 76,863 921

Utah 60,990 35,709 26,619 584 13,826 166,270 2,716

Wyoming 40,263 15,138 16,490 1,717 49,319 16,494 272,709 11,115

PM

Colorado 133,108 2,253 3,534 1,403 15,612 2,615

Idaho 85,168 404 1,451 0 1,859 54,248

Kansas 16,503 15 45 0 0

Montana 249,621 210 600 36,592 814 57,346

Nebraska 80,502 129 1,335 7 1,604 11,015

Nevada 15,732 19 38 0 0 318

North Dakota 12,799 10 134 0 0 125

South Dakota 132,319 139 435 37 420 2,759

Utah 276,336 1,286 3,265 3,005 11,678 7,872

Wyoming 170,506 624 3,046 7,050 29,342 3,224 32,177
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-55

Table G-24 2005 CDC 4 km Domain Emission Summary (tpy). 

Compressor Drilling Production Area Onroad Offroad EGU NEGU Trona Biogenic Fire

Colorado 774 118 160 2,426 21,481 7,582 1,276 56 0 10,053 2,224

Idaho 242.8 0 0 472 3,058 4,597 0 9,527 0 6,777 16,701

Utah 2,343 1,220 3,166 1,915 22,990 11,504 525 748 0 2,504 17,793

Wyoming (5 counties) 5,095 2,265 5,395 5,474 40,804 17,676 3,405 2,892 14,022 8,667 6,157

Wyoming (rest) 119 780 933 8,094 46,126 17,199 2 3,762 0 9,532 2,434

Colorado 1,305 322 144 143 2,120 1,299 25,825 85 0 566 66

Idaho 1392.8 0 0 308 373 667 0 1,836 0 352 575

Utah 4,392 3,232 3,101 201 2,387 1,858 7,405 1,329 0 140 515

Wyoming (5 counties) 8,838 5,820 3,004 2,731 5,099 12,909 47,180 3,903 10,208 443 210

Wyoming (rest) 538 1,667 3,510 3,873 5,738 8,244 10 3,282 0 490 85

Colorado 1,110 19 72,003 1,536 1,770 1,709 127 256 0 53,008 116

Idaho 505.6 0 0 3,476 262 1,638 0 11 0 32,183 704

Utah 16,692 374 136,540 1,817 1,789 3,378 76 2,127 0 13,009 945

Wyoming (5 counties) 21,409 446 747,700 10,367 3,317 5,035 479 3,628 16,515 38,617 273

Wyoming (rest) 1,101 106 158,910 7,098 4,000 972 2 8,804 0 42,181 102

Colorado 10 49 16 10,423 56 141 373 3,919 0 0 320

Idaho 0 0 0 9,059 10 108 0 561 0 0 1,950

Utah 42 239 156 6,571 64 209 681 216 0 0 2,602

Wyoming (5 counties) 14 297 222 27,760 136 639 1,419 9,269 3,723 0 751

Wyoming (rest) 0 0 4 18,494 153 377 1 476 0 0 282

Colorado 0 14 10 76 56 42 6,970 4 0 0 20

Idaho 1.3 0 0 15 11 55 0 9,892 0 0 125

Utah 4 244 15 140 65 110 1,230 5 0 0 159

Wyoming (5 counties) 135 393 7,100 1,943 142 676 45,177 4,607 10,359 0 48

Wyoming (rest) 51 41 936 3,937 159 437 1 3,135 0 0 18

STATE

Oil and Gas Sources Non-Oil and Gas Sources

CO

NOx

TOG

PM

SO2
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-56

Table G-25 2006 CDC 4 km Domain Emission Summary (tpy). 

Compressor Drilling Production Area Onroad Offroad EGU NEGU Trona Biogenic Fire

Colorado 774 118 160 2,434 22,689 10,407 1,276 56 0 10,462 2,073

Idaho 242.8 0 0 477 2,722 4,759 0 9,527 0 6,916 13,597

Utah 2,343 1,220 3,166 1,917 20,458 11,864 525 748 0 2,597 6,011

Wyoming (5 counties) 6,042 2,179 2,863 5,506 36,418 18,150 3,490 2,893 15,052 9,391 15,119

Wyoming (rest) 119 780 933 8,132 41,300 17,441 2 3,472 0 10,071 48,047

Colorado 1,305 322 144 145 2,219 1,562 24,819 85 0 607 70

Idaho 1392.8 0 0 315 336 666 0 1,836 0 373 491

Utah 4,392 3,232 3,101 204 2,138 1,812 7,354 1,329 0 150 197

Wyoming (5 counties) 11,461 5,882 3,539 2,777 4,577 12,463 42,493 4,030 9,781 492 443

Wyoming (rest) 538 1,667 3,510 3,925 5,156 7,954 10 3,510 0 530 1,446

Colorado 1,110 19 72,003 1,560 1,784 2,255 127 256 0 54,105 94

Idaho 505.6 0 0 3,600 238 1,654 0 11 0 31,941 545

Utah 16,692 374 136,540 1,882 1,622 3,491 76 2,127 0 13,133 274

Wyoming (5 counties) 25,756 449 792,633 10,660 3,022 5,113 484 3,514 16,459 42,058 800

Wyoming (rest) 1,101 106 158,881 7,169 3,646 937 2 8,621 0 44,609 2,510

Colorado 10 49 16 8,295 57 139 372 3,918 0 261

Idaho 0 0 0 8,785 10 106 0 561 0 1,513

Utah 42 239 156 5,244 60 207 691 216 0 756

Wyoming (5 counties) 47 310 249 25,915 129 632 1,961 10,381 3,223 0 2,203

Wyoming (rest) 0 0 4 16,971 145 368 1 538 0 0 6,936

Colorado 0 14 1 77 70 48 6,245 4 0 16

Idaho 1.3 0 0 15 9 42 0 9,892 0 97

Utah 0 244 15 140 50 88 864 5 0 48

Wyoming (5 counties) 131 277 4,688 1,992 112 530 40,932 4,343 10,558 0 134

Wyoming (rest) 51 41 936 3,991 124 344 1 3,562 0 0 422

STATE

Oil and Gas Sources Non-Oil and Gas Sources

CO

NOx

TOG

PM

SO2
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-57

(a) Compressors (b) Drill Rigs (c) Production

Figure G-19. Spatial distribution of CO, NOx, TOG, and PM emissions (TPY) in 2006 from (a) compressors, (b) drill rigs, and (c) 

productions within the 12 km domain.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-58

(a) Compressors (b) Drill Rigs (c) Production

Figure G-20. (cont.) Spatial distribution of CO, NOx, TOG, and PM emissions (TPY) in 2006 from (a) compressors, (b) drill rigs, and 

(c) productions within the 12 km domain.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-59

(a) Area (b) On-road (c) Off-road (d) Biogenic

Figure G-21. Spatial distribution of CO, NOx, TOG, and PM emissions (TPY) in 2005 from (a) Area, (b) On-road Mobile, (c) Off-road 

Mobile and (d) Biogenic within the 12 km domain.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-60

(a) Area (b) On-road (c) Off-road (d) Biogenic

Figure G-22. (cont.) Spatial distribution of CO, NOx, TOG, and PM emissions (TPY) in 2005 from (a) Area, (b) On-road Mobile, (c) 

Off-road Mobile and (d) Biogenic within the 12 km domain.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-61

(a) Area (b) On-road (c) Off-road (d) Biogenic

Figure G-23. (cont.) Spatial distribution of CO, NOx, TOG, and PM emissions (TPY) in 2006 from (a) Area, (b) On-road Mobile, (c) 

Off-road Mobile and (d) Biogenic within the 12 km domain.
APPENDIX G – DEVELOPMENT OF THE 2005-2006 BASE CASE EMISSION INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 G-62

(a) Area (b) On-road (c) Off-road (d) Biogenic

Figure G-24. Spatial distribution of CO, NOx, TOG, and PM emissions (TPY) in 2006 from (a) Area, (b) On-road Mobile, (c) Off-road 

Mobile and (d) Biogenic within the 12 km domain.
Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016

Appendix H

Continental Divide-Creston Proposed Action Project Emissions Inventory
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016

List of Acronyms

Note: Central Facility refers to gas plants and compressor stations.

B Billion

BACT Best Available Control Technology

bpd Barrel Per Day

BSFC Brake Specific Fuel Consumption

BTU British Thermal Unit

CD-C Continental Divide-Creston

CH4 Methane

CO Carbon Monoxide

CO2 Carbon Dioxide

d Day

EC Elemental Carbon

EF Emission Factor

G Gram

HC Hydrocarbons

HD Heavy Duty

HHV Higher Heating Value

HP Horsepower

hp-hr Horsepower-Hour

hr Hour

ICE Internal Combustion Engine

Lb Pound

LD Light Duty

M Thousand

mi Miles

MM Million

mph Miles Per Hour

N2O Nitrous Oxide

NG Natural Gas

NMHC Non-Methane Hydrocarbon

NOx Oxides Of Nitrogen

PM Particulate Matter

PM_cond Condensable Particulate Matter

PM_filt Filterable Particulate Matter

Scf Standard Cubic Feet

SOA Secondary Organic Aerosols

SO2 Sulfur Dioxide

THC Total Hydrocarbons

TOC Total Organic Carbon

tpy Tons Per Year

TSP Total Suspended Particles

VMT Vehicle Miles Traveled

VOC Volatile Organic Compounds

Wt% Weight Percentage

WtFraction Weight Fraction

yr Year
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-1

Continental Divide-Creston Proposed Action Project Emissions 

Inventory

In Appendix H, we present the detailed emissions calculations used to develop the CD-C Project 

Emission Inventory for the Proposed Action. 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-2

Existing Wells Emissions Inventory
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-3

Table 1. Summary of Existing Wells Activity Data by Project Year.

Year

Project 

Yr

Well Pads 

Constructed Spuds

Active Well 

Count

Annual 

Condensate 

Production 

(Mbbl/yr)

Annual Gas 

Production 

(MMSCF/yr)

Cumulative 

Well Pads 

Constructed

Cumulative 

Spuds

Cumulative 

Condensate 

Production 

(Mbbl)

Cumulative 

Gas 

Production 

(BSCF)

2008 1 462 462 2,850 2,726 193,570 462 462 2,726 194

2009 2 0 0 2,821 2,569 182,685 462 462 5,295 376

2010 3 0 0 2,792 2,211 157,216 462 462 7,507 533

2011 4 0 0 2,763 2,013 143,095 462 462 9,519 677

2012 5 0 0 2,736 1,976 140,480 462 462 11,495 817

2013 6 0 0 2,709 1,950 138,671 462 462 13,445 956

2014 7 0 0 2,682 1,851 131,597 462 462 15,296 1,087

2015 8 0 0 2,656 1,748 124,251 462 462 17,044 1,212

2016 9 0 0 2,629 1,657 117,844 462 462 18,701 1,329

2017 10 0 0 2,602 1,579 112,265 462 462 20,280 1,442

2018 11 0 0 2,575 1,510 107,356 462 462 21,790 1,549

2019 12 0 0 2,548 1,447 102,899 462 462 23,237 1,652

2020 13 0 0 2,524 1,389 98,793 462 462 24,627 1,751

2021 14 0 0 2,499 1,338 95,116 462 462 25,964 1,846

2022 15 0 0 2,475 1,267 90,091 462 462 27,232 1,936

2023 16 0 0 2,450 1,223 86,926 462 462 28,454 2,023

2024 17 0 0 2,426 1,181 83,975 462 462 29,635 2,107

2025 18 0 0 2,401 1,145 81,413 462 462 30,780 2,188

2026 19 0 0 2,376 1,110 78,899 462 462 31,890 2,267

2027 20 0 0 2,352 1,077 76,569 462 462 32,967 2,344

2028 21 0 0 2,305 1,047 74,456 462 462 34,014 2,418

2029 22 0 0 2,283 995 70,757 462 462 35,009 2,489

2030 23 0 0 2,260 968 68,803 462 462 35,977 2,558

2031 24 0 0 2,238 942 66,989 462 462 36,919 2,625

2032 25 0 0 2,216 917 65,232 462 462 37,836 2,690

2033 26 0 0 2,193 893 63,513 462 462 38,730 2,753

2034 27 0 0 2,171 871 61,923 462 462 39,601 2,815

2035 28 0 0 2,149 850 60,426 462 462 40,450 2,876

2036 29 0 0 2,126 831 59,091 462 462 41,282 2,935

2037 30 0 0 2,104 813 57,799 462 462 42,094 2,993

Total 462 462
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-4

Table 2. Projection Parameters Used in Future Year Emission Inventory Development for 

Existing Wells by Source Category.

Source Category Projection Parameter

Completion Equipment (diesel ICE) totals for year with spuds

Condensate Tank Flashing Losses annual condensate production

Dehydrator Venting - Well Site active well counts

Heaters active well counts

Initial Completion Venting totals for year with spuds

Pneumatic Devices active well counts

Pneumatic Pumps active well counts

Tank Loadout (vapor losses) annual condensate production

Well Stream Fugitive Devices active well counts

Gas Stream Fugitive Devices active well counts

Condensate Fugitive Devices active well counts

Well Venting active well counts

Condensate Tank Working Losses total turnovers per year

Condensate Tank Breathing Losses active well counts

Drilling Equip (diesel ICE) totals for year with spuds

Drilling Traffic (LD) total spuds

Drilling Traffic (HD) total spuds

Completion Traffic (LD) total spuds

Completion Traffic (HD) total spuds

Well Pad Const Equip (diesel ICE) new pads

Construction Dust, Fugitive new pads

Construction Dust, Wind Erosion new pads

Construction Traffic, Road and Well pad (LD) new pads

Construction Traffic, Road and Well pad (HD) new pads

Production Traffic (LD) active well counts

Production Traffic (HD) active well counts

Drilling Traffic (LD) Dust total spuds

Drilling Traffic (HD) Dust total spuds

Completion Traffic (LD) Dust total spuds

Completion Traffic (HD) Dust total spuds

Construction Traffic, Road and Well pad (LD) Dust new pads

Construction Traffic, Road and Well pad (HD) Dust new pads

Production Traffic (LD) Dust active well counts

Production Traffic (HD) Dust active well counts

Workover Equipment (diesel ICE) active well counts

WorkoverTraffic (LD) active well counts

WorkoverTraffic (HD) active well counts

WorkoverTraffic (LD) Dust active well counts

WorkoverTraffic (HD) Dust active well counts
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-5

Source Category Projection Parameter

Compressor Station (Reciprocating Engine Rich Burn) totals for year with compressor station

Compressor Station (Reciprocating Engine Lean Burn) totals for year with compressor station

Compressor Station (Turbine) totals for year with compressor station

Compressor Station (Venting) totals for year with compressor station

Compressor Station (External NG Combustion) totals for year with compressor station

Compressor Station (Flashing) totals for year with compressor station

Compressor Station (Working/Breathing) totals for year with compressor station

Compressor Station (Flaring) totals for year with compressor station

Gas Plant (Reciprocating Engine) totals for year with gas plant

Gas Plant (Turbine) totals for year with gas plant

Gas Plant (flaring) totals for year with gas plant

Gas Plant (natural gas external combustion (boiler/heater)) totals for year with gas plant

Gas Plant (venting) totals for year with gas plant

Condensate Tank Flashing Flaring annual condensate production

Condensate Tank Working Flaring total turnovers per year

Condensate Tank Breathing Flaring active well counts

Production Traffic, Central Facility (HD) None

Production Traffic, Central Facility (HD) Dust None

Evaporation Ponds active well counts
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-6

Table 3. Summary of Projection Factors Used in Future Year Emission Inventory Development for Existing Wells.

Projection New pads 

per Year

Active Well 

Counts per Year

Total Spuds 

per Year

Annual Gas 

Production

(MMSCF/yr)

Annual 

Condensate 

Production

(bbl/yr)

Total 

Turnovers per 

Year

Totals for Year 

with Spuds

Totals for Year 

with 

Compressor 

Station

Totals for 

Year with 

Gas Plant

None

2008 462 2,850 462 193,570 2,726,059 2,850 1 1 1 1

2009 0 2,821 0 182,685 2,569,379 2,821 0 1 1 1

2010 0 2,792 0 157,216 2,211,169 2,792 0 1 1 1

2011 0 2,763 0 143,095 2,012,559 2,763 0 1 1 1

2012 0 2,736 0 140,480 1,975,782 2,736 0 1 1 1

2013 0 2,709 0 138,671 1,950,348 2,709 0 1 1 1

2014 0 2,682 0 131,597 1,850,855 2,682 0 1 1 1

2015 0 2,656 0 124,251 1,747,525 2,656 0 1 1 1

2016 0 2,629 0 117,844 1,657,424 2,629 0 1 1 1

2017 0 2,602 0 112,265 1,578,959 2,602 0 1 1 1

2018 0 2,575 0 107,356 1,509,910 2,575 0 1 1 1

2019 0 2,548 0 102,899 1,447,219 2,548 0 1 1 1

2020 0 2,524 0 98,793 1,389,480 2,524 0 1 1 1

2021 0 2,499 0 95,116 1,337,765 2,499 0 1 1 1

2022 0 2,475 0 90,091 1,267,081 2,475 0 1 1 1

2023 0 2,450 0 86,926 1,222,568 2,450 0 1 1 1

2024 0 2,426 0 83,975 1,181,063 2,426 0 1 1 1

2025 0 2,401 0 81,413 1,145,037 2,401 0 1 1 1

2026 0 2,376 0 78,899 1,109,676 2,376 0 1 1 1

2027 0 2,352 0 76,569 1,076,911 2,352 0 1 1 1

2028 0 2,305 0 74,456 1,047,183 2,305 0 1 1 1

2029 0 2,283 0 70,757 995,158 2,283 0 1 1 1

2030 0 2,260 0 68,803 967,685 2,260 0 1 1 1

2031 0 2,238 0 66,989 942,173 2,238 0 1 1 1

2032 0 2,216 0 65,232 917,459 2,216 0 1 1 1

2033 0 2,193 0 63,513 893,285 2,193 0 1 1 1

2034 0 2,171 0 61,923 870,920 2,171 0 1 1 1

2035 0 2,149 0 60,426 849,856 2,149 0 1 1 1

2036 0 2,126 0 59,091 831,090 2,126 0 1 1 1

2037 0 2,104 0 57,799 812,920 2,104 0 1 1 1
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-7

Gas Composition Analysis

Table 4. Summary of Gas Composition Analysis as Provided in Table 5 through Table 11.
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-8

Assumptions 

Data obtained from operators in blue text

Table 5. Sales Gas Composition Analysis.
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-9

Table 6. Fugitive Post-Flash Gas Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 2.79% 2.79% 44.0 1.2 3.0190% N

Nitrogen 0.02% 0.02% 28.0 0.0 0.0151% N

Methane 34.37% 34.37% 16.0 5.5 13.5728% N

Ethane 13.30% 13.30% 30.1 4.0 9.8429% N

Propane 17.80% 17.80% 44.1 7.9 19.3288% Y 26.28% 11.59

Isobutane 6.84% 6.84% 58.1 4.0 9.7798% Y 13.30% 7.73

n-Butane 9.37% 9.37% 58.1 5.4 13.4078% Y 18.23% 10.60

Isopentane 4.55% 4.55% 72.2 3.3 8.0782% Y 10.98% 7.92

n-Pentane 3.97% 3.97% 72.2 2.9 7.0578% Y 9.60% 6.92

Cyclopentane 0.00% 0.00% 70.1 0.0 0.0000% Y 0.00% 0.00

n-Hexane 1.37% 1.37% 86.2 1.2 2.9160% Y 3.96% 3.42

Cyclohexane 0.30% 0.30% 84.2 0.3 0.6178% Y 0.84% 0.71

2,2-Dimethylbutane 0.09% 0.09% 86.2 0.1 0.1907% Y 0.26% 0.22

2,3-Dimethylbutane 0.35% 0.35% 86.2 0.3 0.7423% Y 1.01% 0.87

2-Methylpentane 1.06% 1.06% 86.2 0.9 2.2383% Y 3.04% 2.62

3-Methylpentane 0.54% 0.54% 86.2 0.5 1.1373% Y 1.55% 1.33

n-Heptane 1.85% 1.85% 100.2 1.9 4.5651% Y 6.21% 6.22

Methylcyclohexane 0.18% 0.18% 98.2 0.2 0.4350% Y 0.59% 0.58

2,2,4-Trimethylpentane 0.07% 0.07% 114.2 0.1 0.1980% Y 0.27% 0.31

Benzene 0.32% 0.32% 78.1 0.2 0.6104% Y 0.83% 0.65

Toluene 0.38% 0.38% 92.1 0.3 0.8601% Y 1.17% 1.08

Ethylbenzene 0.00% 0.00% 106.2 0.0 0.0114% Y 0.02% 0.02

m-Xylene 0.16% 0.16% 106.2 0.2 0.4206% Y 0.57% 0.61

o-Xylene 0.02% 0.02% 106.2 0.0 0.0399% Y 0.05% 0.06

n-Octane 0.22% 0.22% 114.2 0.3 0.6172% Y 0.84% 0.96

n-Nonane 0.05% 0.05% 128.3 0.1 0.1582% Y 0.22% 0.28

n-Decane 0.04% 0.04% 142.3 0.1 0.1395% Y 0.19% 0.27

Total 100.00% 100.00% 40.6 100.00% 65.0
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-10

Table 7. Flash Gas Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 2.80% 2.80% 44.0 1.2 3.0392% N

Nitrogen 0.02% 0.02% 28.0 0.0 0.0149% N

Methane 34.25% 34.25% 16.0 5.5 13.5394% N

Ethane 13.42% 13.42% 30.1 4.0 9.9421% N

Propane 17.98% 17.98% 44.1 7.9 19.5446% Y 26.60% 11.73

Isobutane 6.85% 6.85% 58.1 4.0 9.8099% Y 13.35% 7.76

n-Butane 9.34% 9.34% 58.1 5.4 13.3756% Y 18.21% 10.58

Isopentane 4.48% 4.48% 72.2 3.2 7.9707% Y 10.85% 7.83

n-Pentane 3.91% 3.91% 72.2 2.8 6.9497% Y 9.46% 6.83

Cyclopentane 0.00% 0.00% 70.1 0.0 0.0000% Y 0.00% 0.00

n-Hexane 1.36% 1.36% 86.2 1.2 2.8850% Y 3.93% 3.38

Cyclohexane 0.30% 0.30% 84.2 0.2 0.6125% Y 0.83% 0.70

2,2-Dimethylbutane 0.09% 0.09% 86.2 0.1 0.1877% Y 0.26% 0.22

2,3-Dimethylbutane 0.34% 0.34% 86.2 0.3 0.7319% Y 1.00% 0.86

2-Methylpentane 1.04% 1.04% 86.2 0.9 2.2086% Y 3.01% 2.59

3-Methylpentane 0.53% 0.53% 86.2 0.5 1.1231% Y 1.53% 1.32

n-Heptane 1.85% 1.85% 100.2 1.9 4.5682% Y 6.22% 6.23

Methylcyclohexane 0.18% 0.18% 98.2 0.2 0.4348% Y 0.59% 0.58

2,2,4-Trimethylpentane 0.07% 0.07% 114.2 0.1 0.1981% Y 0.27% 0.31

Benzene 0.31% 0.31% 78.1 0.2 0.6038% Y 0.82% 0.64

Toluene 0.38% 0.38% 92.1 0.3 0.8615% Y 1.17% 1.08

Ethylbenzene 0.00% 0.00% 106.2 0.0 0.0115% Y 0.02% 0.02

m-Xylene 0.16% 0.16% 106.2 0.2 0.4243% Y 0.58% 0.61

o-Xylene 0.02% 0.02% 106.2 0.0 0.0403% Y 0.05% 0.06

n-Octane 0.22% 0.22% 114.2 0.3 0.6219% Y 0.85% 0.97

n-Nonane 0.05% 0.05% 128.3 0.1 0.1598% Y 0.22% 0.28

n-Decane 0.04% 0.04% 142.3 0.1 0.1410% Y 0.19% 0.27

Total 100.00% 100.00% 40.6 100.00% 64.9
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-11

Table 8. Produced Water Working and Breathing Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 29.14% 29.14% 44.010 12.822 24.76% N

Nitrogen 0.00% 0.00% 28.010 0.000 0.00% N

Methane 12.59% 12.59% 16.040 2.019 3.90% N

Ethane 3.02% 3.02% 30.070 0.909 1.76% N

Propane 11.24% 11.24% 44.100 4.956 9.57% Y 13.76% 6.066

Isobutane 8.05% 8.05% 58.120 4.679 9.04% Y 12.99% 7.548

n-Butane 12.65% 12.65% 58.120 7.352 14.20% Y 20.41% 11.861

Isopentane 6.97% 6.97% 72.150 5.031 9.72% Y 13.96% 10.075

n-Pentane 5.97% 5.97% 72.150 4.308 8.32% Y 11.96% 8.628

Cyclopentane 0.00% 0.00% 70.130 0.000 0.00% Y 0.00% 0.000

n-Hexane 2.09% 2.09% 86.180 1.804 3.48% Y 5.01% 4.316

Cyclohexane 3.09% 3.09% 84.160 2.600 5.02% Y 7.22% 6.073

2,2-Dimethylbutane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

2,3-Dimethylbutane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

2-Methylpentane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

3-Methylpentane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

n-Heptane 3.55% 3.55% 100.202 3.558 6.87% Y 9.88% 9.897

Methylcyclohexane 0.00% 0.00% 98.190 0.000 0.00% Y 0.00% 0.000

2,2,4-Trimethylpentane 0.12% 0.12% 114.229 0.142 0.27% Y 0.39% 0.451

Benzene 0.26% 0.26% 78.110 0.200 0.39% Y 0.56% 0.434

Toluene 0.44% 0.44% 92.140 0.406 0.78% Y 1.13% 1.038

Ethylbenzene 0.02% 0.02% 106.170 0.017 0.03% Y 0.05% 0.051

m-Xylene 0.15% 0.15% 106.160 0.156 0.30% Y 0.43% 0.458

o-Xylene 0.00% 0.00% 106.160 0.000 0.00% Y 0.00% 0.000

n-Octane 0.36% 0.36% 114.229 0.415 0.80% Y 1.15% 1.316

n-Nonane 0.12% 0.12% 128.255 0.149 0.29% Y 0.41% 0.531

n-Decane 0.18% 0.18% 142.290 0.254 0.49% Y 0.70% 1.003

Total 100.00% 100.00% 51.777 100.00% 69.745
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-12

Table 9. Condensate Tank Pos.

t-Flash Gas Composition Analysis.

Table 10. Regenerated Overhead Vent Stream Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 0.00% 0.00% 44.010 0.000 0.00% N

Nitrogen 0.00% 0.00% 28.010 0.000 0.00% N

Methane 46.18% 46.18% 16.040 7.407 21.23% N

Ethane 14.42% 14.42% 30.070 4.335 12.43% N

Propane 15.42% 15.42% 44.100 6.801 19.50% Y 29.39% 12.960

Isobutane 5.69% 5.70% 58.120 3.310 9.49% Y 14.30% 8.313

n-Butane 7.51% 7.51% 58.120 4.364 12.51% Y 18.86% 10.961

Isopentane 3.54% 3.54% 72.150 2.557 7.33% Y 11.05% 7.972

n-Pentane 2.87% 2.87% 72.150 2.070 5.93% Y 8.94% 6.453

n-Hexane 0.91% 0.91% 86.180 0.786 2.25% Y 3.40% 2.928

Cyclohexane 0.15% 0.15% 84.160 0.125 0.36% Y 0.54% 0.454

2,2-Dimethylbutane 0.07% 0.07% 86.177 0.062 0.18% Y 0.27% 0.233

2,3-Dimethylbutane 0.24% 0.24% 86.177 0.207 0.59% Y 0.90% 0.771

2-Methylpentane 0.71% 0.71% 86.177 0.614 1.76% Y 2.65% 2.287

3-Methylpentane 0.34% 0.34% 86.177 0.294 0.84% Y 1.27% 1.093

n-Heptane 1.23% 1.23% 100.202 1.228 3.52% Y 5.31% 5.319

Methylcyclohexane 0.10% 0.10% 98.190 0.098 0.28% Y 0.42% 0.414

2,2,4-Trimethylpentane 0.04% 0.04% 114.229 0.049 0.14% Y 0.21% 0.242

Benzene 0.14% 0.14% 78.110 0.111 0.32% Y 0.48% 0.373

Toluene 0.16% 0.16% 92.140 0.145 0.42% Y 0.63% 0.579

Ethylbenzene 0.00% 0.00% 106.170 0.002 0.01% Y 0.01% 0.009

Xylenes 0.08% 0.08% 106.170 0.081 0.23% Y 0.35% 0.370

n-Octane 0.11% 0.11% 114.229 0.131 0.37% Y 0.56% 0.645

n-Nonane 0.04% 0.04% 128.255 0.046 0.13% Y 0.20% 0.257

n-Decane 0.04% 0.04% 142.290 0.061 0.17% Y 0.26% 0.374

Total 100.00% 100.00% 0.000 34.884 100.00% 100.00% 63.007

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Water 17.54% 17.54% 18.010 3.159 11.56% N

Carbon Dioxide 5.47% 5.47% 44.010 2.407 8.81% N

Nitrogen 0.11% 0.11% 28.010 0.032 0.12% N

Methane 55.61% 55.61% 16.040 8.920 32.64% N

Ethane 6.19% 6.19% 30.070 1.861 6.81% N

Propane 3.98% 3.98% 44.100 1.755 6.42% Y 16.03% 7.069

Isobutane 1.07% 1.07% 58.120 0.622 2.28% Y 5.68% 3.301

n-Butane 1.49% 1.49% 58.120 0.866 3.17% Y 7.91% 4.597

Isopentane 0.57% 0.57% 72.150 0.413 1.51% Y 3.77% 2.719

n-Pentane 0.58% 0.58% 72.150 0.421 1.54% Y 3.85% 2.776

n-Hexane 0.33% 0.33% 86.180 0.286 1.05% Y 2.61% 2.252

Cyclohexane 0.62% 0.62% 84.160 0.523 1.92% Y 4.78% 4.024

Other Hexanes 0.37% 0.37% 86.180 0.320 1.17% Y 2.92% 2.517

n-Heptane 0.61% 0.61% 100.202 0.615 2.25% Y 5.62% 5.630

Methylcyclohexane 0.79% 0.79% 98.190 0.775 2.83% Y 7.08% 6.947

2,2,4-Trimethylpentane 0.02% 0.02% 114.229 0.022 0.08% Y 0.20% 0.226

Benzene 1.35% 1.35% 78.110 1.055 3.86% Y 9.63% 7.522

Toluene 1.89% 1.89% 92.140 1.741 6.37% Y 15.90% 14.654

Ethylbenzene 0.06% 0.06% 106.170 0.065 0.24% Y 0.59% 0.628

Xylenes 0.60% 0.60% 106.170 0.641 2.35% Y 5.86% 6.218

n-Octane 0.73% 0.73% 114.229 0.829 3.03% Y 7.57% 8.652

Total 100.00% 100.00% 27.329 100.00% 100.00% 79.734
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-13

Table 11. Wet Gas Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 2.73% 2.73% 44.010 1.203 6.09% N

Nitrogen 0.17% 0.17% 28.010 0.048 0.24% N

Methane 84.98% 84.98% 16.040 13.631 69.04% N

Ethane 6.81% 6.81% 30.070 2.049 10.38% N

Propane 3.17% 3.17% 44.100 1.398 7.08% Y 49.67% 21.906

Isobutane 0.64% 0.64% 58.120 0.370 1.87% Y 13.14% 7.634

n-Butane 0.71% 0.71% 58.120 0.413 2.09% Y 14.67% 8.528

Isopentane 0.24% 0.24% 72.150 0.175 0.88% Y 6.21% 4.478

n-Pentane 0.20% 0.20% 72.150 0.144 0.73% Y 5.11% 3.686

n-Hexane 0.06% 0.06% 86.180 0.056 0.28% Y 1.98% 1.710

Cyclohexane 0.03% 0.03% 84.160 0.027 0.14% Y 0.95% 0.800

2,2-Dimethylbutane 0.00% 0.00% 86.177 0.004 0.02% Y 0.13% 0.113

2,3-Dimethylbutane 0.02% 0.02% 86.177 0.014 0.07% Y 0.50% 0.433

2-Methylpentane 0.05% 0.05% 86.177 0.042 0.21% Y 1.49% 1.288

3-Methylpentane 0.03% 0.03% 86.177 0.022 0.11% Y 0.77% 0.662

n-Heptane 0.06% 0.06% 100.202 0.059 0.30% Y 2.09% 2.094

Methylcyclohexane 0.03% 0.03% 98.190 0.032 0.16% Y 1.12% 1.103

2,2,4-Trimethylpentane 0.00% 0.00% 114.229 0.004 0.02% Y 0.15% 0.176

Benzene 0.01% 0.01% 78.110 0.012 0.06% Y 0.41% 0.323

Toluene 0.02% 0.02% 92.140 0.016 0.08% Y 0.57% 0.525

Ethylbenzene 0.00% 0.00% 106.170 0.001 0.00% Y 0.02% 0.020

m&p-Xylene 0.00% 0.00% 106.160 0.004 0.02% Y 0.15% 0.164

o-Xylene 0.00% 0.00% 106.160 0.001 0.00% Y 0.02% 0.024

n-Octane 0.01% 0.01% 114.229 0.016 0.08% Y 0.56% 0.635

n-Nonane 0.01% 0.01% 128.255 0.008 0.04% Y 0.27% 0.345

n-Decane 0.00% 0.00% 142.290 0.000 0.00% Y 0.00% 0.000

Total 100.00% 100.00% 19.745 100.00% 100.00% 56.648
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-14

Table 12. Toxic Speciation Profiles Used in Future Year Emission Inventory Development for Existing Wells.

benzene toluene ethylbenzene xylenes n-hexane formaldehyde

venting other than well venting, initial completion 

and dehydrator 0.403% 0.555% 0.017% 0.320% 4.744% 0.000%

flashing loss 0.822% 1.173% 0.016% 0.632% 3.927% 0.000%

Fugitive -working/breathing loss 0.830% 1.169% 0.016% 0.626% 3.965% 0.000%

diesel ICE 1.045% 1.518% 0.179% 1.205% 0.000% 8.510%

HD traffic 1.132% 0.613% 0.152% 0.801% 0.129% 7.924%

LD traffic 3.711% 10.147% 1.459% 5.744% 0.879% 2.456%

natural gas external combustion (boiler/heater) 4.000% 2.000% 0.000% 0.000% 0.000% 8.000%

dust 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%

compressor engine, lean burn 0.373% 0.346% 0.034% 0.156% 0.941% 44.746%

compressor engine, rich burn 5.338% 1.885% 0.084% 0.659% 0.000% 69.257%

natural gas drilling engine 0.373% 0.346% 0.034% 0.156% 0.941% 44.746%

flaring 0.000% 0.000% 0.000% 0.000% 0.000% 40.000%

diesel external combustion boiler 0.000% 0.000% 0.000% 0.000% 10.800% 48.700%

Reciprocating Engine 1.182% 0.430% 0.107% 0.430% 0.215% 8.700%

Turbine 0.000% 0.000% 0.000% 0.000% 0.000% 100.000%

produced water evaporation 13.858% 18.028% 1.529% 24.393% 0.147% 0.000%

Tank -working/breathing loss 0.478% 0.629% 0.009% 0.348% 3.398% 0.000%

Dehydrator Venting 9.631% 15.905% 0.591% 5.857% 2.613% 0.000%

venting -Well Venting and Initial completion 0.414% 0.570% 0.019% 0.177% 1.984% 0.000%

Source Type for lookup

VOC fractions

Source

Wamsutter Produced Gas Composition

Flash speciation from Wamsutter HYSYS

Wamsutter Fugitive Composition (Post Flash)

SPECIATE4, Profile 4674

From Catherine Yanca at EPA based on CRC E-55/E-59 Study

From David Brzezinski at EPA and MOVES

SPECIATE4, Profile 0003

AP-42, CH 3.2

AP-42, CH 3.2

AP-42, CH 3.2

SPECIATE4, Profile 1001

SPECIATE4, Profile 0002

SPECIATE4, Profile 1001

SPECIATE4, Profile 0007

EPA, Water 9 model Output. Based on data from evaporation 

facilities at Wamsutter Operations Center

Wamsutter Condensate Composition (Post Flash)

Wamsutter Regenerator Overhead Vent Stream Composition

Wamsutter Wet Gas Composition
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-15

Table 13. List of Toxic Speciation Profiles Used in Emission Inventory Development for 

Existing Wells by Source Category.
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-16

2008 Well Pad Construction Equipment Emissions 

ASSUMPTIONS

Activity data obtained from operator in blue text

Assumptions:

* Emission factors from EPA Federal Diesel Engine Standards 

http://www.epa.gov/otaq/standar

ds/nonroad/nonroadci.htm

* VOC/THC= 1.053 Conversion for HC->VOC for diesel engines (EPA, 2005; EPA420-R-05-0159, p. 5)

*

37% of fine particles assumed to be filterable and all filterable are assigned to EC (Source: AQTSD for Hell’s Gulch 

and Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

*

63% of fine particles assumed to be filterable and all filterable are assigned to SOA (Source: AQTSD for Hell’s Gulch 

and Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

EPA NONROAD model Fully Deteriorated Tier Emission Factors

N2O Emission factors (g/gallons) from The Climate Registry, General Reporting Protocol v1.1, Table 13.6

Equations:

Emissions (tons/year-well) = Emission factor (g/hp-hr) * Horsepower * Time Used (hours) * Load

453.6 (g/lb) * 2000 (lbs/ton)

PM2.5/PM10 = 97% EPA (2004) NONROAD

VOC/HC= 1.053 EPA NONROAD HC Conversions

NMHC/THC= 98.40% EPA NONROAD HC Conversions

SO2 Emission Factor Calculation Information 

2008 Fuel Sulfur content 0.0355 sulfur fuel weight percent from EPA's NMIM 

County Database

soxcnv Tiers I-III 0.02247 grams PM sulfur/grams fuel sulfur consumed

soxcnv Tier IV 0.3

grams PM sulfate/grams PM sulfur 7

soxbas 0.33

Density of Diesel Fuel 7.09 lb/gallons

Molecular weight of S 32 g/mol

Molecular weight of S02 64 g/mol

453.6 g/lb
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-17

Table 14. 2008 Well Pad Construction Equipment Emissions (lb/well pad) by Pollutants 

and by Equipment Type.

Loader

1

Diesel

Tier 1

200

175-300

60

0.4

0.433

293

NOx 6.860 72.60

VOC 1.021 10.80

CO 8.501 89.96

PM10 0.403 4.26

PM2.5 0.391 4.13

SO2 0.136 1.44

CO2 623 6597.37

CH4 0.016 0.16

PM_filt 0.145 1.53

PM_cond 0.246 2.60

(g/gal) N2O 0.260 0.17

Dozer

1

Diesel

Tier 1

500

300-600

60

0.4

0.371

628

NOx 6.860 181.49

VOC 1.021 27.00

CO 8.501 224.89

PM10 0.403 10.65

PM2.5 0.391 10.33

SO2 0.116 3.07

CO2 534 14120.07

CH4 0.016 0.41

PM_filt 0.145 3.82

PM_cond 0.246 6.51

(g/gal) N2O 0.260 0.36

Scraper

2

Diesel

Tier 1

700

600-750

60

0.4

0.371

1758

NOx 6.860 508.18

VOC 1.021 75.61

CO 8.501 629.70

PM10 0.403 29.83

PM2.5 0.391 28.93

SO2 0.116 8.60

CO2 534 39536.20

CH4 0.016 1.15

PM_filt 0.145 10.71

PM_cond 0.246 18.23

(g/gal) N2O 0.260 1.01

Engine Function

Number of Engines

Fuel Type

Engine Technology

Fuel Consumption 

Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Engine 2

Emission 

Factors 

(g/bhp-hr)

Emission 

Factors 

(g/bhp-hr)

Engine Technology

Rated horsepower

Load Factor

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Engine Function

Number of Engines

Fuel Type

BSFC (lb/hp-hr)

Rated horsepower

Horsepower Range

Time used (hrs)

Engine 1

Fuel Consumption 

Load Factor

BSFC (lb/hp-hr)

Equipment

Activity & Emission 

Factors

Emissions 

(lb/well pad)

Emission 

Factors 

(g/bhp-hr)

Engine 3

Fuel Consumption 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-18

Grader

1

Diesel

Tier 1

350

300-600

60

0.4

0.371

440

NOx 6.860 127.05

VOC 1.021 18.90

CO 8.501 157.43

PM10 0.403 7.46

PM2.5 0.391 7.23

SO2 0.116 2.15

CO2 534 9884.05

CH4 0.016 0.29

PM_filt 0.145 2.68

PM_cond 0.246 4.56

(g/gal) N2O 0.260 0.25

Backhoe

1

Diesel

Tier 1

60

50-75

60

0.4

0.481

98

NOx 6.860 21.78

VOC 1.314 4.17

CO 6.425 20.40

PM10 1.076 3.42

PM2.5 1.044 3.31

SO2 0.151 0.48

CO2 692 2196.89

CH4 0.020 0.06

PM_filt 0.386 1.23

PM_cond 0.658 2.09

(g/gal) N2O 0.260 0.06

Roller

1

Diesel

Tier 1

200

175-300

60

0.4

0.371

251

NOx 6.860 72.60

VOC 1.021 10.80

CO 8.501 89.96

PM10 0.403 4.26

PM2.5 0.391 4.13

SO2 0.116 1.23

CO2 534 5648.03

CH4 0.016 0.16

PM_filt 0.145 1.53

PM_cond 0.246 2.60

(g/gal) N2O 0.260 0.14

Emission 

Factors 

(g/bhp-hr)

Emission 

Factors 

(g/bhp-hr)

Emission 

Factors 

(g/bhp-hr)

Activity & Emission 

Factors

Emissions 

(lb/well pad)

BSFC (lb/hp-hr)

Fuel Consumption 

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

Engine Function

Number of Engines

Equipment

BSFC (lb/hp-hr)

Engine 4

Fuel Consumption 

Engine 5 Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Fuel Consumption 

Engine 6 Engine Function

Number of Engines

Fuel Type
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-19

Water Truck

1

Diesel

Tier 1

210

175-300

60

0.4

0.371

264

NOx 6.860 76.23

VOC 1.021 11.34

CO 8.501 94.46

PM10 0.403 4.47

PM2.5 0.391 4.34

SO2 0.116 1.29

CO2 534 5930.43

CH4 0.016 0.17

PM_filt 0.145 1.61

PM_cond 0.246 2.73

(g/gal) N2O 0.260 0.15

Dump Truck

1

Diesel

Tier 1

330

300-600

60

0.4

0.371

414

NOx 6.860 119.79

VOC 1.021 17.82

CO 8.501 148.43

PM10 0.403 7.03

PM2.5 0.391 6.82

SO2 0.116 2.03

CO2 534 9319.25

CH4 0.016 0.27

PM_filt 0.145 2.52

PM_cond 0.246 4.30

(g/gal) N2O 0.260 0.24

Trencher

1

Diesel

Tier 1

250

175-300

60

0.4

0.371

314

NOx 6.860 90.75

VOC 1.021 13.50

CO 8.501 112.45

PM10 0.403 5.33

PM2.5 0.391 5.17

SO2 0.116 1.54

CO2 534 7060.04

CH4 0.016 0.21

PM_filt 0.145 1.91

PM_cond 0.246 3.25

(g/gal) N2O 0.260 0.18

Emission 

Factors 

(g/bhp-hr)

Emission 

Factors 

(g/bhp-hr)

Emission 

Factors 

(g/bhp-hr)

Equipment

Activity & Emission 

Factors

Emissions 

(lb/well pad)

Engine 8 Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Fuel Consumption 

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Engine 7 Engine Function

Number of Engines

Fuel Type

Engine 9 Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Fuel Consumption 

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Fuel Consumption 

BSFC (lb/hp-hr)

Load Factor
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-20

Table 15. Summary of 2008 Well Pad Construction Emissions (lb/well pad) by Pollutants for All Equipment.

Table 16. 2008 Well Pad Construction Equipment Emissions in tons per pad.

NOx 1,270

VOC 190

CO 1,568

PM10 77

PM2.5 74

SO2 22

CO2 100,292

CH4 3

PM_filt 28

PM_cond 47

N2O 3

Equipment Type Pollutant Emissions

(lb/year-well pad) 

Well Pad 

Construction 

Equipment

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Well Pad Const Equip (diesel ICE) 0.6352 0.0950 0.7838 0.0384 0.0372 0.0109 50.1462 0.0014 0.0138 0.0234 0.0013 new pads

Description Projection Well Pad Construction Equipment Emissions (tons per pad)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-21

Table 17. Percent Change in Emission from Base Year 2008 for Well Pad Construction (aggregate factors to apply to total emissions across 

all equipment types).

Technology 

Assumption Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

Tier 1 2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-22

2008 Drilling and Completion Equipment Emissions

ASSUMPTIONS

Data provided by operators in blue text

Annual drill rig and well completion emissions (NOx, CO, VOC, SO2, and PM10) were developed 

for all drill rig and completion events that were recorded in the CDC project area during 2008. 

Emissions were developed based on Wyoming Oil and Gas Conservation Commission (WOGCC) 

data and from data provided by the operators to the WDEQ-AQD as part of the 2008 minor 

source inventory submittals. 

Well spud date and well depth data were obtained from the Wyoming Oil and Gas Commission 

(WOGCC) for all wells drilled in the project area beginning in November 2007 through 

December 2008. Well identification numbers were crossed checked between the WOGCC data 

and the WDEQ inventory files. Based on this comparison three data groups were established:

(1) Drilling and completion events that were included in the WDEQ data but not listed in the 

WOGCC database.

(2) Drilling and completion events common to both the WDEQ operator data and to WOGCC 

files.

(3) WOGCC well spud data information that was not included the WDEQ operator data.

The operator provided well completion data included in groups (1) and (2) were incorporated 

directly into the database.

For data group (3), where WOGCC spud information was available but no operator data were 

provided, average drilling rig emissions were developed from the operator data in group (2) and 

average completion emissions were developed from the operator data in groups (1) and (2). 

Specifically, average drill rig emissions and average well depth were determined for the wells in 

group (2). The drill rig emissions for wells in group (3) were determined by scaling the average 

emissions from the group (2) wells by the ratio of the average well depth of group (2) wells by 

the well depth of the group (3) well. [Note group (1) drilling data did not include WOGCC well 

depth so it was not used for the group (3) averages] Average completion emissions for the 

group (1) and (2) wells were applied for all group (3) wells. Where information was available 

that indicated that a drilling event had not completed during 2008 then completion emissions 

were not applied to these wells. For these drilling events, the drilling emissions were scaled 

based on the percent completed during 2008. 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-23

Table 18. Summary of 2008 Drilling and Completion Emissions (tons/year) by Pollutant.

Diesel Exhuast HC conversions (source: EPA NONROAD model documentation)

VOC/THC 1.053

NMHC/THC 0.984

CH4/THC 0.016

CH4/VOC 0.015

Diesel Exhuast PM2.5 conversions (source: EPA NONROAD model documentation)

PM2.5/PM10 97%

Fuel Consumption Drilling Completion

fuel sulfur 355 355 ppmw

fuel consumption 28,022,106 22,336,171 gallons

CO2/fuel consumption 10.21 10.21 kgCO2/gallon (source Climate Registry GHG Protocol)

diesel density 7.1 7.1 pounds/gallon

conversion 2.204 2.204 pounds/kilogram

CO2/fuel consumption 3.169 3.169 lbCO2/lbfuel

CO2 emissions 44,407 35,396 tons

N2O emission factor 0.260 0.260 grams/gallons

Molecular weight of S 32 32 g/mol

Molecular weight of S02 64 64 g/mol

Per NSPS Guidance, 37% of fine particles assumed to be filterable and all filterable are assigned to EC

Per NSPS Guidance, 63% of fine particles assumed to be filterable and all filterable are assigned toSOA

Venting GHG Conversions

VOC Fraction (weight) 15%

CO2 Fraction (weight) 6%

CH4 Fraction (weight) 69%

CH4/VOC 471%

CO2/VOC 42%

Emissions 

(tons/year) Drilling Completion (diesel ICE)

Completion 

(venting)

NOx 1166.3 168.8 0.0

VOC 105.9 0.0 129.8

CO 503.8 131.7 0.0

PM10 55.8 12.4 0.0

PM2.5 54.1 12.0 0.0

SO2 70.6 56.3 0.0

CO2 44,406.8 35,396.3 53.9

CH4 1.6 0.0 611.0

PM_filt 20.0 4.4 0.0

PM_cond 34.1 7.6 0.0

N2O 8.0 6.4 0.0

assumed all VOC emissions from venting
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-24

Table 19. Total 2008 Drilling and Completion Equipment Emissions in tons per year.

Table 20. Percent Change in Emission from Base Year 2008 for Drilling and Completion 

(aggregate factors to apply to total emissions across all equipment types).

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Drilling Equip (diesel ICE) 1,166.29 105.91 503.84 55.75 54.08 70.63 44,406.83 1.61 20.01 34.07 8.03

totals for year with 

spuds

Completion Equipment (diesel 

ICE) 168.79 0 131.70 12.37 11.99 56.30 35,396.29 0 4.44 7.56 6.40

totals for year with 

spuds

Initial Completion Venting 0 129.77 0 0 0 0 53.91 610.97 0 0 0

totals for year with 

spuds

Description Projection Drill Rig Emissions - total 2008 tons per year Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

unused values - no drilling activity post-2008 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-25

2008 Well Pad and Access Road Construction Traffic Emissions

ASSUMPTIONS

Data provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2008 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

CONSTRUCTION TRAFFIC.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-26

NOx 2.67 1.649

SO2 0.02 0.015

CO 19.44 12.002

CO2 677.28 418

VOC 1.57 0.968

PM10 0.09 0.056

PM2.5 0.09 0.053

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.057

N2O 0.05 0.030

NOx 21.75 20.140

SO2 0.08 0.076

CO 15.96 14.782

CO2 2612.85 2419.310

VOC 1.93 1.789

PM10 1.30 1.206

PM2.5 1.26 1.169

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.084

N2O 0.04 0.035

Vehicle Type Pollutant 2008 Emission 

Factors (g/mile)

Base year 

Emissions 

(lb/well pad)

Heavy-Duty Truck 

Light-Duty Truck

Table 21. Summary of Traffic Activity Data Associated with Well Pad and Access Road 

Construction Phase.

Table 22. 2008 Exhaust Emissions (lb/pad) Associated with Well Pad and Access Road 

Construction Traffic by Vehicle Type.

Light Truck 20 20 14

Heavy Truck 20 20 21

Number of 

Round Trips 

Per Well

Equipment Type Mean Vehicle 

Speed (mph)

Round Trip OffRoad Trip Distance 

(miles)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-27

Table 23. Summary of 2008 Fugitive Dust Emissions (tons/well pad) Associated with Well Pad and Access Road Construction Traffic.

Table 24. 2008 Exhaust and Fugitive Dust Emissions Associated with Well Pad and Access Road Construction Traffic in tons per well pad.

Travel to well Light truck 7,000 20 14 14 20 280 0.20 0.03 0.02 0.00

Travel to well Heavy Truck 70,000 20 21 21 20 420 0.20 0.04 0.02 0.00

Total 0.07 0.01

P M2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well)

Activity Vehicle Type Av. Vehicle Weight (lb) Mean vehicle speed 

(mph)

# of Visits per 

Year 

Total # of Round 

Trips

Round Trip 

Distance (mi)

Total Miles 

Traveled

P M10

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Construction Traffic, Road 

and Well pad (LD) 0.0008 0.0005 0.0060 2.79E-05 2.65E-05 7.30E-06 0.2090 2.86E-05 0 0 1.50E-05 new pads 0.0277 0.0028

Construction Traffic, Road 

and Well pad (HD) 0.0101 0.0009 0.0074 0.0006 0.0006 3.80E-05 1.2097 4.18E-05 0 0 1.73E-05 new pads 0.0416 0.0041

Description Total Road and Well Pad Construction Traffic Emissions (tons per well pad) Fugitive Road Projection
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-28

Table 25. Percent Change in Emission from Base Year 2008 due to Fleet Turnover for Well Pad and Access Road Construction Traffic.

NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 -6% -39% -6% 0% -6% -4% -4% 0% 0% -8% -6% -7% -2% -6% 0% -4% -7% -7% 0% 0% 0% -5%

2010 -10% -46% -10% -1% -10% -9% -9% 0% 0% -12% -12% -16% -47% -9% 0% -6% -14% -14% 0% 0% 4% -10%

2011

-15% -50% -13% -2% -15% -16% -16% 0% 0% -15% -19% -25% -75% -14% 0% -13% -24% -24% 0% 0% 13% -16%

2012 -21% -55% -16% -3% -21% -22% -22% 0% 0% -19% -25% -33% -75% -19% 0% -21% -33% -33% 0% 0% 20% -21%

2013 -26% -56% -20% -4% -26% -27% -28% 0% 0% -22% -32% -41% -76% -24% 0% -28% -41% -41% 0% 0% 24% -27%

2014 -32% -57% -24% -5% -32% -33% -33% 0% 0% -25% -37% -48% -76% -28% 0% -34% -49% -49% 0% 0% 28% -32%

2015 -37% -57% -27% -7% -36% -38% -38% 0% 0% -28% -42% -54% -76% -32% 0% -40% -56% -56% 0% 0% 30% -36%

2016 -42% -58% -30% -9% -41% -42% -43% 0% 0% -31% -47% -60% -77% -37% 0% -46% -63% -63% 0% 0% 31% -40%

2017 -46% -59% -33% -10% -45% -46% -47% 0% 0% -34% -51% -65% -77% -40% 0% -51% -68% -68% 0% 0% 32% -44%

2018 -50% -60% -35% -12% -49% -50% -50% 0% 0% -36% -55% -69% -77% -43% 0% -56% -73% -73% 0% 0% 32% -47%

2019 -53% -60% -37% -13% -52% -53% -53% 0% 0% -38% -58% -73% -77% -45% 0% -60% -77% -77% 0% 0% 33% -50%

2020 -57% -61% -38% -14% -55% -55% -56% 0% 0% -39% -61% -76% -77% -47% 0% -64% -81% -81% 0% 0% 34% -53%

2021 -59% -62% -40% -16% -58% -57% -58% 0% 0% -41% -64% -78% -77% -49% 0% -67% -83% -83% 0% 0% 34% -55%

2022 -66% -63% -44% -19% -64% -63% -64% 0% 0% -43% -71% -84% -78% -53% 0% -74% -90% -90% 0% 0% 34% -61%

2023 -62% -62% -41% -17% -60% -59% -60% 0% 0% -42% -67% -81% -78% -51% 0% -70% -86% -86% 0% 0% 34% -58%

2024 -64% -63% -43% -18% -63% -61% -62% 0% 0% -43% -69% -82% -78% -52% 0% -72% -88% -88% 0% 0% 34% -60%

2025 -68% -64% -45% -19% -67% -64% -65% 0% 0% -44% -72% -85% -78% -54% 0% -76% -91% -91% 0% 0% 34% -63%

2026 -70% -64% -46% -20% -69% -66% -66% 0% 0% -43% -74% -86% -78% -56% 0% -79% -92% -92% 0% 0% 36% -65%

2027 -71% -64% -47% -21% -71% -67% -68% 0% 0% -43% -75% -87% -78% -56% 0% -80% -93% -93% 0% 0% 36% -66%

2028 -72% -64% -48% -21% -72% -68% -69% 0% 0% -44% -76% -88% -78% -57% 0% -81% -94% -94% 0% 0% 36% -67%

2029 -73% -65% -48% -22% -73% -69% -70% 0% 0% -45% -78% -88% -78% -58% 0% -83% -94% -94% 0% 0% 35% -68%

2030 -74% -65% -49% -22% -75% -70% -70% 0% 0% -45% -78% -89% -78% -58% 0% -84% -95% -95% 0% 0% 35% -69%

2031 -75% -65% -50% -23% -76% -70% -71% 0% 0% -47% -79% -89% -78% -59% 0% -85% -95% -95% 0% 0% 34% -70%

2032 -76% -65% -50% -23% -76% -71% -72% 0% 0% -47% -80% -89% -78% -60% 0% -85% -95% -95% 0% 0% 34% -70%

2033 -77% -66% -51% -24% -77% -72% -72% 0% 0% -48% -80% -89% -78% -61% 0% -86% -95% -95% 0% 0% 33% -71%

2034 -77% -66% -52% -24% -78% -72% -73% 0% 0% -48% -81% -90% -78% -61% 0% -86% -96% -96% 0% 0% 33% -71%

2035 -78% -66% -52% -24% -78% -73% -73% 0% 0% -48% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 33% -72%

2036 -78% -66% -53% -24% -79% -73% -74% 0% 0% -49% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 32% -72%

2037 -78% -66% -53% -25% -79% -73% -74% 0% 0% -49% -81% -90% -78% -63% -1% -87% -96% -96% 0% 0% 32% -72%

Year

Light-Duty Truck Heavy-Duty Truck 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-29

2008 Drilling Construction Traffic Emissions

ASSUMPTIONS

Data Provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2008 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

DRILLING TRAFFIC

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-30

Table 26. Summary of Traffic Activity Data Associated with Drilling Phase.

Table 27. 2008 Exhaust Emissions (lb/spud) Associated with Drilling Traffic by Vehicle Type.

Table 28. Summary of 2008 Fugitive Dust Emissions (tons/spud) Associated with Drilling 

Traffic.

Table 29. 2008 Exhaust and Fugitive Dust Emissions Associated with Drilling Traffic in tons 

per spud.

Light Truck 20 20 98

Heavy Truck 20 20 224

Number of 

Round Trips 

Per Well

Equipment Type Mean Vehicle 

Speed (mph)

Round Trip Off-Road 

Trip Distance (miles)

NOx 2.67 11.546

SO2 0.02 0.102

CO 19.44 84.017

CO2 677.28 2927

VOC 1.57 6.777

PM10 0.09 0.390

PM2.5 0.09 0.370

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.401

N2O 0.05 0.209

NOx 21.75 214.823

SO2 0.08 0.810

CO 15.96 157.678

CO2 2612.85 25805.971

VOC 1.93 19.086

PM10 1.30 12.868

PM2.5 1.26 12.474

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.893

N2O 0.04 0.369

Vehicle Type Pollutant 2008 Emission 

Factors (g/mile)

Base year Emissions 

(lb/spud)

Light-Duty 

Truck

Heavy-Duty 

Truck 

Travel to well Light truck 7,000 20 98 98 20 1960 0.20 0.1940 0.02 0.0193

Travel to well Heavy Truck 70,000 20 224 224 20 4480 0.20 0.4435 0.02 0.0440

Total 0.40 0.64 0.04 0.06

Total # of 

Round 

Trips

Round 

Trip 

Distance 

(mi)

Total 

Miles 

Traveled

PM10

Activity Vehicle 

Type

Av. Vehicle 

Weight (lb)

Mean vehicle 

speed (mph)

# of Visits 

per Year 

PM2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spudl)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spud)

Projection

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Drilling Traffic (LD) 0.0058 0.0034 0.0420 0.0002 0.0002 5.11E-05 1.4633 0.0002 0 0 0.0001 total spuds 0.1940 0.0193

Drilling Traffic (HD) 0.1074 0.0095 0.0788 0.0064 0.0062 0.0004 12.9030 0.0004 0 0 0.0002 total spuds 0.4435 0.0440

Description Total Drill Traffic Emissions (tons per spud) Fugitive Road Dust 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-31

Table 30. Percent Change in Emission from Base Year 2008 Due to Fleet Turnover for Drilling Traffic.

NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 -6% -39% -6% 0% -6% -4% -4% 0% 0% -8% -6% -7% -2% -6% 0% -4% -7% -7% 0% 0% 0% -5%

2010 -10% -46% -10% -1% -10% -9% -9% 0% 0% -12% -12% -16% -47% -9% 0% -6% -14% -14% 0% 0% 4% -10%

2011 -15% -50% -13% -2% -15% -16% -16% 0% 0% -15% -19% -25% -75% -14% 0% -13% -24% -24% 0% 0% 13% -16%

2012 -21% -55% -16% -3% -21% -22% -22% 0% 0% -19% -25% -33% -75% -19% 0% -21% -33% -33% 0% 0% 20% -21%

2013 -26% -56% -20% -4% -26% -27% -28% 0% 0% -22% -32% -41% -76% -24% 0% -28% -41% -41% 0% 0% 24% -27%

2014 -32% -57% -24% -5% -32% -33% -33% 0% 0% -25% -37% -48% -76% -28% 0% -34% -49% -49% 0% 0% 28% -32%

2015 -37% -57% -27% -7% -36% -38% -38% 0% 0% -28% -42% -54% -76% -32% 0% -40% -56% -56% 0% 0% 30% -36%

2016 -42% -58% -30% -9% -41% -42% -43% 0% 0% -31% -47% -60% -77% -37% 0% -46% -63% -63% 0% 0% 31% -40%

2017 -46% -59% -33% -10% -45% -46% -47% 0% 0% -34% -51% -65% -77% -40% 0% -51% -68% -68% 0% 0% 32% -44%

2018 -50% -60% -35% -12% -49% -50% -50% 0% 0% -36% -55% -69% -77% -43% 0% -56% -73% -73% 0% 0% 32% -47%

2019 -53% -60% -37% -13% -52% -53% -53% 0% 0% -38% -58% -73% -77% -45% 0% -60% -77% -77% 0% 0% 33% -50%

2020 -57% -61% -38% -14% -55% -55% -56% 0% 0% -39% -61% -76% -77% -47% 0% -64% -81% -81% 0% 0% 34% -53%

2021 -59% -62% -40% -16% -58% -57% -58% 0% 0% -41% -64% -78% -77% -49% 0% -67% -83% -83% 0% 0% 34% -55%

2022 -66% -63% -44% -19% -64% -63% -64% 0% 0% -43% -71% -84% -78% -53% 0% -74% -90% -90% 0% 0% 34% -61%

2023 -62% -62% -41% -17% -60% -59% -60% 0% 0% -42% -67% -81% -78% -51% 0% -70% -86% -86% 0% 0% 34% -58%

2024 -64% -63% -43% -18% -63% -61% -62% 0% 0% -43% -69% -82% -78% -52% 0% -72% -88% -88% 0% 0% 34% -60%

2025 -68% -64% -45% -19% -67% -64% -65% 0% 0% -44% -72% -85% -78% -54% 0% -76% -91% -91% 0% 0% 34% -63%

2026 -70% -64% -46% -20% -69% -66% -66% 0% 0% -43% -74% -86% -78% -56% 0% -79% -92% -92% 0% 0% 36% -65%

2027 -71% -64% -47% -21% -71% -67% -68% 0% 0% -43% -75% -87% -78% -56% 0% -80% -93% -93% 0% 0% 36% -66%

2028 -72% -64% -48% -21% -72% -68% -69% 0% 0% -44% -76% -88% -78% -57% 0% -81% -94% -94% 0% 0% 36% -67%

2029 -73% -65% -48% -22% -73% -69% -70% 0% 0% -45% -78% -88% -78% -58% 0% -83% -94% -94% 0% 0% 35% -68%

2030 -74% -65% -49% -22% -75% -70% -70% 0% 0% -45% -78% -89% -78% -58% 0% -84% -95% -95% 0% 0% 35% -69%

2031 -75% -65% -50% -23% -76% -70% -71% 0% 0% -47% -79% -89% -78% -59% 0% -85% -95% -95% 0% 0% 34% -70%

2032 -76% -65% -50% -23% -76% -71% -72% 0% 0% -47% -80% -89% -78% -60% 0% -85% -95% -95% 0% 0% 34% -70%

2033 -77% -66% -51% -24% -77% -72% -72% 0% 0% -48% -80% -89% -78% -61% 0% -86% -95% -95% 0% 0% 33% -71%

2034 -77% -66% -52% -24% -78% -72% -73% 0% 0% -48% -81% -90% -78% -61% 0% -86% -96% -96% 0% 0% 33% -71%

2035 -78% -66% -52% -24% -78% -73% -73% 0% 0% -48% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 33% -72%

2036 -78% -66% -53% -24% -79% -73% -74% 0% 0% -49% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 32% -72%

2037 -78% -66% -53% -25% -79% -73% -74% 0% 0% -49% -81% -90% -78% -63% -1% -87% -96% -96% 0% 0% 32% -72%

Heavy-Duty Truck 

Year

Light-Duty Truck
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-32

2008 Well Completion Traffic Emissions

ASSUMPTIONS

Data Provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2008 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

WELL COMPLETION TRAFFIC

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-33

Table 31. Summary of Traffic Activity Data Associated with Well Completion Phase.

Table 32. 2008 Exhaust Emissions (lb/spud) Associated with Completion Traffic by 

Vehicle Type.

Light Truck 20 20 66

Heavy Truck 20 20 138

Number of 

Round Trips 

Per Well

Equipment Type Mean Vehicle 

Speed (mph)

Round Trip OffRoad Trip 

Distance (miles)

NOx 2.67 7.776

SO2 0.02 0.069

CO 19.44 56.583

CO2 677.28 1971

VOC 1.57 4.564

PM10 0.09 0.263

PM2.5 0.09 0.249

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.270

N2O 0.05 0.141

NOx 21.75 132.347

SO2 0.08 0.499

CO 15.96 97.141

CO2 2612.85 15898.322

VOC 1.93 11.759

PM10 1.30 7.927

PM2.5 1.26 7.685

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.550

N2O 0.04 0.227

Vehicle Type Pollutant

2008 Emission 

Factors 

(g/mile)

Base year 

Emissions 

(lb/spud)

Light-Duty Truck

Heavy-Duty 

Truck 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-34

Table 33. Summary of 2008 Fugitive Dust Emissions (tons/spud) Associated with Well Completion Traffic.

Table 34. 2008 Exhaust and Fugitive Dust Emissions Associated with Well Completion Traffic in tons per spud.

Travel to well Light truck 7,000 20 66 66 20 1320 0.20 0.13 0.02 0.01

Travel to well Heavy Truck 70,000 20 138 138 20 2760 0.20 0.27 0.02 0.03

Total 0.40 0.40 0.04 0.04

PM2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spud)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spud)

Operators

Total # of 

Round 

Trips

Round 

Trip 

Distance 

(mi)

Total 

Miles 

Traveled

PM10

Units Activity Vehicle Type Av. Vehicle 

Weight (lb)

Mean 

vehicle 

speed 

(mph)

# of Visits 

per Year 

Projection

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Completion Traffic (LD) 0.0039 0.0023 0.0283 0.0001 0.0001 3.44E-05 0.9855 0.0001 0 0 7.05E-05 total spuds 0.1307 0.0130

Completion Traffic (HD) 0.0662 0.0059 0.0486 0.0040 0.0038 0.0002 7.9492 0.0003 0 0 0.0001 total spuds 0.2732 0.0271

Description Total Completion Traffic Emissions (tons per spud) Fugitive Road Dust 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-35

Table 35. Percent Change in Emission from Base Year 2008 Due to Fleet Turnover for Well Completion Traffic.

NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 -6% -39% -6% 0% -6% -4% -4% 0% 0% -8% -6% -7% -2% -6% 0% -4% -7% -7% 0% 0% 0% -5%

2010 -10% -46% -10% -1% -10% -9% -9% 0% 0% -12% -12% -16% -47% -9% 0% -6% -14% -14% 0% 0% 4% -10%

2011 -15% -50% -13% -2% -15% -16% -16% 0% 0% -15% -19% -25% -75% -14% 0% -13% -24% -24% 0% 0% 13% -16%

2012 -21% -55% -16% -3% -21% -22% -22% 0% 0% -19% -25% -33% -75% -19% 0% -21% -33% -33% 0% 0% 20% -21%

2013 -26% -56% -20% -4% -26% -27% -28% 0% 0% -22% -32% -41% -76% -24% 0% -28% -41% -41% 0% 0% 24% -27%

2014 -32% -57% -24% -5% -32% -33% -33% 0% 0% -25% -37% -48% -76% -28% 0% -34% -49% -49% 0% 0% 28% -32%

2015 -37% -57% -27% -7% -36% -38% -38% 0% 0% -28% -42% -54% -76% -32% 0% -40% -56% -56% 0% 0% 30% -36%

2016 -42% -58% -30% -9% -41% -42% -43% 0% 0% -31% -47% -60% -77% -37% 0% -46% -63% -63% 0% 0% 31% -40%

2017 -46% -59% -33% -10% -45% -46% -47% 0% 0% -34% -51% -65% -77% -40% 0% -51% -68% -68% 0% 0% 32% -44%

2018 -50% -60% -35% -12% -49% -50% -50% 0% 0% -36% -55% -69% -77% -43% 0% -56% -73% -73% 0% 0% 32% -47%

2019 -53% -60% -37% -13% -52% -53% -53% 0% 0% -38% -58% -73% -77% -45% 0% -60% -77% -77% 0% 0% 33% -50%

2020 -57% -61% -38% -14% -55% -55% -56% 0% 0% -39% -61% -76% -77% -47% 0% -64% -81% -81% 0% 0% 34% -53%

2021 -59% -62% -40% -16% -58% -57% -58% 0% 0% -41% -64% -78% -77% -49% 0% -67% -83% -83% 0% 0% 34% -55%

2022 -66% -63% -44% -19% -64% -63% -64% 0% 0% -43% -71% -84% -78% -53% 0% -74% -90% -90% 0% 0% 34% -61%

2023 -62% -62% -41% -17% -60% -59% -60% 0% 0% -42% -67% -81% -78% -51% 0% -70% -86% -86% 0% 0% 34% -58%

2024 -64% -63% -43% -18% -63% -61% -62% 0% 0% -43% -69% -82% -78% -52% 0% -72% -88% -88% 0% 0% 34% -60%

2025 -68% -64% -45% -19% -67% -64% -65% 0% 0% -44% -72% -85% -78% -54% 0% -76% -91% -91% 0% 0% 34% -63%

2026 -70% -64% -46% -20% -69% -66% -66% 0% 0% -43% -74% -86% -78% -56% 0% -79% -92% -92% 0% 0% 36% -65%

2027 -71% -64% -47% -21% -71% -67% -68% 0% 0% -43% -75% -87% -78% -56% 0% -80% -93% -93% 0% 0% 36% -66%

2028 -72% -64% -48% -21% -72% -68% -69% 0% 0% -44% -76% -88% -78% -57% 0% -81% -94% -94% 0% 0% 36% -67%

2029 -73% -65% -48% -22% -73% -69% -70% 0% 0% -45% -78% -88% -78% -58% 0% -83% -94% -94% 0% 0% 35% -68%

2030 -74% -65% -49% -22% -75% -70% -70% 0% 0% -45% -78% -89% -78% -58% 0% -84% -95% -95% 0% 0% 35% -69%

2031 -75% -65% -50% -23% -76% -70% -71% 0% 0% -47% -79% -89% -78% -59% 0% -85% -95% -95% 0% 0% 34% -70%

2032 -76% -65% -50% -23% -76% -71% -72% 0% 0% -47% -80% -89% -78% -60% 0% -85% -95% -95% 0% 0% 34% -70%

2033 -77% -66% -51% -24% -77% -72% -72% 0% 0% -48% -80% -89% -78% -61% 0% -86% -95% -95% 0% 0% 33% -71%

2034 -77% -66% -52% -24% -78% -72% -73% 0% 0% -48% -81% -90% -78% -61% 0% -86% -96% -96% 0% 0% 33% -71%

2035 -78% -66% -52% -24% -78% -73% -73% 0% 0% -48% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 33% -72%

2036 -78% -66% -53% -24% -79% -73% -74% 0% 0% -49% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 32% -72%

2037 -78% -66% -53% -25% -79% -73% -74% 0% 0% -49% -81% -90% -78% -63% -1% -87% -96% -96% 0% 0% 32% -72%

Year Light-Duty Truck Heavy-Duty Truck 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-36

2008 Construction Fugitive Dust Emissions

ASSUMPTIONS

Watering control efficiency assumed to be 50%

Information from operators:

Data Provided by operator in blue text

Equations

Emissions equations from AP-42 Table 11.9-1 for Bulldozing Overburden emissions, Western 

Surface Coal Mining

For total suspended particles (TSP) ≤ 30 microns:

Emissions (TSP lbs/hr) =[ 5.7 s^1.2 / M ^1.3 ] * Control Efficiency

For PM ≤ 15 microns:

Emissions (PM15 lbs/hr) =[ 1.0 s^1.5 / M ^1.4 ] * Control Efficiency

Emissions (PM10 lbs/hr) = PM15 * 0.75

Emissions (PM2.5 lbs/hr) = TSP * 0.105

See variables definition in following table:

Table 36. Parameters Used in Emission Equations.

Description Parameter Reference

Watering control efficiency 50%

M=soil moisture content 7.9 (AP-42 Table 11.9-3)

s=Soil silt content 6.9 (AP-42 Table 11.9-3)

PM10 multiplier 0.75 (AP-42 Table 11.9-1)

PM2.5 multiplier 0.105 (AP-42 Table 11.9-1)

Control of Open Fugitive Dust Sources, Section 

5.3.1 Watering of Unpaved Surfaces (1988). EPA
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-37

Table 37. Summary of 2008 Well Pad and Pipeline Construction Equipment Utilization 

Data.

Time Used 

Per Pad

 (hours)

Well Pad-Access Road Construction Loader 1 60

Well Pad-Access Road Construction Dozer 1 60

Well Pad-Access Road Construction Scraper 2 60

Well Pad-Access Road Construction Grader 1 60

Well Pad-Access Road Construction Backhoe 1 60

Well Pad-Access Road Construction Roller 1 60

Well Pad-Access Road Construction Water Truck 1 60

Well Pad-Access Road Construction Dump Truck 1 60

Well Pad-Access Road Construction Trencher 1 60

* assumed hours of use consistent with activity estimates used in equipment exhaust emission estimates

Phase Equipment Tye # Units
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-38

Table 38. Summary of 2008 Fugitive Dust Emissions (tons/well pad) from Well Pad and 

Access Road Construction Equipment.

Table 39. 2008 Construction Fugitive Dust Emissions in tons per well pad.

Table 40. Percent Change in Emission from Base Year 2008 for Construction Fugitive 

Dust.

Phase

Equipment 

Type TSP PM10 PM2.5 PM15

Well Pad-Access Road Construction Loader 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Dozer 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Scraper 0.1182 0.0226 0.0124 0.0301

Well Pad-Access Road Construction Grader 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Backhoe 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Roller 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Water Truck 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Dump Truck 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Trencher 0.0591 0.0113 0.0062 0.0151

Total 0.5911 0.1129 0.0621 0.1506

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Construction Dust, Fugitive 0 0 0 0.1129 0.0621 0 0 0 0 0 0 new pads

Description Projection Construction Fugitive Dust Emissions (tons per well pad)

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-39

2008 Construction Wind Erosion Emissions

ASSUMPTIONS

Emissions (

tons

yr ) = 

k* Erosion Potential (g/m2/year) * Disturbed Area (m2) * (#Disturbances/year)

453.6 (g/lb) *2000 (lbs/ton)

Table 41. 2008 Construction Dust Wind Erosion Emissions in tons per well pad.

Data obtained from operators in blue text

Disturbed Area Per Well:

Disturbed Area Per Well: 235224 ft221853.05 m

2

1 Acre 43,560 square feet

* AP-42 methodology described to the right was implemented in a computer program with hourly wind speed data

* 2007, 2008, and 2009 Wind Speed data from the Wamsutter Station were used as inputs

* Of all years evaluated, 2007 showed the greatest per pad wind erosion emissions:

Friction Velocity U* = 0.053 U10* (AP-42 Section 13.2.5.3 Equation 4)

Erosion Potential P (g/m2-time) = 58(U*-Ut*)2 + 25(U*-Ut*) for U*>Ut*; P=0 otherwise (AP-42 Section 13.2.5.3 Equation 3)

k is a particle size multiplier that depends on the aerodynamic size of the particle (from AP-42 Section 13.2.5.3). 

k = 0.5 for PM10

k = 0.075 for PM2.5

1.02 m/s = Threshold friction velocity for well pads (AP-42 Table 13.2.5-2 Overburden, Western Surface Coal Mine)

1.33 m/s = Threshold friction velocity for roads (AP-42 Table 13.2.5-2 Roadbed Material)

0.5 = Particle size multiplier for PM10

0.075 = Particle size multiplier for PM2.5

1 squ mile = 640 acres

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Construction Dust, Wind Erosion 0 0 0 3.06E-01 4.59E-02 0 0 0 0 0 0 new pads

Description Projection Construction Dust Wind Erosion Emissions (tons/well pad)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-40

Table 42. Percent Change in Emission from Base Year 2008 for Construction Dust Wind 

Erosion.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-41

2008 Workover Equipment Emissions

ASSUMPTIONS

Activity data obtained from operators in blue text

Assumptions:

* Emission factors from EPA Federal Diesel Engine Standards 

http://www.epa.gov/otaq/standards/n

onroad/nonroadci.htm

* Crankcase Emission factors are 2% of HC Exhaust Emission Factor for Tier II and earlier per 

* EPA NONROAD Modeling Guidance p. 23 (EPA, 2004; EPA420-P-04-009). 

* VOC/THC= 1.053 Conversion for HC->VOC for diesel engines (EPA, 2005; EPA420-R-05-0159, p. 5)

*

37% of fine particles assumed to be filterable and all filterable are assigned to EC (Source: AQTSD for Hell’s Gulch and 

Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

*

63% of fine particles assumed to be filterable and all filterable are assigned to SOA (Source: AQTSD for Hell’s Gulch and 

Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

EPA NONROAD model Fully Deteriorated Tier 0 Emission Factors

N2O Emission factors (g/gallons) from The Climate Registry, General Reporting Protocol v1.1, Table 13.6

Equations:

Emissions (tons/year-well) = Emission factor (g/hp-hr) * Horsepower * Time Used (hours) * Load

453.6 (g/lb) * 2000 (lbs/ton)

PM2.5/PM10 = 97% EPA (2004) NONROAD

VOC/HC 1.053 EPA NONROAD HC Conversions

NMHC/THC 98.40% EPA NONROAD HC Conversions

SO2 Emission Factor Calculation Information 

2008 Fuel Sulfur content 0.0355 sulfur fuel weight percent From NMIM

soxcnv Tiers I-III 0.02247 grams PM sulfur/grams fuel sulfur consumed

soxcnv Tier IV 0.3

grams PM sulfate/grams PM sulfur 7

soxbas 0.33

Density of Diesel Fuel 7.09 lb/gallons

Molecular weight of S 32 g/mol

Molecular weight of S02 64 g/mol

453.6 g/lb
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-42

Table 43. 2008 Workover Rig Equipment Emissions (lb/well) by Pollutants and by 

Equipment Type.

Rig

1

Diesel

Tier 0

475

300-600

36

0.07

0.3

0.367

18

NOx 8.581 6.47

VOC 0.764 0.58

CO 3.200 2.41

PM10 0.512 0.39

PM2.5 0.497 0.37

SO2 0.115 0.09

CO2 529 398.64

CH4 0.012 0.01

PM_filt 0.184 0.14

PM_cond 0.313 0.24

N2O 0.260 0.01

Snubbing unit

1

Diesel

Tier 0

475

300-600

36

0.07

0.3

0.367

18

NOx 8.581 6.47

VOC 0.764 0.58

CO 3.200 2.41

PM10 0.512 0.39

PM2.5 0.497 0.37

SO2 0.115 0.09

CO2 529 398.64

CH4 0.012 0.01

PM_filt 0.184 0.14

PM_cond 0.313 0.24

N2O 0.260 0.01

Light plant

1

Diesel

Tier 0

45

25-50

0.07

36

0.7

0.408

4

NOx 7.066 1.18

VOC 2.022 0.34

CO 5.925 0.99

PM10 1.093 0.18

PM2.5 1.060 0.18

SO2 0.127 0.02

CO2 584 97.37

CH4 0.031 0.01

PM_filt 0.392 0.07

PM_cond 0.668 0.11

N2O 0.260 0.00

Emissions 

(lb/well)

Engine Function

Load Factor

Fuel Type

Engine Technology

Engine Technology

Rated horsepower

Horsepower Range

Rated horsepower

Engine 1

Fuel Consumption (Gallons)

Emission 

Factors 

(g/bhp-hr)

BSFC (lb/hp-hr)

Equipment

Activity & 

Emission 

Number of Engines

Fuel Type

BSFC (lb/hp-hr)

Horsepower Range

Time used (hrs)

Well workeover requirement (Yrs)

Load Factor

BSFC (lb/hp-hr)

Horsepower Range

Well workeover requirement (Yrs)

Time used (hrs)

Load Factor

Engine Function

Number of Engines

Fuel Type

Engine Technology

Engine 2

Fuel Consumption (Gallons)

Emission 

Factors 

(g/bhp-hr)

Time used (hrs)

Well workover frequency (events/yr)

Engine 3

Engine Function

Number of Engines

Fuel Consumption (Gallons)

Emission 

Factors 

(g/bhp-hr)

Rated horsepower
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-43

Table 44. Summary of 2008 Workover Rig Emissions (lb/well) by Pollutants for All 

Equipment.

Table 45. 2008 Workover Rig Equipment Emissions in tons per well.

Table 46. Percent Change in Emission from Base Year 2008 for Workover Rig Equipment

(aggregate factors to apply to total emissions across all equipment types).

NOx 14

VOC 1

CO 6

PM10 1

PM2.5 1

SO2 0

CO2 895

CH4 0

PM_filt 0

PM_cond 1

N2O 0

Equipment 

Type Pollutant

Emissions 

(lb/year-well) 

Workover Rig 

Equipment NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Workover Equipment (diesel ICE) 0.0071 0.0007 0.0029 0.0005 0.0005 9.73E-05 0.4473 1.13E-05 0.0002 0.0003 1.14E-05 active well counts

Description Projection Workover Rig Emissions (tons per well)

Technology 

Assumption Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

Tier 0 2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-44

2008 Workover Traffic Emissions

ASSUMPTIONS

Data Provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2008 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

WORKOVER TRAFFIC.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-45

Table 47. Summary of Traffic Activity Data Associated with Well Workover Phase.

Table 48. 2008 Exhaust Emissions (lb/well) Associated with Workover Traffic by Vehicle 

Type.

Table 49. Summary of 2008 Fugitive Dust Emissions (tons/well) Associated with 

Workover Traffic.

Light Truck 20 20 6 0.07

Heavy Truck 20 20 8 0.07

Well workover 

frequency 

(events/yr)

Equipment 

Type

Mean Vehicle 

Speed (mph)

Round Trip OffRoad Trip 

Distance 

Number of 

Round Trips 

Per Well

NOx 2.67 0.047

SO2 0.02 0.000

CO 19.44 0.343

CO2 677.28 11.945

VOC 1.57 0.028

PM10 0.09 0.002

PM2.5 0.09 0.002

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.002

N2O 0.05 0.001

NOx 21.75 0.511

SO2 0.08 0.002

CO 15.96 0.375

CO2 2612.85 61.443

VOC 1.93 0.045

PM10 1.30 0.031

PM2.5 1.26 0.030

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.002

N2O 0.04 0.001

Heavy-Duty 

Truck 

Light-Duty Truck

Vehicle Type Pollutant

 2008 Emission 

Factors 

(g/mile)

Base year 

Emissions 

(lb/well)

Travel to well Light truck 7,000 20 6 0.4 20 8 0.20 0.00 0.02 0.00

Travel to well Heavy Truck 70,000 20 8 1 20 10.67 0.20 0.00 0.02 0.00

Total 0.40 0.00 0.04 0.00

PM2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well)

Em. Factor 

(lb/VMT) Emissions (tpy/well) Activity Vehicle Type Av. Vehicle 

Weight (lb)

Mean vehicle 

speed (mph) # of Visits per Year 

Total # of 

Round 

Trips

Round Trip 

Distance 

(mi)

Total 

Miles 

Traveled

PM10
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-46

Table 50. 2008 Exhaust and Fugitive Dust Emissions Associated with Workover Rigs Traffic in tons per well.

Table 51. Percent Change in Emission from Base Year 2008 Due to Fleet Turnover for Workover Rigs Traffic.

Projection

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

WorkoverTraffic (LD) 2.36E-05 1.38E-05 0.0002 7.96E-07 7.56E-07 2.09E-07 0.0060 8.18E-07 0 0 4.28E-07 active well counts 0.0008 0.0001

WorkoverTraffic (HD) 0.0003 2.27E-05 0.0002 1.53E-05 1.49E-05 9.65E-07 0.0307 1.06E-06 0 0 4.39E-07 active well counts 0.0011 0.0001

Description Total Workover Traffic Emissions (tons per well) Fugitive Road 

NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O N2O SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 -6% -39% -6% 0% -6% -4% -4% 0% 0% -8% -6% -5% -2% -6% 0% -4% -7% -7% 0% 0% 0% -5%

2010 -10% -46% -10% -1% -10% -9% -9% 0% 0% -12% -12% -10% -47% -9% 0% -6% -14% -14% 0% 0% 4% -10%

2011 -15% -50% -13% -2% -15% -16% -16% 0% 0% -15% -19% -16% -75% -14% 0% -13% -24% -24% 0% 0% 13% -16%

2012 -21% -55% -16% -3% -21% -22% -22% 0% 0% -19% -25% -21% -75% -19% 0% -21% -33% -33% 0% 0% 20% -21%

2013 -26% -56% -20% -4% -26% -27% -28% 0% 0% -22% -32% -27% -76% -24% 0% -28% -41% -41% 0% 0% 24% -27%

2014 -32% -57% -24% -5% -32% -33% -33% 0% 0% -25% -37% -32% -76% -28% 0% -34% -49% -49% 0% 0% 28% -32%

2015 -37% -57% -27% -7% -36% -38% -38% 0% 0% -28% -42% -36% -76% -32% 0% -40% -56% -56% 0% 0% 30% -36%

2016 -42% -58% -30% -9% -41% -42% -43% 0% 0% -31% -47% -40% -77% -37% 0% -46% -63% -63% 0% 0% 31% -40%

2017 -46% -59% -33% -10% -45% -46% -47% 0% 0% -34% -51% -44% -77% -40% 0% -51% -68% -68% 0% 0% 32% -44%

2018 -50% -60% -35% -12% -49% -50% -50% 0% 0% -36% -55% -47% -77% -43% 0% -56% -73% -73% 0% 0% 32% -47%

2019 -53% -60% -37% -13% -52% -53% -53% 0% 0% -38% -58% -50% -77% -45% 0% -60% -77% -77% 0% 0% 33% -50%

2020 -57% -61% -38% -14% -55% -55% -56% 0% 0% -39% -61% -53% -77% -47% 0% -64% -81% -81% 0% 0% 34% -53%

2021 -59% -62% -40% -16% -58% -57% -58% 0% 0% -41% -64% -55% -77% -49% 0% -67% -83% -83% 0% 0% 34% -55%

2022 -66% -63% -44% -19% -64% -63% -64% 0% 0% -43% -71% -61% -78% -53% 0% -74% -90% -90% 0% 0% 34% -61%

2023 -62% -62% -41% -17% -60% -59% -60% 0% 0% -42% -67% -58% -78% -51% 0% -70% -86% -86% 0% 0% 34% -58%

2024 -64% -63% -43% -18% -63% -61% -62% 0% 0% -43% -69% -60% -78% -52% 0% -72% -88% -88% 0% 0% 34% -60%

2025 -68% -64% -45% -19% -67% -64% -65% 0% 0% -44% -72% -63% -78% -54% 0% -76% -91% -91% 0% 0% 34% -63%

2026 -70% -64% -46% -20% -69% -66% -66% 0% 0% -43% -74% -65% -78% -56% 0% -79% -92% -92% 0% 0% 36% -65%

2027 -71% -64% -47% -21% -71% -67% -68% 0% 0% -43% -75% -66% -78% -56% 0% -80% -93% -93% 0% 0% 36% -66%

2028 -72% -64% -48% -21% -72% -68% -69% 0% 0% -44% -76% -67% -78% -57% 0% -81% -94% -94% 0% 0% 36% -67%

2029 -73% -65% -48% -22% -73% -69% -70% 0% 0% -45% -78% -68% -78% -58% 0% -83% -94% -94% 0% 0% 35% -68%

2030 -74% -65% -49% -22% -75% -70% -70% 0% 0% -45% -78% -69% -78% -58% 0% -84% -95% -95% 0% 0% 35% -69%

2031 -75% -65% -50% -23% -76% -70% -71% 0% 0% -47% -79% -70% -78% -59% 0% -85% -95% -95% 0% 0% 34% -70%

2032 -76% -65% -50% -23% -76% -71% -72% 0% 0% -47% -80% -70% -78% -60% 0% -85% -95% -95% 0% 0% 34% -70%

2033 -77% -66% -51% -24% -77% -72% -72% 0% 0% -48% -80% -71% -78% -61% 0% -86% -95% -95% 0% 0% 33% -71%

2034 -77% -66% -52% -24% -78% -72% -73% 0% 0% -48% -81% -71% -78% -61% 0% -86% -96% -96% 0% 0% 33% -71%

2035 -78% -66% -52% -24% -78% -73% -73% 0% 0% -48% -81% -72% -78% -62% 0% -87% -96% -96% 0% 0% 33% -72%

2036 -78% -66% -53% -24% -79% -73% -74% 0% 0% -49% -81% -72% -78% -62% 0% -87% -96% -96% 0% 0% 32% -72%

2037 -78% -66% -53% -25% -79% -73% -74% 0% 0% -49% -81% -72% -78% -63% -1% -87% -96% -96% 0% 0% 32% -72%

Light-Duty Truck Heavy-Duty Truck 

Year
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-47

2008 Heaters Emissions

ASSUMPTIONS

Table 52. Natural Gas Fired Heaters Emission Factors (lb/MMscf).

Table 53. Summary of Heaters Operational Data.

Table 54. Summary of 2008 Well-site Heater/Reboiler Emissions (lbs/well).

Table 55. 2008 Heater/Reboiler Emissions in tons per well.

Data Provided by operator in blue text

Assumptions

Assume no controls on the heater

Assume 10 percent of all wells have tank heaters

Equations

Emissions (tons/year) = Emission Factor (lbs/MMscf) * Heater Size (Btu/hr) * Time On (Hours/Year) 

Fuel Heat Value (Btu/scf) * 1x106 (scf/MMscf) * 2000 (lbs/ton)

NOx SO2 CO VOC PM10 PM2.5 PM_filt PM_cond CO2 CH4 N2O

100 0.6 84 5.5 7.6 7.6 1.9 5.7 120,000 2.3 2.2

Heaters (lb/MMscf) (from AP-42 Tables 1.4-1 and 1.4-2)

 (btu/hr) (Btu/scf) (hours)

Dehydrator Heater 500,000 1000 1 8760 0.5 4380

Separator Heater 500,000 1000 1 6552 0.5 3276

Tank Heater 500,000 1000 0.1 6750 0.5 3375

Equipment Type Heat Input Local Heating 

Value # Units/well

Time Used 

Per Unit Cycle 

Fraction

Actual 

Firing 

hours

Equipment Type NOx SO2 CO VOC PM10 PM2.5 PM_filt PM_cond CO2 CH4 N2O

Dehydrator Heater 219 0 184 12 17 17 4 12 262,800 5 5

Separator Heater 164 0 138 9 12 12 3 9 196,560 4 4

Tank Heater 17 0 14 0.93 1.28 1.28 0.32 0.96 20,250 0.39 0.37

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Heaters 0.1998 0.0110 0.1679 0.0152 0.0152 0 239.8050 0.0046 0.0038 0.0114 0.0044 active well counts

Description Projection Heater/Reboiler Emissions (tons per well)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-48

Table 56. Percent Change in Emission from Base Year 2008 for Heaters/Reboilers.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-49

2008 Fugitive Devices Emissions

ASSUMPTIONS

Activity data provided by operators in blue text

Hours of operation was assumed to be year round 24-7

Equation

where:

Efugitive is the fugitive VOC emissions per well [ton-VOC/yr]

EFi is the emission factor of TOC [kg/hr/source]

N is the total number of devices

Y is the ratio of VOC to TOC in the vented gas

tannual is total annual hours of operation

CH4 and CO2 emissions

Emissions.CH4 = Emission.VOC * WeightFraction.CH4 / WeightFraction.CO2

Emissions.CO2 = Emission.VOC * WeightFraction.CO2 / WeightFraction.VOC

Table 57. Total Organic Compound (TOC) Emission Factor (kg/hr/component).

Table 58. VOC, CO2 and CH4 Sales Gas and Condensate Gas Weight Fractions.

Efugitive  EFi  N  tannual Y

Light Oil Heavy Oil

>20o API <20o API

valves 4.50E-03 2.50E-03 8.40E-06 9.80E-05

pump seals 2.40E-03 1.30E-02 3.20E-05 2.40E-05

others 8.80E-03 7.50E-03 3.20E-05 1.40E-02

connectors 2.00E-04 2.10E-04 7.50E-06 1.10E-04

flanges 3.90E-04 1.10E-04 3.90E-07 2.90E-06

open-ended lines 2.00E-03 1.40E-03 1.40E-04 2.50E-04

Pump seals Heavy Oil EF uses other Heavy Oil EF

"Other" category includes compressor seals, pressure relief valves, diaphragms, drains, 

dump arms, hatches, instruments, meters, polished rods and vents

Do not calculate fugitives from pipelines containing only water

Emission Factors are from EPA, 1995 -AP-42 Table 2-4. "Oil and Gas Production 

Operations Average Emission Factors"

Well Equipment 

Component Gas Water/Oil Component Sales Gas Fugitive

VOC Fraction (weight) 14.60% 73.55%

CO2 Fraction (weight) 6.07% 3.02%

CH4 Fraction (weight) 68.75% 13.57%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-50

Table 59. 2008 TOC and VOC Emissions (lbs/well) by Media and Equipment Type.

Table 60. 2008 Fugitive Device Emissions in tons per well.

Well Stream Gas Condensate

Well Stream Gas Condensate Well Stream Gas Condensate

valves 10 10 - 4.50E-03 869 869 0 135.48 135.48 0.00

pump seals 1 0 - 2.40E-03 46 0 0 7.23 0.00 0.00

others 0 0 - 8.80E-03 0 0 0 0.00 0.00 0.00

connectors 150 50 - 2.00E-04 579 193 0 90.32 30.11 0.00

flanges 15 15 - 3.90E-04 113 113 0 17.61 17.61 0.00

open-ended lines 0 0 - 2.00E-03 0 0 0 0.00 0.00 0.00

valves - - 20 2.50E-03 0 0 966 0.00 0.00 732.57

pump seals - - 0 1.30E-02 0 0 0 0.00 0.00 0.00

others - - 0 7.50E-03 0 0 0 0.00 0.00 0.00

connectors - - 50 2.10E-04 0 0 203 0.00 0.00 153.84

flanges - - 10 1.10E-04 0 0 21 0.00 0.00 16.12

open-ended lines - - 0 1.40E-03 0 0 0 0.00 0.00 0.00

valves - - - 8.40E-06 0 0 0 0.00 0.00 0.00

pump seals - - - 3.20E-05 0 0 0 0.00 0.00 0.00

others - - - 3.20E-05 0 0 0 0.00 0.00 0.00

connectors - - - 7.50E-06 0 0 0 0.00 0.00 0.00

flanges - - - 3.90E-07 0 0 0 0.00 0.00 0.00

open-ended lines - - - 1.40E-04 0 0 0 0.00 0.00 0.00

valves - - - 9.80E-05 0 0 0 0.00 0.00 0.00

pump seals - - - 2.40E-05 0 0 0 0.00 0.00 0.00

others - - - 1.40E-02 0 0 0 0.00 0.00 0.00

connectors - - - 1.10E-04 0 0 0 0.00 0.00 0.00

flanges - - - 2.90E-06 0 0 0 0.00 0.00 0.00

open-ended lines - - - 2.50E-04 0 0 0 0.00 0.00 0.00

VOC Emissions (lbs/yr)

Heavy Oil <20o API

Water/Oil

TOC Emission 

Factor (kg / hr / 

component)

TOC Emissions (lbs/yr)

Media

Type

Well Equipment Component

Gas

Light Oil >20o API

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Well Stream Fugitive 

Devices 0 0.1253 0 0 0 0 0.0521 0.5900 0 0 0 active well counts

Gas Stream Fugitive 

Devices 0 0.0916 0 0 0 0 0.0381 0.4313 0 0 0 active well counts

Condensate Fugitive 0 0.4513 0 0 0 0 0.0185 0.0833 0 0 0 active well counts

Description Projection Fugitive Device Emissions (tons per well)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-51

Table 61. Percent Change in Emission from Base Year 2008 for Fugitive Devices.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-52

2008 Pneumatic Devices Emissions

ASSUMPTIONS

As per operator's input no bleed devices are used exclusively, hence zero emissions from this 

category

Table 62. 2008 Pneumatic Devices Emissions in tons per well.

Table 63. Percent Change in Emission from Base Year 2008 for Pneumatic Devices.

NOx VOC CO PM10 PM2.5 SO2 CH4 CO2 PM_filt PM_cond N2O

Pneumatic Devices 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 active well counts

Description Projection Pneumatic Devices Emissions (tons per well)

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-53

2008 Tank Loadout (vapor losses) Emissions

ASSUMPTIONS

Table 64. VOC, CO2 and CH4 Condensate Post-Flash Gas Weight Fractions.

Table 65. Summary of Truck Load Activity Data.

Table 66. 2008 Well Site Condensate Tank Loadout Emissions in tons per barrel.

Data Provided by operator in blue text

Method from Wyoming Permitting Guidance for Oil and Gas Production Facilities

Wyoming DEQ, March, 2010, Chapter 6, Section 2, p.65 for Crude Oil, RVP 5

After AP-42, Section 5.2.1

Emissions VOC (tpy) =

Loading losses determined using AP-42 Section 5.2.2.1.1 Equation 1

LL =12.46 x S x P x M/T

LL=Loading Loss in (lbs/1000gallons)

S= Saturation Factor

P = true vapor pressure of liquid loaded (psia)

M = molecular weight of tank vapors (lb/(lb-mol))

T = temperature of bulk liquid loaded (R=F+460)

Loading Loss (lbs/1000 gal) * truck load rate (bbl/year) * 42 (gal/bbl) * VOC mass fraction

2000 (lbs/ton)

Compound Weight (%)

Methane (weight) 21.23%

VOC Fraction (weight) 66.34%

CO2 Fraction (weight) 0.00%

Type of Petroleum Liquid 

Loaded

Saturation 

Factor

True Vapor 

Pressure of 

Liquid Loaded 

(psia)

Molecular Weight 

of Vapors (lb/lbmole)

Temperature 

of Bulk Liquid 

(°R)

Mode of 

Operation

Loading Losses 

(lb/1000 gallons)

Capacity of 

Truck

Condensate RVP 8 0.6 7.2 50 520

Submerged loading: 

dedicated normal 

service 5.18 80 bbl

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Tank Loadout (vapor 

losses) 0 7.21E-05 0 0 0 0 0 2.31E-05 0 0 0

annual condensate 

production

Description Projection Base Year Well Site Condensate Tank Loadout Emissions (tons per barrel)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-54

Table 67. Percent Change in Emission from Base Year 2008 for Condensate Tank Loadout.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-55

2008 Well Venting Emissions

ASSUMPTIONS

Table 68. Well Venting VOC, CH4 and CO2 Emission Factors (tons/well).

Table 69. 2008 Well Venting Emissions in tons per well.

Data provided by operator in blue text

Well venting includes all emissions from venting categories other than fugitive devices, pneumatic devices, 

chemical injection pumps, tank load out, condensate tanks, completion and dehydrator venting.

Weight (%) : Well 

Stream Gas (t/yr/well)

Venting VOC Emission Factor 0.75

Methane 69.04% 3.624

Carbon Dioxide 6.09% 0.320

VOC Fraction (weight) 14.25%

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Well Venting 0 0.7483 0 0 0 0 0.3198 3.6240 0 0 0 active well counts

Description Projection Base Year Well Venting Emissions (tons per well)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-56

Table 70. Percent Change in Emission from Base Year 2008 for Well Venting.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-57

2008 Condensate Tank Flashing/Working/Breathing Emissions 

ASSUMPTIONS

where WtFraction = weight fraction of the pollutant 

Data provided by operator in blue text

Assume one tank per well

where:

E condensate,tanks is the per well emissions from condensate tanks [tons/yr-well]

EF condensate,tank is the derived VOC emissions factor for condensate tanks [lb-VOC/bbl]

P condensatetanks is the condensate production per gas wells throughput [bbl/well]

CF = Percentage of Volume Controlled

CO2 emissions

Emissions.CO2 = Emission.VOC * WtFraction.CO2 / WtFraction.VOC

 =

 

2000 ( )

68% percentage of condensate volume controlled

Flash Wt % Post-Flash Wt %

Carbon Dioxide 3.04% 0.00%

VOC Fraction 

(weight) 73.46% 66.34%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-58

Table 71. Flash speciation from Wamsutter HYSYS.

Chemical Mole %1

Molecular 

Weight

 (lb/lb-mol)2

Pounds per 

Bbl @ 365 

psig

Carbon Dioxide 2.80% 44.01 1.24

Nitrogen 0.02% 28.01 0.01

Methane 34.25% 16.04 5.52

Ethane 13.42% 30.07 4.05

Propane 17.98% 44.10 7.96

Isobutane 6.85% 58.12 4.00

n-Butane 9.34% 58.12 5.45

Isopentane 4.48% 72.15 3.25

n-Pentane 3.91% 72.15 2.83

Cyclopentane 0.00% 72.15 0.00

n-Hexane 1.36% 86.18 1.18

Cyclohexane 0.30% 84.16 0.25

2,2-Dimethylbutane 0.09% 86.18 0.08

2,3-Dimethylbutane 0.34% 86.18 0.30

2-Methylpentane 1.04% 86.18 0.90

3-Methylpentane 0.53% 86.18 0.46

n-Heptane 1.85% 100.20 1.86

Methylcylcohexane 0.18% 98.19 0.18

2,2,4 Trimethylpentane 0.07% 114.23 0.08

Benzene 0.31% 78.11 0.25

Toluene 0.38% 92.14 0.35

Ethylbenzene 0.00% 106.17 0.00

m-Xylene 0.16% 106.17 0.17

o-Xylene 0.02% 106.17 0.02

n-Octane 0.22% 114.23 0.25

n-Nonane 0.05% 128.26 0.07

n-Decane 0.04% 142.28 0.06

Total 100.00% 40.58 40.75

Total VOC 49.51% 29.93

1

 The flash gas composition is based on the 2008 HYSYS model for 

2

 The molecular weights and the higher heating values are from the 

"GSPA Engineering Data Book", Twelfth Edition, Section 23 Physical 

Properties, 2004.

Assumptions 365 PSIG Separator Pressure

75 Degrees F Temperature (Tank)

379.48 SCF/Mole

Total Flash @ 365 psig 381.05 SCF/Bbl Produced (From Wamsutter SCC Heat Input File)

Net Throughput(gal/yr): 47,632 bbls/yr: 1510

Turnovers: 2.93

From EPA's TANKS 4.09 Output based on the condensate composition from 2007 

Wamsutter HYSYS model. 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-59

Table 72. Working and Breathing Loss Calculations.

Table 73. TANKS 4.0.9d Emissions Report. Tank Identification and Physical Characteristics

Components

Working 

Loss 

(lbs/yr)

Working Loss 

(lb/turnover)

Breathing 

Loss 

(lbs/yr)

Total 

Emissions 

(lbs/yr)

Condensate 368.64 125.82 3,232.66 3,601.30

Methane 78.28 26.72 686.48 764.76

Ethane 45.81 15.63 401.75 447.57

Propane 71.86 24.53 630.14 702

Isobutane 34.98 11.94 306.72 341.7

n-Butane 46.12 15.74 404.46 450.58

Isopentane 27.02 9.22 236.95 263.97

n-Pentane 21.87 7.46 191.8 213.68

n-Hexane 8.31 2.84 72.84 81.15

Cyclohexene 1.32 0.45 11.54 12.86

2,2-Dimethylbutane 0.66 0.23 5.79 6.45

2,3-Dimethylbutane 2.19 0.75 19.19 21.37

2-Methylpentane 6.49 2.22 56.93 63.42

3-Methylpentane 3.1 1.06 27.22 30.32

n-Heptane 12.98 4.43 113.84 126.82

Methylcyclohexane 1.03 0.35 9.06 10.09

2,2,4-Trimethylpentane 0.52 0.18 4.54 5.06

Benzene 1.17 0.40 10.23 11.4

Toluene 1.54 0.53 13.46 15

Ethylbenzene 0.02 0.01 0.19 0.21

Xylenes 0.85 0.29 7.48 8.34

n-Octane 1.38 0.47 12.1 13.49

n-Nonane 0.49 0.17 4.3 4.79

n-Decane 0.64 0.22 5.65 6.3

THC 368.63 125.81 3,232.66 3,601.33

VOC 244.54 83.46 2,144.43 2,389.00
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-60

Table 74. TANKS 4.0.9d Emissions Report. Liquid Contents of Storage Tank
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-61

Table 75. TANKS 4.0.9d Emissions Report. Detail Calculations. 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-62

Table 76. TANKS 4.0.9d Emissions Report. Individual Tank Emissions Total (lbs).

Table 77. VOC and CH4 Flashing, Working and Breathing Emission Factors (lb/activity).

Table 78. 2008 Uncontrolled Condensate Tank Emissions in tons per activity.

Condensate tank losses 29.93 83.46 2144.43 5.52 26.72 686.48

Uncontrolled CH4 Emission Factors 

Flashing

 (lb per barrel)

Working

 (lb per turnover 

per well)

Breathing 

Losses 

(lb per well)

Flashing

 (lb per barrel)

Working

 (lb per turnover 

per well)

Breathing 

Losses 

(lb per well)

Source

Uncontrolled VOC Emission Factors NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Condensate Tank 

Flashing Losses 0.0000 0.0048 0.0000 0.0000 0.0000 0.0000 0.0002 0.0009 0.0000 0.0000 0.0000

annual 

condensate 

production

Condensate Tank 

Working Losses 0.0000 0.0134 0.0000 0.0000 0.0000 0.0000 0.0000 0.0043 0.0000 0.0000 0.0000

total turnovers 

per year

Condensate Tank 

Breathing Losses 0.0000 0.3431 0.0000 0.0000 0.0000 0.0000 0.0000 0.1098 0.0000 0.0000 0.0000

active well 

counts

Description Projection Condensate Tank Venting Emissions- Uncontrolled Volume (tons per barrel or tons per turnover per well or tons per well)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-63

Table 79. Percent Change in Emission from Base Year 2008 for Condensate Tank Losses.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-64

2008 Condensate Tank Flaring Emissions

ASSUMPTIONS

Data provided by operator in blue text

 O2Emissions ( p r ivi y) = (Total CO2 Emission Potential of the Entire Gas – THC Component to CO2 Emission 

Potential – CO Component to CO2 Emission Potential) x Percentage of Production Controlled

THC Component CO2 Emissions Potentials (

tons

activity) =∑

(

lb emissions emitted

activity ) i×

N . f M l f C i mp u 

N . f M l f C i CO2

×Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of Compound C (lb/lb-mol) × 2000

CO component CO2 emissions potentials (

tons

activity) = 

CO emissions from flaring(

lb

activity)×

No.of Moles of C in compound

No.of Moles of C in CO2 × Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of CO ( lb

lb-mol

) × 2000

.

Where,

i= each compound identified in flaring gas speciation profile 

(lb emissions emitted/activity)i = Total TOG Emissions (lb/activity) from flaring X Weight 

Fraction of the Compound 

Table 80. Flaring Emission Factors.

NOx, VOC, CH4, N2O and CO Emissions Calculation

where:

E flare is the flaring emissions per well [lb/yr]

EF i is the emissions factor for pollutant i [lb/MMBtu]

Q is the volume of gas flared supplied by operator [MMscf/yr]

HV is the heating value of the gas as provided by the operators [MMBtu/MMscf]

E flare  EF i  Q  HV NOx CO THC

0.068 0.37 0.14 25% 1.44 63%

Flaring Emission Factor (lb/MMBtu)* Fraction of THC 

as CH4

N2O 

(lb/MMSCF)b VOC/THCc 

b Emission Factor from API Compendium of greenhouse gas emissions methodologies for 

the oil and natural gas industry,2009 Table 4-11, GHG Emission Factors for Gas Flares in 

Developed Countries - Footnote C

cEPA SPECIATE Profile 0051

*Emission Factors are from AP-42

Condensate 2246.45 Btu/scf

Total Flash @ 381.05 SCF/Bbl Produced 

68% percentage of condensate volume controlled

1

2008 HYSYS model runs for the Wamsutter Operations Center at 365 psig.
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-65

Table 81. 2008 CO2 Emissions (tons/bbl) Potential for All Gas Sample Species from 

Flashing Loss.

365.00 PSIG Separator Pressure

75.00 Degrees F Temperature (Tank)

379.48 SCF/lb-mole

Chemical Mole %1 

Molecular 

Weight

 (lb/lb-mol)2

Pounds per Bbl 

@ 365 psig

lb/

MMscf

lb CO2/ 

MMscf

HHV 

(Btu/scf)2

2008 CO2 

emission 

potential of the 

entire gas 

(tons/bbl)

Carbon Dioxide 2.80% 44.01 1.24 3,250 3,250 0 6.E-04

Nitrogen 0.02% 28.01 0.01 16 0 0.E+00

Methane 34.25% 16.04 5.52 14,478 39,725 1010 8.E-03

Ethane 13.42% 30.07 4.05 10,631 31,120 1770 6.E-03

Propane 17.98% 44.10 7.96 20,900 62,571 2516 1.E-02

Isobutane 6.85% 58.12 4.00 10,490 31,773 3252 6.E-03

n-Butane 9.34% 58.12 5.45 14,303 43,322 3262 8.E-03

Isopentane 4.48% 72.15 3.25 8,523 25,995 4001 5.E-03

n-Pentane 3.91% 72.15 2.83 7,432 22,665 4009 4.E-03

n-Hexane 1.36% 86.18 1.18 3,085 9,453 4756 2.E-03

Cyclohexane 0.30% 84.16 0.25 655 2,055 4482 4.E-04

2,2-Dimethylbutane 0.09% 86.18 0.08 201 615 4736 1.E-04

2,3-Dimethylbutane 0.34% 86.18 0.30 783 2,398 4745 5.E-04

2-Methylpentane 1.04% 86.18 0.90 2,362 7,237 4747 1.E-03

3-Methylpentane 0.53% 86.18 0.46 1,201 3,680 4750 7.E-04

n-Heptane 1.85% 100.20 1.86 4,885 15,019 5503 3.E-03

Methylcyclohexane 0.18% 98.19 0.18 465 1,667 5216 3.E-04

2,2,4-Trimethylpentane 0.07% 114.23 0.08 212 653 6249 1.E-04

Benzene 0.31% 78.11 0.25 646 2,183 3742 4.E-04

Toluene 0.38% 92.14 0.35 921 3,080 4475 6.E-04

Ethylbenzene 0.00% 106.17 0.00 12 41 5222 8.E-06

m-Xylene 0.16% 106.16 0.17 454 1,505 5208 3.E-04

o-Xylene 0.02% 106.16 0.02 43 143 5210 3.E-05

n-Octane 0.22% 114.23 0.25 665 2,050 6249 4.E-04

n-Nonane 0.05% 128.26 0.07 171 528 6996 1.E-04

n-Decane 0.04% 142.29 0.06 151 466 7743 9.E-05

VOC 100.00% 40.58 40.75 106,934 309,944 2246 0.059

Total VOC 49.51% 29.93 78,558

2

 The molecular weights and the higher heating values are from the "GSPA Engineering Data Book", Twelfth Edition, 

1

 The flash gas composition is based on the 2008 HYSYS model for Wamsutter at 365 psig.
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-66

Table 82. 2008 CO2 Emissions (tons/turnover) Potential for All Gas Sample Species from 

Working Loss.

Throughput 1509.94 bbls/yr

Turnovers: 2.93

Vapor Density 0.06 lb/ft3

Components

Working 

Loss 

(lbs/yr)

Working Loss

(lb/ turnover well) Weight %

Molecular 

Weight

 (lb/lb-mol)1

Mole %

HHV 

(Btu/scf)1

lb/

MMscf

lb CO2/ 

MMscf

2008 CO2 

emission 

potential of the 

entire gas 

(Tons/turnover)

Methane 78.28 26.72 21.23% 16.04 46.18% 1010 19,519 53,555 0.0121

Ethane 45.81 15.63 12.43% 30.07 14.42% 1770 11,425 33,442 0.0044

Propane 71.86 24.53 19.50% 44.10 15.42% 2516 17,921 53,654 0.0111

Isobutane 34.98 11.94 9.49% 58.12 5.70% 3252 8,722 26,419 0.0027

n-Butane 46.12 15.74 12.51% 58.12 7.51% 3262 11,501 34,835 0.0046

Isopentane 27.02 9.22 7.33% 72.15 3.54% 4001 6,738 20,551 0.0016

n-Pentane 21.87 7.46 5.93% 72.15 2.87% 4009 5,454 16,634 0.0011

n-Hexane 8.31 2.84 2.25% 86.18 0.91% 4756 2,072 6,349 0.0002

Cyclohexane 1.32 0.45 0.36% 84.16 0.15% 4482 329 1,031 0.0000

2,2-Dimethylbutane 0.66 0.23 0.18% 86.18 0.07% 4736 165 504 0.0000

2,3-Dimethylbutane 2.19 0.75 0.59% 86.18 0.24% 4745 546 1,673 0.0000

2-Methylpentane 6.49 2.22 1.76% 86.18 0.71% 4747 1,619 4,960 0.0001

3-Methylpentane 3.10 1.06 0.84% 86.18 0.34% 4750 774 2,370 0.0000

n-Heptane 12.98 4.43 3.52% 100.20 1.23% 5503 3,237 9,952 0.0004

Methylcyclohexane 1.03 0.35 0.28% 98.19 0.10% 5216 257 922 0.0000

2,2,4-Trimethylpentane 0.52 0.18 0.14% 114.23 0.04% 6249 129 399 0.0000

Benzene 1.17 0.40 0.32% 78.11 0.14% 3742 291 985 0.0000

Toluene 1.54 0.53 0.42% 92.14 0.16% 4475 383 1,282 0.0000

Ethylbenzene 0.02 0.01 0.01% 106.17 0.00% 5222 5 17 0.0000

Xylenes 0.85 0.29 0.23% 106.17 0.08% 5208 212 704 0.0000

n-Octane 1.38 0.47 0.37% 114.23 0.11% 6249 344 1,061 0.0000

n-Nonane 0.49 0.17 0.13% 128.26 0.04% 6996 122 378 0.0000

n-Decane 0.64 0.22 0.17% 142.29 0.04% 7743 160 495 0.0000

THC 368.63 125.81 100.00% 34.88 100.00% 2016 91,926 272,174 0.04

VOC 244.54 83.46 66.34% 39.40% 60,983

From EPA's TANKS 4.09 Output based on the condensate composition from 2007 

Wamsutter HYSYS model. 

1

 The molecular weights and the higher heating values are from the "GSPA Engineering Data Book", Twelfth Edition, Section 23 Physical 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-67

Table 83. 2008 CO2 Emissions (tons/well) Potential for All Gas Sample Species from 

Breathing Loss.

Throughput 1509.94 bbls/yr

Turnovers: 2.93

Vapor Density 0.06 lb/ft3

Components

Breathing 

Loss 

(lbs/well)

Weight %

Molecular 

Weight

 (lb/lb-mol)1

Mole %

HHV 

(Btu/scf)1

lb/

MMscf

lb CO2/ 

MMscf

2008 CO2 emission 

potential of the 

entire gas 

(tons/well)

Methane 686.48 21.23% 16.04 46.18% 1010 19,519 53,555 0.31

Ethane 401.75 12.43% 30.07 14.42% 1770 11,425 33,442 0.11

Propane 630.14 19.50% 44.10 15.42% 2516 17,921 53,654 0.29

Isobutane 306.72 9.49% 58.12 5.70% 3252 8,722 26,419 0.07

n-Butane 404.46 12.51% 58.12 7.51% 3262 11,501 34,835 0.12

Isopentane 236.95 7.33% 72.15 3.54% 4001 6,738 20,551 0.04

n-Pentane 191.8 5.93% 72.15 2.87% 4009 5,454 16,634 0.03

n-Hexane 72.84 2.25% 86.18 0.91% 4756 2,072 6,349 0.00

Cyclohexane 11.54 0.36% 84.16 0.15% 4482 329 1,031 0.00

2,2-Dimethylbutane 5.79 0.18% 86.18 0.07% 4736 165 504 0.00

2,3-Dimethylbutane 19.19 0.59% 86.18 0.24% 4745 546 1,673 0.00

2-Methylpentane 56.93 1.76% 86.18 0.71% 4747 1,619 4,960 0.00

3-Methylpentane 27.22 0.84% 86.18 0.34% 4750 774 2,370 0.00

n-Heptane 113.84 3.52% 100.20 1.23% 5503 3,237 9,952 0.01

Methylcyclohexane 9.06 0.28% 98.19 0.10% 5216 257 922 0.00

2,2,4-Trimethylpentane 4.54 0.14% 114.23 0.04% 6249 129 399 0.00

Benzene 10.23 0.32% 78.11 0.14% 3742 291 985 0.00

Toluene 13.46 0.42% 92.14 0.16% 4475 383 1,282 0.00

Ethylbenzene 0.19 0.01% 106.17 0.00% 5222 5 17 0.00

Xylenes 7.48 0.23% 106.17 0.08% 5208 212 704 0.00

n-Octane 12.1 0.37% 114.23 0.11% 6249 344 1,061 0.00

n-Nonane 4.3 0.13% 128.26 0.04% 6996 122 378 0.00

n-Decane 5.65 0.17% 142.29 0.04% 7743 160 495 0.00

THC 3232.66 100.00% 34.88 100.00% 2016 91,926 272,174 0.98

VOC 2144.43 66.34% 39.40% 60,983

1

 The molecular weights and the higher heating values are from the "GSPA Engineering Data Book", Twelfth Edition, Section 23 Physical 

Properties, 2004.

From EPA's TANKS 4.09 Output based on the condensate composition from 

2007 Wamsutter HYSYS model. 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-68

Table 84. Summary of THC and CO Component to CO2 Emissions Potentials (tons/activity) for 2008.

Table 85. 2008 Condensate Tank Flaring Emissions per activity metric of each Category.

Compound MW

(lb/lb-mol)

Flashing 

Emissions 

(lb/bbl)

Working 

Emissions

(lb/turnover)

Breathing 

Emissions

(lb/well)

TOG 31.47 0.15 0.75 19.30

CO 28.01 0.32 1.59 40.80

lb 

emitted/w

ell

Moles C in 

compound/

Moles C in 

CO2

CO2 

Emissions 

(tons/bbl)

lb 

emitted/t

urnover

Moles C in 

compound

/Moles C in 

CO2

CO2 Emissions 

(Tons/turnover)

lb 

emitted/well

Moles C in 

compound/M

oles C in 

CO2

CO2 

Emissions 

(tons/well)

Ethane Y N 30 30.07 0.04 2 0.0001 0.23 2 0.0003 5.79 2 0.0085

Formaldehyde N Y 20 30.03 0.03 1 0.0000 0.15 1 0.0001 3.86 1 0.0028

Methane Y N 20 16.04 0.03 1 0.0000 0.15 1 0.0002 3.86 1 0.0053

Propane Y Y 30 44.10 0.04 3 0.0001 0.23 3 0.0003 5.79 3 0.0087

100 0.15 0.0002 0.0002 0.75 0.0010 0.0012 19.30 0.0253 0.0321

0.0002 0.0012

Name HC? VOC?

WEIGHT_PER

(Flaring 

Speciation Profile 

(EPA SPECIATE 

0051))

Molecular 

Weight

 (lb/lb-mol)2

0.0321

Flashing 2008 CO2 emissions Working 2008 CO2 emissions Breathing 2008 CO2 emissions

THC component CO2 emissions CO component 

CO2 emissions 

potentials 

(tons/bbl) 

THC component CO2 emissions CO component 

CO2 emissions 

potentials 

(tons/well) 

THC component CO2 emissions CO component 

CO2 emissions 

potentials 

(tons/well) 

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Condensate Tank 

Flashing Flaring 1.98E-05 2.55E-05 0.0001 0 0 0 0.0399 1.02E-05 0 0 1.86E-07

annual condensate 

production

Condensate Tank 

Working Flaring 9.92E-05 0.0001 0.0005 0 0 0 0.0245 5.11E-05 0 0 1.04E-06

total turnovers per 

year

Condensate Tank 

Breathing Flaring 0.0025 0.0033 0.0139 0 0 0 0.6302 0.0013 0 0 2.67E-05 active well counts

Description Projection Condensate Tank Flaring Emissions (tons per activity metric)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-69

Table 86. Percent Change in Emission from Base Year 2008 for Condensate Tank Flaring

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-70

2008 Dehydrator Venting Emissions

ASSUMPTIONS

Table 87. Dehydrator Uncontrolled and Controlled VOC and CH4 Emissions (tons per 

well).

Data Provided by operator in blue text

Assume no change in pressure (365 psi)

Dehydrator VOC Emissions (t/yr)=2.0254*ln(flow (MMscf/yr))+0.9636

Dehydrator CH4 Emissions (t/yr)=0.0543*ln(flow (MMscf/yr))+7.3694

Assume one dehydrator per well

Total Waste Gas Stream (MMscf/yr/ well) =0.0013*flow(MMscf/yr)+0.5094

assumed no wells subject of control based on estimated uncontrolled VOC emissions below 15tpy VOC threshold

CO2 Emissions (tons/well/yr) = ((lb CO2/MMscf)* Total Waste Gas Stream (MMscf/well/yr))

2000

Year

Average 

production per 

year per well 

(MMscf/yr/well)

Uncontrolled VOC 

Emissions

(tons per well)

Controlled VOC 

Emissions

(tons per well)

Uncontrolled 

CH4 Emissions

(tons per well)

Controlled CH4 

Emissions*

(tons per well)

Uncontrolled C2H6 

Emissions (tons per 

well)

Total Waste 

Gas Stream 

(MMscf/yr/ well)

CO2 Emissions 

(tons per well)

2008 67.92 9.51 9.51 7.60 7.60 2 0.598 1.8358

2009 64.76 9.41 9.41 7.60 7.60 2 0.594 1.8232

2010 56.31 9.13 9.13 7.59 7.59 2 0.583 1.7895

2011 51.79 8.96 8.96 7.58 7.58 2 0.577 1.7714

2012 51.34 8.94 8.94 7.58 7.58 2 0.576 1.7696

2013 51.18 8.93 8.93 7.58 7.58 2 0.576 1.7690

2014 49.06 8.85 8.85 7.58 7.58 2 0.573 1.7605

2015 46.79 8.75 8.75 7.58 7.58 2 0.570 1.7514

2016 44.83 8.67 8.67 7.58 7.58 2 0.568 1.7436

2017 43.14 8.59 8.59 7.57 7.57 2 0.565 1.7369

2018 41.69 8.52 8.52 7.57 7.57 2 0.564 1.7311

2019 40.38 8.45 8.45 7.57 7.57 2 0.562 1.7258

2020 39.14 8.39 8.39 7.57 7.57 2 0.560 1.7209

2021 38.06 8.33 8.33 7.57 7.57 2 0.559 1.7166

2022 36.40 8.24 8.24 7.56 7.56 2 0.557 1.7100

2023 35.48 8.19 8.19 7.56 7.56 2 0.556 1.7063

2024 34.62 8.14 8.14 7.56 7.56 2 0.554 1.7028

2025 33.91 8.10 8.10 7.56 7.56 2 0.553 1.7000

2026 33.20 8.06 8.06 7.56 7.56 2 0.553 1.6972

2027 32.56 8.02 8.02 7.56 7.56 2 0.552 1.6946

2028 32.30 8.00 8.00 7.56 7.56 2 0.551 1.6936

2029 31.00 7.92 7.92 7.56 7.56 2 0.550 1.6884

2030 30.44 7.88 7.88 7.55 7.55 2 0.549 1.6861

2031 29.93 7.85 7.85 7.55 7.55 2 0.548 1.6841

2032 29.44 7.81 7.81 7.55 7.55 2 0.548 1.6822

2033 28.96 7.78 7.78 7.55 7.55 2 0.547 1.6802

2034 28.52 7.75 7.75 7.55 7.55 2 0.546 1.6785

2035 28.12 7.72 7.72 7.55 7.55 2 0.546 1.6769

2036 27.79 7.70 7.70 7.55 7.55 2 0.546 1.6756

2037 27.47 7.67 7.67 7.55 7.55 2 0.545 1.6743

* assumed CH4 control would be analagous to VOC control
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-71

Table 88. Summary of lb CO2 per MMSCF Estimation.

Chemical Mole %1 

Molecular Weight

 (lb/lb-mol)2

lb/

MMscf lb CO2/ MMscf HHV (Btu/scf)2

Water 17.54% 18.01 8060.8 0.0

Carbon Dioxide 5.47% 44.01 6142.9 6142.9 0

Nitrogen 0.11% 28.01 80.8 0

Methane 55.61% 16.04 22761.2 1010

Ethane 6.19% 30.07 4749.6 1770

Propane 3.98% 44.10 4478.8 2516

Isobutane 1.07% 58.12 1586.9 3252

n-Butane 1.49% 58.12 2209.8 3262

Isopentane 0.57% 72.15 1053.1 4001

n-Pentane 0.58% 72.15 1075.2 4009

n-Hexane 0.33% 86.18 730.1 4756

Cyclohexane 0.62% 84.16 1335.8 4482

Other Hexanes 0.37% 86.18 815.9 4745

n-Heptane 0.61% 100.20 1569.9 5503

Methylcyclohexane 0.79% 98.19 1976.9 5216

2,2,4-Trimethylpentane 0.02% 114.23 55.4 6249

Benzene 1.35% 78.11 2690.8 3742

Toluene 1.89% 92.14 4443.7 4475

Ethylbenzene 0.06% 106.17 165.3 5222

Xylenes 0.60% 106.17 1636.3 5208

n-Octane 0.73% 114.23 2116.2 6249

Total 100.00% 27.33 69735.3 6142.9 1254

Total VOC 15.07% 27940.0

1

 Mole percent is based on the GLYCalc run at 0.25 MMscf/day for Wamsutter.

2

 The molecular weights and the higher heating values are from GSPA Engineering Data Book, 12th Edition.

Assumptions

0.0821 L-atm/K-mol

298.15 oK

1 1 atm

1 ft3 28.31685 L

453.59237 mol/lb-mol

391.90 scf/lbmol
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-72

Table 89. Summary of Well Site Dehydrator Emissions in tons per well by Project Year. 

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Dehydrator Venting - Well Site 2008 0 9.5074 0 0 0 0 1.8358 7.5985 0 0 0 active well counts

Dehydrator Venting - Well Site 2009 0 9.4109 0 0 0 0 1.8232 7.5959 0 0 0 active well counts

Dehydrator Venting - Well Site 2010 0 9.1278 0 0 0 0 1.7895 7.5883 0 0 0 active well counts

Dehydrator Venting - Well Site 2011 0 8.9583 0 0 0 0 1.7714 7.5837 0 0 0 active well counts

Dehydrator Venting - Well Site 2012 0 8.9407 0 0 0 0 1.7696 7.5833 0 0 0 active well counts

Dehydrator Venting - Well Site 2013 0 8.9344 0 0 0 0 1.7690 7.5831 0 0 0 active well counts

Dehydrator Venting - Well Site 2014 0 8.8485 0 0 0 0 1.7605 7.5808 0 0 0 active well counts

Dehydrator Venting - Well Site 2015 0 8.7525 0 0 0 0 1.7514 7.5782 0 0 0 active well counts

Dehydrator Venting - Well Site 2016 0 8.6658 0 0 0 0 1.7436 7.5759 0 0 0 active well counts

Dehydrator Venting - Well Site 2017 0 8.5883 0 0 0 0 1.7369 7.5738 0 0 0 active well counts

Dehydrator Venting - Well Site 2018 0 8.5187 0 0 0 0 1.7311 7.5719 0 0 0 active well counts

Dehydrator Venting - Well Site 2019 0 8.4540 0 0 0 0 1.7258 7.5702 0 0 0 active well counts

Dehydrator Venting - Well Site 2020 0 8.3912 0 0 0 0 1.7209 7.5685 0 0 0 active well counts

Dehydrator Venting - Well Site 2021 0 8.3342 0 0 0 0 1.7166 7.5670 0 0 0 active well counts

Dehydrator Venting - Well Site 2022 0 8.2442 0 0 0 0 1.7100 7.5646 0 0 0 active well counts

Dehydrator Venting - Well Site 2023 0 8.1920 0 0 0 0 1.7063 7.5632 0 0 0 active well counts

Dehydrator Venting - Well Site 2024 0 8.1425 0 0 0 0 1.7028 7.5619 0 0 0 active well counts

Dehydrator Venting - Well Site 2025 0 8.1004 0 0 0 0 1.7000 7.5607 0 0 0 active well counts

Dehydrator Venting - Well Site 2026 0 8.0577 0 0 0 0 1.6972 7.5596 0 0 0 active well counts

Dehydrator Venting - Well Site 2027 0 8.0180 0 0 0 0 1.6946 7.5585 0 0 0 active well counts

Dehydrator Venting - Well Site 2028 0 8.0021 0 0 0 0 1.6936 7.5581 0 0 0 active well counts

Dehydrator Venting - Well Site 2029 0 7.9186 0 0 0 0 1.6884 7.5559 0 0 0 active well counts

Dehydrator Venting - Well Site 2030 0 7.8818 0 0 0 0 1.6861 7.5549 0 0 0 active well counts

Dehydrator Venting - Well Site 2031 0 7.8478 0 0 0 0 1.6841 7.5540 0 0 0 active well counts

Dehydrator Venting - Well Site 2032 0 7.8143 0 0 0 0 1.6822 7.5531 0 0 0 active well counts

Dehydrator Venting - Well Site 2033 0 7.7807 0 0 0 0 1.6802 7.5522 0 0 0 active well counts

Dehydrator Venting - Well Site 2034 0 7.7501 0 0 0 0 1.6785 7.5513 0 0 0 active well counts

Dehydrator Venting - Well Site 2035 0 7.7215 0 0 0 0 1.6769 7.5506 0 0 0 active well counts

Dehydrator Venting - Well Site 2036 0 7.6974 0 0 0 0 1.6756 7.5499 0 0 0 active well counts

Dehydrator Venting - Well Site 2037 0 7.6740 0 0 0 0 1.6743 7.5493 0 0 0 active well counts

Description Year Projection Dehydrator Emissions - Weighted Average (tons per well)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-73

Table 90. Percent Change in Emission from Base Year 2008 for Dehydrators.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-74

2008 Production Traffic Emissions

ASSUMPTIONS

Data Provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

PRODUCTION TRAFFIC.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-75

Table 91. Summary of Traffic Activity Data Associated with Production Traffic.

Table 92. 2008 Exhaust Emissions (lb/well) Associated with Production Traffic by Vehicle 

Type.

Light Truck 20 20 52

Heavy Truck 20 20 14

Heavy Trucks - Central Facility 0 0 0

Production traffic assumes that vehicles end up at the central facility

Equipment Type

Field

Mean Vehicle 

Speed (mph)

Round Trip OffRoad Trip Distance 

(miles)

Number of Round 

Trips Per Well 

(annual)

NOx 2.67 6.127

SO2 0.02 0.054

CO 19.44 44.580

CO2 677.28 1553

VOC 1.57 3.596

PM10 0.09 0.207

PM2.5 0.09 0.197

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.213

N2O 0.05 0.111

NOx 21.75 13.426

SO2 0.08 0.051

CO 15.96 9.855

CO2 2612.85 1612.873

VOC 1.93 1.193

PM10 1.30 0.804

PM2.5 1.26 0.780

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.056

N2O 0.04 0.023

NOx 21.75 0.000

SO2 0.08 0.000

CO 15.96 0.000

CO2 2612.85 0.000

VOC 1.93 0.000

PM10 1.30 0.000

PM2.5 1.26 0.000

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.000

N2O 0.04 0.000

Heavy-Duty Truck 

Light-Duty Truck

Vehicle Type Pollutant 2008 Emission 

Factors (g/mile)

Base year 

Emissions (lb/well)

Heavy-Duty Diesel Truck Travel 

to Central Facility
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-76

Table 93. Summary of 2008 Fugitive Dust Emissions (tons/well) Associated with 

Production Traffic.

Travel to well Light truck 7,000 20 52 52 20 1040 0.20 0.10 0.02 0.01

Travel to well Heavy Truck 70,000 20 14 14 20 280 0.20 0.03 0.02 0.00

Travel to Central Facility Heavy Truck 70,000 0 0 0 0 0 0.00 0.00 0.02 0.00

Total 0.13 0.01

Total # of 

Round Trips

Round Trip 

Distance 

(mi)

Total Miles 

Traveled

P M10

Activity Vehicle Type Av. Vehicle Weight 

(lb)

Mean vehicle 

speed (mph)

# of Visits 

per Year 

P M2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-77

Table 94. 2008 Exhaust and Fugitive Dust Emissions Associated with Production Traffic.

Table 95. Percent Change in Emission from Base Year 2009 due to Fleet Turnover for Production Traffic.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Production Traffic (LD) 0.0031 0.0018 0.0223 0.0001 9.83E-05 2.71E-05 0.7764 0.0001 0 0 5.56E-05 active well counts 0.1030 0.0102

Production Traffic (HD) 0.0067 0.0006 0.0049 0.0004 0.0004 2.53E-05 0.8064 2.79E-05 0 0 1.15E-05 active well counts 0.0277 0.0028

Production Traffic, Central Facility 

(HD) 0 0 0 0 0 0 0 0 0 0 0 None 0.0000 0.0000

Description Projection Total Production Traffic Emissions (tons per well) Fugitive Road NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 -6% -39% -6% 0% -6% -4% -4% 0% 0% -8% -6% -7% -2% -6% 0% -4% -7% -7% 0% 0% 0% -5%

2010 -10% -46% -10% -1% -10% -9% -9% 0% 0% -12% -12% -16% -47% -9% 0% -6% -14% -14% 0% 0% 4% -10%

2011 -15% -50% -13% -2% -15% -16% -16% 0% 0% -15% -19% -25% -75% -14% 0% -13% -24% -24% 0% 0% 13% -16%

2012 -21% -55% -16% -3% -21% -22% -22% 0% 0% -19% -25% -33% -75% -19% 0% -21% -33% -33% 0% 0% 20% -21%

2013 -26% -56% -20% -4% -26% -27% -28% 0% 0% -22% -32% -41% -76% -24% 0% -28% -41% -41% 0% 0% 24% -27%

2014 -32% -57% -24% -5% -32% -33% -33% 0% 0% -25% -37% -48% -76% -28% 0% -34% -49% -49% 0% 0% 28% -32%

2015 -37% -57% -27% -7% -36% -38% -38% 0% 0% -28% -42% -54% -76% -32% 0% -40% -56% -56% 0% 0% 30% -36%

2016 -42% -58% -30% -9% -41% -42% -43% 0% 0% -31% -47% -60% -77% -37% 0% -46% -63% -63% 0% 0% 31% -40%

2017 -46% -59% -33% -10% -45% -46% -47% 0% 0% -34% -51% -65% -77% -40% 0% -51% -68% -68% 0% 0% 32% -44%

2018 -50% -60% -35% -12% -49% -50% -50% 0% 0% -36% -55% -69% -77% -43% 0% -56% -73% -73% 0% 0% 32% -47%

2019 -53% -60% -37% -13% -52% -53% -53% 0% 0% -38% -58% -73% -77% -45% 0% -60% -77% -77% 0% 0% 33% -50%

2020 -57% -61% -38% -14% -55% -55% -56% 0% 0% -39% -61% -76% -77% -47% 0% -64% -81% -81% 0% 0% 34% -53%

2021 -59% -62% -40% -16% -58% -57% -58% 0% 0% -41% -64% -78% -77% -49% 0% -67% -83% -83% 0% 0% 34% -55%

2022 -66% -63% -44% -19% -64% -63% -64% 0% 0% -43% -71% -84% -78% -53% 0% -74% -90% -90% 0% 0% 34% -61%

2023 -62% -62% -41% -17% -60% -59% -60% 0% 0% -42% -67% -81% -78% -51% 0% -70% -86% -86% 0% 0% 34% -58%

2024 -64% -63% -43% -18% -63% -61% -62% 0% 0% -43% -69% -82% -78% -52% 0% -72% -88% -88% 0% 0% 34% -60%

2025 -68% -64% -45% -19% -67% -64% -65% 0% 0% -44% -72% -85% -78% -54% 0% -76% -91% -91% 0% 0% 34% -63%

2026 -70% -64% -46% -20% -69% -66% -66% 0% 0% -43% -74% -86% -78% -56% 0% -79% -92% -92% 0% 0% 36% -65%

2027 -71% -64% -47% -21% -71% -67% -68% 0% 0% -43% -75% -87% -78% -56% 0% -80% -93% -93% 0% 0% 36% -66%

2028 -72% -64% -48% -21% -72% -68% -69% 0% 0% -44% -76% -88% -78% -57% 0% -81% -94% -94% 0% 0% 36% -67%

2029 -73% -65% -48% -22% -73% -69% -70% 0% 0% -45% -78% -88% -78% -58% 0% -83% -94% -94% 0% 0% 35% -68%

2030 -74% -65% -49% -22% -75% -70% -70% 0% 0% -45% -78% -89% -78% -58% 0% -84% -95% -95% 0% 0% 35% -69%

2031 -75% -65% -50% -23% -76% -70% -71% 0% 0% -47% -79% -89% -78% -59% 0% -85% -95% -95% 0% 0% 34% -70%

2032 -76% -65% -50% -23% -76% -71% -72% 0% 0% -47% -80% -89% -78% -60% 0% -85% -95% -95% 0% 0% 34% -70%

2033 -77% -66% -51% -24% -77% -72% -72% 0% 0% -48% -80% -89% -78% -61% 0% -86% -95% -95% 0% 0% 33% -71%

2034 -77% -66% -52% -24% -78% -72% -73% 0% 0% -48% -81% -90% -78% -61% 0% -86% -96% -96% 0% 0% 33% -71%

2035 -78% -66% -52% -24% -78% -73% -73% 0% 0% -48% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 33% -72%

2036 -78% -66% -53% -24% -79% -73% -74% 0% 0% -49% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 32% -72%

2037 -78% -66% -53% -25% -79% -73% -74% 0% 0% -49% -81% -90% -78% -63% -1% -87% -96% -96% 0% 0% 32% -72%

Light-Duty Truck (%) Heavy-Duty Truck (%)

Year
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-78

2008 Chemical Injection Pump Emissions

ASSUMPTIONS

Data provided by operators in blue text

No statewide requirement for Pneumatic Pumps (Ref: OIL AND GAS PRODUCTION FACILITIES 

CHAPTER 6, SECTION 2 PERMITTING GUIDANCE, August 2007)

Table 96. Summary of Chemical Injection Pump Data.

VOC and CH4 Emissions (tons/well) = (lb/MMscf)c* Volume of Gas Vented per well

(lb/MMscf)c = Mole %(c)*(Weight (lb/lb-mol))(c)*sfc/mol

CO2 Emissions (tons/well) = (lb CO2/MMscf)* Volume of Gas Vented per well

where,

(lb/MMscf)c= lb emissions per MMscf for a particular compound

c = compound identified in Sales Gas Composition 

Mole% = Mole percentage of compound

Weight (lb/lb-mol)(c) = Molecular weight of a compound

Calculation Inputs

VOC Fraction (molar) 5.39%

VOC molecular weight 57.50

R 0.08206 L atm / K-mol

standard temp 298.15 K

standard press 1 atm

MCF to 1000 liter conversion 28.317 1000L/MCF

L/mol 24.47 L/mol

28.32 L/SCF

453.59237 mol/lb-mol

391.90 scf/lbmol

Methanol 1,381,989 1,368 47 1 - - 64.31 0.06

Glycol Heat Medium Pumps - - - 1 273 2.84 1,116.73 1.12

Total - - - - - - 1181.04 1.18

Gallons/well SCF/Gallon 

Number 

of Pump

Days 

Used in 

Quarter

SCF/Pump/Mi

 Type Gallons Used nute

Vented Volume 

(MCF/year)

Vented Volume 

(MMSCF/year)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-79

Table 97. Uncontrolled 2008 Emissions (tons/well) Estimation by Compound.

Table 98. 2008 Chemical Injection Pump Emissions in tons per well.

Component Mole %1

Molecular 

Weight

 (lb/lb-mol)2 Weight %

lb/

MMscf

lb CO2/ 

MMscf

HHV 

(Btu/scf)2

Uncontrolled 

Emissions 

(TPY/well)

Carbon Dioxide 2.73% 44.01 6.07% 3066.1 3066.1 0 1.8106

Nitrogen 0.17% 28.01 0.24% 122.3 0 0.0722

Methane 84.90% 16.04 68.75% 34749.6 1010 20.5203

Ethane 6.81% 30.07 10.33% 5222.5 1770 3.0840

Propane 3.17% 44.10 7.05% 3564.0 2516 2.1046

Isobutane 0.64% 58.12 1.86% 942.4 3252 0.5565

n-Butane 0.71% 58.12 2.08% 1052.8 3262 0.6217

Isopentane 0.24% 72.15 0.88% 445.4 4001 0.2630

n-Pentane 0.20% 72.15 0.73% 366.5 4009 0.2164

n-Hexane 0.16% 86.18 0.69% 350.1 4756 0.2068

Cyclohexane 0.03% 84.16 0.13% 68.2 4482 0.0403

2,2-Dimethylbutane 0.00% 86.18 0.02% 9.4 4736 0.0055

2,3-Dimethylbutane 0.02% 86.18 0.07% 36.0 4745 0.0213

2-Methylpentane 0.05% 86.18 0.21% 107.2 4747 0.0633

3-Methylpentane 0.03% 86.18 0.11% 55.1 4750 0.0325

n-Heptane 0.06% 100.20 0.30% 149.9 5503 0.0885

Methylcyclohexane 0.03% 98.19 0.16% 80.6 5216 0.0476

2,2,4-Trimethylpentane 0.00% 114.23 0.02% 11.0 6249 0.0065

Benzene 0.01% 78.11 0.06% 29.8 3742 0.0176

Toluene 0.02% 92.14 0.08% 41.0 4475 0.0242

Ethylbenzene 0.00% 106.17 0.00% 1.2 5222 0.0007

m-Xylene 0.00% 106.16 0.03% 12.6 5208 0.0075

o-Xylene 0.00% 106.16 0.02% 11.0 5210 0.0065

n-Octane 0.00% 114.23 0.00% 1.8 6249 0.0010

n-Nonane 0.01% 128.26 0.09% 44.8 6996 0.0264

n-Decane 0.00% 142.29 0.00% 0.0 7743 0.0000

Total 100.00% 19.81 100.00% 50541.4 3066.1 1140.5767 29.8457

Total VOC 5.39% 14.60% 7380.8 4.3585

1 Mole percentage of the sales gas 

2

 The molecular weights and the higher heating values are from GSPA Engineering Data Book, 12th Edition.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Pneumatic Pumps 0 4.3585 0 0 0 0 1.8106 20.5203 0 0 0 active well counts

Description Projection

Chemical Injection Pump Emissions -Weighted Average(tons per well)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-80

Table 99. Percent Change in Emission from Base Year 2008 for Chemical Injection Pump.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-81

2008 Compressor Emissions

ASSUMPTIONS

Data provided by operators in blue text

Table 100. Speciation Profiles used to Calculate CH4 and CO2 Emissions.

Table 101. Compressor Engine Emission Factors (turbine and rich burn SI).

Operator provided NOx, VOC and CO emissions for each compressor station. For remaining pollutants the unknown pollutant to NOx emission 

factor was multiplied by NOx emissions to get unknown pollutant emissions except for CH4 and CO2 either speciation profile or CO2/VOC and 

CH4/VOC weight ratio was multiplied to VOC emissions. 

Turbine CH4/VOC 2.33 SPECIATE PROFILE

4-Stroke Rich Burn CH4/VOC 8.24 SPECIATE PROFILE

Venting CH4/VOC 4.71 Sales/Produced Gas Composition

Venting CO2/VOC 0.42 Sales/Produced Gas Composition

4-Stroke Lean Burn CH4/VOC 8.24 SPECIATE PROFILE

EF (g/hp-hr) source EF (g/hp-hr) source

PM10 0.0240 EPA,AP-42 Turbine EFs 0.0704

EPA,AP-42, 4-Stroke Rich 

Burn Engine Efs

PM2.5 0.0240 EPA,AP-42 Turbine EFs 0.0704

EPA,AP-42, 4-Stroke Rich 

Burn Engine Efs

SO2 0.0000 0.0000

CO2 399.1680 EPA,AP-42 Turbine EFs 399.1680

EPA,AP-42, 4-Stroke Rich 

Burn Engine Efs

CH4 0.0210 SPECIATE Profile 0.7669 SPECIATE Profile

PM_cond 0.0171 EPA,AP-42 Turbine EFs 0.0360

EPA,AP-42, 4-Stroke Rich 

Burn Engine Efs

PM_filt 0.0069 EPA,AP-42 Turbine EFs 0.0345

EPA,AP-42, 4-Stroke Rich 

Burn Engine Efs

N2O 0.0109 EPA,AP-42 Turbine EFs 0.00076 API Compendium

Turbine

source: API Compendium Table 4-5. CH4 and N2O Combustion Emission Factors (Fuel Basis) for 

Common Industry Fuel Types - Natural Gas (tonnes/MMBtu)

Pollutant

Emission Factors

Reciprocating
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-82

Table 102. EPA AP-42 Compressor Engine Emission Factors (lean burn SI).

Pollutant

Emission Factor 

(lb/MMBTU)

Emission Factor 

(g/hp-hr)

PM_filt 7.71E-05 2.80E-04

PM_cond 9.91E-03 3.60E-02

PM10 9.99E-03 3.62E-02

PM2.5 9.99E-03 3.62E-02

CH4 1.25E+00 4.54E+00

CO2 1.10E+02 3.99E+02

N2O 0.00076

Assumed 8000 Btu/hp-hr heat input

Source: API Compendium Table 4-5. CH4 and N2O Combustion Emission 

Factors (Fuel Basis) for Common Industry Fuel Types - Natural Gas 

(tonnes/MMBtu)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-83

Table 103. 2008 Actual Emissions (tons/year) by Facility and Process.

Station (Process) NOx VOC C O PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O Wamsutter Compressor Station (Colorado Interstate Gas) (Reciprocating Engine Rich Burn)

 - - - - - - - - - - - Wamsutter Compressor Station (Colorado Interstate Gas) (Reciprocating Engine 

Lean Burn)

 - - - - - - - - - - - Wamsutter Compressor Station (Colorado Interstate Gas) (Turbine) 155.9 22.8 109.0 7.0 7.0 2.0 291,586.4 53.2 2.0 5.0 8.0 Wamsutter Compressor Station (Colorado Interstate Gas) (Venting) - - - - - - - - - - - Wamsutter Compressor Station (Colorado Interstate Gas) (External NG Combustion)

 - - - - - - - - - - - Wamsutter Compressor Station (Colorado Interstate Gas) (Flashing) - - - - - - - - - - - Wamsutter Compressor Station (Colorado Interstate Gas) (working and breathing) - - - - - - - - - - - Wamsutter Compressor Station (Colorado Interstate Gas) (Flaring) - - - - - - - - - - -

Table Rock (Reciprocating Engine Rich Burn) 130.4 4.9 86.9 13.1 13.1 - 74,359.3 40.4 6.4 6.7 0.1

Table Rock (Reciprocating Engine Lean Burn) - - - - - - - - - - -

Table Rock (Turbine) - - - - - - - - - - -

Table Rock (Venting) - - - - - - - - - - -

Table Rock (External NG Combustion) - - - - - - - - - - -

Table Rock (Flashing) - - - - - - - - - - -

Table Rock (working and breathing) - - - - - - - - - - -

Table Rock (Flaring) - - - - - - - - - - -

Creston 221 (Reciprocating Engine Rich Burn) - - - - - - - - - - -

Creston 221 (Reciprocating Engine Lean Burn) 37.7 6.7 37.9 0.91 0.91 - 10,026.30 54.83 0.01 0.90 0.02

Creston 221 (Turbine) - - - - - - - - - - -

Creston 221 (Venting) 0.0 2.7 - - - - 1.12 12.72 - - -

Creston 221 (External NG Combustion) 2.1 0.0 1.8 0.16 0.16 0.01 2,542.57 0.05 0.04 0.12 0.05

Creston 221 (Flashing) - - - - - - - - - - -

Creston 221 (working and breathing) - - - - - - - - - - -

Creston 221 (Flaring) - - - - - - - - - - -

Fillmore Compressor Station (Reciprocating Engine Rich Burn) - - - - - - - - - - -

Fillmore Compressor Station (Reciprocating Engine Lean Burn) 6.6 14.8 12.6 0.16 0.16 - 1,764.00 121.62 0.00 0.16 0.00

Fillmore Compressor Station (Turbine) - - - - - - - - - - -

Fillmore Compressor Station (Venting) - 7.3 - - - - 3.04 34.46 - - -

Fillmore Compressor Station (External NG Combustion) 0.5 0.1 0.5 0.04 0.04 0.00 565.45 0.01 0.01 0.03 0.01

Fillmore Compressor Station (Flashing) - - - - - - - - - - -

Fillmore Compressor Station (working and breathing) - - - - - - - - - - -

Fillmore Compressor Station (Flaring) - - - - - - - - - - -

Frewen Lake Compressor Station (Reciprocating Engine Rich Burn) - - - - - - - - - - -

Frewen Lake Compressor Station (Reciprocating Engine Lean Burn) 53.8 10.0 85.5 1.30 1.30 - 14,307.43 82.56 0.01 1.29 0.03

Frewen Lake Compressor Station (Turbine) 91.9 30.2 19.1 10.32 10.32 - ######## 70.46 2.97 7.35 4.7

Frewen Lake Compressor Station (Venting) - 17.2 - - - - 7.14 80.89 - - -

Frewen Lake Compressor Station (External NG Combustion) - - - - - - - - - - -

Frewen Lake Compressor Station (Flashing) - - - - - - - - - - -

Frewen Lake Compressor Station (working and breathing) - - - - - - - - - - -

Frewen Lake Compressor Station (Flaring) - - - - - - - - - - -

Siberia Ridge Compressor Station (Reciprocating Engine Rich Burn) - - - - - - - - - - -

Siberia Ridge Compressor Station (Reciprocating Engine Lean Burn) 1.4 0.1 1.5 0.03 0.03 - 383.07 0.91 0.00 0.03 0.00

Siberia Ridge Compressor Station (Turbine) - - - - - - - - - - -

Siberia Ridge Compressor Station (Venting) - 1.1 - - - - 0.45 5.11 - - -

Siberia Ridge Compressor Station (External NG Combustion) 1.1 0.0 1.0 0.08 0.08 0.01 1,272.59 0.02 0.02 0.06 0.02

Siberia Ridge Compressor Station (Flashing) - - - - - - - - - - -

Siberia Ridge Compressor Station (working and breathing) - - - - - - - - - - -

Siberia Ridge Compressor Station (Flaring) - - - - - - - - - - -

Wamsutter Compressor Station (Rockies Express Pipeline) (Reciprocating Engine Rich Burn)

 - - - - - - - - - - - Wamsutter Compressor Station (Rockies Express Pipeline) (Reciprocating Engine 

Lean Burn)

 - - - - - - - - - - - Wamsutter Compressor Station (Rockies Express Pipeline) (Turbine) 84.3 49.1 71.5 9.5 9.5 - 157,669.9 114.6 2.7 6.7 4.3 Wamsutter Compressor Station (Rockies Express Pipeline) (Venting) - - - - - - - - - - - Wamsutter Compressor Station (Rockies Express Pipeline) (External NG Combustion)

 - - - - - - - - - - - Wamsutter Compressor Station (Rockies Express Pipeline) (Flashing) - - - - - - - - - - - Wamsutter Compressor Station (Rockies Express Pipeline) (working and 

breathing)

 - - - - - - - - - - - Wamsutter Compressor Station (Rockies Express Pipeline) (Flaring) - - - - - - - - - - -

Wamsutter A-6 Compressor Station (Marathon Oil) (Reciprocating Engine Rich 

Burn)

 - - - - - - - - - - - Wamsutter A-6 Compressor Station (Marathon Oil) (Reciprocating Engine Lean 

Burn)

 - - - - - - - - - - - Wamsutter A-6 Compressor Station (Marathon Oil) (Turbine) 40.0 42.2 13.6 4.5 4.5 - 74,813.7 98.5 1.3 3.2 2.0 Wamsutter A-6 Compressor Station (Marathon Oil) (Venting) - - - - - - - - - - - Wamsutter A-6 Compressor Station (Marathon Oil)) (External NG Combustion) - - - - - - - - - - - Wamsutter A-6 Compressor Station (Marathon Oil) (Flashing) - - - - - - - - - - - Wamsutter A-6 Compressor Station (Marathon Oil) (working and breathing) - - - - - - - - - - - Wamsutter A-6 Compressor Station (Marathon Oil) (Flaring) - - - - - - - - - - -

Table Rock Compressor Station (Chevron) (Reciprocating Engine Rich Burn) 14.8 11.6 8.1 1.5 1.5 - 8,439.6 95.6 0.7 0.8 0.0

Table Rock Compressor Station (Chevron) (Reciprocating Engine Lean Burn) - - - - - - - - - - -

Table Rock Compressor Station (Chevron) (Turbine) - - - - - - - - - - -

Table Rock Compressor Station (Chevron) (Venting) - - - - - - - - - - -

Table Rock Compressor Station (Chevron)k (External NG Combustion) - - - - - - - - - - -

Table Rock Compressor Station (Chevron) (Flashing) - - - - - - - - - - -

Table Rock Compressor Station (Chevron) (working and breathing) - - - - - - - - - - -

Table Rock Compressor Station (Chevron) (Flaring) - - - - - - - - - - -

Wamsutter A-6 Compressor Station (Marathon Oil) and Wamsutter Compressor Station (Rockies Express Pipeline) emissions assumed to be entirely from compressor engines. Assumed a turbine natural gas emission factor of 

0.21341975308642 g/hp-hr NOx to estimate CO2 and N2O emissions

Table Rock Compressor Station (Chevron) emissions assumed to be entirely from compressor engines. Assumed a spark ignition natural gas emission factor of 0.7 g/hp-hr NOx to estimate CO2 , N2O and PM emissions
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-84

Table 104. Compressor Engine Emissions in tons per activity.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Compressor Station (Reciprocating Engine Rich Burn) 145.20 16.50 95.00 14.61 14.61 0 82798.85 135.92 7.15 7.46 0.1576

totals for year with 

compressor station

Compressor Station (Reciprocating Engine Lean Burn) 99.51 31.55 137.47 2.40 2.40 0 26480.80 259.91 0.0186 2.39 0.0504

totals for year with 

compressor station

Compressor Station (Turbine) 372.14 144.30 213.20 31.27 31.27 2.00 696020.41 336.69 9.00 22.27 18.98

totals for year with 

compressor station

Compressor Station (Venting) 0.0042 28.29 0 0 0 0 11.75 133.18 0 0 0

totals for year with 

compressor station

Compressor Station (External NG Combustion) 3.65 0.1631 3.33 0.2774 0.2774 0.0219 4380.61 0.0840 0.0694 0.2081 0.0803

totals for year with 

compressor station

Compressor Station (Flashing) 0 0 0 0 0 0 0 0 0 0 0

totals for year with 

compressor station

Compressor Station (Working/Breathing) 0 0 0 0 0 0 0 0 0 0 0

totals for year with 

compressor station

Compressor Station (Flaring) 0 0 0 0 0 0 0 0 0 0 0

totals for year with 

compressor station

Description Projection Compressor Engine Emissions (tons total)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-85

2008 Gas Plants Emissions

ASSUMPTIONS

Data provided by operators in blue text.

Table 105. Emission rates (lb/MMBTU or g/hp-hr) for estimating PM and GHG emissions.

Table 106. 2008 Actual Total Facility Emissions (tons/yr) for the Echo Springs Gas Plant.

Pollutant

Echo Springs 

Gas Plant 

Emissions 

(tons/yr) 

NOx 568.1

CO 740.6

VOC 198.4

PM10 -

SO2 -

Reference Permits 0

Permit No. MD-10112

Permit date 40395

Table 107. Summary of Gas Plants Emissions in tons per year.

Operator provided the total facility NOx, VOC and CO actual emissions and permitted Nox,VOC and CO emissions by source for the 

Echo Spring Gas Plant. NOx, VOC and CO actual emissions by sources were then calculated by multiplying total facility actual 

emissions with the ratio of the gas plant permitted emissions by-source over total gas plant permitted emissions. For remaining 

pollutants, the unknown pollutant emission factor to NOx emission factor was multiplied by NOx emissions to get unknown pollutant 

emissions except for CH4 and CO2. Emissions for these pollutants were estimated either using speciation profiles or CO2/VOC and 

CH4/VOC weight ratio to VOC emissions.

Process NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

(Reciprocating Engine) 1.56 - - 0.04 0.04 0.00 399.17 4.54 0.00 0.04 0.00076

(Turbine) 0.35 - - 0.02 0.02 0.00 399.17 0.02 0.01 0.02 0.01089

(flaring) 0.068 - - 0 0 0 113 0.035 0 0 0.00131

(natural gas external combustion (boiler/heater)) 100 - - 7.6 7.6 0 120,000 2 1.9 5.7 2.2

(venting) - 14.60% - - - - 6.07% 68.75% - - -

gas fractions (wt)

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Gas Plant (Reciprocating Engine) 99.48 59.65 142.53 2.32 2.32 0 25510.69 289.89 0.0179 2.30 0.0486

totals for year 

with gas plant

Gas Plant (Turbine) 339.13 61.71 435.78 22.94 22.94 0 382382.05 20.12 6.60 16.34 10.43

totals for year 

with gas plant

Gas Plant (flaring) 40.70 38.57 110.89 0 0 0 67603.22 20.95 0 0 0.7812

totals for year 

with gas plant

Gas Plant (natural gas external 

combustion (boiler/heater)) 88.80 34.44 51.40 6.75 6.75 0 106558.39 2.04 1.69 5.06 1.95

totals for year 

with gas plant

Gas Plant (venting) 0 4.02 0 0 0 0 1.67 18.93 0 0 0

totals for year 

with gas plant

Description Gas Plant Emissions (tons total) Projection
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-86

2008 Evaporative Pond Emissions

Table 108. 2008 Emissions (tons/year) from Wamsutter North and South Evaporation

Ponds.

Table 109. 2008 Average VOC emissions per well.

Table 110. VOC, CO2 and CH4 Weight Fractions (Produced Water Composition).

Table 111. 2008 Evaporation Pond Emissions in tons per well.

Parameter

Wamsutter 

North Pond

Wamsutter South 

Pond

4.67 5.85

Benzene 0.62 0.84

Ethylbenzene 0.07 0.09

Hexane (-n) 0.01 0.01

Methanol 2.09 2.31

Toluene 0.80 1.11

Xylene 0.92 1.25

Xylene (-o) 0.17 0.24

VOC Emissions (tpy)

Emissions (tpy) based on Water 9 model Output*

*based on data from evaporation facilities at Wamsutter Operations Center

Average VOC emissions per evaporation basin (tpy) 5.26

Average Evaporation Facilities per well a0.133%

Average VOC emissions per well (tpy) 0.01

a Based on two existing evaporation facilities for existing 1500 CDC wells

Methane 3.90% 0.0004

Carbon Dioxide 24.76% 0.0025

VOC Fraction (weight) 69.58%

Component % Wt Average per 

Well Emissions

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Evaporation Ponds 0 0.0070 0 0 0 0 0.0025 0.0004 0 0 0 active well counts

Description Evaporation Pond Emissions -Weighted Average(tons per well) Projection
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-87

Table 112. Percent Change in Emission from Base Year 2008 for Evaporation Ponds.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-88

Table 113. Existing Wells NOx Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 1. Existing Wells NOx Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 293 5 1,166 52 169 32 0 0 0 570 0 0 29 0 62 20 0 568 621 0 0 3,587

2009 0 0 0 0 0 0 0 0 0 0 564 0 0 28 0 58 20 0 568 621 0 0 1,859

2010 0 0 0 0 0 0 0 0 0 0 558 0 0 28 0 51 20 0 568 621 0 0 1,845

2011 0 0 0 0 0 0 0 0 0 0 552 0 0 28 0 47 20 0 568 621 0 0 1,835

2012 0 0 0 0 0 0 0 0 0 0 547 0 0 27 0 46 19 0 568 621 0 0 1,828

2013 0 0 0 0 0 0 0 0 0 0 541 0 0 27 0 46 19 0 568 621 0 0 1,822

2014 0 0 0 0 0 0 0 0 0 0 536 0 0 27 0 44 19 0 568 621 0 0 1,814

2015 0 0 0 0 0 0 0 0 0 0 531 0 0 26 0 42 19 0 568 621 0 0 1,806

2016 0 0 0 0 0 0 0 0 0 0 525 0 0 26 0 40 19 0 568 621 0 0 1,798

2017 0 0 0 0 0 0 0 0 0 0 520 0 0 26 0 38 18 0 568 621 0 0 1,791

2018 0 0 0 0 0 0 0 0 0 0 515 0 0 26 0 37 18 0 568 621 0 0 1,784

2019 0 0 0 0 0 0 0 0 0 0 509 0 0 25 0 35 18 0 568 621 0 0 1,777

2020 0 0 0 0 0 0 0 0 0 0 504 0 0 25 0 34 18 0 568 621 0 0 1,770

2021 0 0 0 0 0 0 0 0 0 0 499 0 0 25 0 33 18 0 568 621 0 0 1,764

2022 0 0 0 0 0 0 0 0 0 0 495 0 0 24 0 32 17 0 568 621 0 0 1,757

2023 0 0 0 0 0 0 0 0 0 0 490 0 0 24 0 31 17 0 568 621 0 0 1,750

2024 0 0 0 0 0 0 0 0 0 0 485 0 0 24 0 30 17 0 568 621 0 0 1,744

2025 0 0 0 0 0 0 0 0 0 0 480 0 0 24 0 29 17 0 568 621 0 0 1,738

2026 0 0 0 0 0 0 0 0 0 0 475 0 0 23 0 28 17 0 568 621 0 0 1,732

2027 0 0 0 0 0 0 0 0 0 0 470 0 0 23 0 28 17 0 568 621 0 0 1,726

2028 0 0 0 0 0 0 0 0 0 0 461 0 0 23 0 27 16 0 568 621 0 0 1,715

2029 0 0 0 0 0 0 0 0 0 0 456 0 0 23 0 26 16 0 568 621 0 0 1,709

2030 0 0 0 0 0 0 0 0 0 0 452 0 0 22 0 25 16 0 568 621 0 0 1,704

2031 0 0 0 0 0 0 0 0 0 0 447 0 0 22 0 25 16 0 568 621 0 0 1,698

2032 0 0 0 0 0 0 0 0 0 0 443 0 0 22 0 24 16 0 568 621 0 0 1,693

2033 0 0 0 0 0 0 0 0 0 0 438 0 0 22 0 23 15 0 568 621 0 0 1,688

2034 0 0 0 0 0 0 0 0 0 0 434 0 0 21 0 23 15 0 568 621 0 0 1,682

2035 0 0 0 0 0 0 0 0 0 0 429 0 0 21 0 23 15 0 568 621 0 0 1,677

2036 0 0 0 0 0 0 0 0 0 0 425 0 0 21 0 22 15 0 568 621 0 0 1,672

2037 0 0 0 0 0 0 0 0 0 0 420 0 0 21 0 22 15 0 568 621 0 0 1,666

TOTAL 0 293 5 1,166 52 169 32 0 0 0 14,770 0 0 733 0 1,029 522 0 17,043 18,615 0 0 54,431

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

NOx [tpy]

0

720

1,440

2,160

2,880

3,600

4,320

5,040

5,760

6,480

7,200

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well NOx Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-89

Table 114. Existing Wells VOC Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 2. Existing Wells VOC Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 44 1 106 6 0 4 130 27,096 1,904 31 0 12,422 7 197 79 2 2,133 198 221 14,072 20 58,672

2009 0 0 0 0 0 0 0 0 26,548 1,885 31 0 12,295 7 185 75 2 2,111 198 221 13,311 20 56,889

2010 0 0 0 0 0 0 0 0 25,484 1,866 31 0 12,169 7 159 66 2 2,089 198 221 11,585 20 53,896

2011 0 0 0 0 0 0 0 0 24,751 1,846 30 0 12,042 7 145 61 2 2,067 198 221 10,624 19 52,014

2012 0 0 0 0 0 0 0 0 24,463 1,828 30 0 11,925 7 142 60 2 2,047 198 221 10,438 19 51,381

2013 0 0 0 0 0 0 0 0 24,206 1,810 30 0 11,808 7 141 59 2 2,027 198 221 10,307 19 50,835

2014 0 0 0 0 0 0 0 0 23,736 1,792 29 0 11,692 6 133 56 2 2,007 198 221 9,821 19 49,714

2015 0 0 0 0 0 0 0 0 23,244 1,774 29 0 11,575 6 126 54 2 1,987 198 221 9,316 19 48,551

2016 0 0 0 0 0 0 0 0 22,781 1,757 29 0 11,458 6 120 51 2 1,967 198 221 8,875 18 47,484

2017 0 0 0 0 0 0 0 0 22,347 1,739 29 0 11,341 6 114 49 2 1,947 198 221 8,490 18 46,501

2018 0 0 0 0 0 0 0 0 21,938 1,721 28 0 11,224 6 109 47 2 1,927 198 221 8,150 18 45,590

2019 0 0 0 0 0 0 0 0 21,545 1,703 28 0 11,108 6 104 46 2 1,907 198 221 7,840 18 44,725

2020 0 0 0 0 0 0 0 0 21,179 1,686 28 0 11,000 6 100 44 2 1,889 198 221 7,555 18 43,925

2021 0 0 0 0 0 0 0 0 20,830 1,670 27 0 10,893 6 96 43 2 1,870 198 221 7,298 18 43,173

2022 0 0 0 0 0 0 0 0 20,403 1,654 27 0 10,786 6 91 41 2 1,852 198 221 6,951 17 42,249

2023 0 0 0 0 0 0 0 0 20,072 1,637 27 0 10,679 6 88 39 2 1,833 198 221 6,729 17 41,549

2024 0 0 0 0 0 0 0 0 19,751 1,621 27 0 10,572 6 85 38 2 1,815 198 221 6,521 17 40,874

2025 0 0 0 0 0 0 0 0 19,449 1,604 26 0 10,465 6 83 37 2 1,797 198 221 6,340 17 40,245

2026 0 0 0 0 0 0 0 0 19,149 1,588 26 0 10,358 6 80 36 2 1,778 198 221 6,162 17 39,621

2027 0 0 0 0 0 0 0 0 18,858 1,572 26 0 10,251 6 78 35 2 1,760 198 221 5,996 16 39,018

2028 0 0 0 0 0 0 0 0 18,445 1,540 25 0 10,046 6 76 35 2 1,725 198 221 5,837 16 38,171

2029 0 0 0 0 0 0 0 0 18,076 1,525 25 0 9,949 5 72 33 2 1,708 198 221 5,580 16 37,410

2030 0 0 0 0 0 0 0 0 17,816 1,510 25 0 9,852 5 70 32 2 1,691 198 221 5,440 16 36,879

2031 0 0 0 0 0 0 0 0 17,564 1,495 25 0 9,754 5 68 32 2 1,675 198 221 5,310 16 36,364

2032 0 0 0 0 0 0 0 0 17,314 1,480 24 0 9,657 5 66 31 2 1,658 198 221 5,184 16 35,856

2033 0 0 0 0 0 0 0 0 17,066 1,466 24 0 9,560 5 64 30 2 1,641 198 221 5,060 15 35,353

2034 0 0 0 0 0 0 0 0 16,826 1,451 24 0 9,462 5 63 30 2 1,624 198 221 4,945 15 34,866

2035 0 0 0 0 0 0 0 0 16,591 1,436 24 0 9,365 5 61 29 2 1,608 198 221 4,836 15 34,390

2036 0 0 0 0 0 0 0 0 16,367 1,421 23 0 9,268 5 60 28 2 1,591 198 221 4,738 15 33,938

2037 0 0 0 0 0 0 0 0 16,146 1,406 23 0 9,170 5 59 28 2 1,574 198 221 4,643 15 33,490

TOTAL 0 44 1 106 6 0 4 130 620,038 49,387 812 0 322,148 178 3,035 1,324 55 55,305 5,952 6,624 227,956 518 1,293,623

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

VOC [tpy]

0

6,160

12,320

18,480

24,640

30,800

36,960

43,120

49,280

55,440

61,600

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well VOC Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-90

Table 115. Existing Wells SO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 3. Existing Wells SO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 5 0 71 0 56 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 135

2009 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2010 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2011 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2012 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2013 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2014 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2015 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2016 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2017 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2018 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2019 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2020 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2021 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2022 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2023 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2024 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2025 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2026 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2027 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2028 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2029 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2030 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2031 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2032 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2033 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2034 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2035 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2036 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2037 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

TOTAL 0 5 0 71 0 56 0 0 0 0 0 0 0 4 0 0 1 0 0 61 0 0 198

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

SO2 [tpy]

0.0

14.0

28.0

42.0

56.0

70.0

84.0

98.0

112.0

126.0

140.0

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well SO2 Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-91

Table 116. Existing Wells PM10 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 4. Existing Wells PM10 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 194 18 32 56 298 12 188 0 0 0 43 0 0 379 0 0 1 0 32 49 0 0 1,302

2009 0 0 0 0 0 0 0 0 0 0 43 0 0 375 0 0 1 0 32 49 0 0 500

2010 0 0 0 0 0 0 0 0 0 0 42 0 0 371 0 0 1 0 32 49 0 0 496

2011 0 0 0 0 0 0 0 0 0 0 42 0 0 368 0 0 1 0 32 49 0 0 491

2012 0 0 0 0 0 0 0 0 0 0 42 0 0 364 0 0 1 0 32 49 0 0 487

2013 0 0 0 0 0 0 0 0 0 0 41 0 0 360 0 0 1 0 32 49 0 0 483

2014 0 0 0 0 0 0 0 0 0 0 41 0 0 357 0 0 1 0 32 49 0 0 479

2015 0 0 0 0 0 0 0 0 0 0 40 0 0 353 0 0 1 0 32 49 0 0 475

2016 0 0 0 0 0 0 0 0 0 0 40 0 0 350 0 0 1 0 32 49 0 0 471

2017 0 0 0 0 0 0 0 0 0 0 40 0 0 346 0 0 1 0 32 49 0 0 467

2018 0 0 0 0 0 0 0 0 0 0 39 0 0 343 0 0 1 0 32 49 0 0 464

2019 0 0 0 0 0 0 0 0 0 0 39 0 0 339 0 0 1 0 32 49 0 0 460

2020 0 0 0 0 0 0 0 0 0 0 38 0 0 336 0 0 1 0 32 49 0 0 456

2021 0 0 0 0 0 0 0 0 0 0 38 0 0 332 0 0 1 0 32 49 0 0 452

2022 0 0 0 0 0 0 0 0 0 0 38 0 0 329 0 0 1 0 32 49 0 0 449

2023 0 0 0 0 0 0 0 0 0 0 37 0 0 326 0 0 1 0 32 49 0 0 445

2024 0 0 0 0 0 0 0 0 0 0 37 0 0 323 0 0 1 0 32 49 0 0 441

2025 0 0 0 0 0 0 0 0 0 0 36 0 0 319 0 0 1 0 32 49 0 0 438

2026 0 0 0 0 0 0 0 0 0 0 36 0 0 316 0 0 1 0 32 49 0 0 434

2027 0 0 0 0 0 0 0 0 0 0 36 0 0 313 0 0 1 0 32 49 0 0 430

2028 0 0 0 0 0 0 0 0 0 0 35 0 0 307 0 0 1 0 32 49 0 0 423

2029 0 0 0 0 0 0 0 0 0 0 35 0 0 304 0 0 1 0 32 49 0 0 420

2030 0 0 0 0 0 0 0 0 0 0 34 0 0 301 0 0 1 0 32 49 0 0 417

2031 0 0 0 0 0 0 0 0 0 0 34 0 0 298 0 0 1 0 32 49 0 0 413

2032 0 0 0 0 0 0 0 0 0 0 34 0 0 295 0 0 1 0 32 49 0 0 410

2033 0 0 0 0 0 0 0 0 0 0 33 0 0 292 0 0 1 0 32 49 0 0 407

2034 0 0 0 0 0 0 0 0 0 0 33 0 0 289 0 0 1 0 32 49 0 0 403

2035 0 0 0 0 0 0 0 0 0 0 33 0 0 286 0 0 1 0 32 49 0 0 400

2036 0 0 0 0 0 0 0 0 0 0 32 0 0 283 0 0 1 0 32 49 0 0 397

2037 0 0 0 0 0 0 0 0 0 0 32 0 0 280 0 0 1 0 32 49 0 0 393

TOTAL 194 18 32 56 298 12 188 0 0 0 1,123 0 0 9,833 0 0 35 0 960 1,457 0 0 14,206

Production Total (Costruction + 

Drilling + Completion 

+ Production)

PM10 [tpy]

Pollutant Year

Construction Drilling Completion

0

284

568

852

1,136

1,420

1,704

1,988

2,272

2,556

2,840

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well PM10 Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-92

Table 117. Existing Wells PM2.5 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 5. Existing Wells PM2.5 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 50 17 3 54 32 12 20 0 0 0 43 0 0 39 0 0 1 0 32 49 0 0 353

2009 0 0 0 0 0 0 0 0 0 0 43 0 0 39 0 0 1 0 32 49 0 0 163

2010 0 0 0 0 0 0 0 0 0 0 42 0 0 38 0 0 1 0 32 49 0 0 162

2011 0 0 0 0 0 0 0 0 0 0 42 0 0 38 0 0 1 0 32 49 0 0 162

2012 0 0 0 0 0 0 0 0 0 0 42 0 0 37 0 0 1 0 32 49 0 0 161

2013 0 0 0 0 0 0 0 0 0 0 41 0 0 37 0 0 1 0 32 49 0 0 160

2014 0 0 0 0 0 0 0 0 0 0 41 0 0 37 0 0 1 0 32 49 0 0 159

2015 0 0 0 0 0 0 0 0 0 0 40 0 0 36 0 0 1 0 32 49 0 0 158

2016 0 0 0 0 0 0 0 0 0 0 40 0 0 36 0 0 1 0 32 49 0 0 158

2017 0 0 0 0 0 0 0 0 0 0 40 0 0 36 0 0 1 0 32 49 0 0 157

2018 0 0 0 0 0 0 0 0 0 0 39 0 0 35 0 0 1 0 32 49 0 0 156

2019 0 0 0 0 0 0 0 0 0 0 39 0 0 35 0 0 1 0 32 49 0 0 155

2020 0 0 0 0 0 0 0 0 0 0 38 0 0 34 0 0 1 0 32 49 0 0 155

2021 0 0 0 0 0 0 0 0 0 0 38 0 0 34 0 0 1 0 32 49 0 0 154

2022 0 0 0 0 0 0 0 0 0 0 38 0 0 34 0 0 1 0 32 49 0 0 153

2023 0 0 0 0 0 0 0 0 0 0 37 0 0 33 0 0 1 0 32 49 0 0 152

2024 0 0 0 0 0 0 0 0 0 0 37 0 0 33 0 0 1 0 32 49 0 0 152

2025 0 0 0 0 0 0 0 0 0 0 36 0 0 33 0 0 1 0 32 49 0 0 151

2026 0 0 0 0 0 0 0 0 0 0 36 0 0 32 0 0 1 0 32 49 0 0 150

2027 0 0 0 0 0 0 0 0 0 0 36 0 0 32 0 0 1 0 32 49 0 0 149

2028 0 0 0 0 0 0 0 0 0 0 35 0 0 31 0 0 1 0 32 49 0 0 148

2029 0 0 0 0 0 0 0 0 0 0 35 0 0 31 0 0 1 0 32 49 0 0 147

2030 0 0 0 0 0 0 0 0 0 0 34 0 0 31 0 0 1 0 32 49 0 0 147

2031 0 0 0 0 0 0 0 0 0 0 34 0 0 31 0 0 1 0 32 49 0 0 146

2032 0 0 0 0 0 0 0 0 0 0 34 0 0 30 0 0 1 0 32 49 0 0 145

2033 0 0 0 0 0 0 0 0 0 0 33 0 0 30 0 0 1 0 32 49 0 0 145

2034 0 0 0 0 0 0 0 0 0 0 33 0 0 30 0 0 1 0 32 49 0 0 144

2035 0 0 0 0 0 0 0 0 0 0 33 0 0 29 0 0 1 0 32 49 0 0 144

2036 0 0 0 0 0 0 0 0 0 0 32 0 0 29 0 0 1 0 32 49 0 0 143

2037 0 0 0 0 0 0 0 0 0 0 32 0 0 29 0 0 1 0 32 49 0 0 142

TOTAL 50 17 3 54 32 12 20 0 0 0 1,123 0 0 1,009 0 0 34 0 960 1,457 0 0 4,772

Production Total (Costruction + 

Drilling + Completion 

+ Production)

PM2.5 [tpy]

Pollutant Year

Construction Drilling Completion

0

67

134

201

268

335

402

469

536

603

670

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well PM2.5 Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-93

Table 118. Existing Wells CO Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 6. Existing Wells CO Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 362 6 504 56 132 36 0 0 0 478 0 0 79 0 335 8 0 741 449 0 0 3,185

2009 0 0 0 0 0 0 0 0 0 0 474 0 0 78 0 317 8 0 741 449 0 0 2,066

2010 0 0 0 0 0 0 0 0 0 0 469 0 0 77 0 278 8 0 741 449 0 0 2,022

2011 0 0 0 0 0 0 0 0 0 0 464 0 0 76 0 257 8 0 741 449 0 0 1,994

2012 0 0 0 0 0 0 0 0 0 0 459 0 0 75 0 252 8 0 741 449 0 0 1,984

2013 0 0 0 0 0 0 0 0 0 0 455 0 0 74 0 249 8 0 741 449 0 0 1,976

2014 0 0 0 0 0 0 0 0 0 0 450 0 0 74 0 238 8 0 741 449 0 0 1,959

2015 0 0 0 0 0 0 0 0 0 0 446 0 0 73 0 226 8 0 741 449 0 0 1,943

2016 0 0 0 0 0 0 0 0 0 0 441 0 0 72 0 216 8 0 741 449 0 0 1,927

2017 0 0 0 0 0 0 0 0 0 0 437 0 0 71 0 208 8 0 741 449 0 0 1,913

2018 0 0 0 0 0 0 0 0 0 0 432 0 0 71 0 200 7 0 741 449 0 0 1,900

2019 0 0 0 0 0 0 0 0 0 0 428 0 0 70 0 193 7 0 741 449 0 0 1,887

2020 0 0 0 0 0 0 0 0 0 0 424 0 0 69 0 186 7 0 741 449 0 0 1,876

2021 0 0 0 0 0 0 0 0 0 0 420 0 0 69 0 180 7 0 741 449 0 0 1,865

2022 0 0 0 0 0 0 0 0 0 0 415 0 0 68 0 172 7 0 741 449 0 0 1,852

2023 0 0 0 0 0 0 0 0 0 0 411 0 0 67 0 167 7 0 741 449 0 0 1,842

2024 0 0 0 0 0 0 0 0 0 0 407 0 0 66 0 162 7 0 741 449 0 0 1,832

2025 0 0 0 0 0 0 0 0 0 0 403 0 0 66 0 158 7 0 741 449 0 0 1,823

2026 0 0 0 0 0 0 0 0 0 0 399 0 0 65 0 154 7 0 741 449 0 0 1,814

2027 0 0 0 0 0 0 0 0 0 0 395 0 0 64 0 150 7 0 741 449 0 0 1,806

2028 0 0 0 0 0 0 0 0 0 0 387 0 0 63 0 146 7 0 741 449 0 0 1,792

2029 0 0 0 0 0 0 0 0 0 0 383 0 0 63 0 140 7 0 741 449 0 0 1,782

2030 0 0 0 0 0 0 0 0 0 0 379 0 0 62 0 137 7 0 741 449 0 0 1,774

2031 0 0 0 0 0 0 0 0 0 0 376 0 0 61 0 134 7 0 741 449 0 0 1,767

2032 0 0 0 0 0 0 0 0 0 0 372 0 0 61 0 131 6 0 741 449 0 0 1,759

2033 0 0 0 0 0 0 0 0 0 0 368 0 0 60 0 128 6 0 741 449 0 0 1,752

2034 0 0 0 0 0 0 0 0 0 0 364 0 0 59 0 125 6 0 741 449 0 0 1,745

2035 0 0 0 0 0 0 0 0 0 0 361 0 0 59 0 122 6 0 741 449 0 0 1,738

2036 0 0 0 0 0 0 0 0 0 0 357 0 0 58 0 120 6 0 741 449 0 0 1,731

2037 0 0 0 0 0 0 0 0 0 0 353 0 0 58 0 118 6 0 741 449 0 0 1,724

TOTAL 0 362 6 504 56 132 36 0 0 0 12,407 0 0 2,028 0 5,598 215 0 22,218 13,470 0 0 57,031

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

CO [tpy]

0

1,100

2,200

3,300

4,400

5,500

6,600

7,700

8,800

9,900

11,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well CO Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-94

Table 119. Existing Wells Formaldehyde Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 7. Existing Wells Formaldehyde Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 4 0 9 0 0 0 0 0 0 3 0 0 0 0 32 0 0 85 148 0 0 282

2009 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 30 0 0 85 148 0 0 267

2010 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 26 0 0 85 148 0 0 263

2011 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 24 0 0 85 148 0 0 261

2012 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 24 0 0 85 148 0 0 260

2013 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 24 0 0 85 148 0 0 260

2014 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 23 0 0 85 148 0 0 259

2015 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 21 0 0 85 148 0 0 258

2016 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 20 0 0 85 148 0 0 257

2017 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 20 0 0 85 148 0 0 256

2018 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 19 0 0 85 148 0 0 255

2019 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 18 0 0 85 148 0 0 254

2020 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 18 0 0 85 148 0 0 254

2021 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 17 0 0 85 148 0 0 253

2022 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 16 0 0 85 148 0 0 252

2023 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 16 0 0 85 148 0 0 252

2024 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 15 0 0 85 148 0 0 251

2025 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 15 0 0 85 148 0 0 251

2026 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 15 0 0 85 148 0 0 251

2027 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 14 0 0 85 148 0 0 250

2028 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 14 0 0 85 148 0 0 250

2029 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 13 0 0 85 148 0 0 249

2030 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 13 0 0 85 148 0 0 249

2031 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 13 0 0 85 148 0 0 249

2032 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 12 0 0 85 148 0 0 248

2033 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 12 0 0 85 148 0 0 248

2034 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 12 0 0 85 148 0 0 248

2035 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 12 0 0 85 148 0 0 247

2036 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 11 0 0 85 148 0 0 247

2037 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 11 0 0 85 148 0 0 247

TOTAL 0 4 0 9 0 0 0 0 0 0 65 0 0 7 0 530 5 0 2,553 4,455 0 0 7,627

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

formaldehyde 

[tpy]

0

84

168

252

336

420

504

588

672

756

840

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well Formaldehyde Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-95

Table 120. Existing Wells n-hexane Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 8. Existing Wells n-hexane Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 3 708 80 0 0 589 0 7 0 0 42 0 1 547 0 1,978

2009 0 0 0 0 0 0 0 0 694 79 0 0 583 0 6 0 0 42 0 1 517 0 1,924

2010 0 0 0 0 0 0 0 0 666 79 0 0 577 0 5 0 0 41 0 1 450 0 1,820

2011 0 0 0 0 0 0 0 0 647 78 0 0 571 0 5 0 0 41 0 1 412 0 1,756

2012 0 0 0 0 0 0 0 0 639 77 0 0 566 0 5 0 0 41 0 1 405 0 1,734

2013 0 0 0 0 0 0 0 0 633 76 0 0 560 0 5 0 0 40 0 1 400 0 1,716

2014 0 0 0 0 0 0 0 0 620 76 0 0 555 0 5 0 0 40 0 1 381 0 1,677

2015 0 0 0 0 0 0 0 0 607 75 0 0 549 0 4 0 0 39 0 1 361 0 1,638

2016 0 0 0 0 0 0 0 0 595 74 0 0 544 0 4 0 0 39 0 1 344 0 1,601

2017 0 0 0 0 0 0 0 0 584 73 0 0 538 0 4 0 0 39 0 1 328 0 1,568

2018 0 0 0 0 0 0 0 0 573 73 0 0 532 0 4 0 0 38 0 1 315 0 1,537

2019 0 0 0 0 0 0 0 0 563 72 0 0 527 0 4 0 0 38 0 1 303 0 1,508

2020 0 0 0 0 0 0 0 0 553 71 0 0 522 0 3 0 0 37 0 1 292 0 1,481

2021 0 0 0 0 0 0 0 0 544 70 0 0 517 0 3 0 0 37 0 1 282 0 1,456

2022 0 0 0 0 0 0 0 0 533 70 0 0 512 0 3 0 0 37 0 1 268 0 1,425

2023 0 0 0 0 0 0 0 0 525 69 0 0 507 0 3 0 0 36 0 1 260 0 1,401

2024 0 0 0 0 0 0 0 0 516 68 0 0 502 0 3 0 0 36 0 1 252 0 1,378

2025 0 0 0 0 0 0 0 0 508 68 0 0 496 0 3 0 0 36 0 1 244 0 1,357

2026 0 0 0 0 0 0 0 0 500 67 0 0 491 0 3 0 0 35 0 1 237 0 1,336

2027 0 0 0 0 0 0 0 0 493 66 0 0 486 0 3 0 0 35 0 1 231 0 1,316

2028 0 0 0 0 0 0 0 0 482 65 0 0 477 0 3 0 0 34 0 1 225 0 1,287

2029 0 0 0 0 0 0 0 0 472 64 0 0 472 0 2 0 0 34 0 1 215 0 1,262

2030 0 0 0 0 0 0 0 0 466 64 0 0 467 0 2 0 0 34 0 1 209 0 1,244

2031 0 0 0 0 0 0 0 0 459 63 0 0 463 0 2 0 0 33 0 1 204 0 1,226

2032 0 0 0 0 0 0 0 0 452 62 0 0 458 0 2 0 0 33 0 1 199 0 1,209

2033 0 0 0 0 0 0 0 0 446 62 0 0 453 0 2 0 0 33 0 1 195 0 1,192

2034 0 0 0 0 0 0 0 0 440 61 0 0 449 0 2 0 0 32 0 1 190 0 1,176

2035 0 0 0 0 0 0 0 0 434 61 0 0 444 0 2 0 0 32 0 1 186 0 1,160

2036 0 0 0 0 0 0 0 0 428 60 0 0 440 0 2 0 0 32 0 1 182 0 1,145

2037 0 0 0 0 0 0 0 0 422 59 0 0 435 0 2 0 0 31 0 1 178 0 1,130

TOTAL 0 0 0 0 0 0 0 3 16,202 2,083 0 0 15,282 1 103 0 0 1,097 10 43 8,812 1 43,638

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

n-hexane [tpy]

0

208

416

624

832

1,040

1,248

1,456

1,664

1,872

2,080

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well n-hexane Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-96

Table 121. Existing Wells Benzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 9. Existing Wells Benzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 1 0 0 0 1 2,610 13 1 0 50 0 1 0 0 9 2 1 112 3 2,804

2009 0 0 0 0 0 0 0 0 2,557 13 1 0 50 0 1 0 0 9 2 1 106 3 2,742

2010 0 0 0 0 0 0 0 0 2,454 13 1 0 49 0 1 0 0 9 2 1 92 3 2,624

2011 0 0 0 0 0 0 0 0 2,384 13 1 0 49 0 1 0 0 9 2 1 84 3 2,545

2012 0 0 0 0 0 0 0 0 2,356 13 1 0 48 0 1 0 0 8 2 1 82 3 2,515

2013 0 0 0 0 0 0 0 0 2,331 13 1 0 48 0 1 0 0 8 2 1 81 3 2,489

2014 0 0 0 0 0 0 0 0 2,286 12 1 0 47 0 1 0 0 8 2 1 77 3 2,439

2015 0 0 0 0 0 0 0 0 2,239 12 1 0 47 0 1 0 0 8 2 1 73 3 2,386

2016 0 0 0 0 0 0 0 0 2,194 12 1 0 46 0 1 0 0 8 2 1 70 3 2,337

2017 0 0 0 0 0 0 0 0 2,152 12 1 0 46 0 1 0 0 8 2 1 67 3 2,292

2018 0 0 0 0 0 0 0 0 2,113 12 1 0 45 0 1 0 0 8 2 1 64 3 2,249

2019 0 0 0 0 0 0 0 0 2,075 12 1 0 45 0 0 0 0 8 2 1 61 2 2,208

2020 0 0 0 0 0 0 0 0 2,040 12 1 0 44 0 0 0 0 8 2 1 59 2 2,169

2021 0 0 0 0 0 0 0 0 2,006 12 1 0 44 0 0 0 0 8 2 1 57 2 2,133

2022 0 0 0 0 0 0 0 0 1,965 11 1 0 43 0 0 0 0 8 2 1 54 2 2,088

2023 0 0 0 0 0 0 0 0 1,933 11 1 0 43 0 0 0 0 8 2 1 52 2 2,054

2024 0 0 0 0 0 0 0 0 1,902 11 1 0 43 0 0 0 0 8 2 1 51 2 2,021

2025 0 0 0 0 0 0 0 0 1,873 11 1 0 42 0 0 0 0 7 2 1 49 2 1,990

2026 0 0 0 0 0 0 0 0 1,844 11 1 0 42 0 0 0 0 7 2 1 48 2 1,959

2027 0 0 0 0 0 0 0 0 1,816 11 1 0 41 0 0 0 0 7 2 1 46 2 1,929

2028 0 0 0 0 0 0 0 0 1,776 11 1 0 40 0 0 0 0 7 2 1 45 2 1,886

2029 0 0 0 0 0 0 0 0 1,741 11 1 0 40 0 0 0 0 7 2 1 43 2 1,848

2030 0 0 0 0 0 0 0 0 1,716 10 1 0 40 0 0 0 0 7 2 1 42 2 1,821

2031 0 0 0 0 0 0 0 0 1,691 10 1 0 39 0 0 0 0 7 2 1 41 2 1,795

2032 0 0 0 0 0 0 0 0 1,667 10 1 0 39 0 0 0 0 7 2 1 40 2 1,770

2033 0 0 0 0 0 0 0 0 1,644 10 1 0 39 0 0 0 0 7 2 1 39 2 1,744

2034 0 0 0 0 0 0 0 0 1,620 10 1 0 38 0 0 0 0 7 2 1 38 2 1,720

2035 0 0 0 0 0 0 0 0 1,598 10 1 0 38 0 0 0 0 7 2 1 37 2 1,696

2036 0 0 0 0 0 0 0 0 1,576 10 1 0 37 0 0 0 0 7 2 1 36 2 1,673

2037 0 0 0 0 0 0 0 0 1,555 10 1 0 37 0 0 0 0 7 2 1 36 2 1,650

TOTAL 0 0 0 1 0 0 0 1 59,713 341 32 0 1,299 5 14 0 1 229 63 21 1,783 72 63,576

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

benzene [tpy]

0

294

588

882

1,176

1,471

1,765

2,059

2,353

2,647

2,941

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well Benzene Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-97

Table 122. Existing Wells Ethylbenzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 10 Existing Wells Ethylbenzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 160 0 0 0 2 0 0 0 0 0 0 0 2 0 166

2009 0 0 0 0 0 0 0 0 157 0 0 0 2 0 0 0 0 0 0 0 2 0 162

2010 0 0 0 0 0 0 0 0 151 0 0 0 2 0 0 0 0 0 0 0 2 0 156

2011 0 0 0 0 0 0 0 0 146 0 0 0 2 0 0 0 0 0 0 0 2 0 151

2012 0 0 0 0 0 0 0 0 145 0 0 0 2 0 0 0 0 0 0 0 2 0 149

2013 0 0 0 0 0 0 0 0 143 0 0 0 2 0 0 0 0 0 0 0 2 0 148

2014 0 0 0 0 0 0 0 0 140 0 0 0 2 0 0 0 0 0 0 0 1 0 145

2015 0 0 0 0 0 0 0 0 137 0 0 0 2 0 0 0 0 0 0 0 1 0 142

2016 0 0 0 0 0 0 0 0 135 0 0 0 2 0 0 0 0 0 0 0 1 0 139

2017 0 0 0 0 0 0 0 0 132 0 0 0 2 0 0 0 0 0 0 0 1 0 136

2018 0 0 0 0 0 0 0 0 130 0 0 0 2 0 0 0 0 0 0 0 1 0 134

2019 0 0 0 0 0 0 0 0 127 0 0 0 2 0 0 0 0 0 0 0 1 0 132

2020 0 0 0 0 0 0 0 0 125 0 0 0 2 0 0 0 0 0 0 0 1 0 129

2021 0 0 0 0 0 0 0 0 123 0 0 0 2 0 0 0 0 0 0 0 1 0 127

2022 0 0 0 0 0 0 0 0 121 0 0 0 2 0 0 0 0 0 0 0 1 0 125

2023 0 0 0 0 0 0 0 0 119 0 0 0 2 0 0 0 0 0 0 0 1 0 123

2024 0 0 0 0 0 0 0 0 117 0 0 0 2 0 0 0 0 0 0 0 1 0 121

2025 0 0 0 0 0 0 0 0 115 0 0 0 2 0 0 0 0 0 0 0 1 0 119

2026 0 0 0 0 0 0 0 0 113 0 0 0 2 0 0 0 0 0 0 0 1 0 117

2027 0 0 0 0 0 0 0 0 112 0 0 0 2 0 0 0 0 0 0 0 1 0 115

2028 0 0 0 0 0 0 0 0 109 0 0 0 2 0 0 0 0 0 0 0 1 0 113

2029 0 0 0 0 0 0 0 0 107 0 0 0 2 0 0 0 0 0 0 0 1 0 110

2030 0 0 0 0 0 0 0 0 105 0 0 0 2 0 0 0 0 0 0 0 1 0 109

2031 0 0 0 0 0 0 0 0 104 0 0 0 2 0 0 0 0 0 0 0 1 0 107

2032 0 0 0 0 0 0 0 0 102 0 0 0 2 0 0 0 0 0 0 0 1 0 106

2033 0 0 0 0 0 0 0 0 101 0 0 0 2 0 0 0 0 0 0 0 1 0 104

2034 0 0 0 0 0 0 0 0 100 0 0 0 2 0 0 0 0 0 0 0 1 0 103

2035 0 0 0 0 0 0 0 0 98 0 0 0 2 0 0 0 0 0 0 0 1 0 101

2036 0 0 0 0 0 0 0 0 97 0 0 0 2 0 0 0 0 0 0 0 1 0 100

2037 0 0 0 0 0 0 0 0 96 0 0 0 2 0 0 0 0 0 0 0 1 0 99

TOTAL 0 0 0 0 0 0 0 0 3,667 8 0 0 54 2 0 0 0 10 2 2 34 8 3,788

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

ethylbenzene 

[tpy]

0

1 7

3 5

5 2

7 0

8 7

104

122

139

157

174

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well Ethylbenzene Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-98

Table 123. Existing Wells Toluene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 11. Existing Wells Toluene Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 1 0 2 0 0 0 1 4,310 18 1 0 69 1 1 0 0 12 1 0 159 4 4,579

2009 0 0 0 0 0 0 0 0 4,222 18 1 0 68 1 1 0 0 12 1 0 151 4 4,479

2010 0 0 0 0 0 0 0 0 4,053 18 1 0 68 1 1 0 0 12 1 0 130 4 4,288

2011 0 0 0 0 0 0 0 0 3,937 18 1 0 67 1 1 0 0 12 1 0 119 3 4,159

2012 0 0 0 0 0 0 0 0 3,891 18 1 0 66 1 1 0 0 12 1 0 117 3 4,110

2013 0 0 0 0 0 0 0 0 3,850 18 1 0 66 1 1 0 0 12 1 0 116 3 4,067

2014 0 0 0 0 0 0 0 0 3,775 17 1 0 65 1 1 0 0 11 1 0 110 3 3,985

2015 0 0 0 0 0 0 0 0 3,697 17 1 0 64 0 1 0 0 11 1 0 104 3 3,900

2016 0 0 0 0 0 0 0 0 3,623 17 1 0 64 0 1 0 0 11 1 0 99 3 3,821

2017 0 0 0 0 0 0 0 0 3,554 17 1 0 63 0 1 0 0 11 1 0 95 3 3,746

2018 0 0 0 0 0 0 0 0 3,489 17 1 0 62 0 1 0 0 11 1 0 91 3 3,676

2019 0 0 0 0 0 0 0 0 3,427 17 1 0 62 0 1 0 0 11 1 0 87 3 3,609

2020 0 0 0 0 0 0 0 0 3,368 16 1 0 61 0 1 0 0 11 1 0 84 3 3,546

2021 0 0 0 0 0 0 0 0 3,313 16 1 0 60 0 1 0 0 11 1 0 81 3 3,487

2022 0 0 0 0 0 0 0 0 3,245 16 1 0 60 0 1 0 0 11 1 0 77 3 3,414

2023 0 0 0 0 0 0 0 0 3,192 16 1 0 59 0 1 0 0 10 1 0 74 3 3,358

2024 0 0 0 0 0 0 0 0 3,141 16 1 0 59 0 1 0 0 10 1 0 72 3 3,304

2025 0 0 0 0 0 0 0 0 3,093 16 1 0 58 0 1 0 0 10 1 0 70 3 3,253

2026 0 0 0 0 0 0 0 0 3,046 15 1 0 58 0 1 0 0 10 1 0 68 3 3,202

2027 0 0 0 0 0 0 0 0 2,999 15 1 0 57 0 0 0 0 10 1 0 66 3 3,153

2028 0 0 0 0 0 0 0 0 2,934 15 1 0 56 0 0 0 0 10 1 0 64 3 3,084

2029 0 0 0 0 0 0 0 0 2,875 15 1 0 55 0 0 0 0 10 1 0 61 3 3,021

2030 0 0 0 0 0 0 0 0 2,833 15 0 0 55 0 0 0 0 10 1 0 59 3 2,977

2031 0 0 0 0 0 0 0 0 2,793 15 0 0 54 0 0 0 0 10 1 0 58 3 2,935

2032 0 0 0 0 0 0 0 0 2,754 14 0 0 54 0 0 0 0 9 1 0 56 3 2,893

2033 0 0 0 0 0 0 0 0 2,714 14 0 0 53 0 0 0 0 9 1 0 55 3 2,851

2034 0 0 0 0 0 0 0 0 2,676 14 0 0 53 0 0 0 0 9 1 0 54 3 2,811

2035 0 0 0 0 0 0 0 0 2,639 14 0 0 52 0 0 0 0 9 1 0 53 3 2,772

2036 0 0 0 0 0 0 0 0 2,603 14 0 0 51 0 0 0 0 9 1 0 51 3 2,734

2037 0 0 0 0 0 0 0 0 2,568 14 0 0 51 0 0 0 0 9 1 0 50 3 2,697

TOTAL 0 1 0 2 0 0 0 1 98,614 479 16 0 1,789 14 19 0 1 315 29 11 2,530 93 103,914

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

toluene [tpy]

0

480

960

1,440

1,920

2,400

2,880

3,360

3,840

4,320

4,800

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well Toluene Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-99

Table 124. Existing Wells Xylenes Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 12. Existing Wells Xylenes Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 1 0 1 0 0 0 0 1,587 10 0 0 40 0 1 0 0 4 0 0 86 5 1,735

2009 0 0 0 0 0 0 0 0 1,555 10 0 0 39 0 1 0 0 4 0 0 81 5 1,696

2010 0 0 0 0 0 0 0 0 1,493 10 0 0 39 0 1 0 0 4 0 0 70 5 1,622

2011 0 0 0 0 0 0 0 0 1,450 10 0 0 39 0 1 0 0 4 0 0 64 5 1,572

2012 0 0 0 0 0 0 0 0 1,433 10 0 0 38 0 0 0 0 4 0 0 63 5 1,553

2013 0 0 0 0 0 0 0 0 1,418 10 0 0 38 0 0 0 0 4 0 0 62 5 1,537

2014 0 0 0 0 0 0 0 0 1,390 9 0 0 37 0 0 0 0 4 0 0 59 5 1,506

2015 0 0 0 0 0 0 0 0 1,361 9 0 0 37 0 0 0 0 4 0 0 56 5 1,473

2016 0 0 0 0 0 0 0 0 1,334 9 0 0 37 0 0 0 0 3 0 0 53 4 1,443

2017 0 0 0 0 0 0 0 0 1,309 9 0 0 36 0 0 0 0 3 0 0 51 4 1,415

2018 0 0 0 0 0 0 0 0 1,285 9 0 0 36 0 0 0 0 3 0 0 49 4 1,388

2019 0 0 0 0 0 0 0 0 1,262 9 0 0 36 0 0 0 0 3 0 0 47 4 1,362

2020 0 0 0 0 0 0 0 0 1,240 9 0 0 35 0 0 0 0 3 0 0 45 4 1,339

2021 0 0 0 0 0 0 0 0 1,220 9 0 0 35 0 0 0 0 3 0 0 44 4 1,316

2022 0 0 0 0 0 0 0 0 1,195 9 0 0 35 0 0 0 0 3 0 0 41 4 1,288

2023 0 0 0 0 0 0 0 0 1,176 9 0 0 34 0 0 0 0 3 0 0 40 4 1,267

2024 0 0 0 0 0 0 0 0 1,157 9 0 0 34 0 0 0 0 3 0 0 39 4 1,246

2025 0 0 0 0 0 0 0 0 1,139 8 0 0 34 0 0 0 0 3 0 0 38 4 1,227

2026 0 0 0 0 0 0 0 0 1,121 8 0 0 33 0 0 0 0 3 0 0 37 4 1,208

2027 0 0 0 0 0 0 0 0 1,104 8 0 0 33 0 0 0 0 3 0 0 36 4 1,189

2028 0 0 0 0 0 0 0 0 1,080 8 0 0 32 0 0 0 0 3 0 0 35 4 1,163

2029 0 0 0 0 0 0 0 0 1,059 8 0 0 32 0 0 0 0 3 0 0 33 4 1,140

2030 0 0 0 0 0 0 0 0 1,043 8 0 0 32 0 0 0 0 3 0 0 32 4 1,123

2031 0 0 0 0 0 0 0 0 1,029 8 0 0 31 0 0 0 0 3 0 0 31 4 1,107

2032 0 0 0 0 0 0 0 0 1,014 8 0 0 31 0 0 0 0 3 0 0 31 4 1,091

2033 0 0 0 0 0 0 0 0 999 8 0 0 31 0 0 0 0 3 0 0 30 4 1,075

2034 0 0 0 0 0 0 0 0 985 8 0 0 30 0 0 0 0 3 0 0 29 4 1,060

2035 0 0 0 0 0 0 0 0 972 8 0 0 30 0 0 0 0 3 0 0 28 4 1,045

2036 0 0 0 0 0 0 0 0 959 7 0 0 30 0 0 0 0 3 0 0 28 4 1,031

2037 0 0 0 0 0 0 0 0 946 7 0 0 29 0 0 0 0 3 0 0 27 4 1,017

TOTAL 0 1 0 1 0 0 0 0 36,314 260 0 0 1,032 8 11 0 1 98 8 9 1,367 126 39,235

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

xylenes [tpy]

0

182

364

546

728

910

1,092

1,274

1,456

1,638

1,820

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well Xylenes Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-100

Table 125. Existing Wells CO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 13. Existing Wells CO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 23,168 655 44,407 6,637 35,396 4,128 54 5,232 310 683,444 0 5,160 4,616 0 110,507 1,275 911 582,056 809,692 540 7 2,318,196

2009 0 0 0 0 0 0 0 0 5,143 306 676,481 0 5,108 4,569 0 104,244 1,262 902 582,056 809,692 509 7 2,190,280

2010 0 0 0 0 0 0 0 0 4,996 303 669,518 0 5,055 4,522 0 89,949 1,249 893 582,056 809,692 438 7 2,168,679

2011 0 0 0 0 0 0 0 0 4,894 300 662,555 0 5,003 4,474 0 82,015 1,236 883 582,056 809,692 399 7 2,153,515

2012 0 0 0 0 0 0 0 0 4,842 297 656,128 0 4,954 4,431 0 80,532 1,224 875 582,056 809,692 391 7 2,145,429

2013 0 0 0 0 0 0 0 0 4,793 294 649,701 0 4,905 4,387 0 79,501 1,212 866 582,056 809,692 386 7 2,137,801

2014 0 0 0 0 0 0 0 0 4,722 291 643,273 0 4,857 4,343 0 75,518 1,200 858 582,056 809,692 367 7 2,127,185

2015 0 0 0 0 0 0 0 0 4,651 289 636,846 0 4,808 4,300 0 71,383 1,188 849 582,056 809,692 346 7 2,116,415

2016 0 0 0 0 0 0 0 0 4,584 286 630,418 0 4,760 4,256 0 67,774 1,176 841 582,056 809,692 328 7 2,106,178

2017 0 0 0 0 0 0 0 0 4,519 283 623,991 0 4,711 4,212 0 64,630 1,164 832 582,056 809,692 313 6 2,096,410

2018 0 0 0 0 0 0 0 0 4,458 280 617,564 0 4,663 4,169 0 61,860 1,152 823 582,056 809,692 299 6 2,087,023

2019 0 0 0 0 0 0 0 0 4,398 277 611,136 0 4,614 4,125 0 59,344 1,140 815 582,056 809,692 287 6 2,077,892

2020 0 0 0 0 0 0 0 0 4,343 274 605,245 0 4,570 4,085 0 57,027 1,129 807 582,056 809,692 275 6 2,069,510

2021 0 0 0 0 0 0 0 0 4,290 272 599,353 0 4,525 4,045 0 54,950 1,118 799 582,056 809,692 265 6 2,061,372

2022 0 0 0 0 0 0 0 0 4,232 269 593,461 0 4,481 4,005 0 52,117 1,107 791 582,056 809,692 251 6 2,052,469

2023 0 0 0 0 0 0 0 0 4,181 266 587,569 0 4,436 3,966 0 50,327 1,096 783 582,056 809,692 242 6 2,044,621

2024 0 0 0 0 0 0 0 0 4,130 264 581,677 0 4,392 3,926 0 48,657 1,085 776 582,056 809,692 234 6 2,036,895

2025 0 0 0 0 0 0 0 0 4,082 261 575,786 0 4,347 3,886 0 47,205 1,074 768 582,056 809,692 227 6 2,029,389

2026 0 0 0 0 0 0 0 0 4,033 258 569,894 0 4,303 3,846 0 45,780 1,063 760 582,056 809,692 220 6 2,021,911

2027 0 0 0 0 0 0 0 0 3,986 256 564,002 0 4,258 3,806 0 44,458 1,052 752 582,056 809,692 213 6 2,014,537

2028 0 0 0 0 0 0 0 0 3,904 250 552,754 0 4,173 3,730 0 43,242 1,031 737 582,056 809,692 207 6 2,001,784

2029 0 0 0 0 0 0 0 0 3,854 248 547,398 0 4,133 3,694 0 41,154 1,021 730 582,056 809,692 197 6 1,994,184

2030 0 0 0 0 0 0 0 0 3,811 246 542,042 0 4,093 3,657 0 40,045 1,011 723 582,056 809,692 192 6 1,987,573

2031 0 0 0 0 0 0 0 0 3,769 243 536,686 0 4,052 3,621 0 39,014 1,001 716 582,056 809,692 187 6 1,981,042

2032 0 0 0 0 0 0 0 0 3,727 241 531,330 0 4,012 3,585 0 38,014 991 708 582,056 809,692 182 6 1,974,544

2033 0 0 0 0 0 0 0 0 3,685 238 525,974 0 3,971 3,549 0 37,036 981 701 582,056 809,692 177 5 1,968,067

2034 0 0 0 0 0 0 0 0 3,644 236 520,617 0 3,931 3,513 0 36,130 971 694 582,056 809,692 173 5 1,961,663

2035 0 0 0 0 0 0 0 0 3,603 233 515,261 0 3,890 3,476 0 35,276 961 687 582,056 809,692 168 5 1,955,311

2036 0 0 0 0 0 0 0 0 3,563 231 509,905 0 3,850 3,440 0 34,513 951 680 582,056 809,692 165 5 1,949,052

2037 0 0 0 0 0 0 0 0 3,523 229 504,549 0 3,810 3,404 0 33,775 941 673 582,056 809,692 161 5 1,942,817

TOTAL 0 23,168 655 44,407 6,637 35,396 4,128 54 127,593 8,030 17,724,559 0 133,827 119,638 0 1,725,977 33,063 23,634 17,461,681 24,290,773 8,340 184 61,771,744

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2 [tpy]

Pollutant Year

Construction Drilling Completion

0

716,000

1,432,000

2,148,000

2,864,000

3,580,000

4,296,000

5,012,000

5,728,000

6,444,000

7,160,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well CO2 Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-101

Table 126. Existing Wells CO2e - from CH4 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 14. Existing Wells CO2e - from CH4 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 14 1 34 6 0 4 12,830 454,768 66,108 275 0 1,228,142 8 1,321 665 1 216,897 7,391 18,182 57,368 24 2,064,038

2009 0 0 0 0 0 0 0 0 449,981 65,435 272 0 1,215,630 8 1,245 630 1 214,687 7,391 18,182 54,394 23 2,027,879

2010 0 0 0 0 0 0 0 0 444,904 64,761 269 0 1,203,117 8 1,072 553 1 212,477 7,391 18,182 47,684 23 2,000,442

2011 0 0 0 0 0 0 0 0 440,014 64,088 267 0 1,190,605 8 975 510 1 210,267 7,391 18,182 43,932 23 1,976,261

2012 0 0 0 0 0 0 0 0 435,718 63,466 264 0 1,179,055 8 958 501 1 208,228 7,391 18,182 43,186 23 1,956,978

2013 0 0 0 0 0 0 0 0 431,440 62,844 262 0 1,167,505 8 945 495 1 206,188 7,391 18,182 42,650 22 1,937,932

2014 0 0 0 0 0 0 0 0 427,042 62,223 259 0 1,155,955 8 897 473 1 204,148 7,391 18,182 40,741 22 1,917,341

2015 0 0 0 0 0 0 0 0 422,632 61,601 256 0 1,144,405 8 847 450 1 202,108 7,391 18,182 38,762 22 1,896,663

2016 0 0 0 0 0 0 0 0 418,238 60,979 254 0 1,132,855 8 803 430 1 200,068 7,391 18,182 37,027 22 1,876,257

2017 0 0 0 0 0 0 0 0 413,861 60,358 251 0 1,121,305 7 765 412 1 198,029 7,391 18,182 35,508 21 1,856,090

2018 0 0 0 0 0 0 0 0 409,497 59,736 249 0 1,109,756 7 732 397 1 195,989 7,391 18,182 34,164 21 1,836,119

2019 0 0 0 0 0 0 0 0 405,142 59,114 246 0 1,098,206 7 701 383 1 193,949 7,391 18,182 32,937 21 1,816,279

2020 0 0 0 0 0 0 0 0 401,147 58,544 244 0 1,087,618 7 673 369 1 192,079 7,391 18,182 31,808 21 1,798,084

2021 0 0 0 0 0 0 0 0 397,162 57,974 241 0 1,077,031 7 648 358 1 190,209 7,391 18,182 30,790 21 1,780,014

2022 0 0 0 0 0 0 0 0 393,132 57,404 239 0 1,066,443 7 614 342 1 188,340 7,391 18,182 29,421 20 1,761,536

2023 0 0 0 0 0 0 0 0 389,157 56,835 236 0 1,055,856 7 593 332 1 186,470 7,391 18,182 28,537 20 1,743,615

2024 0 0 0 0 0 0 0 0 385,187 56,265 234 0 1,045,268 7 572 322 1 184,600 7,391 18,182 27,709 20 1,725,757

2025 0 0 0 0 0 0 0 0 381,229 55,695 232 0 1,034,681 7 555 314 1 182,730 7,391 18,182 26,982 20 1,708,016

2026 0 0 0 0 0 0 0 0 377,271 55,125 229 0 1,024,094 7 538 305 1 180,860 7,391 18,182 26,267 20 1,690,289

2027 0 0 0 0 0 0 0 0 373,318 54,555 227 0 1,013,506 7 522 298 1 178,991 7,391 18,182 25,601 19 1,672,616

2028 0 0 0 0 0 0 0 0 365,852 53,467 222 0 993,294 7 508 290 1 175,421 7,391 18,182 24,937 19 1,639,590

2029 0 0 0 0 0 0 0 0 362,200 52,949 220 0 983,669 7 482 278 1 173,721 7,391 18,182 23,919 19 1,623,037

2030 0 0 0 0 0 0 0 0 358,609 52,431 218 0 974,044 6 469 272 1 172,021 7,391 18,182 23,357 19 1,607,018

2031 0 0 0 0 0 0 0 0 355,023 51,913 216 0 964,419 6 457 266 1 170,322 7,391 18,182 22,830 18 1,591,042

2032 0 0 0 0 0 0 0 0 351,438 51,395 214 0 954,794 6 445 260 1 168,622 7,391 18,182 22,318 18 1,575,082

2033 0 0 0 0 0 0 0 0 347,854 50,877 212 0 945,169 6 433 254 1 166,922 7,391 18,182 21,817 18 1,559,133

2034 0 0 0 0 0 0 0 0 344,274 50,358 210 0 935,544 6 422 248 1 165,222 7,391 18,182 21,349 18 1,543,224

2035 0 0 0 0 0 0 0 0 340,697 49,840 207 0 925,919 6 412 243 1 163,522 7,391 18,182 20,905 18 1,527,343

2036 0 0 0 0 0 0 0 0 337,127 49,322 205 0 916,294 6 403 239 1 161,823 7,391 18,182 20,503 18 1,511,512

2037 0 0 0 0 0 0 0 0 333,558 48,804 203 0 906,669 6 394 234 0 160,123 7,391 18,182 20,113 17 1,495,694

TOTAL 0 14 1 34 6 0 4 12,830 11,747,471 1,714,466 7,134 0 31,850,850 211 20,401 11,121 18 5,625,033 221,715 545,445 957,515 610 52,714,880

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

CO2e-from 

CH4 [tpy]

0

278,000

556,000

834,000

1,112,000

1,390,000

1,668,000

1,946,000

2,224,000

2,502,000

2,780,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well CO2e - from CH4 Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-102

Table 127. Existing Wells CO2e - from N2O Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 15. Existing Wells CO2e - from N2O Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 183 5 2,490 41 1,984 26 0 0 0 3,884 0 0 60 0 182 10 0 4,096 5,974 0 0 18,935

2009 0 0 0 0 0 0 0 0 0 0 3,845 0 0 59 0 172 10 0 4,096 5,974 0 0 14,156

2010 0 0 0 0 0 0 0 0 0 0 3,805 0 0 59 0 152 10 0 4,096 5,974 0 0 14,095

2011 0 0 0 0 0 0 0 0 0 0 3,766 0 0 58 0 140 10 0 4,096 5,974 0 0 14,043

2012 0 0 0 0 0 0 0 0 0 0 3,729 0 0 57 0 137 10 0 4,096 5,974 0 0 14,003

2013 0 0 0 0 0 0 0 0 0 0 3,692 0 0 57 0 136 10 0 4,096 5,974 0 0 13,964

2014 0 0 0 0 0 0 0 0 0 0 3,656 0 0 56 0 130 9 0 4,096 5,974 0 0 13,921

2015 0 0 0 0 0 0 0 0 0 0 3,619 0 0 56 0 124 9 0 4,096 5,974 0 0 13,878

2016 0 0 0 0 0 0 0 0 0 0 3,583 0 0 55 0 118 9 0 4,096 5,974 0 0 13,835

2017 0 0 0 0 0 0 0 0 0 0 3,546 0 0 55 0 113 9 0 4,096 5,974 0 0 13,793

2018 0 0 0 0 0 0 0 0 0 0 3,510 0 0 54 0 109 9 0 4,096 5,974 0 0 13,752

2019 0 0 0 0 0 0 0 0 0 0 3,473 0 0 53 0 105 9 0 4,096 5,974 0 0 13,711

2020 0 0 0 0 0 0 0 0 0 0 3,440 0 0 53 0 102 9 0 4,096 5,974 0 0 13,673

2021 0 0 0 0 0 0 0 0 0 0 3,406 0 0 52 0 99 9 0 4,096 5,974 0 0 13,636

2022 0 0 0 0 0 0 0 0 0 0 3,373 0 0 52 0 94 9 0 4,096 5,974 0 0 13,597

2023 0 0 0 0 0 0 0 0 0 0 3,339 0 0 51 0 92 9 0 4,096 5,974 0 0 13,560

2024 0 0 0 0 0 0 0 0 0 0 3,306 0 0 51 0 89 9 0 4,096 5,974 0 0 13,524

2025 0 0 0 0 0 0 0 0 0 0 3,272 0 0 50 0 87 8 0 4,096 5,974 0 0 13,487

2026 0 0 0 0 0 0 0 0 0 0 3,239 0 0 50 0 84 8 0 4,096 5,974 0 0 13,451

2027 0 0 0 0 0 0 0 0 0 0 3,205 0 0 49 0 82 8 0 4,096 5,974 0 0 13,415

2028 0 0 0 0 0 0 0 0 0 0 3,141 0 0 48 0 80 8 0 4,096 5,974 0 0 13,348

2029 0 0 0 0 0 0 0 0 0 0 3,111 0 0 48 0 77 8 0 4,096 5,974 0 0 13,313

2030 0 0 0 0 0 0 0 0 0 0 3,081 0 0 47 0 75 8 0 4,096 5,974 0 0 13,281

2031 0 0 0 0 0 0 0 0 0 0 3,050 0 0 47 0 74 8 0 4,096 5,974 0 0 13,248

2032 0 0 0 0 0 0 0 0 0 0 3,020 0 0 46 0 72 8 0 4,096 5,974 0 0 13,215

2033 0 0 0 0 0 0 0 0 0 0 2,989 0 0 46 0 70 8 0 4,096 5,974 0 0 13,183

2034 0 0 0 0 0 0 0 0 0 0 2,959 0 0 45 0 69 8 0 4,096 5,974 0 0 13,150

2035 0 0 0 0 0 0 0 0 0 0 2,928 0 0 45 0 67 8 0 4,096 5,974 0 0 13,118

2036 0 0 0 0 0 0 0 0 0 0 2,898 0 0 44 0 66 8 0 4,096 5,974 0 0 13,086

2037 0 0 0 0 0 0 0 0 0 0 2,868 0 0 44 0 65 7 0 4,096 5,974 0 0 13,053

TOTAL 0 183 5 2,490 41 1,984 26 0 0 0 100,735 0 0 1,547 0 3,063 261 0 122,871 179,218 0 0 412,425

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2e-from 

N2O [tpy]

Pollutant Year

Construction Drilling Completion

0

3,900

7,800

11,700

15,600

19,500

23,400

27,300

31,200

35,100

39,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well CO2e - from N2O Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Existing Wells Emissions Inventory

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-103

Table 128. Existing Wells CO2e - total Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 16. Existing Wells CO2e - total Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 23,365 661 46,930 6,685 37,381 4,158 12,884 460,000 66,418 687,604 0 1,233,303 4,684 1,321 111,354 1,286 217,808 593,542 833,848 57,908 31 4,401,169

2009 0 0 0 0 0 0 0 0 455,124 65,741 680,598 0 1,220,738 4,636 1,245 105,047 1,273 215,589 593,542 833,848 54,903 30 4,232,315

2010 0 0 0 0 0 0 0 0 449,900 65,065 673,593 0 1,208,173 4,588 1,072 90,654 1,259 213,370 593,542 833,848 48,122 30 4,183,215

2011 0 0 0 0 0 0 0 0 444,908 64,388 666,587 0 1,195,608 4,540 975 82,665 1,246 211,151 593,542 833,848 44,331 30 4,143,819

2012 0 0 0 0 0 0 0 0 440,560 63,763 660,121 0 1,184,009 4,496 958 81,170 1,234 209,102 593,542 833,848 43,577 29 4,116,411

2013 0 0 0 0 0 0 0 0 436,233 63,139 653,654 0 1,172,411 4,452 945 80,131 1,222 207,054 593,542 833,848 43,037 29 4,089,697

2014 0 0 0 0 0 0 0 0 431,765 62,514 647,188 0 1,160,812 4,407 897 76,121 1,210 205,006 593,542 833,848 41,108 29 4,058,447

2015 0 0 0 0 0 0 0 0 427,283 61,889 640,722 0 1,149,214 4,363 847 71,956 1,198 202,957 593,542 833,848 39,108 29 4,026,956

2016 0 0 0 0 0 0 0 0 422,822 61,265 634,255 0 1,137,615 4,319 803 68,322 1,186 200,909 593,542 833,848 37,355 28 3,996,270

2017 0 0 0 0 0 0 0 0 418,380 60,640 627,789 0 1,126,017 4,274 765 65,155 1,174 198,861 593,542 833,848 35,821 28 3,966,294

2018 0 0 0 0 0 0 0 0 413,955 60,016 621,322 0 1,114,418 4,230 732 62,366 1,162 196,812 593,542 833,848 34,463 28 3,936,894

2019 0 0 0 0 0 0 0 0 409,540 59,391 614,856 0 1,102,820 4,186 701 59,832 1,150 194,764 593,542 833,848 33,224 27 3,907,881

2020 0 0 0 0 0 0 0 0 405,490 58,818 608,928 0 1,092,188 4,145 673 57,499 1,139 192,886 593,542 833,848 32,083 27 3,881,267

2021 0 0 0 0 0 0 0 0 401,452 58,246 603,000 0 1,081,556 4,105 648 55,406 1,127 191,009 593,542 833,848 31,055 27 3,855,022

2022 0 0 0 0 0 0 0 0 397,364 57,673 597,073 0 1,070,924 4,064 614 52,553 1,116 189,131 593,542 833,848 29,672 27 3,827,601

2023 0 0 0 0 0 0 0 0 393,338 57,101 591,145 0 1,060,292 4,024 593 50,750 1,105 187,253 593,542 833,848 28,779 26 3,801,797

2024 0 0 0 0 0 0 0 0 389,318 56,528 585,217 0 1,049,660 3,983 572 49,068 1,094 185,376 593,542 833,848 27,943 26 3,776,176

2025 0 0 0 0 0 0 0 0 385,311 55,956 579,290 0 1,039,028 3,943 555 47,605 1,083 183,498 593,542 833,848 27,209 26 3,750,893

2026 0 0 0 0 0 0 0 0 381,304 55,383 573,362 0 1,028,396 3,902 538 46,169 1,072 181,620 593,542 833,848 26,487 26 3,725,651

2027 0 0 0 0 0 0 0 0 377,304 54,810 567,435 0 1,017,765 3,862 522 44,838 1,061 179,743 593,542 833,848 25,814 25 3,700,568

2028 0 0 0 0 0 0 0 0 369,756 53,717 556,118 0 997,467 3,785 508 43,613 1,040 176,158 593,542 833,848 25,145 25 3,654,721

2029 0 0 0 0 0 0 0 0 366,054 53,197 550,730 0 987,802 3,748 482 41,510 1,030 174,451 593,542 833,848 24,117 25 3,630,534

2030 0 0 0 0 0 0 0 0 362,420 52,676 545,341 0 978,137 3,711 469 40,392 1,020 172,744 593,542 833,848 23,548 24 3,607,872

2031 0 0 0 0 0 0 0 0 358,792 52,156 539,952 0 968,471 3,674 457 39,353 1,010 171,037 593,542 833,848 23,017 24 3,585,332

2032 0 0 0 0 0 0 0 0 355,165 51,635 534,563 0 958,806 3,638 445 38,346 999 169,330 593,542 833,848 22,500 24 3,562,841

2033 0 0 0 0 0 0 0 0 351,539 51,115 529,175 0 949,140 3,601 433 37,360 989 167,623 593,542 833,848 21,994 24 3,540,383

2034 0 0 0 0 0 0 0 0 347,918 50,594 523,786 0 939,475 3,564 422 36,447 979 165,916 593,542 833,848 21,521 23 3,518,037

2035 0 0 0 0 0 0 0 0 344,300 50,074 518,397 0 929,810 3,527 412 35,587 969 164,209 593,542 833,848 21,073 23 3,495,772

2036 0 0 0 0 0 0 0 0 340,690 49,553 513,008 0 920,144 3,491 403 34,818 959 162,502 593,542 833,848 20,668 23 3,473,650

2037 0 0 0 0 0 0 0 0 337,081 49,033 507,620 0 910,479 3,454 394 34,074 949 160,796 593,542 833,848 20,274 23 3,451,565

TOTAL 0 23,365 661 46,930 6,685 37,381 4,158 12,884 11,875,065 1,722,495 17,832,428 0 31,984,677 121,396 20,401 1,740,161 33,342 5,648,668 17,806,267 25,015,436 965,855 794 114,899,049

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2e-total 

[tpy]

Pollutant Year

Construction Drilling Completion

0

998,400

1,996,800

2,995,200

3,993,600

4,992,000

5,990,400

6,988,800

7,987,200

8,985,600

9,984,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well CO2e - total Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-104

Project Emissions Inventory for Future Wells
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-105

Table 129. Summary of Future Wells Activity Data by Project Year

Year Project Yr

Well Pads 

Constructed Spuds

Active Well 

Count

Annual 

Condensate 

Production 

(Mbbl/yr)

Annual Gas 

Production 

(MMSCF/yr)

Cumulative 

Well Pads 

Constructed

Cumulative 

Spuds

Cumulative 

Condensate 

Production 

(Mbbl)

Cumulative Gas 

Production (BSCF)

2008 1 0 0 0 0 0 0 0 0 0

2009 2 278 480 480 845 42,879 278 480 845 43

2010 3 374 644 1,124 2,598 131,879 652 1,124 3,443 175

2011 4 371 640 1,764 3,910 198,498 1,023 1,764 7,353 373

2012 5 364 628 2,392 4,848 246,066 1,387 2,392 12,201 619

2013 6 371 640 3,032 5,729 290,834 1,759 3,032 17,930 910

2014 7 368 634 3,666 6,382 323,956 2,126 3,666 24,312 1,234

2015 8 379 654 4,320 6,966 353,579 2,506 4,320 31,278 1,588

2016 9 296 511 4,831 7,369 374,085 2,802 4,831 38,647 1,962

2017 10 389 671 5,502 7,816 396,752 3,191 5,502 46,463 2,359

2018 11 428 738 6,240 9,043 459,014 3,619 6,240 55,506 2,818

2019 12 345 594 6,834 9,510 482,764 3,964 6,834 65,016 3,300

2020 13 345 595 7,429 9,854 500,212 4,309 7,429 74,870 3,801

2021 14 389 671 8,100 10,120 513,728 4,698 8,100 84,991 4,314

2022 15 369 637 8,736 10,847 550,628 5,067 8,736 95,838 4,865

2023 16 124 214 8,950 10,487 532,345 5,191 8,950 106,325 5,397

2024 17 0 0 8,950 9,235 468,804 5,191 8,950 115,561 5,866

2025 18 0 0 8,950 8,418 427,312 5,191 8,950 123,979 6,293

2026 19 0 0 8,950 7,837 397,804 5,191 8,950 131,815 6,691

2027 20 0 0 8,950 7,366 373,908 5,191 8,950 139,181 7,065

2028 21 0 0 8,950 6,964 353,503 5,191 8,950 146,145 7,419

2029 22 0 0 8,950 6,612 335,618 5,191 8,950 152,757 7,754

2030 23 0 0 8,950 6,296 319,610 5,191 8,950 159,053 8,074

2031 24 0 0 8,950 6,011 305,143 5,191 8,950 165,065 8,379

2032 25 0 0 8,950 5,749 291,843 5,191 8,950 170,814 8,671

2033 26 0 0 8,950 5,508 279,574 5,191 8,950 176,322 8,950

2034 27 0 0 8,950 5,283 268,151 5,191 8,950 181,604 9,218

2035 28 0 0 8,950 5,070 257,382 5,191 8,950 186,675 9,476

2036 29 0 0 8,950 4,870 247,200 5,191 8,950 191,545 9,723

2037 30 0 0 8,950 4,680 237,559 5,191 8,950 196,224 9,961

Total 5,191 8,950
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-106

Table 130. Projection Parameters used in Future Year Emission Inventory Development 

for New Wells by Source Category.

Source Category Projection

Added Compression (reciprocating) totals for CY 2012+

Added Compression (turbine) totals for CY 2012+

Added Gas Plant (Duct Burner) totals for CY 2012+

Added Gas Plant (Flares) totals for CY 2012+

Added Gas Plant (Fugitives) totals for CY 2012+

Added Gas Plant (Heaters) totals for CY 2012+

Added Gas Plant (Process) totals for CY 2012+

Added Gas Plant (Recip Engines) totals for CY 2012+

Added Gas Plant (Turbine Engines) totals for CY 2012+

Completion Equipment (diesel ICE) total spuds

Completion Traffic (HD) total spuds

Completion Traffic (HD) Dust total spuds

Completion Traffic (LD) total spuds

Completion Traffic (LD) Dust total spuds

Condensate Fugitive Devices active well counts

Condensate Tank Breathing Flaring breathing flares

Condensate Tank Breathing Losses active well counts

Condensate Tank Flashing Flaring flashing flares

Condensate Tank Flashing Losses annual condensate production

Condensate Tank Working Flaring working flares

Condensate Tank Working Losses total turnovers per year

Construction Dust, Fugitive new pads

Construction Dust, Wind Erosion new pads

Construction Traffic, Road and Well pad (HD) new pads

Construction Traffic, Road and Well pad (HD) Dust new pads

Construction Traffic, Road and Well pad (LD) new pads

Construction Traffic, Road and Well pad (LD) Dust new pads

Dehydrator Flaring dehydrator flares

Dehydrator Venting - Well Site active well counts

Drilling Equip (diesel ICE 125HP) total spuds

Drilling Equip (diesel ICE 1476HP) total spuds

Drilling Traffic (HD) total spuds

Drilling Traffic (HD) Dust total spuds

Drilling Traffic (LD) total spuds

Drilling Traffic (LD) Dust total spuds

Evaporation Ponds active well counts

Gas Stream Fugitive Devices active well counts

Heaters active well counts

Initial Completion Flaring total spuds

Initial Completion Venting total spuds

Pneumatic Devices active well counts

Pneumatic Pump Flaring pneumatic pump flares

Pneumatic Pumps active well counts

Production Traffic (HD) active well counts

Production Traffic (HD) Dust active well counts

Production Traffic (LD) active well counts

Production Traffic (LD) Dust active well counts

Production Traffic, Central Facility (HD) totals for CY 2012+

Production Traffic, Central Facility (HD) Dust totals for CY 2012+

Tank Loadout (vapor losses) annual condensate production

Well Pad Const Equip (diesel ICE) new pads

Well Stream Fugitive Devices active well counts

Well Venting active well counts

Workover Equipment (diesel ICE) active well counts

WorkoverTraffic (HD) active well counts

WorkoverTraffic (HD) Dust active well counts

WorkoverTraffic (LD) active well counts

WorkoverTraffic (LD) Dust active well counts
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Draft Final EIS • April 2016 H-107

Table 131. Summary of Projection Factors used in Future Year Emission Inventory Development for New Wells.

Projection New pads 

per Year

Active Well 

Counts per Year

Total 

Spuds per 

Year

Annual Gas 

Production 

(MMscf/yr)

Annual 

Condensate 

Production 

(bbl/yr)

Totals for CY 

2012+

Total 

Turnovers 

per Year

Flashing 

Flares

Working 

Flares

Breathing 

Flares

Dehydrator 

Flares

Pneumatic 

Pump 

Flares

None

2008 0 0 0 0 0 0 0 0 0 0 0 0 1

2009 278 480 480 42879 844710 0 559 844710 559 480 480 480 1

2010 374 1124 644 131879 2598025 0 1721 2598025 1721 1124 1189 1124 1

2011 371 1764 640 198498 3910403 0 2590 3910403 2590 1764 1849 1764 1

2012 364 2392 628 246066 4847507 1 3210 4847507 3210 2392 2459 2392 1

2013 371 3032 640 290834 5729425 1 3794 5729425 3794 3032 3074 3032 1

2014 368 3666 634 323956 6381932 1 4226 6381932 4226 3666 3659 3666 1

2015 379 4320 654 353579 6965513 1 4613 6965513 4613 4320 4253 4320 1

2016 296 4831 511 374085 7369471 1 4880 7369471 4880 4831 4712 4831 1

2017 389 5502 671 396752 7816018 1 5502 7816018 5502 5502 5305 5502 1

2018 428 6240 738 459014 9042569 1 6240 9042569 6240 6240 6035 6240 1

2019 345 6834 594 482764 9510444 1 6834 9510444 6834 6834 6569 6834 1

2020 345 7429 595 500212 9854172 1 7429 9854172 7429 7429 7089 7429 1

2021 389 8100 671 513728 10120451 1 8100 10120451 8100 8100 7663 8100 1

2022 369 8736 637 550628 10847380 1 8736 10847380 8736 8736 8258 8736 1

2023 124 8950 214 532345 10487190 1 8950 10487190 8950 8950 8394 8950 1

2024 0 8950 0 468804 9235443 1 8950 9235443 8950 8950 8262 8950 1

2025 0 8950 0 427312 8418050 1 8950 8418050 8950 8950 8176 8950 1

2026 0 8950 0 397804 7836739 1 8950 7836739 8950 8950 8115 8950 1

2027 0 8950 0 373908 7365979 1 8950 7365979 8950 8950 8065 8950 1

2028 0 8950 0 353503 6964003 1 8950 6964003 8950 8950 8023 8950 1

2029 0 8950 0 335618 6611673 1 8950 6611673 8950 8950 7986 8950 1

2030 0 8950 0 319610 6296321 1 8950 6296321 8950 8950 7952 8950 1

2031 0 8950 0 305143 6011315 1 8950 6011315 8950 8950 7922 8950 1

2032 0 8950 0 291843 5749315 1 8950 5749315 8950 8950 7895 8950 1

2033 0 8950 0 279574 5507609 1 8950 5507609 8950 8950 7869 8950 1

2034 0 8950 0 268151 5282566 1 8950 5282566 8950 8950 7845 8950 1

2035 0 8950 0 257382 5070431 1 8950 5070431 8950 8950 7823 8950 1

2036 0 8950 0 247200 4869849 1 8950 4869849 8950 8950 7802 8950 1

2037 0 8950 0 237559 4679907 1 8950 4679907 8950 8950 7782 8950 1
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Draft Final EIS • April 2016 H-108

Gas Composition Analysis

Table 132. Summary of Gas Composition Analysis as Provided in 

Table 133 through Table 139.

Property

Sales/Produced 

Gas

Fugitive

(Post-Flash) Flashing Produced Water

Condensate (PostFlash)

Regenerator 

Overhead Vent 

Stream

Wet Gas

VOC Fraction (molar) 5.39% 49.52% 49.51% 55.26% 39.40% 15.07% 5.30%

VOC/TOC (weight) 15.59% 75.85% 75.78% 92.48% 66.34% 50.39% 15.22%

VOC MW 57.50 64.95 64.85 69.75 63.01 79.73 56.65

VOC Fraction (weight) 14.60% 73.55% 73.46% 69.58% 66.34% 40.07% 14.25%

CO2 Fraction (weight) 6.07% 3.02% 3.04% 24.76% 0.00% 8.81% 6.09%

CH4 Fraction (weight) 68.75% 13.57% 13.5% 3.9% 21.2% 32.6% 69.0%

H2S Fraction (weight) 0.00% 0.00% 0.0% 0.0% 0.0% 0.0% 0.0%

Heat Content (BTU/SCF) 1000 - - - - - -

benzene/VOC (weight) 0.40% 0.83% 0.82% 0.56% 0.48% 9.63% 0.41%

toluene/VOC (weight) 0.56% 1.17% 1.17% 1.13% 0.63% 15.90% 0.57%

ethylbenzene/VOC (weight) 0.02% 0.02% 0.02% 0.05% 0.01% 0.59% 0.02%

xylenes/VOC (weight) 0.32% 0.63% 0.63% 0.43% 0.35% 5.86% 0.18%

n-hexane/VOC (weight) 4.74% 3.96% 3.93% 5.01% 3.40% 2.61% 1.98%

formaldehyde/VOC (weight) 0% 0% 0% 0% 0% 0% 0%

Assumptions

Data obtained from operators in blue 

text
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-109

Table 133. Sales Gas Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 2.73% 2.73% 44.0 1.2 6.0666% N

Nitrogen 0.17% 0.17% 28.0 0.0 0.2420% N

Methane 84.99% 84.90% 16.0 13.6 68.7549% N

Ethane 6.81% 6.81% 30.1 2.0 10.3331% N

Propane 3.17% 3.17% 44.1 1.4 7.0516% Y 48.29% 21.29

Isobutane 0.64% 0.64% 58.1 0.4 1.8647% Y 12.77% 7.42

n-Butane 0.71% 0.71% 58.1 0.4 2.0830% Y 14.26% 8.29

Isopentane 0.24% 0.24% 72.2 0.2 0.8812% Y 6.03% 4.35

n-Pentane 0.20% 0.20% 72.2 0.1 0.7252% Y 4.97% 3.58

Cyclopentane 0.00% 0.00% 70.1 0.0 0.0000% Y 0.00% 0.00

n-Hexane 0.16% 0.16% 86.2 0.1 0.6928% Y 4.74% 4.09

Cyclohexane 0.03% 0.03% 84.2 0.0 0.1349% Y 0.92% 0.78

2,2-Dimethylbutane 0.00% 0.00% 86.2 0.0 0.0186% Y 0.13% 0.11

2,3-Dimethylbutane 0.02% 0.02% 86.2 0.0 0.0712% Y 0.49% 0.42

2-Methylpentane 0.05% 0.05% 86.2 0.0 0.2121% Y 1.45% 1.25

3-Methylpentane 0.03% 0.03% 86.2 0.0 0.1091% Y 0.75% 0.64

n-Heptane 0.06% 0.06% 100.2 0.1 0.2967% Y 2.03% 2.04

Methylcyclohexane 0.03% 0.03% 98.2 0.0 0.1594% Y 1.09% 1.07

2,2,4-Trimethylpentane 0.00% 0.00% 114.2 0.0 0.0218% Y 0.15% 0.17

Benzene 0.01% 0.01% 78.1 0.0 0.0589% Y 0.40% 0.31

Toluene 0.02% 0.02% 92.1 0.0 0.0811% Y 0.56% 0.51

Ethylbenzene 0.00% 0.00% 106.2 0.0 0.0024% Y 0.02% 0.02

m-Xylene 0.00% 0.00% 106.2 0.0 0.0250% Y 0.17% 0.18

o-Xylene 0.00% 0.00% 106.2 0.0 0.0218% Y 0.15% 0.16

n-Octane 0.00% 0.00% 114.2 0.0 0.0035% Y 0.02% 0.03

n-Nonane 0.01% 0.01% 128.3 0.0 0.0886% Y 0.61% 0.78

n-Decane 0.00% 0.00% 142.3 0.0 0.0000% Y 0.00% 0.00

Total 100.10% 100.00% 19.8 100.00% 57.5

ASSUMPTIONS

Data obtained from operators in blue 

text
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-110

Table 134. Fugitive Post-Flash Gas Composition Analysis.

Table 135. Flash Gas Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 2.79% 2.79% 44.0 1.2 3.0190% N

Nitrogen 0.02% 0.02% 28.0 0.0 0.0151% N

Methane 34.37% 34.37% 16.0 5.5 13.5728% N

Ethane 13.30% 13.30% 30.1 4.0 9.8429% N

Propane 17.80% 17.80% 44.1 7.9 19.3288% Y 26.28% 11.59

Isobutane 6.84% 6.84% 58.1 4.0 9.7798% Y 13.30% 7.73

n-Butane 9.37% 9.37% 58.1 5.4 13.4078% Y 18.23% 10.60

Isopentane 4.55% 4.55% 72.2 3.3 8.0782% Y 10.98% 7.92

n-Pentane 3.97% 3.97% 72.2 2.9 7.0578% Y 9.60% 6.92

Cyclopentane 0.00% 0.00% 70.1 0.0 0.0000% Y 0.00% 0.00

n-Hexane 1.37% 1.37% 86.2 1.2 2.9160% Y 3.96% 3.42

Cyclohexane 0.30% 0.30% 84.2 0.3 0.6178% Y 0.84% 0.71

2,2-Dimethylbutane 0.09% 0.09% 86.2 0.1 0.1907% Y 0.26% 0.22

2,3-Dimethylbutane 0.35% 0.35% 86.2 0.3 0.7423% Y 1.01% 0.87

2-Methylpentane 1.06% 1.06% 86.2 0.9 2.2383% Y 3.04% 2.62

3-Methylpentane 0.54% 0.54% 86.2 0.5 1.1373% Y 1.55% 1.33

n-Heptane 1.85% 1.85% 100.2 1.9 4.5651% Y 6.21% 6.22

Methylcyclohexane 0.18% 0.18% 98.2 0.2 0.4350% Y 0.59% 0.58

2,2,4-Trimethylpentane 0.07% 0.07% 114.2 0.1 0.1980% Y 0.27% 0.31

Benzene 0.32% 0.32% 78.1 0.2 0.6104% Y 0.83% 0.65

Toluene 0.38% 0.38% 92.1 0.3 0.8601% Y 1.17% 1.08

Ethylbenzene 0.00% 0.00% 106.2 0.0 0.0114% Y 0.02% 0.02

m-Xylene 0.16% 0.16% 106.2 0.2 0.4206% Y 0.57% 0.61

o-Xylene 0.02% 0.02% 106.2 0.0 0.0399% Y 0.05% 0.06

n-Octane 0.22% 0.22% 114.2 0.3 0.6172% Y 0.84% 0.96

n-Nonane 0.05% 0.05% 128.3 0.1 0.1582% Y 0.22% 0.28

n-Decane 0.04% 0.04% 142.3 0.1 0.1395% Y 0.19% 0.27

Total 100.00% 100.00% 40.6 100.00% 65.0

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 2.80% 2.80% 44.0 1.2 3.0392% N

Nitrogen 0.02% 0.02% 28.0 0.0 0.0149% N

Methane 34.25% 34.25% 16.0 5.5 13.5394% N

Ethane 13.42% 13.42% 30.1 4.0 9.9421% N

Propane 17.98% 17.98% 44.1 7.9 19.5446% Y 26.60% 11.73

Isobutane 6.85% 6.85% 58.1 4.0 9.8099% Y 13.35% 7.76

n-Butane 9.34% 9.34% 58.1 5.4 13.3756% Y 18.21% 10.58

Isopentane 4.48% 4.48% 72.2 3.2 7.9707% Y 10.85% 7.83

n-Pentane 3.91% 3.91% 72.2 2.8 6.9497% Y 9.46% 6.83

Cyclopentane 0.00% 0.00% 70.1 0.0 0.0000% Y 0.00% 0.00

n-Hexane 1.36% 1.36% 86.2 1.2 2.8850% Y 3.93% 3.38

Cyclohexane 0.30% 0.30% 84.2 0.2 0.6125% Y 0.83% 0.70

2,2-Dimethylbutane 0.09% 0.09% 86.2 0.1 0.1877% Y 0.26% 0.22

2,3-Dimethylbutane 0.34% 0.34% 86.2 0.3 0.7319% Y 1.00% 0.86

2-Methylpentane 1.04% 1.04% 86.2 0.9 2.2086% Y 3.01% 2.59

3-Methylpentane 0.53% 0.53% 86.2 0.5 1.1231% Y 1.53% 1.32

n-Heptane 1.85% 1.85% 100.2 1.9 4.5682% Y 6.22% 6.23

Methylcyclohexane 0.18% 0.18% 98.2 0.2 0.4348% Y 0.59% 0.58

2,2,4-Trimethylpentane 0.07% 0.07% 114.2 0.1 0.1981% Y 0.27% 0.31

Benzene 0.31% 0.31% 78.1 0.2 0.6038% Y 0.82% 0.64

Toluene 0.38% 0.38% 92.1 0.3 0.8615% Y 1.17% 1.08

Ethylbenzene 0.00% 0.00% 106.2 0.0 0.0115% Y 0.02% 0.02

m-Xylene 0.16% 0.16% 106.2 0.2 0.4243% Y 0.58% 0.61

o-Xylene 0.02% 0.02% 106.2 0.0 0.0403% Y 0.05% 0.06

n-Octane 0.22% 0.22% 114.2 0.3 0.6219% Y 0.85% 0.97

n-Nonane 0.05% 0.05% 128.3 0.1 0.1598% Y 0.22% 0.28

n-Decane 0.04% 0.04% 142.3 0.1 0.1410% Y 0.19% 0.27

Total 100.00% 100.00% 40.6 100.00% 64.9
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-111

Table 136. Produced Water Working and Breathing Gas Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 29.14% 29.14% 44.010 12.822 24.76% N

Nitrogen 0.00% 0.00% 28.010 0.000 0.00% N

Methane 12.59% 12.59% 16.040 2.019 3.90% N

Ethane 3.02% 3.02% 30.070 0.909 1.76% N

Propane 11.24% 11.24% 44.100 4.956 9.57% Y 13.76% 6.066

Isobutane 8.05% 8.05% 58.120 4.679 9.04% Y 12.99% 7.548

n-Butane 12.65% 12.65% 58.120 7.352 14.20% Y 20.41% 11.861

Isopentane 6.97% 6.97% 72.150 5.031 9.72% Y 13.96% 10.075

n-Pentane 5.97% 5.97% 72.150 4.308 8.32% Y 11.96% 8.628

Cyclopentane 0.00% 0.00% 70.130 0.000 0.00% Y 0.00% 0.000

n-Hexane 2.09% 2.09% 86.180 1.804 3.48% Y 5.01% 4.316

Cyclohexane 3.09% 3.09% 84.160 2.600 5.02% Y 7.22% 6.073

2,2-Dimethylbutane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

2,3-Dimethylbutane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

2-Methylpentane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

3-Methylpentane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

n-Heptane 3.55% 3.55% 100.202 3.558 6.87% Y 9.88% 9.897

Methylcyclohexane 0.00% 0.00% 98.190 0.000 0.00% Y 0.00% 0.000

2,2,4-Trimethylpentane 0.12% 0.12% 114.229 0.142 0.27% Y 0.39% 0.451

Benzene 0.26% 0.26% 78.110 0.200 0.39% Y 0.56% 0.434

Toluene 0.44% 0.44% 92.140 0.406 0.78% Y 1.13% 1.038

Ethylbenzene 0.02% 0.02% 106.170 0.017 0.03% Y 0.05% 0.051

m-Xylene 0.15% 0.15% 106.160 0.156 0.30% Y 0.43% 0.458

o-Xylene 0.00% 0.00% 106.160 0.000 0.00% Y 0.00% 0.000

n-Octane 0.36% 0.36% 114.229 0.415 0.80% Y 1.15% 1.316

n-Nonane 0.12% 0.12% 128.255 0.149 0.29% Y 0.41% 0.531

n-Decane 0.18% 0.18% 142.290 0.254 0.49% Y 0.70% 1.003

Total 100.00% 100.00% 51.777 100.00% 69.745
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-112

Table 137. Condensate Tank Post-Flash Gas Composition Analysis.

Table 138. Regenerated Overhead Vent Stream Composition Analysis.

Component Component Moles 

Percent Normalized Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 0.00% 0.00% 44.01 0.0000 0.00% N

Nitrogen 0.00% 0.00% 28.01 0.0000 0.00% N

Methane 46.18% 46.18% 16.04 7.4070 21.23% N

Ethane 14.42% 14.42% 30.07 4.3354 12.43% N

Propane 15.42% 15.42% 44.1 6.8008 19.50% Y 29.39% 12.960

Isobutane 5.69% 5.70% 58.12 3.3100 9.49% Y 14.30% 8.313

n-Butane 7.51% 7.51% 58.12 4.3644 12.51% Y 18.86% 10.961

Isopentane 3.54% 3.54% 72.15 2.5570 7.33% Y 11.05% 7.972

n-Pentane 2.87% 2.87% 72.15 2.0697 5.93% Y 8.94% 6.453

n-Hexane 0.91% 0.91% 86.18 0.7863 2.25% Y 3.40% 2.928

Cyclohexane 0.15% 0.15% 84.16 0.1247 0.36% Y 0.54% 0.454

2,2-Dimethylbutane 0.07% 0.07% 86.177 0.0625 0.18% Y 0.27% 0.233

2,3-Dimethylbutane 0.24% 0.24% 86.177 0.2072 0.59% Y 0.90% 0.771

2-Methylpentane 0.71% 0.71% 86.177 0.6143 1.76% Y 2.65% 2.287

3-Methylpentane 0.34% 0.34% 86.177 0.2936 0.84% Y 1.27% 1.093

n-Heptane 1.23% 1.23% 100.202 1.2284 3.52% Y 5.31% 5.319

Methylcyclohexane 0.10% 0.10% 98.19 0.0976 0.28% Y 0.42% 0.414

2,2,4-Trimethylpentane 0.04% 0.04% 114.229 0.0491 0.14% Y 0.21% 0.242

Benzene 0.14% 0.14% 78.11 0.1106 0.32% Y 0.48% 0.373

Toluene 0.16% 0.16% 92.14 0.1455 0.42% Y 0.63% 0.579

Ethylbenzene 0.00% 0.00% 106.17 0.0020 0.01% Y 0.01% 0.009

Xylenes 0.08% 0.08% 106.17 0.0806 0.23% Y 0.35% 0.370

n-Octane 0.11% 0.11% 114.2285 0.1306 0.37% Y 0.56% 0.645

n-Nonane 0.04% 0.04% 128.255 0.0464 0.13% Y 0.20% 0.257

n-Decane 0.04% 0.04% 142.29 0.0608 0.17% Y 0.26% 0.374

Total 100% 100% 34.8843 100% 100% 63.007

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Water 17.54% 17.54% 18.010 3.159 11.56% N

Carbon Dioxide 5.47% 5.47% 44.010 2.407 8.81% N

Nitrogen 0.11% 0.11% 28.010 0.032 0.12% N

Methane 55.61% 55.61% 16.040 8.920 32.64% N

Ethane 6.19% 6.19% 30.070 1.861 6.81% N

Propane 3.98% 3.98% 44.100 1.755 6.42% Y 16.03% 7.069

Isobutane 1.07% 1.07% 58.120 0.622 2.28% Y 5.68% 3.301

n-Butane 1.49% 1.49% 58.120 0.866 3.17% Y 7.91% 4.597

Isopentane 0.57% 0.57% 72.150 0.413 1.51% Y 3.77% 2.719

n-Pentane 0.58% 0.58% 72.150 0.421 1.54% Y 3.85% 2.776

n-Hexane 0.33% 0.33% 86.180 0.286 1.05% Y 2.61% 2.252

Cyclohexane 0.62% 0.62% 84.160 0.523 1.92% Y 4.78% 4.024

Other Hexanes 0.37% 0.37% 86.180 0.320 1.17% Y 2.92% 2.517

n-Heptane 0.61% 0.61% 100.202 0.615 2.25% Y 5.62% 5.630

Methylcyclohexane 0.79% 0.79% 98.190 0.775 2.83% Y 7.08% 6.947

2,2,4-Trimethylpentane 0.02% 0.02% 114.229 0.022 0.08% Y 0.20% 0.226

Benzene 1.35% 1.35% 78.110 1.055 3.86% Y 9.63% 7.522

Toluene 1.89% 1.89% 92.140 1.741 6.37% Y 15.90% 14.654

Ethylbenzene 0.06% 0.06% 106.170 0.065 0.24% Y 0.59% 0.628

Xylenes 0.60% 0.60% 106.170 0.641 2.35% Y 5.86% 6.218

n-Octane 0.73% 0.73% 114.229 0.829 3.03% Y 7.57% 8.652

Total 100.00% 100.00% 27.329 100.00% 100.00% 79.734
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-113

Table 139. Wet Gas Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 2.73% 2.73% 44.010 1.203 6.09% N

Nitrogen 0.17% 0.17% 28.010 0.048 0.24% N

Methane 84.98% 84.98% 16.040 13.631 69.04% N

Ethane 6.81% 6.81% 30.070 2.049 10.38% N

Propane 3.17% 3.17% 44.100 1.398 7.08% Y 49.67% 21.906

Isobutane 0.64% 0.64% 58.120 0.370 1.87% Y 13.14% 7.634

n-Butane 0.71% 0.71% 58.120 0.413 2.09% Y 14.67% 8.528

Isopentane 0.24% 0.24% 72.150 0.175 0.88% Y 6.21% 4.478

n-Pentane 0.20% 0.20% 72.150 0.144 0.73% Y 5.11% 3.686

n-Hexane 0.06% 0.06% 86.180 0.056 0.28% Y 1.98% 1.710

Cyclohexane 0.03% 0.03% 84.160 0.027 0.14% Y 0.95% 0.800

2,2-Dimethylbutane 0.00% 0.00% 86.177 0.004 0.02% Y 0.13% 0.113

2,3-Dimethylbutane 0.02% 0.02% 86.177 0.014 0.07% Y 0.50% 0.433

2-Methylpentane 0.05% 0.05% 86.177 0.042 0.21% Y 1.49% 1.288

3-Methylpentane 0.03% 0.03% 86.177 0.022 0.11% Y 0.77% 0.662

n-Heptane 0.06% 0.06% 100.202 0.059 0.30% Y 2.09% 2.094

Methylcyclohexane 0.03% 0.03% 98.190 0.032 0.16% Y 1.12% 1.103

2,2,4-Trimethylpentane 0.00% 0.00% 114.229 0.004 0.02% Y 0.15% 0.176

Benzene 0.01% 0.01% 78.110 0.012 0.06% Y 0.41% 0.323

Toluene 0.02% 0.02% 92.140 0.016 0.08% Y 0.57% 0.525

Ethylbenzene 0.00% 0.00% 106.170 0.001 0.00% Y 0.02% 0.020

m&p-Xylene 0.00% 0.00% 106.160 0.004 0.02% Y 0.15% 0.164

o-Xylene 0.00% 0.00% 106.160 0.001 0.00% Y 0.02% 0.024

n-Octane 0.01% 0.01% 114.229 0.016 0.08% Y 0.56% 0.635

n-Nonane 0.01% 0.01% 128.255 0.008 0.04% Y 0.27% 0.345

n-Decane 0.00% 0.00% 142.290 0.000 0.00% Y 0.00% 0.000

Total 100.00% 100.00% 19.745 100.00% 100.00% 56.648
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-114

Table 140. Toxic Speciation Profiles used in Future Year Emission Inventory Development for Future Wells.

benzene toluene ethylbenzene xylenes n-hexane formaldehyde

venting other than well venting, initial completion 

and dehydrator 0.403% 0.555% 0.017% 0.320% 4.744% 0.000%

flashing loss 0.822% 1.173% 0.016% 0.632% 3.927% 0.000%

Fugitive -working/breathing loss 0.830% 1.169% 0.016% 0.626% 3.965% 0.000%

diesel ICE 1.045% 1.518% 0.179% 1.205% 0.000% 8.510%

HD traffic 1.132% 0.613% 0.152% 0.801% 0.129% 7.924%

LD traffic 3.711% 10.147% 1.459% 5.744% 0.879% 2.456%

natural gas external combustion (boiler/heater) 4.000% 2.000% 0.000% 0.000% 0.000% 8.000%

dust 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%

compressor engine, lean burn 0.373% 0.346% 0.034% 0.156% 0.941% 44.746%

compressor engine, rich burn 5.338% 1.885% 0.084% 0.659% 0.000% 69.257%

natural gas drilling engine 0.373% 0.346% 0.034% 0.156% 0.941% 44.746%

flaring 0.000% 0.000% 0.000% 0.000% 0.000% 40.000%

diesel external combustion boiler 0.000% 0.000% 0.000% 0.000% 10.800% 48.700%

Reciprocating Engine 1.182% 0.430% 0.107% 0.430% 0.215% 8.700%

Turbine 0.000% 0.000% 0.000% 0.000% 0.000% 100.000%

produced water evaporation 13.858% 18.028% 1.529% 24.393% 0.147% 0.000%

Tank -working/breathing loss 0.478% 0.629% 0.009% 0.348% 3.398% 0.000%

Dehydrator Venting 9.631% 15.905% 0.591% 5.857% 2.613% 0.000%

venting -Well Venting and Initial completion 0.414% 0.570% 0.019% 0.177% 1.984% 0.000%

Source Type for lookup

VOC fractions

Source

Wamsutter Produced Gas Composition

Flash speciation from Wamsutter HYSYS

Wamsutter Fugitive Composition (Post Flash)

SPECIATE4, Profile 4674

From Catherine Yanca at EPA based on CRC E-55/E-59 Study

From David Brzezinski at EPA and MOVES

SPECIATE4, Profile 0003

AP-42, CH 3.2

AP-42, CH 3.2

AP-42, CH 3.2

SPECIATE4, Profile 1001

SPECIATE4, Profile 0002

SPECIATE4, Profile 1001

SPECIATE4, Profile 0007

EPA, Water 9 model Output. Based on data from evaporation 

facilities at Wamsutter Operations Center

Wamsutter Condensate Composition (Post Flash)

Wamsutter Regenerator Overhead Vent Stream Composition

Wamsutter Wet Gas Composition
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-115

Table 141. List of Toxics Speciation Profiles used in Future Year Emission Inventory 

Development for Future Wells by Source Category.

Source Category Appropriate Speciation Profiles Used

Added Compression (reciprocating) Reciprocating Engine

Added Compression (turbine) Turbine

Added Gas Plant (Duct Burner) natural gas external combustion (boiler/heater)

Added Gas Plant (Flares) flaring

Added Gas Plant (Fugitives) venting other than well venting, initial completion and dehydrator

Added Gas Plant (Heaters) natural gas external combustion (boiler/heater)

Added Gas Plant (Process) natural gas external combustion (boiler/heater)

Added Gas Plant (Recip Engines) Reciprocating Engine

Added Gas Plant (Turbine Engines) Turbine

Completion Equipment (diesel ICE) diesel ICE

Completion Traffic (HD) HD traffic

Completion Traffic (HD) Dust dust

Completion Traffic (LD) LD traffic

Completion Traffic (LD) Dust dust

Condensate Fugitive Devices Fugitive -working/breathing loss 

Condensate Tank Breathing Flaring flaring

Condensate Tank Breathing Losses Tank -working/breathing loss 

Condensate Tank Flashing Flaring flaring

Condensate Tank Flashing Losses flashing loss

Condensate Tank Working Flaring flaring

Condensate Tank Working Losses Tank -working/breathing loss 

Construction Dust, Fugitive dust

Construction Dust, Wind Erosion dust

Construction Traffic, Road and Well pad (HD) HD traffic

Construction Traffic, Road and Well pad (HD) Dust dust

Construction Traffic, Road and Well pad (LD) LD traffic

Construction Traffic, Road and Well pad (LD) Dust dust

Dehydrator Flaring flaring

Dehydrator Venting - Well Site Dehydrator Venting

Drilling Equip (diesel ICE 125HP) diesel ICE

Drilling Equip (diesel ICE 1476HP) diesel ICE

Drilling Traffic (HD) HD traffic

Drilling Traffic (HD) Dust dust

Drilling Traffic (LD) LD traffic

Drilling Traffic (LD) Dust dust

Evaporation Ponds produced water evaporation

Gas Stream Fugitive Devices venting other than well venting, initial completion and dehydrator

Heaters natural gas external combustion (boiler/heater)

Initial Completion Flaring flaring

Initial Completion Venting venting -Well Venting and Initial completion

Pneumatic Devices venting other than well venting, initial completion and dehydrator

Pneumatic Pump Flaring flaring

Pneumatic Pumps venting other than well venting, initial completion and dehydrator

Production Traffic (HD) HD traffic

Production Traffic (HD) Dust dust

Production Traffic (LD) LD traffic

Production Traffic (LD) Dust dust

Production Traffic, Central Facility (HD) HD traffic

Production Traffic, Central Facility (HD) Dust dust

Tank Loadout (vapor losses) Tank -working/breathing loss 

Well Pad Const Equip (diesel ICE) diesel ICE

Well Stream Fugitive Devices venting other than well venting, initial completion and dehydrator

Well Venting venting -Well Venting and Initial completion

Workover Equipment (diesel ICE) diesel ICE

WorkoverTraffic (HD) HD traffic

WorkoverTraffic (HD) Dust dust

WorkoverTraffic (LD) LD traffic

WorkoverTraffic (LD) Dust dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-116

WYDEQ BACT Requirements Accounting

ASSUMPTIONS

Data obtained from operators in blue 

text

Table 142. Summary of Fraction and Number of Wells with WYDEQ BACT Control for 

Pneumatic Pumps.

Percent w/ no 

BACT

Absolute w/ no 

BACT

Absolute w/ 

BACT

Percent with BACT 

where BACT 

equipment is removed

Equipment with 

BACT equipment

Instances where 

BACT equipment 

taken offline Percent Absolute

New Project_2008 0 0

New Project_2009 480 480 0.0% 0 480 0.0% 480 0 100% 480

New Project_2010 644 1,124 0.0% 0 644 0.0% 1124 0 100% 1124

New Project_2011 640 1,764 0.0% 0 640 0.0% 1764 0 100% 1764

New Project_2012 628 2,392 0.0% 0 628 0.0% 2392 0 100% 2392

New Project_2013 640 3,032 0.0% 0 640 0.0% 3032 0 100% 3032

New Project_2014 634 3,666 0.0% 0 634 0.0% 3666 0 100% 3666

New Project_2015 654 4,320 0.0% 0 654 0.0% 4320 0 100% 4320

New Project_2016 511 4,831 0.0% 0 511 0.0% 4831 0 100% 4831

New Project_2017 671 5,502 0.0% 0 671 0.0% 5502 0 100% 5502

New Project_2018 738 6,240 0.0% 0 738 0.0% 6240 0 100% 6240

New Project_2019 594 6,834 0.0% 0 594 0.0% 6834 0 100% 6834

New Project_2020 595 7,429 0.0% 0 595 0.0% 7429 0 100% 7429

New Project_2021 671 8,100 0.0% 0 671 0.0% 8100 0 100% 8100

New Project_2022 637 8,736 0.0% 0 637 0.0% 8736 0 100% 8736

New Project_2023 214 8,950 0.0% 0 214 0.0% 8950 0 100% 8950

New Project_2024 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2025 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2026 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2027 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2028 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2029 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2030 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2031 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2032 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2033 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2034 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2035 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2036 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2037 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

assumed

Inventory_Year

Equipment Installed 

Population

Cumulative 

Equipment 

Population

Pneumatic Pumps

New Equipment Existing Equipment

Total Equipment meeting 

BACT requirements
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-117

Table 143. Summary of Fraction and Number of Wells with WYDEQ BACT Controls for 

Dehydrators.

Table 144. Summary of Fraction and Number of Wells with WYDEQ BACT Control for 

Condensate Tanks.

Percent w/ no 

BACT

Absolute w/ no 

BACT Absolute w/ BACT

Percent with BACT where BACT 

equipment is removed

Equipment with 

BACT equipment

Instances where 

BACT equipment 

taken offline Percent Absolute

New Project_2008 0 0

New Project_2009 480 480 0.0% 0 480 0.0% 480 0 100% 480

New Project_2010 644 1,124 0.0% 0 644 0.0% 1124 0 100% 1124

New Project_2011 640 1,764 0.0% 0 640 0.0% 1764 0 100% 1764

New Project_2012 628 2,392 0.0% 0 628 0.0% 2392 0 100% 2392

New Project_2013 640 3,032 0.0% 0 640 0.0% 3032 0 100% 3032

New Project_2014 634 3,666 0.0% 0 634 0.0% 3666 0 100% 3666

New Project_2015 654 4,320 0.0% 0 654 0.0% 4320 0 100% 4320

New Project_2016 511 4,831 0.0% 0 511 0.0% 4831 0 100% 4831

New Project_2017 671 5,502 0.0% 0 671 0.0% 5502 0 100% 5502

New Project_2018 738 6,240 0.0% 0 738 0.0% 6240 0 100% 6240

New Project_2019 594 6,834 0.0% 0 594 0.0% 6834 0 100% 6834

New Project_2020 595 7,429 0.0% 0 595 0.0% 7429 0 100% 7429

New Project_2021 671 8,100 0.0% 0 671 0.0% 8100 0 100% 8100

New Project_2022 637 8,736 0.0% 0 637 0.0% 8736 0 100% 8736

New Project_2023 214 8,950 0.0% 0 214 0.0% 8950 0 100% 8950

New Project_2024 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2025 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2026 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2027 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2028 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2029 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2030 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2031 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2032 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2033 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2034 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2035 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2036 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2037 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

assumed

Inventory_Year

Equipment Installed 

Population

Cumulative 

Equipment 

Population

Dehydrators

Existing Equipment

Total Equipment meeting BACT 

New Equipment requirements

Percent w/ no 

BACT

Absolute w/ 

no BACT Absolute w/ BACT

Percent with BACT 

where BACT 

equipment is removed

Equipment with 

BACT equipment

Instances where 

BACT equipment 

taken offline Percent Absolute

New Project_2008 0 0

New Project_2009 480 480 0.0% 0 480 0.0% 480 0 100% 480

New Project_2010 644 1,124 0.0% 0 644 0.0% 1124 0 100% 1124

New Project_2011 640 1,764 0.0% 0 640 0.0% 1764 0 100% 1764

New Project_2012 628 2,392 0.0% 0 628 0.0% 2392 0 100% 2392

New Project_2013 640 3,032 0.0% 0 640 0.0% 3032 0 100% 3032

New Project_2014 634 3,666 0.0% 0 634 0.0% 3666 0 100% 3666

New Project_2015 654 4,320 0.0% 0 654 0.0% 4320 0 100% 4320

New Project_2016 511 4,831 0.0% 0 511 0.0% 4831 0 100% 4831

New Project_2017 671 5,502 0.0% 0 671 0.0% 5502 0 100% 5502

New Project_2018 738 6,240 0.0% 0 738 0.0% 6240 0 100% 6240

New Project_2019 594 6,834 0.0% 0 594 0.0% 6834 0 100% 6834

New Project_2020 595 7,429 0.0% 0 595 0.0% 7429 0 100% 7429

New Project_2021 671 8,100 0.0% 0 671 0.0% 8100 0 100% 8100

New Project_2022 637 8,736 0.0% 0 637 0.0% 8736 0 100% 8736

New Project_2023 214 8,950 0.0% 0 214 0.0% 8950 0 100% 8950

New Project_2024 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2025 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2026 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2027 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2028 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2029 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2030 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2031 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2032 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2033 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2034 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2035 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2036 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

New Project_2037 0 8,950 0.0% 0 0 0.0% 8950 0 100% 8950

assumed

Inventory_Year

Equipment Installed 

Population

Cumulative 

Equipment 

Population

Condensate Tanks

New Equipment Existing Equipment

Total Equipment meeting 

BACT requirements
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-118

2009 Well Pad Construction Equipment Emissions

ASSUMPTIONS

Activity data obtained from operator in blue text

Assumptions:

* Emission factors from EPA Federal Diesel Engine Standards 

http://www.epa.gov/otaq/standar

ds/nonroad/nonroadci.htm

* VOC/THC= 1.053 Conversion for HC->VOC for diesel engines (EPA, 2005; EPA420-R-05-0159, p. 5)

*

37% of fine particles assumed to be filterable and all filterable are assigned to EC (Source: AQTSD for Hell’s Gulch 

and Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

*

63% of fine particles assumed to be filterable and all filterable are assigned to SOA (Source: AQTSD for Hell’s Gulch 

and Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

EPA NONROAD model Fully Deteriorated Tier Emission Factors

N2O Emission factors (g/gallons) from The Climate Registry, General Reporting Protocol v1.1, Table 13.6

Equations:

Emissions (tons/year-well) = Emission factor (g/hp-hr) * Horsepower * Time Used (hours) * Load

453.6 (g/lb) * 2000 (lbs/ton)

PM2.5/PM10 = 97% EPA (2004) NONROAD

VOC/HC= 1.053 EPA NONROAD HC Conversions

NMHC/THC= 98.40% EPA NONROAD HC Conversions

SO2 Emission Factor Calculation Information 

2008 Fuel Sulfur content 0.0355 sulfur fuel weight percent from EPA's NMIM 

County Database

soxcnv Tiers I-III 0.02247 grams PM sulfur/grams fuel sulfur consumed

soxcnv Tier IV 0.3

grams PM sulfate/grams PM sulfur 7

soxbas 0.33

Density of Diesel Fuel 7.09 lb/gallons

Molecular weight of S 32 g/mol

Molecular weight of S02 64 g/mol

453.6 g/lb
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-119

Table 145. 2009 Well Pad Construction Equipment Emissions (lb/well pad) by Pollutants 

and by Equipment Type.

Equipment

Activity & 

Emission Factors

Emissions 

(lb/well pad)

Engine 1 Engine Function Loader

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 200

Horsepower Range 175-300

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.433

Fuel Consumption (Gallons) 293

Emission Factors 

(g/bhp-hr)

NOx 6.860 72.60

VOC 1.021 10.80

CO 8.501 89.96

PM10 0.403 4.26

PM2.5 0.391 4.13

SO2 0.136 1.44

CO2 623 6597.37

CH4 0.016 0.16

PM_filt 0.145 1.53

PM_cond 0.246 2.60

N2O 0.260 0.17

Engine 2 Engine Function Dozer

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 500

Horsepower Range 300-600

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.371

Fuel Consumption (Gallons) 628

Emission Factors 

(g/bhp-hr) NOx 6.860 181.49

VOC 1.021 27.00

CO 8.501 224.89

PM10 0.403 10.65

PM2.5 0.391 10.33

SO2 0.116 3.07

CO2 534 14120.07

CH4 0.016 0.41

PM_filt 0.145 3.82

PM_cond 0.246 6.51

N2O 0.260 0.36
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-120

Equipment

Activity & 

Emission Factors

Emissions 

(lb/well pad)

Engine 3 Engine Function Scraper

Number of Engines 2

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 700

Horsepower Range 600-750

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.371

Fuel Consumption (Gallons) 1758

Emission Factors 

(g/bhp-hr)

(g/gal) for N2O

NOx 6.860 508.18

VOC 1.021 75.61

CO 8.501 629.70

PM10 0.403 29.83

PM2.5 0.391 28.93

SO2 0.116 8.60

CO2 534 39536.20

CH4 0.016 1.15

PM_filt 0.145 10.71

PM_cond 0.246 18.23

N2O 0.260 1.01

Engine 4 Engine Function Grader

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 350

Horsepower Range 300-600

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.371

Fuel Consumption (Gallons) 440

Emission Factors 

(g/bhp-hr)

(g/gal) for N2O

NOx 6.860 127.05

VOC 1.021 18.90

CO 8.501 157.43

PM10 0.403 7.46

PM2.5 0.391 7.23

SO2 0.116 2.15

CO2 534 9884.05

CH4 0.016 0.29

PM_filt 0.145 2.68

PM_cond 0.246 4.56

N2O 0.260 0.25

Engine 5 Engine Function Backhoe

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 60

Horsepower Range 50-75

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.481

Fuel Consumption (Gallons) 98

Emission Factors 

(g/bhp-hr)

(g/gal) for N2O

NOx 6.860 21.78

VOC 1.314 4.17

CO 6.425 20.40

PM10 1.076 3.42

PM2.5 1.044 3.31

SO2 0.151 0.48

CO2 692 2196.89

CH4 0.020 0.06

PM_filt 0.386 1.23

PM_cond 0.658 2.09

N2O 0.260 0.06
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-121

Equipment

Activity & 

Emission Factors

Emissions 

(lb/well pad)

Engine 6 Engine Function Roller

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 200

Horsepower Range 175-300

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.371

Fuel Consumption (Gallons) 251

Emission Factors 

(g/bhp-hr)

(g/gal) for N2O

NOx 6.860 72.60

VOC 1.021 10.80

CO 8.501 89.96

PM10 0.403 4.26

PM2.5 0.391 4.13

SO2 0.116 1.23

CO2 534 5648.03

CH4 0.016 0.16

PM_filt 0.145 1.53

PM_cond 0.246 2.60

N2O 0.260 0.14

Engine 7 Engine Function Water Truck

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 210

Horsepower Range 175-300

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.371

Fuel Consumption (Gallons) 264

Emission Factors 

(g/bhp-hr)

(g/gal) for N2O

NOx 6.860 76.23

VOC 1.021 11.34

CO 8.501 94.46

PM10 0.403 4.47

PM2.5 0.391 4.34

SO2 0.116 1.29

CO2 534 5930.43

CH4 0.016 0.17

PM_filt 0.145 1.61

PM_cond 0.246 2.73

N2O 0.260 0.15

Engine 8 Engine Function Dump Truck

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 330

Horsepower Range 300-600

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.371

Fuel Consumption (Gallons) 414

Emission Factors 

(g/bhp-hr)

(g/gal) for N2O

NOx 6.860 119.79

VOC 1.021 17.82

CO 8.501 148.43

PM10 0.403 7.03

PM2.5 0.391 6.82

SO2 0.116 2.03

CO2 534 9319.25

CH4 0.016 0.27

PM_filt 0.145 2.52

PM_cond 0.246 4.30

N2O 0.260 0.24
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-122

Equipment

Activity & 

Emission Factors

Emissions 

(lb/well pad)

Engine 9 Engine Function Trencher

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 250

Horsepower Range 175-300

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.371

Fuel Consumption (Gallons) 314

Emission Factors 

(g/bhp-hr)

(g/gal) for N2O

NOx 6.860 90.75

VOC 1.021 13.50

CO 8.501 112.45

PM10 0.403 5.33

PM2.5 0.391 5.17

SO2 0.116 1.54

CO2 534 7060.04

CH4 0.016 0.21

PM_filt 0.145 1.91

PM_cond 0.246 3.25

N2O 0.260 0.18
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-123

Table 146. Summary of 2009 Well Pad Construction Emissions (lb/well pad) by Pollutants 

for All Equipment.

Equipment Type Pollutant Emissions

(lb/year-well pad) 

Well Pad 

Construction 

Equipment

NOx 1,270

VOC 190

CO 1,568

PM10 77

PM2.5 74

SO2 22

CO2 100,292

CH4 3

PM_filt 28

PM_cond 47

N2O 3

Table 147. 2009 Well Pad Construction Equipment Emissions in tons per Pad.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Well Pad Const Equip 

(diesel ICE) 0.6352 0.0950 0.7838 0.0384 0.0372 0.0109 50.1462 0.0014 0.0138 0.0234 0.0013 new pads

Description Projection Well Pad Construction Equipment Emissions (tons per pad)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-124

Table 148. Percent Change in Emission from Base Year 2009 for Well Pad Construction 

(aggregate factors to apply to total emissions across all equipment types).

Technology Assumption Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

Tier 1 2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-125

2009 Well Pad and Access Road Construction Traffic Emissions

ASSUMPTIONS

Data provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2009 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

CONSTRUCTION TRAFFIC TO WELL.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-126

Table 149. Summary of Traffic Activity Data Associated with Well Pad and Access Road 

Construction Phase.

Table 150. 2009 Exhaust Emissions (lb/pad) Associated with Well Pad and Access Road 

Construction Traffic by Vehicle Type.

Table 151. Summary of 2009 Fugitive Dust Emissions (tons/pad) Associated with Well Pad 

and Access Road Construction Traffic.

Light Truck 20 20 14

Heavy Truck 20 20 21

Equipment Type Mean Vehicle 

Speed (mph)

Round Trip Off-Road 

Trip Distance (miles)

Number of Round Trips 

Per Pad

NOx 2.52 1.556

SO2 0.01 0.009

CO 18.19 11.227

CO2 675.15 417

VOC 1.48 0.913

PM10 0.09 0.054

PM2.5 0.08 0.051

PM_filt - 0.000

PM_cond - 0.000

CH4 0.08 0.052

N2O 0.05 0.028

NOx 20.23 18.728

SO2 0.08 0.074

CO 15.07 13.952

CO2 2612.44 2418.921

VOC 1.86 1.724

PM10 1.21 1.118

PM2.5 1.17 1.084

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.084

N2O 0.04 0.033

Light-Duty Truck

Heavy-Duty Truck 

Pollutant 2009 Emission Factors 

(g/mile)

Base year Emissions 

(lb/well pad) Vehicle Type

Travel to well Light truck 7,000 20 14 14 20 280 0.20 0.03 0.02 0.00

Travel to well Heavy Truck 70,000 20 21 21 20 420 0.20 0.04 0.02 0.00

Total 0.07 0.01

PM2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/pad)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/pad)

Total # of 

Round Trips

Round Trip 

Distance (mi)

Total Miles 

Traveled

PM10

Activity Vehicle Type Av. Vehicle 

Weight (lb)

Mean vehicle 

speed (mph)

# of Visits per 

Year 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-127

Table 152. 2009 Exhaust and Fugitive Dust Emissions Associated with Well Pad and Access Road Construction Traffic in tons per pad.

Table 153. Percent Change in Emission from Base Year 2009 due to fleet turnover for Well Pad and Access Road Construction Traffic.

Projection

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Construction Traffic, Road and Well pad (LD) 0.0008 0.0005 0.0056 2.68E-05 2.55E-05 4.44E-06 0.2084 2.62E-05 0 0 1.41E-05 new pads 0.0277 0.0028

Construction Traffic, Road and Well pad (HD) 0.0094 0.0009 0.0070 0.0006 0.0005 3.72E-05 1.2095 4.18E-05 0 0 1.65E-05 new pads 0.0416 0.0041

Total Road and Well Pad Construction Traffic Emissions (tons per well pad) Description Fugitive Road NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 -5% -11% -3% 0% -4% -6% -6% 0% 0% -3% -7% -10% -45% -4% 0% -3% -7% -7% 0% 0% 4% -5%

2011 -10% -18% -7% -1% -10% -12% -13% 0% 0% -7% -14% -19% -74% -9% 0% -10% -18% -18% 0% 0% 13% -12%

2012 -16% -27% -11% -2% -16% -19% -19% 0% 0% -11% -21% -28% -75% -14% 0% -17% -28% -28% 0% 0% 20% -17%

2013 -22% -28% -15% -4% -22% -25% -25% 0% 0% -15% -28% -36% -75% -19% 0% -25% -37% -37% 0% 0% 24% -23%

2014 -28% -29% -18% -5% -27% -30% -31% 0% 0% -18% -34% -44% -76% -24% 0% -32% -45% -46% 0% 0% 28% -28%

2015 -33% -30% -22% -7% -33% -35% -36% 0% 0% -22% -39% -51% -76% -28% 0% -38% -53% -53% 0% 0% 30% -33%

2016 -38% -31% -26% -8% -38% -40% -40% 0% 0% -25% -44% -57% -76% -33% 0% -44% -60% -60% 0% 0% 31% -37%

2017 -43% -33% -28% -10% -42% -44% -44% 0% 0% -28% -48% -62% -76% -36% 0% -49% -66% -66% 0% 0% 32% -41%

2018 -47% -34% -31% -11% -46% -48% -48% 0% 0% -30% -52% -67% -76% -39% 0% -54% -71% -71% 0% 0% 33% -44%

2019 -51% -35% -33% -13% -49% -51% -51% 0% 0% -32% -56% -71% -77% -42% 0% -59% -75% -75% 0% 0% 33% -48%

2020 -54% -36% -34% -14% -52% -54% -54% 0% 0% -34% -59% -74% -77% -44% 0% -62% -79% -79% 0% 0% 34% -50%

2021 -57% -37% -36% -15% -55% -56% -56% 0% 0% -35% -62% -77% -77% -46% 0% -66% -82% -82% 0% 0% 34% -53%

2022 -64% -39% -40% -18% -62% -61% -62% 0% 0% -38% -69% -83% -77% -50% 0% -73% -89% -89% 0% 0% 35% -60%

2023 -60% -38% -37% -16% -58% -58% -59% 0% 0% -36% -64% -79% -77% -48% 0% -69% -85% -85% 0% 0% 34% -55%

2024 -62% -39% -39% -17% -60% -60% -60% 0% 0% -37% -67% -81% -77% -49% 0% -71% -87% -87% 0% 0% 34% -58%

2025 -66% -40% -41% -19% -65% -63% -64% 0% 0% -39% -71% -84% -77% -52% 0% -76% -90% -90% 0% 0% 34% -61%

2026 -68% -41% -42% -20% -67% -64% -65% 0% 0% -38% -72% -85% -77% -53% 0% -78% -91% -91% 0% 0% 36% -63%

2027 -69% -41% -43% -21% -69% -66% -66% 0% 0% -38% -74% -86% -77% -54% 0% -79% -92% -92% 0% 0% 36% -64%

2028 -71% -42% -44% -21% -70% -67% -68% 0% 0% -39% -75% -87% -77% -54% 0% -81% -93% -93% 0% 0% 36% -65%

2029 -72% -42% -45% -22% -72% -68% -69% 0% 0% -40% -76% -87% -77% -55% 0% -82% -94% -94% 0% 0% 36% -67%

2030 -73% -42% -46% -22% -73% -69% -69% 0% 0% -40% -77% -88% -77% -56% 0% -83% -94% -94% 0% 0% 35% -67%

2031 -74% -43% -46% -23% -74% -69% -70% 0% 0% -42% -78% -88% -77% -57% 0% -84% -95% -95% 0% 0% 34% -69%

2032 -74% -43% -47% -23% -75% -70% -71% 0% 0% -42% -79% -88% -77% -57% 0% -85% -95% -95% 0% 0% 34% -69%

2033 -75% -43% -48% -23% -76% -71% -71% 0% 0% -43% -79% -89% -78% -58% 0% -85% -95% -95% 0% 0% 33% -69%

2034 -76% -44% -48% -24% -76% -71% -72% 0% 0% -43% -79% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2035 -76% -44% -49% -24% -77% -72% -72% 0% 0% -44% -80% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2036 -77% -44% -49% -24% -77% -72% -73% 0% 0% -44% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -70%

2037 -77% -44% -50% -24% -78% -72% -73% 0% 0% -45% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -71%

Light-Duty Truck (%) Heavy-Duty Truck (%)

Year
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-128

2009 Completion Equipment Emissions

ASSUMPTIONS

Activity data obtained from operator in blue text

Assumptions:

Assumed that all equipment uses Tier 2 engines

* Emission factors from EPA Federal Diesel Engine Standards 

http://www.epa.gov/otaq/standar

ds/nonroad/nonroadci.htm

* VOC/THC= 1.053 Conversion for HC->VOC for diesel engines (EPA, 2005; EPA420-R-05-0159, p. 5)

*

37% of fine particles assumed to be filterable and all filterable are assigned to EC (Source: AQTSD for Hell’s Gulch 

and Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

*

63% of fine particles assumed to be filterable and all filterable are assigned to SOA (Source: AQTSD for Hell’s Gulch 

and Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

EPA NONROAD model Fully Deteriorated Tier Emission Factors

N2O Emission factors (g/gallons) from The Climate Registry, General Reporting Protocol v1.1, Table 13.6

Equations:

Emissions (tons/year-well) = Emission factor (g/hp-hr) * Horsepower * Time Used (hours) * Load

453.6 (g/lb) * 2000 (lbs/ton)

PM2.5/PM10 = 97% EPA (2004) NONROAD

VOC/HC= 1.053 EPA NONROAD HC Conversions

NMHC/THC= 98.40% EPA NONROAD HC Conversions

SO2 Emission Factor Calculation Information 

2008 Fuel Sulfur content 0.0355 sulfur fuel weight percent from EPA's NMIM County 

Database

soxcnv Tiers I-III 0.02247 grams PM sulfur/grams fuel sulfur consumed

soxcnv Tier IV 0.3

grams PM sulfate/grams PM sulfur 7

soxbas 0.33

Density of Diesel Fuel 7.09 lb/gallons

Molecular weight of S 32 g/mol

Molecular weight of S02 64 g/mol

453.6 g/lb
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-129

Table 154. 2009 Completion Equipment Emissions (lb/spud) by Pollutants and by 

Equipment Type.

Frac Pump

4

Diesel 

Tier 2

2250

>1200

20

0.3

0.367

2795

NOx 4.534 539.74

VOC 0.255 30.40

CO 2.610 310.71

PM10 0.149 17.75

PM2.5 0.145 17.22

SO2 0.115 13.73

CO2 530 63127.33

CH4 0.004 0.46

PM_filt 0.054 6.37

PM_cond 0.091 10.85

(g/gal) N2O 0.260 1.60

Hydraulic Triplex

2

Diesel 

Tier 2

700

600-750

20

0.3

0.367

435

NOx 4.534 83.96

VOC 0.255 4.73

CO 2.610 48.33

PM10 0.149 2.76

PM2.5 0.145 2.68

SO2 0.115 2.14

CO2 530 9819.81

CH4 0.004 0.07

PM_filt 0.054 0.99

PM_cond 0.091 1.69

(g/gal) N2O 0.260 0.25

Blender

1

Diesel 

Tier 2

350

300-600

20

0.3

0.367

109

NOx 4.534 20.99

VOC 0.255 1.18

CO 2.610 12.08

PM10 0.149 0.69

PM2.5 0.145 0.67

SO2 0.115 0.53

CO2 530 2454.95

CH4 0.004 0.02

PM_filt 0.054 0.25

PM_cond 0.091 0.42

(g/gal) N2O 0.260 0.06

Emission Factors 

(g/bhp-hr)

Emission Factors 

(g/bhp-hr)

BSFC (lb/hp-hr)

Engine 3

Equipment

Activity & Emission 

Factors

Emissions 

(lb/spud)

Fuel Consumption (Gallons)

Engine Function

Time used (hrs)

Load Factor

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Engine 2

Engine 1

Fuel Consumption (Gallons)

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Fuel Consumption (Gallons)

Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Engine Function

Number of Engines

Fuel Type

Engine Technology

Emission Factors 

(g/bhp-hr)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-130

Pre gel

1

Diesel 

Tier 2

250

175-300

20

0.3

0.367

78

NOx 4.676 15.46

VOC 0.263 0.87

CO 2.610 8.63

PM10 0.149 0.49

PM2.5 0.145 0.48

SO2 0.115 0.38

CO2 530 1753.46

CH4 0.004 0.01

PM_filt 0.054 0.18

PM_cond 0.091 0.30

(g/gal) N2O 0.260 0.04

Frac Van

1

Diesel 

Tier 2

50

50-75

20

0.3

0.408

17

NOx 5.313 3.51

VOC 0.299 0.20

CO 3.728 2.47

PM10 0.298 0.20

PM2.5 0.289 0.19

SO2 0.128 0.08

CO2 589 389.86

CH4 0.005 0.00

PM_filt 0.107 0.07

PM_cond 0.182 0.12

(g/gal) N2O 0.260 0.01

Acid Pump

1

Diesel 

Tier 2

50

50-75

20

0.3

0.408

17

NOx 5.313 3.51

VOC 0.299 0.20

CO 3.728 2.47

PM10 0.298 0.20

PM2.5 0.289 0.19

SO2 0.128 0.08

CO2 589 389.86

CH4 0.005 0.00

PM_filt 0.107 0.07

PM_cond 0.182 0.12

(g/gal) N2O 0.260 0.01

Activity & Emission 

Factors

Emissions 

(lb/spud)

Emission Factors 

(g/bhp-hr)

Emission Factors 

(g/bhp-hr)

Emission Factors 

(g/bhp-hr)

Equipment

Engine 4 Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Fuel Consumption (Gallons)

Engine 5 Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Fuel Consumption (Gallons)

Engine 6

Fuel Consumption (Gallons)

Engine Technology

Engine Function

Number of Engines

Fuel Type

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-131

Table 155. Summary of 2009 Completion Emissions (lb/year-spud) by Pollutants for All 

Equipment.

Equipment 

Type Pollutant Emissions(lb/year-spud) 

Completion 

Equipment

NOx 671

VOC 38

CO 387

PM10 22

PM2.5 22

SO2 17

CO2 78,325

CH4 1

PM_filt 8

PM_cond 14

N2O 2

Table 156. 2009 Completion Construction Equipment Emissions in tons per spud.

Wireline 

1

Diesel 

Tier 2

50

50-75

20

0.3

0.408

17

NOx 5.313 3.51

VOC 0.299 0.20

CO 3.728 2.47

PM10 0.298 0.20

PM2.5 0.289 0.19

SO2 0.128 0.08

CO2 589 389.86

CH4 0.005 0.00

PM_filt 0.107 0.07

PM_cond 0.182 0.12

(g/gal) N2O 0.260 0.01

Equipment

Activity & Emission 

Factors

Emissions 

(lb/spud)

Engine 7 Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Emission Factors 

(g/bhp-hr)

Fuel Consumption (Gallons)

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Completion 

Equipment (diesel 

ICE) 0.3353 0.0189 0.1936 0.0111 0.0108 0.0085 39.1626 0.0003 0.0040 0.0068 0.0010 total spuds

Projection Completion Construction Equipment Emissions (tons per spud) Description
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-132

Table 157. Percent Change in Emission from Base Year 2009 for Completion Construction 

Equipment (aggregate factors to apply to total emissions across all equipment types).

Technology 

Assumption Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

Tier 2 2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-133

2009 Well Completion Traffic Emissions

ASSUMPTIONS

Data Provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2009 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

WELL COMPLETION TRAFFIC.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-134

Table 158. Summary of Traffic Activity Data Associated with Well Completion Phase.

Table 159. 2009 Exhaust Emissions (lb/spud) Associated with Well Completion Traffic by 

Vehicle Type.

Table 160. Summary of 2009 Fugitive Dust Emissions (tons/spud) Associated with Well 

Completion Traffic.

Light Truck 20 20 66

Heavy Truck 20 20 138

Mean Vehicle 

Speed (mph)

Round Trip Off-Road 

Trip Distance (miles)

Number of Round 

Trips Per Well Equipment Type

NOx 2.52 7.334

SO2 0.01 0.042

CO 18.19 52.926

CO2 675.15 1965

VOC 1.48 4.302

PM10 0.09 0.253

PM2.5 0.08 0.240

PM_filt - 0.000

PM_cond - 0.000

CH4 0.08 0.247

N2O 0.05 0.133

NOx 20.23 123.068

SO2 0.08 0.489

CO 15.07 91.682

CO2 2612.44 15895.770

VOC 1.86 11.326

PM10 1.21 7.348

PM2.5 1.17 7.123

PM_filt - 0.000

PM_cond - 0.000

CH4

0.09

0.549

N2O 0.04 0.216

Vehicle Type Pollutant 2009 Emission Factors

(g/mile)

Base year Emissions 

(lb/well pad)

Light-Duty Truck

Heavy-Duty Truck 

Travel to 

well Light truck 7,000 20 66 66 20 1320 0.20 0.13 0.02 0.01

Travel to 

well Heavy Truck 70,000 20 138 138 20 2760 0.20 0.27 0.02 0.03

Total 0.40 0.40 0.04 0.04

All Operators

Total # of 

Round Trips

Round Trip 

Distance (mi)

Total Miles 

Traveled Units Activity Vehicle Type Av. Vehicle Weight (lb)

Mean vehicle 

speed (mph)

# of Visits 

per Year 

PM2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spud)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spud)

PM10
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-135

Table 161. 2009 Exhaust and Fugitive Dust Emissions Associated with Well Completion Traffic in tons per spud.

Table 162. Percent Change in Emission from Base Year 2009 Due to Fleet Turnover for Well Completion Traffic.

Projection

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Completion Traffic (LD) 0.0037 0.0022 0.0265 0.0001 0.0001 2.10E-05 0.9824 0.0001 0 0 6.65E-05 total spuds 0.1307 0.0130

Completion Traffic (HD) 0.0615 0.0057 0.0458 0.0037 0.0036 0.0002 7.9479 0.0003 0 0 0.0001 total spuds 0.2732 0.0271

Description Total Completion Traffic Emissions (tons per pad) Fugitive Road NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 -5% -11% -3% 0% -4% -6% -6% 0% 0% -3% -7% -10% -45% -4% 0% -3% -7% -7% 0% 0% 4% -5%

2011 -10% -18% -7% -1% -10% -12% -13% 0% 0% -7% -14% -19% -74% -9% 0% -10% -18% -18% 0% 0% 13% -12%

2012 -16% -27% -11% -2% -16% -19% -19% 0% 0% -11% -21% -28% -75% -14% 0% -17% -28% -28% 0% 0% 20% -17%

2013 -22% -28% -15% -4% -22% -25% -25% 0% 0% -15% -28% -36% -75% -19% 0% -25% -37% -37% 0% 0% 24% -23%

2014 -28% -29% -18% -5% -27% -30% -31% 0% 0% -18% -34% -44% -76% -24% 0% -32% -45% -46% 0% 0% 28% -28%

2015 -33% -30% -22% -7% -33% -35% -36% 0% 0% -22% -39% -51% -76% -28% 0% -38% -53% -53% 0% 0% 30% -33%

2016 -38% -31% -26% -8% -38% -40% -40% 0% 0% -25% -44% -57% -76% -33% 0% -44% -60% -60% 0% 0% 31% -37%

2017 -43% -33% -28% -10% -42% -44% -44% 0% 0% -28% -48% -62% -76% -36% 0% -49% -66% -66% 0% 0% 32% -41%

2018 -47% -34% -31% -11% -46% -48% -48% 0% 0% -30% -52% -67% -76% -39% 0% -54% -71% -71% 0% 0% 33% -44%

2019 -51% -35% -33% -13% -49% -51% -51% 0% 0% -32% -56% -71% -77% -42% 0% -59% -75% -75% 0% 0% 33% -48%

2020 -54% -36% -34% -14% -52% -54% -54% 0% 0% -34% -59% -74% -77% -44% 0% -62% -79% -79% 0% 0% 34% -50%

2021 -57% -37% -36% -15% -55% -56% -56% 0% 0% -35% -62% -77% -77% -46% 0% -66% -82% -82% 0% 0% 34% -53%

2022 -64% -39% -40% -18% -62% -61% -62% 0% 0% -38% -69% -83% -77% -50% 0% -73% -89% -89% 0% 0% 35% -60%

2023 -60% -38% -37% -16% -58% -58% -59% 0% 0% -36% -64% -79% -77% -48% 0% -69% -85% -85% 0% 0% 34% -55%

2024 -62% -39% -39% -17% -60% -60% -60% 0% 0% -37% -67% -81% -77% -49% 0% -71% -87% -87% 0% 0% 34% -58%

2025 -66% -40% -41% -19% -65% -63% -64% 0% 0% -39% -71% -84% -77% -52% 0% -76% -90% -90% 0% 0% 34% -61%

2026 -68% -41% -42% -20% -67% -64% -65% 0% 0% -38% -72% -85% -77% -53% 0% -78% -91% -91% 0% 0% 36% -63%

2027 -69% -41% -43% -21% -69% -66% -66% 0% 0% -38% -74% -86% -77% -54% 0% -79% -92% -92% 0% 0% 36% -64%

2028 -71% -42% -44% -21% -70% -67% -68% 0% 0% -39% -75% -87% -77% -54% 0% -81% -93% -93% 0% 0% 36% -65%

2029 -72% -42% -45% -22% -72% -68% -69% 0% 0% -40% -76% -87% -77% -55% 0% -82% -94% -94% 0% 0% 36% -67%

2030 -73% -42% -46% -22% -73% -69% -69% 0% 0% -40% -77% -88% -77% -56% 0% -83% -94% -94% 0% 0% 35% -67%

2031 -74% -43% -46% -23% -74% -69% -70% 0% 0% -42% -78% -88% -77% -57% 0% -84% -95% -95% 0% 0% 34% -69%

2032 -74% -43% -47% -23% -75% -70% -71% 0% 0% -42% -79% -88% -77% -57% 0% -85% -95% -95% 0% 0% 34% -69%

2033 -75% -43% -48% -23% -76% -71% -71% 0% 0% -43% -79% -89% -78% -58% 0% -85% -95% -95% 0% 0% 33% -69%

2034 -76% -44% -48% -24% -76% -71% -72% 0% 0% -43% -79% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2035 -76% -44% -49% -24% -77% -72% -72% 0% 0% -44% -80% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2036 -77% -44% -49% -24% -77% -72% -73% 0% 0% -44% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -70%

2037 -77% -44% -50% -24% -78% -72% -73% 0% 0% -45% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -71%

Light-Duty Truck Heavy-Duty Truck 

Year
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-136

2009 Drilling Emissions

ASSUMPTIONS

Activity data obtained from the operators

*

Emission factors from EPA Federal Diesel 

Engine Tier 2 Standards http://www.epa.gov/otaq/standards/nonroad/nonroadci.htm

* Crankcase Emission factors are 2% of HC Exhaust Emission Factor for Tier II and earlier per 

* EPA NONROAD Modeling Guidance p. 23 (EPA, 2004; EPA420-P-04-009). 

* VOC/THC= 1.053 Conversion for HC->VOC for diesel engines (EPA, 2005; EPA420-R-05-0159, p. 5)

*

37% of fine particles assumed to be filterable and all filterable are assigned to EC (Source: AQTSD for Hell’s Gulch 

and Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

*

63% of fine particles assumed to be filterable and all filterable are assigned to SOA (Source: AQTSD for Hell’s Gulch 

and Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

* For ICE 125 hp, assumed 50% load factor due to usage in only winter months

Equations:

Emissions (tons/year-well) = Emission factor (g/hp-hr) * Horsepower * Time Used (hours) * Load

453.6 (g/lb) * 2000 (lbs/ton)

EPA Federal Tier 2 Standard Emission Rates

N2O Emission factors (g/gallons) from The Climate Registry, General Reporting Protocol v1.1, Table 13.6

PM2.5/PM10 = 97% EPA (2004) NONROAD

VOC/HC 1.053 EPA NONROAD HC Conversions

NMHC/THC 98.40% EPA NONROAD HC Conversions

SO2 Emission Factor Calculation Information 

2008 Fuel Sulfur content 0.0355 sulfur fuel weight percent

soxcnv Tiers I-III 0.02247 grams PM sulfur/grams fuel sulfur consumed

soxcnv Tier IV 0.3

grams PM sulfate/grams PM sulfur 7

soxbas 0.33

Density of Diesel Fuel 7.09 lb/gallons

Molecular weight of S 32 g/mol

Molecular weight of S02 64 g/mol

453.6 g/lb
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-137

Table 163. 2009 Drilling Equipment Emissions (lb/spud) by Pollutants and by Equipment 

Type.

Cat 3512C

3

Diesel

Tier 2

1476

>1200

240

0.3

0.334

15033

NOx 4.534 3186.65

VOC 0.255 179.48

CO 2.610 1834.42

PM10 0.149 104.82

PM2.5 0.145 101.68

SO2 0.105 73.85

CO2 483 339463.07

CH4 0.004 2.73

PM_filt 0.054 37.62

PM_cond 0.091 64.06

(g/gal) N2O 0.260 8.62

Boiler

1

Diesel

Tier 2

125

100-175

240

0.5

0.334

707

NOx 4.676 154.61

VOC 0.263 8.71

CO 3.728 123.30

PM10 0.224 7.40

PM2.5 0.217 7.18

SO2 0.105 3.47

CO2 483 15970.63

CH4 0.004 0.13

PM_filt 0.080 2.66

PM_cond 0.137 4.52

(g/gal) N2O 0.260 0.41

Time used (hrs)

Fuel Consumption (Gallons)

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Equipment

Activity & Emission 

Factors

Emissions (lb/well 

spud)

Engine Function

Fuel Consumption (Gallons)

Engine 1

Engine 2

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Load Factor

BSFC (lb/hp-hr)

Emission Factors 

(g/bhp-hr)

Emission Factors 

(g/bhp-hr)

Engine Function

Number of Engines

Fuel Type

Engine Technology
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-138

Table 164. Summary of 2009 Drilling Equipment Emissions (lb/spud) by Pollutant and 

Engine Type.

Equipment 

Type Pollutant Engine 1 Engine 2

Drilling 

Equipment

NOx 3,187 155

VOC 179 9

CO 1,834 123

PM10 105 7

PM2.5 102 7

SO2 74 3

CO2 339,463 15,971

CH4 3 0

PM_filt 38 3

PM_cond 64 5

N2O 9 0

Table 165. 2009 Drilling Equipment Emissions in tons per spud.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Drilling Equip (diesel ICE 1476HP) 1.5933 0.0897 0.9172 0.0524 0.0508 0.036927 169.7315 0.0014 0.0188 0.0320 0.0043 total spuds

Drilling Equip (diesel ICE 125HP) 0.0773 0.0044 0.0616 0.0037 0.0036 0.001737 7.9853 0.0001 0.0013 0.0023 0.0002 total spuds

Description Projection Drilling Equipment Emissions (tons per spud)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-139

Table 166. Drilling Equipment Tier Assumptions throughout the Project Life.

Year Tier 2

2009 100%

2010 100%

2011 100%

2012 100%

2013 100%

2014 100%

2015 100%

2016 100%

2017 100%

2018 100%

2019 100%

2020 100%

2021 100%

2022 100%

2023 100%

2024 100%

2025 100%

2026 100%

2027 100%

2028 100%

2029 100%

2030 100%

2031 100%

2032 100%

2033 100%

2034 100%

2035 100%

2036 100%

2037 100%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-140

Table 167. Percent Change in Emission from Base Year 2009 (aggregate factors to apply to 

total emissions to all Diesel ICE 1476 HP Engines) for Drilling Equipment.

Table 168. Percent Change in Emission from Base Year 2009 (aggregate factors to apply to 

total emissions to all Diesel ICE 125HP Engines) for Drilling Equipment.

Technology 

Assumption Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

Tier 2 2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Technology 

Assumption Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

Tier 2 2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-141

2009 Drilling Construction Traffic Emissions

ASSUMPTIONS

Data Provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2009 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

DRILLING TRAFFIC.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-142

Table 169. Summary of Traffic Activity Data Associated with Drilling Phase.

Equipment Type Mean Vehicle 

Speed (mph)

Round Trip OffRoad Trip 

Distance (miles)

Number of 

Round Trips 

Per Spud

Light Truck 20 20 98

Heavy Truck 20 20 224

Table 170. 2009 Exhaust Emissions (lb/spud) Associated with Drilling Traffic by Vehicle 

Type.

Table 171. Summary of 2009 Fugitive Dust Emissions (tons/spud) Associated with Drilling 

Traffic.

Table 172. 2009 Exhaust and Fugitive Dust Emissions Associated with Drilling Traffic in 

tons per spud.

NOx 2.52 10.890

SO2 0.01 0.062

CO 18.19 78.587

CO2 675.15 2917

VOC 1.48 6.388

PM10 0.09 0.376

PM2.5 0.08 0.356

PM_filt -

 

0.000

PM_cond -

 

0.000

CH4 0.08 0.367

N2O 0.05 0.198

NOx 20.23 199.762

SO2 0.08 0.794

CO 15.07 148.818

CO2 2612.44 25801.829

VOC 1.86 18.384

PM10 1.21 11.928

PM2.5 1.17 11.563

PM_filt -

 

0.000

PM_cond -

 

0.000

CH4 0.09 0.891

N2O 0.04 0.351

Pollutant

2009 Emission 

Factors 

(g/mile)

Base Year 

Emissions 

(lb/spud)

Vehicle Type

Light-Duty 

Truck

Heavy-Duty 

Truck 

Travel to well Light truck 7,000 20 98 98 20 1960 0.20 0.19 0.02 0.02

Travel to well Heavy Truck 70,000 20 224 224 20 4480 0.20 0.44 0.02 0.04

Total 0.64 0.06

PM2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spud)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spud)

Total # of 

Round Trips

Round Trip 

Distance (mi)

Total Miles 

Traveled

PM10

Activity Vehicle Type Av. Vehicle 

Weight (lb)

Mean vehicle 

speed (mph)

# of Visits per 

Year 

Projection

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Drilling Traffic (LD) 0.0054 0.0032 0.0393 0.0002 0.0002 3.11E-05 1.4587 0.0002 0 0 9.88E-05 total spuds 0.1940 0.0193

Drilling Traffic (HD) 0.0999 0.0092 0.0744 0.0060 0.0058 0.0004 12.9009 0.0004 0 0 0.0002 total spuds 0.4435 0.0440

Total Drill Traffic Emissions (tons per spud) Description Fugitive Road 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-143

Table 173. Percent Change in Emission from Base Year 2009 Due to Fleet Turnover for Drilling Traffic.

NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 -5% -11% -3% 0% -4% -6% -6% 0% 0% -3% -7% -10% -45% -4% 0% -3% -7% -7% 0% 0% 4% -5%

2011 -10% -18% -7% -1% -10% -12% -13% 0% 0% -7% -14% -19% -74% -9% 0% -10% -18% -18% 0% 0% 13% -12%

2012 -16% -27% -11% -2% -16% -19% -19% 0% 0% -11% -21% -28% -75% -14% 0% -17% -28% -28% 0% 0% 20% -17%

2013 -22% -28% -15% -4% -22% -25% -25% 0% 0% -15% -28% -36% -75% -19% 0% -25% -37% -37% 0% 0% 24% -23%

2014 -28% -29% -18% -5% -27% -30% -31% 0% 0% -18% -34% -44% -76% -24% 0% -32% -45% -46% 0% 0% 28% -28%

2015 -33% -30% -22% -7% -33% -35% -36% 0% 0% -22% -39% -51% -76% -28% 0% -38% -53% -53% 0% 0% 30% -33%

2016 -38% -31% -26% -8% -38% -40% -40% 0% 0% -25% -44% -57% -76% -33% 0% -44% -60% -60% 0% 0% 31% -37%

2017 -43% -33% -28% -10% -42% -44% -44% 0% 0% -28% -48% -62% -76% -36% 0% -49% -66% -66% 0% 0% 32% -41%

2018 -47% -34% -31% -11% -46% -48% -48% 0% 0% -30% -52% -67% -76% -39% 0% -54% -71% -71% 0% 0% 33% -44%

2019 -51% -35% -33% -13% -49% -51% -51% 0% 0% -32% -56% -71% -77% -42% 0% -59% -75% -75% 0% 0% 33% -48%

2020 -54% -36% -34% -14% -52% -54% -54% 0% 0% -34% -59% -74% -77% -44% 0% -62% -79% -79% 0% 0% 34% -50%

2021 -57% -37% -36% -15% -55% -56% -56% 0% 0% -35% -62% -77% -77% -46% 0% -66% -82% -82% 0% 0% 34% -53%

2022 -64% -39% -40% -18% -62% -61% -62% 0% 0% -38% -69% -83% -77% -50% 0% -73% -89% -89% 0% 0% 35% -60%

2023 -60% -38% -37% -16% -58% -58% -59% 0% 0% -36% -64% -79% -77% -48% 0% -69% -85% -85% 0% 0% 34% -55%

2024 -62% -39% -39% -17% -60% -60% -60% 0% 0% -37% -67% -81% -77% -49% 0% -71% -87% -87% 0% 0% 34% -58%

2025 -66% -40% -41% -19% -65% -63% -64% 0% 0% -39% -71% -84% -77% -52% 0% -76% -90% -90% 0% 0% 34% -61%

2026 -68% -41% -42% -20% -67% -64% -65% 0% 0% -38% -72% -85% -77% -53% 0% -78% -91% -91% 0% 0% 36% -63%

2027 -69% -41% -43% -21% -69% -66% -66% 0% 0% -38% -74% -86% -77% -54% 0% -79% -92% -92% 0% 0% 36% -64%

2028 -71% -42% -44% -21% -70% -67% -68% 0% 0% -39% -75% -87% -77% -54% 0% -81% -93% -93% 0% 0% 36% -65%

2029 -72% -42% -45% -22% -72% -68% -69% 0% 0% -40% -76% -87% -77% -55% 0% -82% -94% -94% 0% 0% 36% -67%

2030 -73% -42% -46% -22% -73% -69% -69% 0% 0% -40% -77% -88% -77% -56% 0% -83% -94% -94% 0% 0% 35% -67%

2031 -74% -43% -46% -23% -74% -69% -70% 0% 0% -42% -78% -88% -77% -57% 0% -84% -95% -95% 0% 0% 34% -69%

2032 -74% -43% -47% -23% -75% -70% -71% 0% 0% -42% -79% -88% -77% -57% 0% -85% -95% -95% 0% 0% 34% -69%

2033 -75% -43% -48% -23% -76% -71% -71% 0% 0% -43% -79% -89% -78% -58% 0% -85% -95% -95% 0% 0% 33% -69%

2034 -76% -44% -48% -24% -76% -71% -72% 0% 0% -43% -79% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2035 -76% -44% -49% -24% -77% -72% -72% 0% 0% -44% -80% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2036 -77% -44% -49% -24% -77% -72% -73% 0% 0% -44% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -70%

2037 -77% -44% -50% -24% -78% -72% -73% 0% 0% -45% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -71%

Light-Duty Truck Heavy-Duty Truck 

Year
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-144

2009 Initial Completion Venting Emissions

ASSUMPTIONS

As per the operators, 100% of the Completions will be controlled by Flare. Hence, there will be 

no venting emissions from this category. 

Table 174. 2009 Initial Completion Venting Emissions in tons per pad.

Table 175. Percent Change in Emission from Base Year 2009 for Initial Completion 

Venting.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Initial Completion Venting 0 0 0 0 0 0 0 0 0 0 0 total spuds

Description Projection Well Completion Venting Emissions (tons/well)

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-145

2009 Initial Completion Flaring Emissions

ASSUMPTIONS

Activity data provided by operators in blue text

 O2Emissions ( p r ivi y) = (Total CO2 Emission Potential of the Entire Gas – THC Component to CO2 Emission 

Potential – CO Component to CO2 Emission Potential) x Percentage of Production Controlled

THC Component CO2 Emissions Potentials (

tons

activity) =∑

(

lb emissions emitted

activity ) i×

N . f M l f C i mp u 

N . f M l f C i CO2

×Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of Compound C (lb/lb-mol) × 2000

CO component CO2 emissions potentials (

tons

activity) = 

CO emissions from flaring(

lb

activity)×

No.of Moles of C in compound

No.of Moles of C in CO2 × Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of CO ( lb

lb-mol

) × 2000

.

Where,

i= each compound identified in flaring gas speciation profile 

(lb emissions emitted/activity)i = Total TOG Emissions (lb/activity) from flaring X Weight 

Fraction of the Compound i

Inputs

Average Gas Volume Per Day 1,500.00 MCF/day

Average Days Per Completion 3.00 days/well

Percentage of Gas to Green 

Completions (Sales) 96%

Percentage of Gas Flared 4%

Volume Flared Per Day 60.00 MCF/day

Volume Flared Per Well 180.00 MCF/well

HHV of Flared Gas 1,137.21 Btu/scf

NOx, VOC, CH4, N2O and CO Emissions Calculation

where:

E flare is the flaring emissions per well [lb/yr]

EF i is the emissions factor for pollutant i [lb/MMBtu]

Q is the volume of gas flared supplied by operator [MMscf/yr]

HV is the heating value of the gas as provided by the operators [MMBtu/MMscf]

E flare  EF i  Q  HV
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-146

Table 176. Flaring Emission Factors.

Table 177. Summary of 2009 CO2 Emissions (tons/spud) Potential for All Gas Sample 

Species from Initial Completion Flaring.

NOx CO THC

0.068 0.37 0.14 25% 1.44 63%

Flaring Emission Factor (lb/MMBtu)* Fraction of THC 

as CH4

N2O 

(lb/MMSCF)b VOC/THCc 

b Emission Factor from API Compendium of greenhouse gas emissions methodologies for 

the oil and natural gas industry,2009 Table 4-11, GHG Emission Factors for Gas Flares in 

Developed Countries - Footnote C

cEPA SPECIATE Profile 0051

*Emission Factors are from AP-42

Chemical Mole %

Molecular 

Weight 

(g/mol)1 Weight %

lb/

MCF lb CO2

/MCF HHV (Btu/scf)1

CO2 emission 

potential of the 

entire gas 

(tons/spud)

Carbon Dioxide 2.7329% 44.010 6.0914% 3.07 3.07 0.28

Nitrogen 0.1713% 28.010 0.2430% 0.12 0.00

Methane 84.9820% 16.040 69.0362% 34.78 95.43 1010 8.59

Ethane 6.8128% 30.070 10.3753% 5.23 15.30 1769.7 1.38

Propane 3.1701% 44.100 7.0805% 3.57 10.68 2516.2 0.96

Isobutane 0.6361% 58.120 1.8723% 0.94 2.86 3252 0.26

n-Butane 0.7106% 58.120 2.0916% 1.05 3.19 3262.4 0.29

Isopentane 0.2421% 72.150 0.8846% 0.45 1.36 4000.9 0.12

n-Pentane 0.1993% 72.150 0.7282% 0.37 1.12 4008.7 0.10

n-Hexane 0.0648% 86.180 0.2828% 0.14 0.44 4756 0.04

Cyclohexane 0.0318% 84.160 0.1355% 0.07 0.21 4481.6 0.02

2,2-Dimethylbutane 0.0043% 86.177 0.0188% 0.01 0.03 4735.9 0.00

2,3-Dimethylbutane 0.0164% 86.177 0.0716% 0.04 0.11 4744.9 0.01

2-Methylpentane 0.0488% 86.177 0.2130% 0.11 0.33 4747.4 0.03

3-Methylpentane 0.0251% 86.177 0.1095% 0.06 0.17 4750.3 0.02

n-Heptane 0.0587% 100.202 0.2979% 0.15 0.46 5502.5 0.04

Methylcyclohexane 0.0322% 98.190 0.1601% 0.08 0.25 5215.9 0.02

2,2,4-Trimethylpentane 0.0038% 114.229 0.0220% 0.01 0.03 6146.27 0.00

Benzene 0.0149% 78.110 0.0589% 0.03 0.10 3741.9 0.01

Toluene 0.0174% 92.140 0.0812% 0.04 0.14 4474.9 0.01

Ethylbenzene 0.0005% 106.170 0.0027% 0.00 0.00 5222 0.00

m&p-Xylene 0.0041% 106.160 0.0220% 0.01 0.04 5207.7 0.00

o-Xylene 0.0006% 106.160 0.0032% 0.00 0.01 5209.7 0.00

n-Octane 0.0137% 114.229 0.0793% 0.04 0.12 6248.9 0.01

n-Nonane 0.0059% 128.255 0.0383% 0.02 0.06 6996.4 0.01

n-Decane 0.0000% 142.290 0.0000% 0.00 0.00 7743 0.00

Total 100.0000% 19.74 100.0000% 50.38 135.51 1137.207149 12.20

Total NMHC 12.1139% 24.6294% 12.41

Total VOC 5.3011% 14.2541% 7.18

Total HAPs 0.1061% 0.4729% 0.24

1

 The molecular weights and the higher heating values are from GSPA Engineering Data Book, 12th Edition.
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-147

Table 178. Summary of 2009 THC and CO Component to CO2 Emissions Potentials 

(tons/activity).

Table 179. 2009 Well Completion Flaring Emissions in tons per spud.

MW (lb/lb-mol) lb/well

TOG 31.47 35.82

CO 28.01 75.74

lb 

emitted/spud

Moles C in 

compound/Moles 

C in CO2

CO2 Emissions 

(tons/spud)

Ethane Y N 30 16.04 11 2 0.029

Formaldehyde N Y 20 30.03 7 1 0.005

Methane Y N 20 28.01 7 1 0.006

Propane Y Y 30 30.07 11 3 0.024

100 36 0.064 0.060

CO component CO2 

emissions potentials 

(tons/spud) 

0.060

Name HC? VOC?

WEIGHT_PER

(Flaring Speciation 

Profile (EPA 

SPECIATE 0051))

Molecular 

Weight

(lb/lb-mol)2

THC component CO2 emissions potentials 

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Initial Completion Flaring 0.0070 0.0090 0.0379 0 0 0 12.0729 0.0036 0 0 0.0001 total spuds

Description Projection Well Completion Flaring Emissions (tons/well)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-148

Table 180. Percent Change in Emission from Base Year 2009 for Well Completion Flaring.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-149

2009 Construction Fugitive Dust Emissions

ASSUMPTIONS

Watering control efficiency assumed to be 50%

Due to lack of information on soil moisture or silt content, used values from AP-42 Table 11-

9.3 

Activity data provided by operators in blue

Equations

Emissions equations from AP-42 Table 11.9-1 for Bulldozing Overburden emissions, Western 

Surface Coal Mining

For Total Suspended Particles (TSP) ≤ 30 microns:

Emissions (TSP lbs/hr) =[ 5.7 s^1.2 / M ^1.3 ] * Control Efficiency

For PM ≤ 15 microns:

Emissions (PM15 lbs/hr) =[ 1.0 s^1.5 / M ^1.4 ] * Control Efficiency

Emissions (PM10 lbs/hr) = PM15 * 0.75

Emissions (PM2.5 lbs/hr) = TSP * 0.105

See variables definition in following table:

Table 181. Parameters Used in Emission Equations.

Table 182. Summary of 2009 Well Pad and Pipeline Construction Equipment Utilization 

Data.

Description Parameter Reference

Watering control efficiency 50%

M=soil moisture content 7.9 (AP-42 Table 11.9-3)

s=Soil silt content 6.9 (AP-42 Table 11.9-3)

PM10 multiplier 0.75 (AP-42 Table 11.9-1)

PM2.5 multiplier 0.105 (AP-42 Table 11.9-1)

Control of Open Fugitive Dust Sources, Section 

5.3.1 Watering of Unpaved Surfaces (1988). EPA

Phase Equipment # Units Time Used 

Type Per Pad

 (hours)

Well Pad-Access Road Construction Loader 1 60

Well Pad-Access Road Construction Dozer 1 60

Well Pad-Access Road Construction Scraper 2 60

Well Pad-Access Road Construction Grader 1 60

Well Pad-Access Road Construction Backhoe 1 60

Well Pad-Access Road Construction Roller 1 60

Well Pad-Access Road Construction Water Truck 1 60

Well Pad-Access Road Construction Dump Truck 1 60

Well Pad-Access Road Construction Trencher 1 60

* assumed hours of use consistent with activity estimates used in equipment exhaust emission estimates
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-150

Table 183. Summary of 2009 Fugitive Dust Emissions (tons/well pad) form Well Pad and 

Access Road Construction Equipment.

Table 184. 2009 Construction Fugitive Dust Emissions in tons per well pad.

Table 185. Percent Change in Emission from Base Year 2009 for Construction Fugitive 

Dust.

Fugitive Dust Emissions Per Well (tons/well)

Phase Equipment Type TSP PM10 PM2.5 PM15

Well Pad-Access Road Construction Loader 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Dozer 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Scraper 0.1182 0.0226 0.0124 0.0301

Well Pad-Access Road Construction Grader 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Backhoe 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Roller 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Water Truck 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Dump Truck 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Trencher 0.0591 0.0113 0.0062 0.0151

Total 0.5911 0.1129 0.0621 0.1506

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Construction Dust, Fugitive 0 0 0 0.1129 0.0621 0 0 0 0 0 0 new pads

Description Projection Construction Fugitive Dust Emissions (tons per well pad)

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-151

2009 Construction Wind Erosion Emissions

ASSUMPTIONS

Emissions (

tons

yr ) = 

k* Erosion Potential (g/m2/year) * Disturbed Area (m2) * (#Disturbances/year)

453.6 (g/lb) *2000 (lbs/ton)

Table 186. 2009 Construction Dust Wind Erosion Emissions in tons per well pad.

Data obtained from operators in blue text

Disturbed Area Per Well:

Disturbed Area Per Well: 235224 ft2 21853.05 m

2

1 Acre 43,560 square feet

* AP-42 methodology described to the right was implemented in a computer program with hourly wind speed data

* 2007, 2008, and 2009 Wind Speed data from the Wamsutter Station were used as inputs

* Of all years evaluated, 2007 showed the greatest per pad wind erosion emissions:

Friction Velocity U* = 0.053 U10* (AP-42 Section 13.2.5.3 Equation 4)

Erosion Potential P (g/m2-time) = 58(U*-Ut*)2 + 25(U*-Ut*) for U*>Ut*; P=0 otherwise (AP-42 Section 13.2.5.3 Equation 3)

k is a particle size multiplier that depends on the aerodynamic size of the particle (from AP-42 Section 13.2.5.3). 

k = 0.5 for PM10

k = 0.075 for PM2.5

1.02 m/s = Threshold friction velocity for well pads (AP-42 Table 13.2.5-2 Overburden, Western Surface Coal Mine)

1.33 m/s = Threshold friction velocity for roads (AP-42 Table 13.2.5-2 Roadbed Material)

0.5 = Particle size multiplier for PM10

0.075 = Particle size multiplier for PM2.5

1 squ mile = 640 acres

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Construction Dust, Wind Erosion 0 0 0 0.3061 0.0459 0 0 0 0 0 0 new pads

Description Projection Construction Dust Wind Erosion Emissions (tons/well pad)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-152

Table 187. Percent Change in Emission from Base Year 2009 for Construction Dust Wind 

Erosion.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-153

2009 Workover Equipment Emissions

ASSUMPTIONS

Activity data obtained from operators in blue text

Assumptions:

* Emission factors from EPA Federal Diesel Engine Standards 

http://www.epa.gov/otaq/standards/n

onroad/nonroadci.htm

* Crankcase Emission factors are 2% of HC Exhaust Emission Factor for Tier II and earlier per 

* EPA NONROAD Modeling Guidance p. 23 (EPA, 2004; EPA420-P-04-009). 

* VOC/THC= 1.053 Conversion for HC->VOC for diesel engines (EPA, 2005; EPA420-R-05-0159, p. 5)

*

37% of fine particles assumed to be filterable and all filterable are assigned to EC (Source: AQTSD for Hell’s Gulch and 

Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

*

63% of fine particles assumed to be filterable and all filterable are assigned to SOA (Source: AQTSD for Hell’s Gulch 

and Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

EPA NONROAD model Fully Deteriorated Tier 2 Emission Factors

N2O Emission factors (g/gallons) from The Climate Registry, General Reporting Protocol v1.1, Table 13.6

Equations:

Emissions (tons/year-well) = Emission factor (g/hp-hr) * Horsepower * Time Used (hours) * Load

453.6 (g/lb) * 2000 (lbs/ton)

PM2.5/PM10 = 97% EPA (2004) NONROAD

VOC/HC 1.053 EPA NONROAD HC Conversions

NMHC/THC 98.40% EPA NONROAD HC Conversions

SO2 Emission Factor Calculation Information 

2008 Fuel Sulfur content 0.0355 sulfur fuel weight percent From NMIM

soxcnv Tiers I-III 0.02247 grams PM sulfur/grams fuel sulfur consumed

soxcnv Tier IV 0.3

grams PM sulfate/grams PM sulfur 7

soxbas 0.33

Density of Diesel Fuel 7.09 lb/gallons

Molecular weight of S 32 g/mol

Molecular weight of S02 64 g/mol

453.6 g/lb
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-154

Table 188. 2009 Workover Rig Emissions (lb/well) by Pollutants and by Equipment Type.

Rig

1

Diesel

Tier 2

475

300-600

36

0.07

0.3

0.367

18

NOx 4.534 3.42

VOC 0.255 0.19

CO 2.610 1.97

PM10 0.149 0.11

PM2.5 0.145 0.11

SO2 0.115 0.09

CO2 530 399.81

CH4 0.004 0.00

PM_filt 0.054 0.04

PM_cond 0.091 0.07

N2O 0.260 0.01

Snubbing unit

1

Diesel

Tier 2

475

300-600

36

0.07

0.3

0.367

18

NOx 4.534 3.42

VOC 0.255 0.19

CO 2.610 1.97

PM10 0.149 0.11

PM2.5 0.145 0.11

SO2 0.115 0.09

CO2 530 399.81

CH4 0.004 0.00

PM_filt 0.054 0.04

PM_cond 0.091 0.07

N2O 0.260 0.01

Light plant

1

Diesel

Tier 2

45

25-50

0.07

36

0.7

0.408

4

NOx 5.313 0.89

VOC 0.299 0.05

CO 4.101 0.68

PM10 0.447 0.07

PM2.5 0.434 0.07

SO2 0.128 0.02

CO2 589 98.24

CH4 0.005 0.00

PM_filt 0.161 0.03

PM_cond 0.273 0.05

N2O 0.260 0.00

BSFC (lb/hp-hr)

Equipment

Activity & 

Emission 

Emissions 

(lb/well)

Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Well workover frequency (events/yr)

Load Factor

Load Factor

BSFC (lb/hp-hr)

Emission 

Factors 

(g/bhp-hr)

Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Well workeover requirement (Yrs)

Load Factor

BSFC (lb/hp-hr)

Fuel Consumption (Gallons)

Fuel Consumption (Gallons)

Fuel Consumption (Gallons)

Emission 

Factors 

(g/bhp-hr)

Engine 1

Engine 2

Emission 

Factors 

(g/bhp-hr)

Engine 3 Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Well workeover requirement (Yrs)

Time used (hrs)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-155

Table 189. Summary of 2009 Workover Rig Emissions (lb/well) by Pollutants for All 

Equipment.

Table 190. 2009 Workover Rig Equipment Emissions in tons per well.

Table 191. Percent Change in Emission from Base Year 2009 (aggregate factors to apply to 

total emissions across all equipment types) for Workover Rig Equipment.

NOx 8

VOC 0

CO 5

PM10 0

PM2.5 0

SO2 0

CO2 898

CH4 0

PM_filt 0

PM_cond 0

N2O 0

Workover Rig 

Equipment

Equipment 

Type Pollutant

Emissions (lb/yearwell) 

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Workover Equipment (diesel ICE) 0.0039 0.0002 0.0023 0.0001 0.0001 0.0001 0.4489 0.000003 0.0001 0.0001 0.00001 active well counts

Description Projection Workover Rig Emissions (tons per well)

Technology 

Assumption Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

Tier 2 2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-156

2009 Workover Traffic Emissions

ASSUMPTIONS

Data provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2009 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

WORKOVER TRAFFIC.

Table 192. Summary of Traffic Activity Data Associated with Well Workover Phase.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3

Light Truck 20 20 6 0.07

Heavy Truck 20 20 8 0.07

Well workover frequency 

(events/yr) Equipment Type Mean Vehicle Speed (mph)

Round Trip OffRoad Trip Distance 

(miles)

Number of Round 

Trips Per Well
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-157

Table 193. 2009 Exhaust Emissions (lb/well) Associated with Workover Traffic by Vehicle 

Type.

Table 194. Summary of 2009 Fugitive Dust Emissions (tons/well) Associated with 

Workover Traffic.

NOx 2.52 0.044

SO2 0.01 0.000

CO 18.19 0.321

CO2 675.15 11.907

VOC 1.48 0.026

PM10 0.09 0.002

PM2.5 0.08 0.001

PM_filt - 0.000

PM_cond - 0.000

CH4 0.08 0.001

N2O 0.05 0.001

NOx 20.23 0.476

SO2 0.08 0.002

CO 15.07 0.354

CO2 2612.44 61.433

VOC 1.86 0.044

PM10 1.21 0.028

PM2.5 1.17 0.028

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.002

N2O 0.04 0.001

Vehicle Type Pollutant

2009 

Emission 

Factors 

(g/mile)

Base year 

Emissions 

(lb/well)

Light-Duty 

Truck

Heavy-Duty 

Truck 

Travel to well Light truck 7,000 20 6 0.4 20 8 0.20 0.00 0.02 0.00

Travel to well Heavy Truck 70,000 20 8 1 20 10.67 0.20 0.00 0.02 0.00

Total 0.40 0.00 0.04 0.00

Emissions 

(tpy/well)

Total # of 

Round Trips

PM10 PM2.5

Em. Factor 

(lb/VMT) 

Av. Vehicle 

Weight (lb)

Mean vehicle 

speed (mph)

# of Visits per 

Year 

Round Trip 

Distance (mi)

Total Miles 

Traveled Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well)

Activity Vehicle Type
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-158

Table 195. 2009 Exhaust and Fugitive Dust Emissions Associated with Workover Rigs Traffic in tons per well.

Table 196. Percent Change in Emission from Base Year 2009 due to fleet turnover for Workover Rigs Traffic.

Projection

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

WorkoverTraffic (LD) 2.22E-05 1.30E-05 0.0002 7.67E-07 7.27E-07 1.27E-07 0.0060 7.50E-07 0 0 4.03E-07 active well counts 0.0008 0.0001

WorkoverTraffic (HD) 0.0002 2.19E-05 0.0002 1.42E-05 1.38E-05 9.45E-07 0.0307 1.06E-06 0 0 4.18E-07 active well counts 0.0011 0.0001

Description Total Workover Traffic Emissions (tons per well) Fugitive Road NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 -5% -11% -3% 0% -4% -6% -6% 0% 0% -3% -7% -10% -45% -4% 0% -3% -7% -7% 0% 0% 4% -5%

2011 -10% -18% -7% -1% -10% -12% -13% 0% 0% -7% -14% -19% -74% -9% 0% -10% -18% -18% 0% 0% 13% -12%

2012 -16% -27% -11% -2% -16% -19% -19% 0% 0% -11% -21% -28% -75% -14% 0% -17% -28% -28% 0% 0% 20% -17%

2013 -22% -28% -15% -4% -22% -25% -25% 0% 0% -15% -28% -36% -75% -19% 0% -25% -37% -37% 0% 0% 24% -23%

2014 -28% -29% -18% -5% -27% -30% -31% 0% 0% -18% -34% -44% -76% -24% 0% -32% -45% -46% 0% 0% 28% -28%

2015 -33% -30% -22% -7% -33% -35% -36% 0% 0% -22% -39% -51% -76% -28% 0% -38% -53% -53% 0% 0% 30% -33%

2016 -38% -31% -26% -8% -38% -40% -40% 0% 0% -25% -44% -57% -76% -33% 0% -44% -60% -60% 0% 0% 31% -37%

2017 -43% -33% -28% -10% -42% -44% -44% 0% 0% -28% -48% -62% -76% -36% 0% -49% -66% -66% 0% 0% 32% -41%

2018 -47% -34% -31% -11% -46% -48% -48% 0% 0% -30% -52% -67% -76% -39% 0% -54% -71% -71% 0% 0% 33% -44%

2019 -51% -35% -33% -13% -49% -51% -51% 0% 0% -32% -56% -71% -77% -42% 0% -59% -75% -75% 0% 0% 33% -48%

2020 -54% -36% -34% -14% -52% -54% -54% 0% 0% -34% -59% -74% -77% -44% 0% -62% -79% -79% 0% 0% 34% -50%

2021 -57% -37% -36% -15% -55% -56% -56% 0% 0% -35% -62% -77% -77% -46% 0% -66% -82% -82% 0% 0% 34% -53%

2022 -64% -39% -40% -18% -62% -61% -62% 0% 0% -38% -69% -83% -77% -50% 0% -73% -89% -89% 0% 0% 35% -60%

2023 -60% -38% -37% -16% -58% -58% -59% 0% 0% -36% -64% -79% -77% -48% 0% -69% -85% -85% 0% 0% 34% -55%

2024 -62% -39% -39% -17% -60% -60% -60% 0% 0% -37% -67% -81% -77% -49% 0% -71% -87% -87% 0% 0% 34% -58%

2025 -66% -40% -41% -19% -65% -63% -64% 0% 0% -39% -71% -84% -77% -52% 0% -76% -90% -90% 0% 0% 34% -61%

2026 -68% -41% -42% -20% -67% -64% -65% 0% 0% -38% -72% -85% -77% -53% 0% -78% -91% -91% 0% 0% 36% -63%

2027 -69% -41% -43% -21% -69% -66% -66% 0% 0% -38% -74% -86% -77% -54% 0% -79% -92% -92% 0% 0% 36% -64%

2028 -71% -42% -44% -21% -70% -67% -68% 0% 0% -39% -75% -87% -77% -54% 0% -81% -93% -93% 0% 0% 36% -65%

2029 -72% -42% -45% -22% -72% -68% -69% 0% 0% -40% -76% -87% -77% -55% 0% -82% -94% -94% 0% 0% 36% -67%

2030 -73% -42% -46% -22% -73% -69% -69% 0% 0% -40% -77% -88% -77% -56% 0% -83% -94% -94% 0% 0% 35% -67%

2031 -74% -43% -46% -23% -74% -69% -70% 0% 0% -42% -78% -88% -77% -57% 0% -84% -95% -95% 0% 0% 34% -69%

2032 -74% -43% -47% -23% -75% -70% -71% 0% 0% -42% -79% -88% -77% -57% 0% -85% -95% -95% 0% 0% 34% -69%

2033 -75% -43% -48% -23% -76% -71% -71% 0% 0% -43% -79% -89% -78% -58% 0% -85% -95% -95% 0% 0% 33% -69%

2034 -76% -44% -48% -24% -76% -71% -72% 0% 0% -43% -79% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2035 -76% -44% -49% -24% -77% -72% -72% 0% 0% -44% -80% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2036 -77% -44% -49% -24% -77% -72% -73% 0% 0% -44% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -70%

2037 -77% -44% -50% -24% -78% -72% -73% 0% 0% -45% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -71%

Light-Duty Truck Heavy-Duty Truck 

Year
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-159

2009 Heater Emissions

ASSUMPTIONS

Data provided by operators in blue text

Assumptions

Assume no controls on the heater

Assume 10 percent of all new wells have tank heaters

Equations

Emissions (tons/year) = Emission Factor (lbs/MMscf) * Heater Size (Btu/hr) * Time On (Hours/Year) 

Fuel Heat Value (Btu/scf) * 1x106(scf/MMscf) * 2000 (lbs/ton)

Table 197. Natural Gas Fired Heaters Emission Factors (lb/MMscf).

Table 198. Summary of Heaters Operational Data.

Table 199. 2009 Well-site Heater/Reboiler Emissions (lbs/well).

Table 200. 2009 Heater/Reboiler Emissions in tons per well.

NOx SO2 CO VOC PM10 PM2.5 PM_filt PM_cond CO2 CH4 N2O

100 0.6 84 5.5 7.6 7.6 1.9 5.7 120,000 2.3 2.2

Heaters (lb/MMscf) (from AP-42 Tables 1.4-1 and 1.4-2)

 (btu/hr) (Btu/scf) (hours)

Dehydrator Heater 500,000 1000 1 8760 0.5 4380

Separator Heater 500,000 1000 1 6552 0.5 3276

Tank Heater 500,000 1000 0.1 6750 0.5 3375

Equipment Type Heat Input Local Heating 

Value # Units/well

Time Used 

Per Unit Cycle 

Fraction

Actual 

Firing 

hours

Equipment Type NOx SO2 CO VOC PM10 PM2.5 PM_filt PM_cond CO2 CH4 N2O

Dehydrator Heater 219.0000 0.0000 183.9600 12.0450 16.6440 16.6440 4.1610 12.4830 262800 5.0370 4.8180

Separator Heater 163.8000 0.0000 137.5920 9.0090 12.4488 12.4488 3.1122 9.3366 196560 3.7674 3.6036

Tank Heater 16.8750 0.0000 14.1750 0.9281 1.2825 1.2825 0.3206 0.9619 20250 0.3881 0.3713

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Heaters 0.1998 0.0110 0.1679 0.0152 0.0152 0 239.8050 0.0046 0.0038 0.0114 0.0044 active well counts

Description Projection Heater/Reboiler Emissions (tons per well)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-160

Table 201. Percent Change in Emission from Base Year 2009 for Heaters/Reboilers.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-161

2009 Fugitive Devices Emissions

ASSUMPTIONS

Activity data provided by operators in blue text

Hours of operation was assumed to be year round 24-7

Equation

where:

Efugitive is the fugitive VOC emissions per well [ton-VOC/yr]

EFi is the emission factor of TOC [kg/hr/source]

N is the total number of devices

Y is the ratio of VOC to TOC in the vented gas

tannual is total annual hours of operation

CH4 and CO2 emissions

Emissions.CH4 = Emission.VOC * WeightFraction.CH4 / WeightFraction.CO2

Emissions.CO2 = Emission.VOC * WeightFraction.CO2 / WeightFraction.VOC

Table 202. Total Organic Compound (TOC) Emission Factor (kg/hr/component).

Table 203. VOC, CO2 and CH4 Sales Gas and Condensate Gas Weight Fractions.

Efugitive  EFi  N  tannual Y

Light Oil Heavy Oil

>20o API <20o API

valves 4.50E-03 2.50E-03 8.40E-06 9.80E-05

pump seals 2.40E-03 1.30E-02 3.20E-05 2.40E-05

others 8.80E-03 7.50E-03 3.20E-05 1.40E-02

connectors 2.00E-04 2.10E-04 7.50E-06 1.10E-04

flanges 3.90E-04 1.10E-04 3.90E-07 2.90E-06

open-ended lines 2.00E-03 1.40E-03 1.40E-04 2.50E-04

Do not calculate fugitives from pipelines containing only water

Emission Factors are from EPA, 1995 -AP-42 Table 2-4. "Oil and Gas Production Operations 

Average Emission Factors"

"Other" category includes compressor seals, pressure relief valves, diaphragms, drains, dump arms, hatches, instruments, m

Well Equipment 

Component Gas Water/Oil

Sales Gas Fugitive- Post Flash

VOC Fraction (weight) 14.60% 73.55%

CO2 Fraction (weight) 6.07% 3.02%

CH4 Fraction (weight) 68.75% 13.57%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-162

Table 204. 2009 TOC and VOC Emissions (lbs/well) by Media and Equipment Type.

Table 205. 2009 Fugitive Device Emissions in tons per well.

Well Stream Gas Condensate Well Stream Gas Condensate Well Stream Gas Condensate

valves 10 10 - 4.50E-03 869 869 0 135.48 135.48 0.00

pump seals 1 0 - 2.40E-03 46 0 0 7.23 0.00 0.00

others 0 0 - 8.80E-03 0 0 0 0.00 0.00 0.00

connectors 150 50 - 2.00E-04 579 193 0 90.32 30.11 0.00

flanges 15 15 - 3.90E-04 113 113 0 17.61 17.61 0.00

open-ended lines 0 0 - 2.00E-03 0 0 0 0.00 0.00 0.00

valves - - 20 2.50E-03 0 0 966 0.00 0.00 732.57

pump seals - - 0 1.30E-02 0 0 0 0.00 0.00 0.00

others - - 0 7.50E-03 0 0 0 0.00 0.00 0.00

connectors - - 50 2.10E-04 0 0 203 0.00 0.00 153.84

flanges - - 10 1.10E-04 0 0 21 0.00 0.00 16.12

open-ended lines - - 0 1.40E-03 0 0 0 0.00 0.00 0.00

valves - - - 8.40E-06 0 0 0 0.00 0.00 0.00

pump seals - - - 3.20E-05 0 0 0 0.00 0.00 0.00

others - - - 3.20E-05 0 0 0 0.00 0.00 0.00

connectors - - - 7.50E-06 0 0 0 0.00 0.00 0.00

flanges - - - 3.90E-07 0 0 0 0.00 0.00 0.00

open-ended lines - - - 1.40E-04 0 0 0 0.00 0.00 0.00

valves - - - 9.80E-05 0 0 0 0.00 0.00 0.00

pump seals - - - 2.40E-05 0 0 0 0.00 0.00 0.00

others - - - 1.40E-02 0 0 0 0.00 0.00 0.00

connectors - - - 1.10E-04 0 0 0 0.00 0.00 0.00

flanges - - - 2.90E-06 0 0 0 0.00 0.00 0.00

open-ended lines - - - 2.50E-04 0 0 0 0.00 0.00 0.00

Media

Type Well Equipment Component Counts

Gas

Light Oil >20o API

Heavy Oil <20o API

Water/Oil

TOC Emission Factor 

(kg / hr / component)

TOC Emissions (lbs/yr) VOC Emissions (lbs/yr)

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Well Stream Fugitive Devices 0 0.1253 0 0 0 0 0.0521 0.5900 0 0 0 active well counts

Gas Stream Fugitive Devices 0 0.0916 0 0 0 0 0.0381 0.4313 0 0 0 active well counts

Condensate Fugitive Devices 0 0.4513 0 0 0 0 0.0185 0.0833 0 0 0 active well counts

Description Projection Fugitive Device Emissions (tons per well)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-163

Table 206. Percent Change in Emission from Base Year 2009 for Fugitive Devices.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-164

2009 Pneumatic Devices Emissions

ASSUMPTIONS

As per operator's input no bleed devices are used exclusively, hence zero emissions from this 

category

Table 207. Summary of 2009 Pneumatic Devices Emissions in tons per well.

Table 208. Percent Change in Emission from Base Year 2009 for Pneumatic Devices.

NOx VOC CO PM10 PM2.5 SO2 CH4 CO2 PM_filt PM_cond N2O

Pneumatic Devices 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 active well counts

Description Projection Pneumatic Devices Emissions (tons per well)

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-165

2009 Tank Loadout (vapor losses) Emissions

ASSUMPTIONS

Table 209. VOC, CO2 and CH4 Condensate Post-Flash Gas Weight Fractions.

Table 210. Summary of Truck Load Activity Data.

Table 211. 2009 Well Site Condensate Tank Loadout Emissions in tons per barrel.

Data Provided by operator in blue text

Method from Wyoming Permitting Guidance for Oil and Gas Production Facilities

Wyoming DEQ, March, 2010, Chapter 6, Section 2, p.65 for Crude Oil, RVP 5

After AP-42, Section 5.2.1

Emissions VOC (tpy) =

Loading losses determined using AP-42 Section 5.2.2.1.1 Equation 1

LL =12.46 x S x P x M/T

LL=Loading Loss in (lbs/1000gallons)

S= Saturation Factor

P = true vapor pressure of liquid loaded (psia)

M = molecular weight of tank vapors (lb/(lb-mol))

T = temperature of bulk liquid loaded (R=F+460)

Loading Loss (lbs/1000 gal) * truck load rate (bbl/year) * 42 (gal/bbl) * VOC mass fraction

2000 (lbs/ton)

Compound

Methane (weight) 21.23%

CO2 (weight) 0.00%

VOC Fraction (weight) 66.34%

Type of Petroleum Liquid 

Loaded

Saturation 

Factor

True Vapor 

Pressure of 

Liquid Loaded 

(psia)

Molecular Weight 

of Vapors (lb/lbmole)

Temperature 

of Bulk Liquid 

(°R)

Mode of 

Operation

Loading Losses 

(lb/1000 gallons) Capacity of Truck

Condensate RVP 8 0.6 7.2 50 520

Submerged 

loading: 

dedicated 

normal service 5.18 80 bbl

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Tank Loadout (vapor losses) 0 7.21E-05 0 0 0 0 0 2.31E-05 0 0 0 annual condensate production

Description Projection Base Year Well Site Condensate Tank Loadout Emissions (tons per barrel)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-166

Table 212. Percent Change in Emission from Base Year 2009 for Condensate Tank Loadout.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-167

2009 Well Venting Emissions

ASSUMPTIONS

Data provided by operator in blue 

Well venting includes all emissions from venting categories other than fugitive devices, pneumatic devices, 

chemical injection pumps, tank load out, condensate tanks, completion and dehydrator venting.

Table 213. Well Venting VOC, CH4 and CO2 Emission Factors (tons/well).

Table 214. 2009 Well Venting Emissions in tons per well.

Weight Fraction 

(%)

 

Emission Factor 

(tons/yr/well)

Venting VOC Emission Factor 0.75

Methane (weight) 69.04% 3.624

Carbon Dioxide (weight) 6.09% 0.320

VOC Fraction (weight) 14.25%

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Well Venting 0 0.7483 0 0 0 0 0.3198 3.6240 0 0 0 active well counts

Description Projection Base Year Well Venting Emissions (tons per well)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-168

Table 215. Percent Change in Emission from Base Year 2009 for Well Venting.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-169

2009 Condensate Tank Flashing/Working/Breathing Venting Emissions 

ASSUMPTIONS

As per operator's input 100% production will be controlled with flare, hence zero venting 

emissions from this category.

Table 216. Summary of 2009 Condensate Tank Flashing, Working and Breathing Emissions 

in tons per activity.

Table 217. Percent Change in Emission from Base Year 2009 for Condensate Tank Losses.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Condensate Tank Flashing Losses 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 annual condensate production

Condensate Tank Working Losses 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 total turnovers per year

Condensate Tank Breathing Losses 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 active well counts

Description Projection Condensate Tank Venting Emissions

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2010 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2011 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2012 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2013 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2014 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2015 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2016 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2017 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2018 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2019 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2020 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2021 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2022 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2023 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2024 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2025 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2026 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2027 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2028 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2029 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2030 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2031 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2032 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2033 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2034 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2035 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2036 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2037 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-170

2009 Dehydrator Venting Emissions 

ASSUMPTIONS

As per operator's input 100% gas will be controlled with flare, hence zero venting emissions 

from this category

Table 218. 2009 Dehydrator Venting Emissions in tons per well by Project Year.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

g - Well Site 2009 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2010 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2011 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2012 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2013 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2014 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2015 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2016 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2017 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2018 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2019 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2020 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2021 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2022 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2023 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2024 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2025 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2026 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2027 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2028 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2029 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2030 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2031 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2032 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2033 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2034 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2035 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2036 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2037 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

Year Projection Dehydrator Venting Emissions - Weighted Average (tons per well)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-171

2009 Chemical Injection Pump Venting Emissions 

ASSUMPTIONS

As per operator's input 100% gas will be controlled with flare, hence zero venting emissions 

from this category

Table 219. 2009 Chemical Injection Pump Venting Emissions in tons per well.

Table 220. Percent Change in Emission from Base Year 2009 for Chemical Injection Pump 

Venting.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Pneumatic Pumps 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 active well counts

Description Projection Chemical Injection Pump Emissions (tons per well)

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4

2009 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2010 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2011 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2012 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2013 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2014 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2015 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2016 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2017 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2018 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2019 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2020 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2021 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2022 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2023 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2024 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2025 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2026 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2027 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2028 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2029 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2030 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2031 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2032 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2033 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2034 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2035 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2036 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2037 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-172

2009 Production Flaring Emissions (Condensate Tank Flaring, 

Dehydrator Flaring and Chemical Injection Pump Flaring Emissions)

ASSUMPTIONS

100% percentage of flashing controlled

100% percentage of working controlled

100% percentage of breathing controlled

100%

percentage of dehydrator emissions 

controlled

100% percentage of pneumatic pump emissions 

controlled

 O2Emissions ( p r ivi y) = (Total CO2 Emission Potential of the Entire Gas – THC Component to CO2 Emission 

Potential – CO Component to CO2 Emission Potential) x Percentage of Production Controlled

THC Component CO2 Emissions Potentials (

tons

activity) =∑

(

lb emissions emitted

activity ) i×

N . f M l f C i mp u 

N . f M l f C i CO2

×Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of Compound C (lb/lb-mol) × 2000

CO component CO2 emissions potentials (

tons

activity) = 

CO emissions from flaring(

lb

activity)×

No.of Moles of C in compound

No.of Moles of C in CO2 × Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of CO ( lb

lb-mol

) × 2000

.

Where,

i= each compound identified in flaring gas speciation profile 

(lb emissions emitted/activity)i = Total TOG Emissions (lb/activity) from flaring X Weight 

Fraction of the Compound 

Table 221. Flaring Emission Factors.

NOx CO THC

0.068 0.37 0.14 25% 1.44 63%

Flaring Emission Factor (lb/MMBtu)* Fraction of THC 

as CH4

N2O 

(lb/MMSCF)b VOC/THCc 

b Emission Factor from API Compendium of greenhouse gas emissions methodologies for 

the oil and natural gas industry,2009 Table 4-11, GHG Emission Factors for Gas Flares in 

Developed Countries - Footnote C

cEPA SPECIATE Profile 0051

*Emission Factors are from AP-42

NOx, VOC, CH4, N2O and CO Emissions Calculation

where:

E flare is the flaring emissions per well [lb/yr]

EF i is the emissions factor for pollutant i [lb/MMBtu]

Q is the volume of gas flared supplied by operator [MMscf/yr]

HV is the heating value of the gas as provided by the operators [MMBtu/MMscf]

E flare  EF i  Q  HV
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-173

Table 222. 2009 Flaring Emissions in tons per activity metric of each Category.

Note: Detailed Flaring Emissions calculations for condensate tanks are summarized in Table 224 to Table 229, dehydrator is in 

Table 231 to Table 233 and pneumatic pumps are in Table 235 to Table 238.

Table 223. Change in Per Surrogate Flaring Activity (Multiplicative Scalar).

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Condensate Tank Flashing Flaring 2.91E-05 3.75E-05 0.0002 0 0 0 0.0586 1.50E-05 0 0 2.74E-07 flashing flares

Condensate Tank Working Flaring 0.0001 0.0002 0.0008 0 0 0 0.0361 7.51E-05 0 0 1.53E-06 working flares

Condensate Tank Breathing Flaring 0.0037 0.0048 0.0204 0 0 0 0.9267 0.0019 0 0 3.93E-05 breathing flares

Dehydrator Flaring 0.0267 0.0343 0.1451 0 0 0 53.1885 0.0137 0 0 0.0004 dehydrator flares

Pneumatic Pump Flaring 0.0458 0.0589 0.2492 0 0 0 79.6451 0.0236 0 0 0.0008 pneumatic pump flares

Description Projection Flaring Emissions (tons per activity metric)

Year flashing working breathing dehydrator* pneumatic pump

2009 100% 100% 100% 100% 100%

2010 100% 100% 100% 106% 100%

2011 100% 100% 100% 105% 100%

2012 100% 100% 100% 103% 100%

2013 100% 100% 100% 101% 100%

2014 100% 100% 100% 100% 100%

2015 100% 100% 100% 98% 100%

2016 100% 100% 100% 98% 100%

2017 100% 100% 100% 96% 100%

2018 100% 100% 100% 97% 100%

2019 100% 100% 100% 96% 100%

2020 100% 100% 100% 95% 100%

2021 100% 100% 100% 95% 100%

2022 100% 100% 100% 95% 100%

2023 100% 100% 100% 94% 100%

2024 100% 100% 100% 92% 100%

2025 100% 100% 100% 91% 100%

2026 100% 100% 100% 91% 100%

2027 100% 100% 100% 90% 100%

2028 100% 100% 100% 90% 100%

2029 100% 100% 100% 89% 100%

2030 100% 100% 100% 89% 100%

2031 100% 100% 100% 89% 100%

2032 100% 100% 100% 88% 100%

2033 100% 100% 100% 88% 100%

2034 100% 100% 100% 88% 100%

2035 100% 100% 100% 87% 100%

2036 100% 100% 100% 87% 100%

2037 100% 100% 100% 87% 100%

* incorporates changes over time in per well dehydrator emissions
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-174

2009 Condensate Tank Flashing/Working/Breathing Flaring Emissions

ASSUMPTIONS

Data provided by operator in blue text

 O2Emissions ( p r ivi y) = (Total CO2 Emission Potential of the Entire Gas – THC Component to CO2 Emission 

Potential – CO Component to CO2 Emission Potential) x Percentage of Production Controlled

THC Component CO2 Emissions Potentials (

tons

activity) =∑

(

lb emissions emitted

activity ) i×

N . f M l f C i mp u 

N . f M l f C i CO2

×Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of Compound C (lb/lb-mol) × 2000

CO component CO2 emissions potentials (

tons

activity) = 

CO emissions from flaring(

lb

activity)×

No.of Moles of C in compound

No.of Moles of C in CO2 × Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of CO ( lb

lb-mol

) × 2000

.

Where,

i= each compound identified in flaring gas speciation profile 

(lb emissions emitted/activity)i = Total TOG Emissions (lb/activity) from flaring X Weight 

Fraction of the Compound 

Table 224. Flaring Emission Factors.

NOx, VOC, CH4, N2O and CO Emissions Calculation

where:

E flare is the flaring emissions per well [lb/yr]

EF i is the emissions factor for pollutant i [lb/MMBtu]

Q is the volume of gas flared supplied by operator [MMscf/yr]

HV is the heating value of the gas as provided by the operators [MMBtu/MMscf]

E flare  EF i  Q  HV NOx CO THC

0.068 0.37 0.14 25% 1.44 63%

Flaring Emission Factor (lb/MMBtu)* Fraction of THC 

as CH4

N2O 

(lb/MMSCF)b VOC/THCc 

b Emission Factor from API Compendium of greenhouse gas emissions methodologies for 

the oil and natural gas industry,2009 Table 4-11, GHG Emission Factors for Gas Flares in 

Developed Countries - Footnote C

cEPA SPECIATE Profile 0051

*Emission Factors are from AP-42

Condensate 2246.45 Btu/scf

Total Flash @ 381.05 SCF/Bbl Produced 

100% percentage of condensate volume controlled

1

 2008 HYSYS model runs for the Wamsutter Operations Center at 365 psig.
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-175

Table 225. 2009 CO2 Emissions (tons/bbl) Potential for All Gas Sample Species from 

Flashing Loss.

Assumptions 365.00 PSIG Separator Pressure

75.00 Degrees F Temperature (Tank)

379.48 SCF/lb-mole

Chemical Mole %1 

Molecular 

Weight

 (lb/lb-mol)2

Pounds per Bbl @ 

365 psig

lb/

MMscf lb CO2/ MMscf HHV (Btu/scf)2

2009 CO2 emission 

potential of the 

entire gas 

(tons/bbl)

Carbon Dioxide 2.80% 44.01 1.24 3249.9 3249.9 0 6.E-04

Nitrogen 0.02% 28.01 0.01 16.0 0 0.E+00

Methane 34.25% 16.04 5.52 14478.2 39724.7 1010 8.E-03

Ethane 13.42% 30.07 4.05 10631.5 31120.1 1770 6.E-03

Propane 17.98% 44.10 7.96 20899.7 62571.2 2516 1.E-02

Isobutane 6.85% 58.12 4.00 10490.1 31773.5 3252 6.E-03

n-Butane 9.34% 58.12 5.45 14303.0 43322.4 3262 8.E-03

Isopentane 4.48% 72.15 3.25 8523.4 25995.4 4001 5.E-03

n-Pentane 3.91% 72.15 2.83 7431.5 22665.4 4009 4.E-03

n-Hexane 1.36% 86.18 1.18 3085.0 9452.7 4756 2.E-03

Cyclohexane 0.30% 84.16 0.25 654.9 2054.9 4482 4.E-04

2,2-Dimethylbutane 0.09% 86.18 0.08 200.7 614.9 4736 1.E-04

2,3-Dimethylbutane 0.34% 86.18 0.30 782.7 2398.2 4745 5.E-04

2-Methylpentane 1.04% 86.18 0.90 2361.7 7236.8 4747 1.E-03

3-Methylpentane 0.53% 86.18 0.46 1200.9 3679.9 4750 7.E-04

n-Heptane 1.85% 100.20 1.86 4884.9 15018.6 5503 3.E-03

Methylcyclohexane 0.18% 98.19 0.18 465.0 1667.3 5216 3.E-04

2,2,4-Trimethylpentane 0.07% 114.23 0.08 211.8 652.9 6249 1.E-04

Benzene 0.31% 78.11 0.25 645.7 2182.9 3742 4.E-04

Toluene 0.38% 92.14 0.35 921.2 3080.1 4475 6.E-04

Ethylbenzene 0.00% 106.17 0.00 12.3 40.8 5222 8.E-06

m-Xylene 0.16% 106.16 0.17 453.7 1504.8 5208 3.E-04

o-Xylene 0.02% 106.16 0.02 43.1 142.8 5210 3.E-05

n-Octane 0.22% 114.23 0.25 665.0 2049.8 6249 4.E-04

n-Nonane 0.05% 128.26 0.07 170.9 527.7 6996 1.E-04

n-Decane 0.04% 142.29 0.06 150.8 466.4 7743 9.E-05

VOC 100.00% 40.58 40.75 106933.7 309944.3 2246.4540 0.1

Total VOC 49.51% 29.93 78558.2

2

 The molecular weights and the higher heating values are from the "GSPA Engineering Data Book", Twelfth Edition, Section 23 Physical Properties, 2004.

1

 The flash gas composition is based on the 2008 HYSYS model for Wamsutter at 365 psig.
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-176

Table 226. 2009 CO2 Emissions (tons/turnover) Potential for All Gas Sample Species from 

Working Loss.

Throughput 1509.94 bbls/yr

Turnovers: 2.93

Vapor Density 0.06 lb/ft3

Components

Working Loss 

(lbs/yr)

Working Loss (lb/ 

turnover well) Weight %

Molecular Weight

 (lb/lb-mol)1 Mole % HHV (Btu/scf)1

lb/

MMscf

lb CO2/ 

MMscf

2009 CO2 

emission 

potential of the 

entire gas 

(Tons/turnover)

Methane 78.28 26.72 21.23% 16.04 46.18% 1010 19518.8 53555.1 0.0121

Ethane 45.81 15.63 12.43% 30.07 14.42% 1770 11424.6 33441.8 0.0044

Propane 71.86 24.53 19.50% 44.10 15.42% 2516 17921.3 53654.3 0.0111

Isobutane 34.98 11.94 9.49% 58.12 5.70% 3252 8722.4 26419.2 0.0027

n-Butane 46.12 15.74 12.51% 58.12 7.51% 3262 11501.0 34835.5 0.0046

Isopentane 27.02 9.22 7.33% 72.15 3.54% 4001 6738.2 20550.9 0.0016

n-Pentane 21.87 7.46 5.93% 72.15 2.87% 4009 5454.1 16634.4 0.0011

n-Hexane 8.31 2.84 2.25% 86.18 0.91% 4756 2072.0 6348.6 0.0002

Cyclohexane 1.32 0.45 0.36% 84.16 0.15% 4482 328.7 1031.2 0.0000

2,2-Dimethylbutane 0.66 0.23 0.18% 86.18 0.07% 4736 164.6 504.4 0.0000

2,3-Dimethylbutane 2.19 0.75 0.59% 86.18 0.24% 4745 545.9 1672.8 0.0000

2-Methylpentane 6.49 2.22 1.76% 86.18 0.71% 4747 1618.7 4960.0 0.0001

3-Methylpentane 3.10 1.06 0.84% 86.18 0.34% 4750 773.6 2370.4 0.0000

n-Heptane 12.98 4.43 3.52% 100.20 1.23% 5503 3237.1 9952.4 0.0004

Methylcyclohexane 1.03 0.35 0.28% 98.19 0.10% 5216 257.3 922.5 0.0000

2,2,4-Trimethylpentane 0.52 0.18 0.14% 114.23 0.04% 6249 129.4 398.8 0.0000

Benzene 1.17 0.40 0.32% 78.11 0.14% 3742 291.3 984.9 0.0000

Toluene 1.54 0.53 0.42% 92.14 0.16% 4475 383.4 1281.9 0.0000

Ethylbenzene 0.02 0.01 0.01% 106.17 0.00% 5222 5.2 17.2 0.0000

Xylenes 0.85 0.29 0.23% 106.17 0.08% 5208 212.3 704.2 0.0000

n-Octane 1.38 0.47 0.37% 114.23 0.11% 6249 344.1 1060.6 0.0000

n-Nonane 0.49 0.17 0.13% 128.26 0.04% 6996 122.2 377.5 0.0000

n-Decane 0.64 0.22 0.17% 142.29 0.04% 7743 160.1 495.3 0.0000

THC 368.63 125.81 100.00% 34.88 100.00% 2016.172946 91926.45836 272173.93 0.04

VOC 244.54 83.46 66.34% 39.40% 60983.02218

From EPA's TANKS 4.09 Output based on the condensate composition from 2007 Wamsutter 

HYSYS model. 

1

 The molecular weights and the higher heating values are from the "GSPA Engineering Data Book", Twelfth Edition, Section 23 Physical Properties, 2004.
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-177

Table 227. 2009 CO2 Emissions (tons/well) Potential for All Gas Sample Species from 

Breathing Loss.

Throughput 1509.94 bbls/yr

Turnovers: 2.93

Vapor Density 0.06 lb/ft3

Components

Breathing Loss 

(lbs/well) Weight %

Molecular Weight

 (lb/lb-mol)1 Mole % HHV (Btu/scf)1

lb/

MMscf lb CO2/ MMscf

2009 CO2 

emission 

potential of the 

entire gas 

(tons/well)

Methane 686.48 21.23% 16.04 46.18% 1010 19518.83 53555.1 0.31

Ethane 401.75 12.43% 30.07 14.42% 1770 11424.60 33441.8 0.11

Propane 630.14 19.50% 44.10 15.42% 2516 17921.33 53654.3 0.29

Isobutane 306.72 9.49% 58.12 5.70% 3252 8722.37 26419.2 0.07

n-Butane 404.46 12.51% 58.12 7.51% 3262 11501.01 34835.5 0.12

Isopentane 236.95 7.33% 72.15 3.54% 4001 6738.23 20550.9 0.04

n-Pentane 191.8 5.93% 72.15 2.87% 4009 5454.10 16634.4 0.03

n-Hexane 72.84 2.25% 86.18 0.91% 4756 2071.95 6348.6 0.00

Cyclohexane 11.54 0.36% 84.16 0.15% 4482 328.67 1031.2 0.00

2,2-Dimethylbutane 5.79 0.18% 86.18 0.07% 4736 164.62 504.4 0.00

2,3-Dimethylbutane 19.19 0.59% 86.18 0.24% 4745 545.93 1672.8 0.00

2-Methylpentane 56.93 1.76% 86.18 0.71% 4747 1618.72 4960.0 0.00

3-Methylpentane 27.22 0.84% 86.18 0.34% 4750 773.58 2370.4 0.00

n-Heptane 113.84 3.52% 100.20 1.23% 5503 3237.08 9952.4 0.01

Methylcyclohexane 9.06 0.28% 98.19 0.10% 5216 257.26 922.5 0.00

2,2,4-Trimethylpentane 4.54 0.14% 114.23 0.04% 6249 129.39 398.8 0.00

Benzene 10.23 0.32% 78.11 0.14% 3742 291.33 984.9 0.00

Toluene 13.46 0.42% 92.14 0.16% 4475 383.41 1281.9 0.00

Ethylbenzene 0.19 0.01% 106.17 0.00% 5222 5.20 17.2 0.00

Xylenes 7.48 0.23% 106.17 0.08% 5208 212.35 704.2 0.00

n-Octane 12.1 0.37% 114.23 0.11% 6249 344.11 1060.6 0.00

n-Nonane 4.3 0.13% 128.26 0.04% 6996 122.24 377.5 0.00

n-Decane 5.65 0.17% 142.29 0.04% 7743 160.14 495.3 0.00

THC 3232.66 100.00% 34.88 100.00% 2016.172946 91926.45836 272173.9343 0.98

VOC 2144.43 66.34% 39.40% 60983.02218

From EPA's TANKS 4.09 Output based on the condensate composition from 2007 Wamsutter HYSYS model. 
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-178

Table 228. Summary of 2009 THC and CO Component to CO2 Emissions Potentials (tons/activity).

Table 229. 2009 Condensate Tank Flaring Emissions per activity metric of each Category.

MW 

(lb/lbmol)Flashing 

(lb/bbl)

Working

(lb/turnover)

Breathing

(lb/well)

TOG 31.47 0.15 0.75 19.30

CO 28.01 0.32 1.59 40.80

lb 

emitted/wel

l

Moles C in 

compound/

Moles C in 

CO2

CO2 Emissions 

(tons/bbl)

lb 

emitted/tu

rnover

Moles C in 

compound/

Moles C in 

CO2

CO2 Emissions 

(tons/turnover)

lb 

emitted/w

ell

Moles C in 

compound/Mol

es C in CO2

CO2 

Emissions 

(tons/well)

Ethane Y N 30 30.07 0.04 2 0.0001 0.23 2 0.0003 5.79 2 0.0085

Formaldehyde N Y 20 30.03 0.03 1 0.0000 0.15 1 0.0001 3.86 1 0.0028

Methane Y N 20 16.04 0.03 1 0.0000 0.15 1 0.0002 3.86 1 0.0053

Propane Y Y 30 44.10 0.04 3 0.0001 0.23 3 0.0003 5.79 3 0.0087

100 0.15 0.0002 0.0002 0.75 0.0010 0.0012 19.30 0.0253 0.0321

THC component CO2 emissions CO 

component 

CO2 

emissions 

potentials 

(tons/bbl) 

0.0002

Name HC? VOC?

WEIGHT_PER

(Flaring 

Speciation Profile 

(EPA SPECIATE 

0051))

Molecular 

Weight

(lb/lb-mol) 2

Flashing 2009 CO2 Emissions Working 2009 CO2 Emissions

THC component CO2 emissions potentials 

CO component 

CO2 emissions 

potentials 

(tons/turnover) 

0.0012

Breathing 2009 CO2 Emissions

THC component CO2 emissions 

CO component 

CO2 emissions 

potentials 

(tons/well) 

0.0321

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Condensate Tank Flashing Flaring 2.91E-05 3.75E-05 0.0002 0 0 0 0.0586 1.50E-05 0 0 2.74E-07 flashing flares

Condensate Tank Working Flaring 0.0001 0.0002 0.0008 0 0 0 0.0361 7.51E-05 0 0 1.53E-06 working flares

Condensate Tank Breathing Flaring 0.0037 0.0048 0.0204 0 0 0 0.9267 0.0019 0 0 3.93E-05 breathing flares

Description Projection Flaring Emissions (tons per activity metric)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-179

2009 Dehydrator Flaring Emissions

ASSUMPTIONS

 O2Emissions ( p r ivi y) = (Total CO2 Emission Potential of the Entire Gas – THC Component to CO2 Emission 

Potential – CO Component to CO2 Emission Potential) x Percentage of Production Controlled

THC Component CO2 Emissions Potentials (

tons

activity) =∑

(

lb emissions emitted

activity ) i×

N . f M l f C i mp u 

N . f M l f C i CO2

×Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of Compound C (lb/lb-mol) × 2000

CO component CO2 emissions potentials (

tons

activity) = 

CO emissions from flaring(

lb

activity)×

No.of Moles of C in compound

No.of Moles of C in CO2 × Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of CO ( lb

lb-mol

) × 2000

.

Where,

i= each compound identified in flaring gas speciation profile 

(lb emissions emitted/activity)i = Total TOG Emissions (lb/activity) from flaring X Weight 

Fraction of the Compound 

.

Table 230. Flaring Emission Factors.

Data Provided by operator in blue text

Assume no change in pressure (365 psi)

Assume one dehydrator per well

Total Waste Gas Stream (MMscf/yr/ well) =0.0013*Flow (MMSCF/yr/well)+0.5094

NOx, VOC, CH4, N2O and CO Emissions Calculation

where:

E flare is the flaring emissions per well [lb/yr]

EF i is the emissions factor for pollutant i [lb/MMBtu]

Q is the volume of gas flared supplied by operator [MMscf/yr]

HV is the heating value of the gas as provided by the operators [MMBtu/MMscf]

E flare  EF i  Q  HV NOx CO THC

0.068 0.37 0.14 25% 1.44 63%

Flaring Emission Factor (lb/MMBtu)* Fraction of THC 

as CH4

N2O 

(lb/MMSCF)b VOC/THCc 

b Emission Factor from API Compendium of greenhouse gas emissions methodologies for 

the oil and natural gas industry,2009 Table 4-11, GHG Emission Factors for Gas Flares in 

Developed Countries - Footnote C

cEPA SPECIATE Profile 0051

*Emission Factors are from AP-42
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-180

Table 231. 2009 CO2 Emissions (tons/well) Potential for All Gas Sample Species from 

Dehydrator Flaring.

Table 232. Summary of 2009 THC and CO Component to CO2 Emissions Potentials 

(tons/activity).

Table 233. 2009 Dehydrator Flaring Emissions in tons per activity.

Chemical Mole %1 

Molecular 

Weight

 (lb/lb-mol)2

lb/

MMscf

lb CO2/ 

MMscf

HHV 

(Btu/scf)2

2009 CO2 emission 

potential of the entire gas 

(tons/well)

Water 17.54% 18.01 8060.8 0.0 0.00

Carbon Dioxide 5.47% 44.01 6142.9 6142.9 0 1.92

Nitrogen 0.11% 28.01 80.8 0 0.00

Methane 55.61% 16.04 22761.2 62451.3 1010 19.53

Ethane 6.19% 30.07 4749.6 13903.0 1770 4.35

Propane 3.98% 44.10 4478.8 13408.9 2516 4.19

Isobutane 1.07% 58.12 1586.9 4806.5 3252 1.50

n-Butane 1.49% 58.12 2209.8 6693.2 3262 2.09

Isopentane 0.57% 72.15 1053.1 3211.8 4001 1.00

n-Pentane 0.58% 72.15 1075.2 3279.2 4009 1.03

n-Hexane 0.33% 86.18 730.1 2237.1 4756 0.70

Cyclohexane 0.62% 84.16 1335.8 4191.1 4482 1.31

Other Hexanes 0.37% 86.18 815.9 2499.8 4745 0.78

n-Heptane 0.61% 100.20 1569.9 4826.8 5503 1.51

Methylcyclohexane 0.79% 98.19 1976.9 7088.5 5216 2.22

2,2,4-Trimethylpentane 0.02% 114.23 55.4 170.7 6249 0.05

Benzene 1.35% 78.11 2690.8 9096.5 3742 2.85

Toluene 1.89% 92.14 4443.7 14857.6 4475 4.65

Ethylbenzene 0.06% 106.17 165.3 548.0 5222 0.17

Xylenes 0.60% 106.17 1636.3 5426.4 5208 1.70

n-Octane 0.73% 114.23 2116.2 6522.5 6249 2.04

Total 100.00% 27.33 69735.3 171362.1 1253.5833 53.6

Total VOC 15.07% 27940.0

1

 Mole percent is based on the GLYCalc run at 0.25 MMscf/day for Wamsutter.

2

 The molecular weights and the higher heating values are from GSPA Engineering Data Book, 12th Edition.

Assumptions

0.0821 L-atm/K-mol

298.15 oK

1 1 atm

1 ft3 28.31685 L

453.59237 mol/lb-mol

391.90 scf/lbmol

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Dehydrator Flaring 0.0267 0.0343 0.1451 0 0 0 53.1885 0.0137 0 0 0.0004 dehydrator flares

Description Projection Flaring Emissions (tons per activity metric)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-181

2009 Chemical Injection Pump Flaring Emissions

ASSUMPTIONS

Data provided by operators in blue text

 O2Emissions ( p r ivi y) = (Total CO2 Emission Potential of the Entire Gas – THC Component to CO2 Emission 

Potential – CO Component to CO2 Emission Potential) x Percentage of Production Controlled

THC Component CO2 Emissions Potentials (

tons

activity) =∑

(

lb emissions emitted

activity ) i×

N . f M l f C i mp u 

N . f M l f C i CO2

×Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of Compound C (lb/lb-mol) × 2000

CO component CO2 emissions potentials (

tons

activity) = 

CO emissions from flaring (

lb

activity) ×

No.of Moles of C in compound

No.of Moles of C in CO2 × Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of CO ( lb

lb-mol ) × 2000

Where,

i= each compound identified in flaring gas speciation profile 

(lb emissions emitted/activity)i = Total TOG Emissions (lb/activity) from flaring X Weight 

Fraction of the Compound 

NOx, VOC, CH4, N2O and CO Emissions Calculation

where:

E flare is the flaring emissions per well [lb/yr]

EF i is the emissions factor for pollutant i [lb/MMBtu]

Q is the volume of gas flared supplied by operator [MMscf/yr]

HV is the heating value of the gas as provided by the operators [MMBtu/MMscf]

E flare  EF i  Q  HV

VOC Fraction (molar) 5.39%

VOC molecular weight 57.50

R 0.08206 L atm / K-mol

standard temp 298.15 K

standard press 1 atm

MCF to 1000 liter conversion 28.317 1000L/MCF

L/mol 24.47 L/mol

28.32 L/SCF

453.59237 mol/lb-mol

391.90 scf/lbmol
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-182

Table 234. Flaring Emission Factors.

Table 235. Summary of Chemical Injection Pump Data.

Table 236. 2009 CO2 Emissions (tons/well) Potential for All Gas Sample Species from 

Pump Flaring.

NOx CO THC

0.068 0.37 0.14 25% 1.44 63%

Flaring Emission Factor (lb/MMBtu)* Fraction of THC 

as CH4

N2O 

(lb/MMSCF)b VOC/THCc 

b Emission Factor from API Compendium of greenhouse gas emissions methodologies for 

the oil and natural gas industry,2009 Table 4-11, GHG Emission Factors for Gas Flares in 

Developed Countries - Footnote C

cEPA SPECIATE Profile 0051

*Emission Factors are from AP-42

Methanol 1,381,989 1,368 47 1 - - 64.31 0.06

Glycol Heat Medium Pumps - - - 1 273 2.84 1,116.73 1.12

Total - - - - - - 1181.04 1.18

Vented Volume 

 Type Gallons Used Gallons/well SCF/Gallon Number of Pump (MMSCF/year)

Days Used in 

Quarter SCF/Pump/Minute

Vented Volume 

(MCF/year)

Component Mole %1

Molecular 

Weight

 (lb/lb-mol)2 Weight %

lb/

MMscf lb CO2/ MMscf HHV (Btu/scf)2

CO2 emission 

potential of the 

entire gas 

(tons/well)

Carbon Dioxide 2.73% 44.01 6.07% 3066.1 3066.1 0 1.8106

Nitrogen 0.17% 28.01 0.24% 122.3 0 0.0000

Methane 84.90% 16.04 68.75% 34749.6 95344.9 1010 56.3030

Ethane 6.81% 30.07 10.33% 5222.5 15287.1 1770 9.0273

Propane 3.17% 44.10 7.05% 3564.0 10670.1 2516 6.3009

Isobutane 0.64% 58.12 1.86% 942.4 2854.6 3252 1.6857

n-Butane 0.71% 58.12 2.08% 1052.8 3188.8 3262 1.8830

Isopentane 0.24% 72.15 0.88% 445.4 1358.3 4001 0.8021

n-Pentane 0.20% 72.15 0.73% 366.5 1117.8 4009 0.6601

n-Hexane 0.16% 86.18 0.69% 350.1 1072.8 4756 0.6335

Cyclohexane 0.03% 84.16 0.13% 68.2 213.9 4482 0.1263

2,2-Dimethylbutane 0.00% 86.18 0.02% 9.4 28.8 4736 0.0170

2,3-Dimethylbutane 0.02% 86.18 0.07% 36.0 110.3 4745 0.0652

2-Methylpentane 0.05% 86.18 0.21% 107.2 328.5 4747 0.1940

3-Methylpentane 0.03% 86.18 0.11% 55.1 168.9 4750 0.0997

n-Heptane 0.06% 100.20 0.30% 149.9 461.0 5503 0.2722

Methylcyclohexane 0.03% 98.19 0.16% 80.6 288.9 5216 0.1706

2,2,4-Trimethylpentane 0.00% 114.23 0.02% 11.0 34.0 6249 0.0201

Benzene 0.01% 78.11 0.06% 29.8 100.6 3742 0.0594

Toluene 0.02% 92.14 0.08% 41.0 137.0 4475 0.0809

Ethylbenzene 0.00% 106.17 0.00% 1.2 4.1 5222 0.0024

m-Xylene 0.00% 106.16 0.03% 12.6 41.9 5208 0.0247

o-Xylene 0.00% 106.16 0.02% 11.0 36.5 5210 0.0216

n-Octane 0.00% 114.23 0.00% 1.8 5.4 6249 0.0032

n-Nonane 0.01% 128.26 0.09% 44.8 138.2 6996 0.0816

n-Decane 0.00% 142.29 0.00% 0.0 0.0 7743 0.0000

Total 100.00% 19.81 100.00% 50541.4 136,059 1140.5805 80.3

Total VOC 5.39% 14.60% 7380.8

1 Mole percentage of the sales gas 

2

 The molecular weights and the higher heating values are from GSPA Engineering Data Book, 12th Edition.
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-183

Table 237. Summary of 2009 THC and CO Component to CO2 Emissions Potentials 

(tons/activity).

Table 238. 2009 Chemical Injection Pump Flaring Emissions in tons per well.

lb 

emitted/we

l l

Moles C in 

compound/Moles C in 

CO2

CO2 Emissions 

(tons/well)

Ethane Y N 30 30.07 71 2 0.1

Formaldehyde N Y 20 30.03 47 1 0.0

Methane Y N 20 16.04 47 1 0.1

Propane Y Y 30 44.10 71 3 0.1

100 236 0.31 0.39

THC component CO2 emissions potentials CO component CO2 

emissions potentials 

(tons/well) 

0.4

Name HC? VOC? WEIGHT_

PER

Molecular 

Weight

 (lb/lb-mol)2

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Pneumatic Pump Flaring 0.0458 0.0589 0.2492 0 0 0 79.6451 0.0236 0 0 0.0008 pneumatic pump flares

Description Projection Flaring Emissions (tons per activity metric)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-184

2009 Production Traffic Emissions

ASSUMPTIONS

Data Provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2009 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

PRODUCTION TRAFFIC.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-185

Table 239. Summary of Traffic Activity Data Associated with Production Traffic.

Equipment Type

Field

Mean Vehicle 

Speed (mph)

Round Trip 

Off-Road Trip 

Distance 

(miles)

Number of Round 

Trips Per Well or 

Central Facilities 

(annual)

Light Truck 20 20 52

Heavy Truck 20 20 14

Heavy Trucks - Central Facility 0 0 0

Production traffic assumes that vehicles end up at the central facility

Table 240. 2009 Exhaust Emissions (lb/well) Associated with Production Traffic by Vehicle 

Type.

NOx 2.52 5.779

SO2 0.01 0.033

CO 18.19 41.699

CO2 675.15 1548

VOC 1.48 3.390

PM10 0.09 0.199

PM2.5 0.08 0.189

PM_filt - 0.000

PM_cond - 0.000

CH4 0.08 0.195

N2O 0.05 0.105

NOx 20.23 12.485

SO2 0.08 0.050

CO 15.07 9.301

CO2 2612.44 1612.614

VOC 1.86 1.149

PM10 1.21 0.745

PM2.5 1.17 0.723

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.056

N2O 0.04 0.022

NOx 20.23 0.000

SO2 0.08 0.000

CO 15.07 0.000

CO2 2612.44 0.000

VOC 1.86 0.000

PM10 1.21 0.000

PM2.5 1.17 0.000

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.000

N2O 0.04 0.000

* units are lb totals for travel to central facility

Heavy-Duty Diesel 

Truck Travel to 

Central Facility

Heavy-Duty Truck 

Light-Duty Truck

Vehicle Type Pollutant 2009 Emission 

Factors (g/mile)

Base year Emissions 

(lb/well)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-186

Table 241. Summary of 2009 Fugitive Dust Emissions (tons/well) Associated with 

Production Traffic.

Travel to well Light truck 7,000 20 52 52 20 1040 0.20 0.10 0.02 0.01

Travel to well Heavy Truck 70,000 20 14 14 20 280 0.20 0.03 0.02 0.00

Travel to Central 

Facility Heavy Truck 70,000 0 0 0 0 0 0.00 0.00 0.02 0.00

Total 0.40 0.13 0.06 0.01

Total # of 

Round Trips

Round Trip 

Distance (mi)

Total Miles 

Traveled

PM10

Activity Vehicle Type Av. Vehicle Weight (lb)

Mean vehicle speed 

(mph)

# of Visits per 

Year 

PM2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-187

Table 242. 2009 Exhaust and Fugitive Dust Emissions Associated with Production Traffic in tons per well.

Table 243. Percent Change in Emission from Base Year 2009 due to fleet turnover for Production Traffic.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Production Traffic (LD) 0.0029 0.0017 0.0208 9.97E-05 9.45E-05 1.65E-05 0.7740 9.74E-05 0 0 5.24E-05 active well counts 0.1030 0.0102

Production Traffic (HD) 0.0062 0.0006 0.0047 0.0004 0.0004 2.48E-05 0.8063 2.79E-05 0 0 1.10E-05 active well counts 0.0277 0.0028

Production Traffic, Central Facility (HD) 0 0 0 0 0 0 0 0 0 0 0 totals for CY 2012+ 0 0

Description Projection Total Production Traffic Emissions (tons per well) Fugitive Road NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 -5% -11% -3% 0% -4% -6% -6% 0% 0% -3% -7% -10% -45% -4% 0% -3% -7% -7% 0% 0% 4% -5%

2011 -10% -18% -7% -1% -10% -12% -13% 0% 0% -7% -14% -19% -74% -9% 0% -10% -18% -18% 0% 0% 13% -12%

2012 -16% -27% -11% -2% -16% -19% -19% 0% 0% -11% -21% -28% -75% -14% 0% -17% -28% -28% 0% 0% 20% -17%

2013 -22% -28% -15% -4% -22% -25% -25% 0% 0% -15% -28% -36% -75% -19% 0% -25% -37% -37% 0% 0% 24% -23%

2014 -28% -29% -18% -5% -27% -30% -31% 0% 0% -18% -34% -44% -76% -24% 0% -32% -45% -46% 0% 0% 28% -28%

2015 -33% -30% -22% -7% -33% -35% -36% 0% 0% -22% -39% -51% -76% -28% 0% -38% -53% -53% 0% 0% 30% -33%

2016 -38% -31% -26% -8% -38% -40% -40% 0% 0% -25% -44% -57% -76% -33% 0% -44% -60% -60% 0% 0% 31% -37%

2017 -43% -33% -28% -10% -42% -44% -44% 0% 0% -28% -48% -62% -76% -36% 0% -49% -66% -66% 0% 0% 32% -41%

2018 -47% -34% -31% -11% -46% -48% -48% 0% 0% -30% -52% -67% -76% -39% 0% -54% -71% -71% 0% 0% 33% -44%

2019 -51% -35% -33% -13% -49% -51% -51% 0% 0% -32% -56% -71% -77% -42% 0% -59% -75% -75% 0% 0% 33% -48%

2020 -54% -36% -34% -14% -52% -54% -54% 0% 0% -34% -59% -74% -77% -44% 0% -62% -79% -79% 0% 0% 34% -50%

2021 -57% -37% -36% -15% -55% -56% -56% 0% 0% -35% -62% -77% -77% -46% 0% -66% -82% -82% 0% 0% 34% -53%

2022 -64% -39% -40% -18% -62% -61% -62% 0% 0% -38% -69% -83% -77% -50% 0% -73% -89% -89% 0% 0% 35% -60%

2023 -60% -38% -37% -16% -58% -58% -59% 0% 0% -36% -64% -79% -77% -48% 0% -69% -85% -85% 0% 0% 34% -55%

2024 -62% -39% -39% -17% -60% -60% -60% 0% 0% -37% -67% -81% -77% -49% 0% -71% -87% -87% 0% 0% 34% -58%

2025 -66% -40% -41% -19% -65% -63% -64% 0% 0% -39% -71% -84% -77% -52% 0% -76% -90% -90% 0% 0% 34% -61%

2026 -68% -41% -42% -20% -67% -64% -65% 0% 0% -38% -72% -85% -77% -53% 0% -78% -91% -91% 0% 0% 36% -63%

2027 -69% -41% -43% -21% -69% -66% -66% 0% 0% -38% -74% -86% -77% -54% 0% -79% -92% -92% 0% 0% 36% -64%

2028 -71% -42% -44% -21% -70% -67% -68% 0% 0% -39% -75% -87% -77% -54% 0% -81% -93% -93% 0% 0% 36% -65%

2029 -72% -42% -45% -22% -72% -68% -69% 0% 0% -40% -76% -87% -77% -55% 0% -82% -94% -94% 0% 0% 36% -67%

2030 -73% -42% -46% -22% -73% -69% -69% 0% 0% -40% -77% -88% -77% -56% 0% -83% -94% -94% 0% 0% 35% -67%

2031 -74% -43% -46% -23% -74% -69% -70% 0% 0% -42% -78% -88% -77% -57% 0% -84% -95% -95% 0% 0% 34% -69%

2032 -74% -43% -47% -23% -75% -70% -71% 0% 0% -42% -79% -88% -77% -57% 0% -85% -95% -95% 0% 0% 34% -69%

2033 -75% -43% -48% -23% -76% -71% -71% 0% 0% -43% -79% -89% -78% -58% 0% -85% -95% -95% 0% 0% 33% -69%

2034 -76% -44% -48% -24% -76% -71% -72% 0% 0% -43% -79% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2035 -76% -44% -49% -24% -77% -72% -72% 0% 0% -44% -80% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2036 -77% -44% -49% -24% -77% -72% -73% 0% 0% -44% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -70%

2037 -77% -44% -50% -24% -78% -72% -73% 0% 0% -45% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -71%

Light-Duty Truck Heavy-Duty Truck 

Year
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-188

2009 Compressor Emissions

ASSUMPTIONS

Data provided by operators in blue text

Additional compressor stations will come online from 2012.

Table 244. Compressor Engines Activity Data.

Existing Capacity (Wamsutter and Table Rock) 32,810 hp

1,000 mmscfd

Normalized Capacity 32.81 hp/mmscfd

Gas Production capacity to be added 760 mmscfd

Additional horsepower needed 24,936 hp

Reciprocating 

Engines Turbine

Fraction of horsepower at existing stations 2.7% 97.3%

Additional horsepower needed by type 684 24,252

Estimated Load Factor 100% 100%

Equations:

Emissions (tons/year) = Emission factor (g/hp-hr) * Horsepower * Time Used (hours) * Load

453.5 (g/lb) * 2000 (lbs/ton)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-189

Table 245. Compressor Engine Emission Factors (turbine and rich burn SI) and Compressor 

Emissions in lbs per year.

Table 246. Compression Station Emissions (tons/yr).

Turbine

EF (g/hp-hr) source EF (g/hp-hr) source

NOx 0.21

Average turbine emission 

factor from the existing 

Echo Springs Facility 0.7 Assumed BACT level 99,955 9,247

CO 0.21 min of existing turbines 2.0 Assumed BACT level 98,354 26,419

VOC 0.01 min of existing turbines 0.1

min of existing 

reciprocating engines 4,215 1,230

PM10 0.0240 EPA,AP-42 Turbine EFs 0.0704

EPA,AP-42, 4-Stroke 

Rich Burn Engine Efs 11,217 930

PM2.5 0.0240 EPA,AP-42 Turbine EFs 0.0704

EPA,AP-42, 4-Stroke 

Rich Burn Engine Efs 11,217 930

SO2 0.0000 0.0000 0 0

CO2 399.1680 EPA,AP-42 Turbine EFs 399.1680

EPA,AP-42, 4-Stroke 

Rich Burn Engine Efs 186,950,734 5,272,819

CH4 0.0210 SPECIATE Profile 0.7669 SPECIATE Profile 9,835 10,130

PM_cond 0.0171 EPA,AP-42 Turbine EFs 0.0360

EPA,AP-42, 4-Stroke 

Rich Burn Engine Efs 7,988 475

PM_filt 0.0069 EPA,AP-42 Turbine EFs 0.0345

EPA,AP-42, 4-Stroke 

Rich Burn Engine Efs 3,229 455

N2O 0.0109 EPA,AP-42 Turbine EFs 0.0008 API Compendium 5,099 10

Pollutant

Emission Factors Emissions (lb/yr)

Reciprocating

Turbine Reciprocating

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Added Compression (turbine) 49.9777 2.1076 49.1769 5.6085 5.6085 0.0000 93,475 4.9177 1.6146 3.9939 2.5493 totals for CY 2012+

Added Compression (reciprocating) 4.6233 0.6149 13.2095 0.4652 0.4652 0.0000 2,636 5.0652 0.2277 0.2375 0.0050 totals for CY 2012+

Description Projection Compression Station Emissions (tons)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-190

New Gas Plants Emissions

ASSUMPTIONS

Data provided by operators in blue text

Additional Gas Production Capacity will be added from 2012.

Existing Capacity (Echo Spring Gas Plant) 740 mmscfd

Gas Production capacity to be added 760 mmscfd

Additional horsepower needed 24,936 hp

Table 247. New Gas Plant Emissions by Source in tons per year.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Added Gas Plant (Recip Engines) 43.2959 5.7583 123.7024 4.3565 4.3565 0 24689.0265 47.4337 2.1322 2.2243 0.0470 totals for CY 2012+

Added Gas Plant (Turbine Engines) 195.2504 8.3969 195.9274 22.3451 22.3451 0 372418.7367 19.5927 6.4327 15.9124 10.1569 totals for CY 2012+

Added Gas Plant (Duct Burner) 17.4087 0.8511 9.6715 1.4701 1.4701 0.1161 23211.6324 0.4449 0.3675 1.1026 0.4255 totals for CY 2012+

Added Gas Plant (Heaters) 77.0640 6.6152 53.5697 6.5076 6.5076 0.5138 102751.9589 1.9694 1.6269 4.8807 1.8838 totals for CY 2012+

Added Gas Plant (Flares) 39.5405 36.4595 111.2270 0 0 0 65678.3294 3.7403 0 0 0.8349 totals for CY 2012+

Added Gas Plant (Process) 10.4757 10.3730 9.5514 0.7962 0.7962 0.0629 12570.8108 0.2409 0.1990 0.5971 0.2305 totals for CY 2012+

Added Gas Plant (Fugitives) 0 3.7000 0 0 0 0 1.5371 17.4200 0 0 0 totals for CY 2012+

Description Projection

Well Pad Construction Equipment Emissions (tons)
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-191

Table 248. Summary of New Gas Plant Emissions by source in tons per year.

Unit NOx CO VOC PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O Units

Total Engine Capacity 100,406 100,406 100,406 100,406 100,406 100,406 100,406 100,406 100,406 100406.00 100406.00 hp

Normalized Capacity 136 136 136 136 136 136 136 136 136 136 136 hp/mmscfd

Added Capacity 760 760 760 760 760 760 760 760 760 760.00 760.00 mmscfd

Additional Capacity Needed 103,120 103,120 103,120 103,120 103,120 103,120 103,120 103,120 103,120 103119.68 103119.68 hp

Fraction Recip Engines 0.062 0.062 0.062 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06

Recip Engine Capacity 6,413 6,413 6,413 6,413 6,413 6,413 6,413 6,413 6,413 6412.76 6412.76 hp

Load Factor 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% 100%

Assumed BACT Emission Factor 0.7 2.0 1.0 0.0704 0.0704 0.0000 399 1 0.0345 0.0360 0.0008 g/hp-hr

VOC/HC 9.3% SPECIATE Profile 1001

Recip Engine Emissions 43 124 5.8 4 4 0 24,689 47 2 2 0 t/yr

Turbine Fraction 0.94 0.94 0.94 0.94 0.94 0.94 0.94 0.94 0.94 0.94 0.94

Turbine Capacity 96,707 96,707 96,707 96,707 96,707 96,707 96,707 96,707 96,707 96,707 96,707 hp

Load Factor 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% 100%

Assumed BACT Level 0.209 0.210 0.030 0.0240 0.0240 0.0000 399.1680 0.0210 0.0069 0.0171 0.0109 g/hp-hr

Assumed BACT Level 15

VOC/HC 30% SPECIATE Profile 0007

Turbine Emissions 195 196 8 22 22 0 372,419 20 6 16 10 t/yr

Duct Burner 

Existing Capacity 43 43 43 43.00 43.00 43.00 43.00 43.00 43.00 43.00 43.00 mmbtu/hr

Normalized Capacity 0.058 0.058 0.058 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 mmbtu/mmscfd

Added Capacity 760 760 760 760 760 760 760 760 760 760 760 mmscf/d

Additional Capacity Needed 44 44 44 44.16 44.16 44.16 44.16 44.16 44.16 44.16 44.16 mmbtu/hr

BACT Level Assumed 0.09 0.05 0.01 0.01 0.01 0.00 120.00 0.00 0.00 0.01 0.0022 lbs/mmbtu

VOC/HC 44% SPECIATE Profile 0003

Duct Burner Emissions 17.4 9.7 0.85 1.5 1.5 0.1 23211.6 0.4 0.4 1.1 0.4 t/yr

Total Engine Emissions 256 329 1 5 28 28 0 420319 67 9 19 11 t/yr

Existing Heater Capacity 190 190 190 190 190 190 190 190 190 190 190 mmbtu/hr

Normalized Capacity 0.257 0.257 0.257 0.26 0.26 0.26 0.26 0.26 0.26 0.26 0.26 mmbtu/mmscfd

Added Capacity 760 760 760 760 760 760 760 760 760 760 760 mmscf/d

Additional Capacity Needed 195 195 195 195 195 195 195 195 195 195 195 mmbtu/hr

BACT level assumed 0.09 0.06 0.02 0.01 0.01 0.00 120.00 0.00 0.00 0.01 0.0022 lbs/mmbtu

VOC/HC 44% SPECIATE Profile 0003

Heater Emissions 77.1 53.6 6.62 6.5 6.5 0.5 102752.0 2.0 1.6 4.9 1.9 t/yr

Emissions from Flaring at 740 mmscfd 38.5 108.3 35.5 0.00 0.00 0.00 63,950 4 0.00 0.00 0.81 t/yr

Emissions from Flaring at 760 mmscfd 39.5 111.2 36.5 0.00 0.00 0.00 65,678 4 0.00 0.00 0.83 t/yr

Process Emissions at 740 mmscfd 10.2 9.3 10.1 0.78 0.78 0.06 12240.00 0.23 0.19 0.58 0.22 t/yr

Process Emissions at 760 mmscfd 10.5 9.6 10.4 0.80 0.80 0.06 12570.81 0.24 0.20 0.60 0.23 t/yr

Fugitive Emissions at 740 mmscfd 0 0 3.7 0.00 0.00 0.00 1.54 17.42 0.00 0.00 0.00 t/yr

Fugitive Emissions at 760 mmscfd 0 0 3.7 0.00 0.00 0.00 1.54 17.42 0.00 0.00 0.00 t/yr

Facility Total 383 504 72 35 35 1 601322 91 11 25 14 t/yr

Engines

Duct Burner

Heaters

Flares

Process

Fugitive
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-192

2009 Evaporative Pond Emissions

Data provided by operators in blue text.

Table 249. 2009 Emissions (tons/year) from Wamsutter North and South Evaporation 

Ponds.

Table 250. 2009 Average VOC emissions (tons/year).

Table 251. VOC, CO2 and CH4 Weight Fractions.

Component % Wt

Average per Well 

Emissions

(TPY)

Methane 3.90% 0.0001

Carbon Dioxide 24.76% 0.0006

VOC Fraction (weight) 69.58%

Table 252. 2009 Evaporation Pond Emissions in tons per well.

Parameter

Wamsutter 

North Pond

Wamsutter South 

Pond

4.67 5.85

Benzene 0.62 0.84

Ethylbenzene 0.07 0.09

Hexane (-n) 0.01 0.01

Methanol 2.09 2.31

Toluene 0.80 1.11

Xylene 0.92 1.25

Xylene (-o) 0.17 0.24

VOC Emissions (tpy)

Emissions (tpy) based on Water 9 model Output*

*based on data from evaporation facilities at Wamsutter Operations Center

Average VOC emissions per 

evaporation basin (tpy) 5.26

Average Evaporation Facilities per 

well 0.033%

Average VOC emissions per well 

(tpy) 0.002

Based on two existing evaporation facilities for 1500 CDC wells. 

Only 25% of project wells are assumed to be associated with an 

evaporation pond

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Evaporation Ponds 0 0.0018 0 0 0 0 0.0006 0.0001 0 0 0 active well counts

Description Evaporation Pond Emissions -Weighted Average(tons per well) Projection
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-193

Table 253. Percent Change in Emission from Base Year 2009 for Evaporation Ponds.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-194

Table 254. New Project Wells NOx Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 17. New Project Wells NOx Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction DustConstruction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 177 3 802 51 161 31 3 0 0 96 0 0 5 0 61 2 0 0 0 0 0 1,391

2010 0 237 3 1,076 61 216 38 4 0 0 225 0 0 10 0 163 4 0 0 0 0 0 2,038

2011 0 236 3 1,069 55 215 34 4 0 0 353 0 0 14 0 251 7 0 0 0 0 0 2,240

2012 0 231 3 1,049 48 211 30 4 0 0 478 0 0 17 0 326 9 0 383 55 0 0 2,843

2013 0 236 2 1,069 43 215 27 4 0 0 606 0 0 19 0 399 12 0 383 55 0 0 3,071

2014 0 234 2 1,059 38 213 23 4 0 0 733 0 0 21 0 466 14 0 383 55 0 0 3,244

2015 0 241 2 1,093 35 219 21 5 0 0 863 0 0 22 0 531 17 0 383 55 0 0 3,486

2016 0 188 1 854 24 171 15 4 0 0 965 0 0 22 0 580 19 0 383 55 0 0 3,281

2017 0 247 2 1,121 28 225 17 5 0 0 1,100 0 0 23 0 642 21 0 383 55 0 0 3,868

2018 0 272 2 1,233 27 247 16 5 0 0 1,247 0 0 23 0 734 24 0 383 55 0 0 4,268

2019 0 219 1 992 19 199 12 4 0 0 1,366 0 0 23 0 792 26 0 383 55 0 0 4,091

2020 0 219 1 993 17 199 10 4 0 0 1,484 0 0 22 0 845 29 0 383 55 0 0 4,262

2021 0 247 1 1,121 17 225 11 5 0 0 1,619 0 0 22 0 901 31 0 383 55 0 0 4,638

2022 0 235 1 1,063 12 213 8 4 0 0 1,746 0 0 19 0 970 34 0 383 55 0 0 4,742

2023 0 79 0 357 5 72 3 1 0 0 1,788 0 0 23 0 974 35 0 383 55 0 0 3,774

2024 0 0 0 0 0 0 0 0 0 0 1,788 0 0 21 0 934 35 0 383 55 0 0 3,215

2025 0 0 0 0 0 0 0 0 0 0 1,788 0 0 18 0 908 35 0 383 55 0 0 3,187

2026 0 0 0 0 0 0 0 0 0 0 1,788 0 0 17 0 889 35 0 383 55 0 0 3,167

2027 0 0 0 0 0 0 0 0 0 0 1,788 0 0 16 0 874 35 0 383 55 0 0 3,151

2028 0 0 0 0 0 0 0 0 0 0 1,788 0 0 15 0 861 35 0 383 55 0 0 3,137

2029 0 0 0 0 0 0 0 0 0 0 1,788 0 0 15 0 850 35 0 383 55 0 0 3,125

2030 0 0 0 0 0 0 0 0 0 0 1,788 0 0 14 0 840 35 0 383 55 0 0 3,115

2031 0 0 0 0 0 0 0 0 0 0 1,788 0 0 14 0 831 35 0 383 55 0 0 3,105

2032 0 0 0 0 0 0 0 0 0 0 1,788 0 0 13 0 823 35 0 383 55 0 0 3,097

2033 0 0 0 0 0 0 0 0 0 0 1,788 0 0 13 0 815 35 0 383 55 0 0 3,089

2034 0 0 0 0 0 0 0 0 0 0 1,788 0 0 13 0 808 35 0 383 55 0 0 3,081

2035 0 0 0 0 0 0 0 0 0 0 1,788 0 0 13 0 801 35 0 383 55 0 0 3,074

2036 0 0 0 0 0 0 0 0 0 0 1,788 0 0 13 0 794 35 0 383 55 0 0 3,068

2037 0 0 0 0 0 0 0 0 0 0 1,788 0 0 12 0 788 35 0 383 55 0 0 3,061

TOTAL 0 3,297 27 14,951 479 3,001 297 62 0 0 39,706 0 0 492 0 20,452 767 0 9,959 1,420 0 0 94,910

Production Total (Costruction + Drilling + Completion 

+ Production)

NOx [tpy]

Pollutant Year

Construction Drilling Completion

0

680

1,360

2,040

2,720

3,400

4,080

4,760

5,440

6,120

6,800

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well NOx Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-195

Table 255. New Project Wells VOC Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 18. New Project Wells VOC Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction DustConstruction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 26 0 45 6 9 4 4 0 321 5 0 0 1 61 79 0 359 0 0 0 1 922

2010 0 35 0 61 8 12 5 6 0 751 12 0 0 2 187 210 0 841 0 0 0 2 2,134

2011 0 35 0 60 7 12 4 6 0 1,179 19 0 0 4 282 323 0 1,320 0 0 0 3 3,255

2012 0 35 0 59 6 12 4 6 0 1,598 26 0 0 5 350 419 1 1,790 72 3 0 4 4,389

2013 0 35 0 60 6 12 4 6 0 2,026 33 0 0 5 413 514 1 2,269 72 3 0 5 5,465

2014 0 35 0 60 5 12 3 6 0 2,450 40 0 0 6 460 599 1 2,743 72 3 0 6 6,502

2015 0 36 0 62 5 12 3 6 0 2,887 47 0 0 7 502 683 1 3,232 72 3 0 8 7,566

2016 0 28 0 48 4 10 2 5 0 3,228 53 0 0 7 531 747 1 3,615 72 3 0 8 8,362

2017 0 37 0 63 4 13 3 6 0 3,676 60 0 0 7 564 827 1 4,117 72 3 0 10 9,463

2018 0 41 0 69 4 14 3 7 0 4,169 69 0 0 7 652 945 1 4,669 72 3 0 11 10,737

2019 0 33 0 56 3 11 2 5 0 4,566 75 0 0 8 686 1,019 1 5,114 72 3 0 12 11,666

2020 0 33 0 56 3 11 2 5 0 4,964 82 0 0 8 711 1,087 2 5,558 72 3 0 13 12,609

2021 0 37 0 63 3 13 2 6 0 5,412 89 0 0 8 730 1,160 2 6,061 72 3 0 14 13,674

2022 0 35 0 60 2 12 1 6 0 5,837 96 0 0 7 782 1,248 2 6,537 72 3 0 15 14,716

2023 0 12 0 20 1 4 1 2 0 5,980 98 0 0 8 756 1,253 2 6,697 72 3 0 16 14,924

2024 0 0 0 0 0 0 0 0 0 5,980 98 0 0 8 666 1,202 2 6,697 72 3 0 16 14,742

2025 0 0 0 0 0 0 0 0 0 5,980 98 0 0 7 607 1,168 2 6,697 72 3 0 16 14,649

2026 0 0 0 0 0 0 0 0 0 5,980 98 0 0 6 565 1,144 2 6,697 72 3 0 16 14,583

2027 0 0 0 0 0 0 0 0 0 5,980 98 0 0 6 531 1,125 2 6,697 72 3 0 16 14,529

2028 0 0 0 0 0 0 0 0 0 5,980 98 0 0 6 502 1,108 2 6,697 72 3 0 16 14,483

2029 0 0 0 0 0 0 0 0 0 5,980 98 0 0 5 477 1,094 2 6,697 72 3 0 16 14,443

2030 0 0 0 0 0 0 0 0 0 5,980 98 0 0 5 454 1,081 2 6,697 72 3 0 16 14,407

2031 0 0 0 0 0 0 0 0 0 5,980 98 0 0 5 433 1,069 2 6,697 72 3 0 16 14,375

2032 0 0 0 0 0 0 0 0 0 5,980 98 0 0 5 415 1,058 2 6,697 72 3 0 16 14,345

2033 0 0 0 0 0 0 0 0 0 5,980 98 0 0 4 397 1,049 2 6,697 72 3 0 16 14,317

2034 0 0 0 0 0 0 0 0 0 5,980 98 0 0 4 381 1,039 2 6,697 72 3 0 16 14,292

2035 0 0 0 0 0 0 0 0 0 5,980 98 0 0 4 366 1,031 2 6,697 72 3 0 16 14,268

2036 0 0 0 0 0 0 0 0 0 5,980 98 0 0 4 351 1,022 2 6,697 72 3 0 16 14,245

2037 0 0 0 0 0 0 0 0 0 5,980 98 0 0 4 337 1,015 2 6,697 72 3 0 16 14,223

TOTAL 0 493 4 842 69 169 43 80 0 132,762 2,184 0 0 162 14,148 26,316 43 148,672 1,876 71 0 348 328,285

Production Total (Costruction + Drilling + Completion 

+ Production)

VOC [tpy]

Pollutant Year

Construction Drilling Completion

0

6,160

12,320

18,480

24,640

30,800

36,960

43,120

49,280

55,440

61,600

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well VOC Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-196

Table 256. New Project Wells SO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 19. New Project Wells SO2 Emissions (tons/year) Contribution by Source Category and by Project Year. Construction Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 3 0 19 0 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 26

2010 0 2 0 12 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 16

2011 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3

2012 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 2

2013 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 2

2014 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 2

2015 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 2

2016 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 2

2017 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 2

2018 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 2

2019 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 2

2020 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 2

2021 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 2

2022 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 2

2023 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1

2024 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1

2025 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1

2026 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1

2027 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1

2028 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1

2029 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1

2030 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1

2031 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1

2032 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1

2033 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1

2034 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1

2035 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1

2036 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1

2037 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1

TOTAL 0 7 0 41 1 9 1 0 0 0 0 0 0 3 0 0 1 0 18 0 0 0 81

Production Total (Costruction + Drilling + Completion 

+ Production)

SO2 [tpy]

Pollutant Year

Construction Drilling Completion

0.0

14.0

28.0

42.0

56.0

70.0

84.0

98.0

112.0

126.0

140.0

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well SO2 Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-197

Table 257. New Project Wells PM10 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 20. New Project Wells PM10 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction DustConstruction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 117 11 19 27 309 5 196 0 0 0 7 0 0 64 0 0 0 0 0 0 0 0 755

2010 157 14 26 36 414 7 262 0 0 0 17 0 0 149 0 0 0 0 0 0 0 0 1,084

2011 156 14 26 36 411 7 261 0 0 0 27 0 0 234 0 0 0 0 0 0 0 0 1,172

2012 153 14 25 35 403 7 255 0 0 0 36 0 0 318 0 0 0 0 35 6 0 0 1,289

2013 156 14 26 36 411 7 260 0 0 0 46 0 0 403 0 0 0 0 35 6 0 0 1,400

2014 154 14 26 36 406 7 257 0 0 0 56 0 0 487 0 0 1 0 35 6 0 0 1,485

2015 159 15 26 37 419 7 265 0 0 0 66 0 0 574 0 0 1 0 35 6 0 0 1,609

2016 124 11 21 29 327 6 207 0 0 0 73 0 0 641 0 0 1 0 35 6 0 0 1,482

2017 163 15 27 38 429 7 272 0 0 0 84 0 0 730 0 0 1 0 35 6 0 0 1,807

2018 179 16 30 41 472 8 299 0 0 0 95 0 0 828 0 0 1 0 35 6 0 0 2,011

2019 144 13 24 33 380 7 241 0 0 0 104 0 0 907 0 0 1 0 35 6 0 0 1,895

2020 144 13 24 33 380 7 241 0 0 0 113 0 0 985 0 0 1 0 35 6 0 0 1,983

2021 163 15 27 38 429 7 272 0 0 0 123 0 0 1,074 0 0 1 0 35 6 0 0 2,190

2022 155 14 26 36 406 7 257 0 0 0 133 0 0 1,158 0 0 1 0 35 6 0 0 2,235

2023 52 5 9 12 136 2 86 0 0 0 136 0 0 1,187 0 0 1 0 35 6 0 0 1,668

2024 0 0 0 0 0 0 0 0 0 0 136 0 0 1,187 0 0 1 0 35 6 0 0 1,366

2025 0 0 0 0 0 0 0 0 0 0 136 0 0 1,187 0 0 1 0 35 6 0 0 1,366

2026 0 0 0 0 0 0 0 0 0 0 136 0 0 1,187 0 0 1 0 35 6 0 0 1,365

2027 0 0 0 0 0 0 0 0 0 0 136 0 0 1,187 0 0 1 0 35 6 0 0 1,365

2028 0 0 0 0 0 0 0 0 0 0 136 0 0 1,187 0 0 1 0 35 6 0 0 1,365

2029 0 0 0 0 0 0 0 0 0 0 136 0 0 1,187 0 0 1 0 35 6 0 0 1,365

2030 0 0 0 0 0 0 0 0 0 0 136 0 0 1,187 0 0 1 0 35 6 0 0 1,365

2031 0 0 0 0 0 0 0 0 0 0 136 0 0 1,187 0 0 1 0 35 6 0 0 1,365

2032 0 0 0 0 0 0 0 0 0 0 136 0 0 1,186 0 0 1 0 35 6 0 0 1,365

2033 0 0 0 0 0 0 0 0 0 0 136 0 0 1,186 0 0 1 0 35 6 0 0 1,365

2034 0 0 0 0 0 0 0 0 0 0 136 0 0 1,186 0 0 1 0 35 6 0 0 1,365

2035 0 0 0 0 0 0 0 0 0 0 136 0 0 1,186 0 0 1 0 35 6 0 0 1,365

2036 0 0 0 0 0 0 0 0 0 0 136 0 0 1,186 0 0 1 0 35 6 0 0 1,365

2037 0 0 0 0 0 0 0 0 0 0 136 0 0 1,186 0 0 1 0 35 6 0 0 1,365

TOTAL 2,175 199 361 502 5,732 100 3,631 0 0 0 3,018 0 0 26,352 0 0 30 0 922 158 0 0 43,180

Production Total (Costruction + Drilling + Completion 

+ Production)

PM10 [tpy]

Pollutant Year

Construction Drilling Completion

0.0

282.0

564.0

846.0

1,128.0

1,410.0

1,692.0

1,974.0

2,256.0

2,538.0

2,820.0

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well PM10 Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-198

Table 258. New Project Wells PM2.5 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 21. New Project Wells PM2.5 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction DustConstruction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 30 10 2 26 33 5 21 0 0 0 7 0 0 7 0 0 0 0 0 0 0 0 142

2010 40 14 3 35 44 7 28 0 0 0 17 0 0 15 0 0 0 0 0 0 0 0 204

2011 40 14 3 35 44 7 28 0 0 0 27 0 0 24 0 0 0 0 0 0 0 0 221

2012 39 14 3 34 42 7 27 0 0 0 36 0 0 32 0 0 0 0 35 6 0 0 276

2013 40 14 3 35 43 7 27 0 0 0 46 0 0 41 0 0 0 0 35 6 0 0 297

2014 40 14 3 35 42 7 27 0 0 0 56 0 0 49 0 0 1 0 35 6 0 0 313

2015 41 14 3 36 43 7 27 0 0 0 66 0 0 58 0 0 1 0 35 6 0 0 337

2016 32 11 2 28 34 6 21 0 0 0 73 0 0 65 0 0 1 0 35 6 0 0 314

2017 42 14 3 37 44 7 28 0 0 0 84 0 0 73 0 0 1 0 35 6 0 0 374

2018 46 16 3 40 48 8 30 0 0 0 95 0 0 83 0 0 1 0 35 6 0 0 412

2019 37 13 2 32 39 6 24 0 0 0 104 0 0 91 0 0 1 0 35 6 0 0 391

2020 37 13 2 32 38 6 24 0 0 0 113 0 0 99 0 0 1 0 35 6 0 0 408

2021 42 14 3 37 43 7 27 0 0 0 123 0 0 107 0 0 1 0 35 6 0 0 447

2022 40 14 3 35 41 7 26 0 0 0 133 0 0 116 0 0 1 0 35 6 0 0 455

2023 13 5 1 12 14 2 9 0 0 0 136 0 0 119 0 0 1 0 35 6 0 0 353

2024 0 0 0 0 0 0 0 0 0 0 136 0 0 119 0 0 1 0 35 6 0 0 297

2025 0 0 0 0 0 0 0 0 0 0 136 0 0 118 0 0 1 0 35 6 0 0 297

2026 0 0 0 0 0 0 0 0 0 0 136 0 0 118 0 0 1 0 35 6 0 0 297

2027 0 0 0 0 0 0 0 0 0 0 136 0 0 118 0 0 1 0 35 6 0 0 297

2028 0 0 0 0 0 0 0 0 0 0 136 0 0 118 0 0 1 0 35 6 0 0 297

2029 0 0 0 0 0 0 0 0 0 0 136 0 0 118 0 0 1 0 35 6 0 0 297

2030 0 0 0 0 0 0 0 0 0 0 136 0 0 118 0 0 1 0 35 6 0 0 297

2031 0 0 0 0 0 0 0 0 0 0 136 0 0 118 0 0 1 0 35 6 0 0 297

2032 0 0 0 0 0 0 0 0 0 0 136 0 0 118 0 0 1 0 35 6 0 0 297

2033 0 0 0 0 0 0 0 0 0 0 136 0 0 118 0 0 1 0 35 6 0 0 297

2034 0 0 0 0 0 0 0 0 0 0 136 0 0 118 0 0 1 0 35 6 0 0 297

2035 0 0 0 0 0 0 0 0 0 0 136 0 0 118 0 0 1 0 35 6 0 0 297

2036 0 0 0 0 0 0 0 0 0 0 136 0 0 118 0 0 1 0 35 6 0 0 297

2037 0 0 0 0 0 0 0 0 0 0 136 0 0 118 0 0 1 0 35 6 0 0 297

TOTAL 560 193 37 487 592 97 375 0 0 0 3,018 0 0 2,634 0 0 29 0 922 158 0 0 9,103

Production Total (Costruction + Drilling + Completion 

+ Production)

PM2.5 [tpy]

Pollutant Year

Construction Drilling Completion

0

64

128

192

256

320

384

448

512

576

640

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well PM2.5 Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-199

Table 259. New Project Wells CO Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 22. New Project Wells CO Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction DustConstruction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 218 4 470 55 93 35 18 0 0 81 0 0 12 0 333 1 0 0 0 0 0 1,319

2010 0 293 5 630 71 125 45 24 0 0 189 0 0 28 0 888 3 0 0 0 0 0 2,300

2011 0 291 4 626 67 124 43 24 0 0 296 0 0 42 0 1,365 4 0 0 0 0 0 2,887

2012 0 286 4 615 62 122 40 24 0 0 402 0 0 55 0 1,772 6 0 504 62 0 0 3,952

2013 0 291 4 626 60 124 38 24 0 0 509 0 0 66 0 2,174 7 0 504 62 0 0 4,490

2014 0 288 4 621 56 123 36 24 0 0 615 0 0 76 0 2,533 8 0 504 62 0 0 4,951

2015 0 297 4 640 55 127 35 25 0 0 725 0 0 86 0 2,888 10 0 504 62 0 0 5,458

2016 0 232 3 500 40 99 26 19 0 0 811 0 0 91 0 3,157 11 0 504 62 0 0 5,556

2017 0 305 3 657 51 130 32 25 0 0 924 0 0 100 0 3,495 13 0 504 62 0 0 6,301

2018 0 336 3 722 53 143 34 28 0 0 1,047 0 0 109 0 3,995 14 0 504 62 0 0 7,052

2019 0 270 3 581 41 115 26 22 0 0 1,147 0 0 116 0 4,307 16 0 504 62 0 0 7,212

2020 0 270 3 582 40 115 26 23 0 0 1,247 0 0 123 0 4,598 17 0 504 62 0 0 7,609

2021 0 305 3 657 44 130 28 25 0 0 1,360 0 0 130 0 4,905 19 0 504 62 0 0 8,171

2022 0 289 3 623 39 123 25 24 0 0 1,466 0 0 132 0 5,278 20 0 504 62 0 0 8,588

2023 0 97 1 209 14 41 9 8 0 0 1,502 0 0 141 0 5,299 21 0 504 62 0 0 7,907

2024 0 0 0 0 0 0 0 0 0 0 1,502 0 0 138 0 5,081 21 0 504 62 0 0 7,308

2025 0 0 0 0 0 0 0 0 0 0 1,502 0 0 132 0 4,939 21 0 504 62 0 0 7,160

2026 0 0 0 0 0 0 0 0 0 0 1,502 0 0 129 0 4,838 21 0 504 62 0 0 7,056

2027 0 0 0 0 0 0 0 0 0 0 1,502 0 0 127 0 4,756 21 0 504 62 0 0 6,972

2028 0 0 0 0 0 0 0 0 0 0 1,502 0 0 125 0 4,687 21 0 504 62 0 0 6,901

2029 0 0 0 0 0 0 0 0 0 0 1,502 0 0 123 0 4,625 21 0 504 62 0 0 6,837

2030 0 0 0 0 0 0 0 0 0 0 1,502 0 0 121 0 4,571 21 0 504 62 0 0 6,781

2031 0 0 0 0 0 0 0 0 0 0 1,502 0 0 119 0 4,521 21 0 504 62 0 0 6,730

2032 0 0 0 0 0 0 0 0 0 0 1,502 0 0 118 0 4,476 21 0 504 62 0 0 6,683

2033 0 0 0 0 0 0 0 0 0 0 1,502 0 0 116 0 4,434 21 0 504 62 0 0 6,639

2034 0 0 0 0 0 0 0 0 0 0 1,502 0 0 115 0 4,395 21 0 504 62 0 0 6,598

2035 0 0 0 0 0 0 0 0 0 0 1,502 0 0 113 0 4,358 21 0 504 62 0 0 6,560

2036 0 0 0 0 0 0 0 0 0 0 1,502 0 0 113 0 4,323 21 0 504 62 0 0 6,525

2037 0 0 0 0 0 0 0 0 0 0 1,502 0 0 111 0 4,290 21 0 504 62 0 0 6,490

TOTAL 0 4,069 48 8,760 748 1,732 476 339 0 0 33,353 0 0 3,008 0 111,280 459 0 13,095 1,622 0 0 178,990

Production Total (Costruction + Drilling + Completion 

+ Production)

CO [tpy]

Pollutant Year

Construction Drilling Completion

0

1,096

2,192

3,288

4,384

5,480

6,576

7,672

8,768

9,864

10,960

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well CO Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-200

Table 260. New Project Wells Formaldehyde Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 23. New Project Wells Formaldehyde Emissions (tons/year) Contribution by Source Category and by Project Year. Construction Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 2 0 4 0 1 0 2 0 0 0 0 0 0 0 32 0 0 0 0 0 0 41

2010 0 3 0 5 1 1 0 2 0 0 1 0 0 0 0 84 0 0 0 0 0 0 98

2011 0 3 0 5 0 1 0 2 0 0 2 0 0 0 0 129 0 0 0 0 0 0 143

2012 0 3 0 5 0 1 0 2 0 0 2 0 0 0 0 168 0 0 25 2 0 0 209

2013 0 3 0 5 0 1 0 2 0 0 3 0 0 0 0 206 0 0 25 2 0 0 248

2014 0 3 0 5 0 1 0 2 0 0 3 0 0 0 0 240 0 0 25 2 0 0 282

2015 0 3 0 5 0 1 0 2 0 0 4 0 0 0 0 273 0 0 25 2 0 0 317

2016 0 2 0 4 0 1 0 2 0 0 4 0 0 0 0 299 0 0 25 2 0 0 340

2017 0 3 0 5 0 1 0 2 0 0 5 0 0 0 0 331 0 0 25 2 0 0 375

2018 0 3 0 6 0 1 0 3 0 0 5 0 0 0 0 378 0 0 25 2 0 0 425

2019 0 3 0 5 0 1 0 2 0 0 6 0 0 0 0 407 0 0 25 2 0 0 452

2020 0 3 0 5 0 1 0 2 0 0 7 0 0 0 0 435 0 0 25 2 0 0 480

2021 0 3 0 5 0 1 0 2 0 0 7 0 0 0 0 464 0 0 25 2 0 0 511

2022 0 3 0 5 0 1 0 2 0 0 8 0 0 0 0 499 0 0 25 2 0 0 546

2023 0 1 0 2 0 0 0 1 0 0 8 0 0 0 0 501 0 0 25 2 0 0 541

2024 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 481 0 0 25 2 0 0 516

2025 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 467 0 0 25 2 0 0 503

2026 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 458 0 0 25 2 0 0 493

2027 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 450 0 0 25 2 0 0 485

2028 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 443 0 0 25 2 0 0 479

2029 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 438 0 0 25 2 0 0 473

2030 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 432 0 0 25 2 0 0 468

2031 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 428 0 0 25 2 0 0 463

2032 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 423 0 0 25 2 0 0 459

2033 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 419 0 0 25 2 0 0 455

2034 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 416 0 0 25 2 0 0 451

2035 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 412 0 0 25 2 0 0 447

2036 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 409 0 0 25 2 0 0 444

2037 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 406 0 0 25 2 0 0 441

TOTAL 0 42 0 72 4 14 3 32 0 0 175 0 0 6 0 10,527 4 0 648 56 0 0 11,582

Production Total (Costruction + Drilling + Completion 

+ Production)

formaldehyde 

[tpy]

Pollutant Year

Construction Drilling Completion

0

84

168

252

336

420

504

588

672

756

840

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well Formaldehyde Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-201

Table 261. New Project Wells n-hexane Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 24. New Project Wells n-hexane Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction DustConstruction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 0 0 0 0 0 0 0 0 14 0 0 0 0 2 0 0 7 0 0 0 0 23

2010 0 0 0 0 0 0 0 0 0 32 0 0 0 0 6 0 0 17 0 0 0 0 55

2011 0 0 0 0 0 0 0 0 0 50 0 0 0 0 10 0 0 26 0 0 0 0 86

2012 0 0 0 0 0 0 0 0 0 67 0 0 0 0 12 0 0 36 0 0 0 0 115

2013 0 0 0 0 0 0 0 0 0 85 0 0 0 0 14 0 0 45 0 0 0 0 145

2014 0 0 0 0 0 0 0 0 0 103 0 0 0 0 16 0 0 54 0 0 0 0 174

2015 0 0 0 0 0 0 0 0 0 122 0 0 0 0 17 0 0 64 0 0 0 0 203

2016 0 0 0 0 0 0 0 0 0 136 0 0 0 0 18 0 0 72 0 0 0 0 226

2017 0 0 0 0 0 0 0 0 0 155 0 0 0 0 19 0 0 82 0 0 0 0 256

2018 0 0 0 0 0 0 0 0 0 176 0 0 0 0 22 0 0 93 0 0 0 0 291

2019 0 0 0 0 0 0 0 0 0 193 0 0 0 0 23 0 0 101 0 0 0 0 318

2020 0 0 0 0 0 0 0 0 0 209 0 0 0 0 24 0 0 110 0 0 0 0 344

2021 0 0 0 0 0 0 0 0 0 228 0 0 0 0 25 0 0 120 0 0 0 0 374

2022 0 0 0 0 0 0 0 0 0 246 0 0 0 0 27 0 0 130 0 0 0 0 403

2023 0 0 0 0 0 0 0 0 0 252 0 0 0 0 26 0 0 133 0 0 0 0 411

2024 0 0 0 0 0 0 0 0 0 252 0 0 0 0 23 0 0 133 0 0 0 0 408

2025 0 0 0 0 0 0 0 0 0 252 0 0 0 0 21 0 0 133 0 0 0 0 406

2026 0 0 0 0 0 0 0 0 0 252 0 0 0 0 19 0 0 133 0 0 0 0 405

2027 0 0 0 0 0 0 0 0 0 252 0 0 0 0 18 0 0 133 0 0 0 0 403

2028 0 0 0 0 0 0 0 0 0 252 0 0 0 0 17 0 0 133 0 0 0 0 402

2029 0 0 0 0 0 0 0 0 0 252 0 0 0 0 16 0 0 133 0 0 0 0 402

2030 0 0 0 0 0 0 0 0 0 252 0 0 0 0 15 0 0 133 0 0 0 0 401

2031 0 0 0 0 0 0 0 0 0 252 0 0 0 0 15 0 0 133 0 0 0 0 400

2032 0 0 0 0 0 0 0 0 0 252 0 0 0 0 14 0 0 133 0 0 0 0 399

2033 0 0 0 0 0 0 0 0 0 252 0 0 0 0 13 0 0 133 0 0 0 0 399

2034 0 0 0 0 0 0 0 0 0 252 0 0 0 0 13 0 0 133 0 0 0 0 398

2035 0 0 0 0 0 0 0 0 0 252 0 0 0 0 12 0 0 133 0 0 0 0 398

2036 0 0 0 0 0 0 0 0 0 252 0 0 0 0 12 0 0 133 0 0 0 0 397

2037 0 0 0 0 0 0 0 0 0 252 0 0 0 0 11 0 0 133 0 0 0 0 397

TOTAL 0 0 0 0 0 0 0 0 0 5,599 0 0 0 1 481 0 0 2,950 5 0 0 1 9,037

Production Total (Costruction + Drilling + Completion 

+ Production)

n-hexane [tpy]

Pollutant Year

Construction Drilling Completion

0

208

416

624

832

1,040

1,248

1,456

1,664

1,872

2,080

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well n-hexane Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-202

Table 262. New Project Wells Benzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 25. New Project Wells Benzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction DustConstruction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 1 0 0 0 0 5

2010 0 0 0 1 0 0 0 0 0 5 0 0 0 0 1 0 0 3 0 0 0 0 12

2011 0 0 0 1 0 0 0 0 0 8 1 0 0 0 1 0 0 5 0 0 0 0 18

2012 0 0 0 1 0 0 0 0 0 11 1 0 0 0 2 0 0 7 1 0 0 1 24

2013 0 0 0 1 0 0 0 0 0 14 1 0 0 0 2 0 0 9 1 0 0 1 30

2014 0 0 0 1 0 0 0 0 0 17 2 0 0 0 2 0 0 11 1 0 0 1 35

2015 0 0 0 1 0 0 0 0 0 20 2 0 0 0 2 0 0 13 1 0 0 1 41

2016 0 0 0 1 0 0 0 0 0 22 2 0 0 0 3 0 0 15 1 0 0 1 45

2017 0 0 0 1 0 0 0 0 0 25 2 0 0 0 3 0 0 17 1 0 0 1 51

2018 0 0 0 1 0 0 0 0 0 29 3 0 0 0 3 0 0 19 1 0 0 2 58

2019 0 0 0 1 0 0 0 0 0 32 3 0 0 0 3 0 0 21 1 0 0 2 63

2020 0 0 0 1 0 0 0 0 0 34 3 0 0 0 3 0 0 23 1 0 0 2 68

2021 0 0 0 1 0 0 0 0 0 37 4 0 0 0 3 0 0 25 1 0 0 2 74

2022 0 0 0 1 0 0 0 0 0 40 4 0 0 0 4 0 0 27 1 0 0 2 79

2023 0 0 0 0 0 0 0 0 0 41 4 0 0 0 4 0 0 28 1 0 0 2 80

2024 0 0 0 0 0 0 0 0 0 41 4 0 0 0 3 0 0 28 1 0 0 2 79

2025 0 0 0 0 0 0 0 0 0 41 4 0 0 0 3 0 0 28 1 0 0 2 79

2026 0 0 0 0 0 0 0 0 0 41 4 0 0 0 3 0 0 28 1 0 0 2 79

2027 0 0 0 0 0 0 0 0 0 41 4 0 0 0 3 0 0 28 1 0 0 2 79

2028 0 0 0 0 0 0 0 0 0 41 4 0 0 0 2 0 0 28 1 0 0 2 79

2029 0 0 0 0 0 0 0 0 0 41 4 0 0 0 2 0 0 28 1 0 0 2 78

2030 0 0 0 0 0 0 0 0 0 41 4 0 0 0 2 0 0 28 1 0 0 2 78

2031 0 0 0 0 0 0 0 0 0 41 4 0 0 0 2 0 0 28 1 0 0 2 78

2032 0 0 0 0 0 0 0 0 0 41 4 0 0 0 2 0 0 28 1 0 0 2 78

2033 0 0 0 0 0 0 0 0 0 41 4 0 0 0 2 0 0 28 1 0 0 2 78

2034 0 0 0 0 0 0 0 0 0 41 4 0 0 0 2 0 0 28 1 0 0 2 78

2035 0 0 0 0 0 0 0 0 0 41 4 0 0 0 2 0 0 28 1 0 0 2 78

2036 0 0 0 0 0 0 0 0 0 41 4 0 0 0 2 0 0 28 1 0 0 2 78

2037 0 0 0 0 0 0 0 0 0 41 4 0 0 0 2 0 0 28 1 0 0 2 78

TOTAL 0 5 0 9 1 2 1 0 0 918 87 0 0 5 68 0 0 615 21 0 0 48 1,780

Production Total (Costruction + Drilling + Completion 

+ Production)

benzene [tpy]

Pollutant Year

Construction Drilling Completion

0

294

589

883

1,178

1,472

1,766

2,061

2,355

2,650

2,944

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well Benzene Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-203

Table 263. New Project Wells Ethylbenzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 26. New Project Wells Ethylbenzene Emissions (tons/year) Contribution by Source Category and by Project Year. Construction Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2010 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2011 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2012 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2013 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2014 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2015 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 2

2016 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 2

2017 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 2

2018 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 2

2019 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 2

2020 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 2

2021 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2022 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2023 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2024 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2025 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2026 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2027 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2028 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2029 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2030 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2031 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2032 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2033 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2034 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2035 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2036 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2037 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

TOTAL 0 1 0 2 0 0 0 0 0 21 0 0 0 2 1 0 0 28 0 0 0 5 61

Production Total (Costruction + Drilling + Completion 

+ Production)

ethylbenzene 

[tpy]

Pollutant Year

Construction Drilling Completion

0.0

17.4

34.8

52.2

69.6

87.0

104.4

121.8

139.2

156.6

174.0

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well Ethylbenzene Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-204

Table 264. New Project Wells Toluene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 27. New Project Wells Toluene Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction DustConstruction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 0 0 1 0 0 0 0 0 3 0 0 0 0 0 0 0 2 0 0 0 0 7

2010 0 1 0 1 0 0 0 0 0 7 0 0 0 0 1 0 0 5 0 0 0 0 16

2011 0 1 0 1 0 0 0 0 0 11 0 0 0 0 2 0 0 8 0 0 0 1 24

2012 0 1 0 1 0 0 0 0 0 16 1 0 0 0 2 0 0 10 0 0 0 1 32

2013 0 1 0 1 0 0 0 0 0 20 1 0 0 0 3 0 0 13 0 0 0 1 40

2014 0 1 0 1 0 0 0 0 0 24 1 0 0 0 3 0 0 16 0 0 0 1 47

2015 0 1 0 1 0 0 0 0 0 28 1 0 0 1 3 0 0 18 0 0 0 1 55

2016 0 0 0 1 0 0 0 0 0 31 1 0 0 1 3 0 0 21 0 0 0 2 60

2017 0 1 0 1 0 0 0 0 0 36 1 0 0 1 4 0 0 23 0 0 0 2 69

2018 0 1 0 1 0 0 0 0 0 40 1 0 0 1 4 0 0 27 0 0 0 2 78

2019 0 0 0 1 0 0 0 0 0 44 2 0 0 1 4 0 0 29 0 0 0 2 84

2020 0 0 0 1 0 0 0 0 0 48 2 0 0 1 4 0 0 32 0 0 0 2 91

2021 0 1 0 1 0 0 0 0 0 52 2 0 0 1 5 0 0 35 0 0 0 3 99

2022 0 1 0 1 0 0 0 0 0 57 2 0 0 1 5 0 0 37 0 0 0 3 106

2023 0 0 0 0 0 0 0 0 0 58 2 0 0 1 5 0 0 38 0 0 0 3 107

2024 0 0 0 0 0 0 0 0 0 58 2 0 0 1 4 0 0 38 0 0 0 3 106

2025 0 0 0 0 0 0 0 0 0 58 2 0 0 1 4 0 0 38 0 0 0 3 106

2026 0 0 0 0 0 0 0 0 0 58 2 0 0 1 4 0 0 38 0 0 0 3 105

2027 0 0 0 0 0 0 0 0 0 58 2 0 0 0 3 0 0 38 0 0 0 3 105

2028 0 0 0 0 0 0 0 0 0 58 2 0 0 0 3 0 0 38 0 0 0 3 105

2029 0 0 0 0 0 0 0 0 0 58 2 0 0 0 3 0 0 38 0 0 0 3 105

2030 0 0 0 0 0 0 0 0 0 58 2 0 0 0 3 0 0 38 0 0 0 3 105

2031 0 0 0 0 0 0 0 0 0 58 2 0 0 0 3 0 0 38 0 0 0 3 105

2032 0 0 0 0 0 0 0 0 0 58 2 0 0 0 3 0 0 38 0 0 0 3 104

2033 0 0 0 0 0 0 0 0 0 58 2 0 0 0 2 0 0 38 0 0 0 3 104

2034 0 0 0 0 0 0 0 0 0 58 2 0 0 0 2 0 0 38 0 0 0 3 104

2035 0 0 0 0 0 0 0 0 0 58 2 0 0 0 2 0 0 38 0 0 0 3 104

2036 0 0 0 0 0 0 0 0 0 58 2 0 0 0 2 0 0 38 0 0 0 3 104

2037 0 0 0 0 0 0 0 0 0 58 2 0 0 0 2 0 0 38 0 0 0 3 104

TOTAL 0 7 0 13 2 3 1 0 0 1,288 44 0 0 13 89 0 1 847 10 0 0 63 2,381

Production Total (Costruction + Drilling + Completion 

+ Production)

toluene [tpy]

Pollutant Year

Construction Drilling Completion

0

481

962

1,443

1,924

2,405

2,886

3,367

3,848

4,329

4,810

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well Toluene Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-205

Table 265. New Project Wells Xylenes Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 28. New Project Wells Xylenes Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction DustConstruction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 0 0 1 0 0 0 0 0 2 0 0 0 0 0 0 0 1 0 0 0 0 4

2010 0 0 0 1 0 0 0 0 0 4 0 0 0 0 1 0 0 1 0 0 0 0 8

2011 0 0 0 1 0 0 0 0 0 6 0 0 0 0 1 0 0 2 0 0 0 1 12

2012 0 0 0 1 0 0 0 0 0 8 0 0 0 0 1 0 0 3 0 0 0 1 16

2013 0 0 0 1 0 0 0 0 0 11 0 0 0 0 1 0 0 4 0 0 0 1 19

2014 0 0 0 1 0 0 0 0 0 13 0 0 0 0 2 0 0 5 0 0 0 2 23

2015 0 0 0 1 0 0 0 0 0 15 0 0 0 0 2 0 0 6 0 0 0 2 26

2016 0 0 0 1 0 0 0 0 0 17 0 0 0 0 2 0 0 6 0 0 0 2 29

2017 0 0 0 1 0 0 0 0 0 19 0 0 0 0 2 0 0 7 0 0 0 2 33

2018 0 0 0 1 0 0 0 0 0 22 0 0 0 0 2 0 0 8 0 0 0 3 37

2019 0 0 0 1 0 0 0 0 0 24 0 0 0 0 2 0 0 9 0 0 0 3 40

2020 0 0 0 1 0 0 0 0 0 26 0 0 0 0 2 0 0 10 0 0 0 3 43

2021 0 0 0 1 0 0 0 0 0 29 0 0 0 0 3 0 0 11 0 0 0 3 47

2022 0 0 0 1 0 0 0 0 0 31 0 0 0 0 3 0 0 12 0 0 0 4 51

2023 0 0 0 0 0 0 0 0 0 32 0 0 0 0 3 0 0 12 0 0 0 4 51

2024 0 0 0 0 0 0 0 0 0 32 0 0 0 0 2 0 0 12 0 0 0 4 50

2025 0 0 0 0 0 0 0 0 0 32 0 0 0 0 2 0 0 12 0 0 0 4 50

2026 0 0 0 0 0 0 0 0 0 32 0 0 0 0 2 0 0 12 0 0 0 4 50

2027 0 0 0 0 0 0 0 0 0 32 0 0 0 0 2 0 0 12 0 0 0 4 49

2028 0 0 0 0 0 0 0 0 0 32 0 0 0 0 2 0 0 12 0 0 0 4 49

2029 0 0 0 0 0 0 0 0 0 32 0 0 0 0 2 0 0 12 0 0 0 4 49

2030 0 0 0 0 0 0 0 0 0 32 0 0 0 0 2 0 0 12 0 0 0 4 49

2031 0 0 0 0 0 0 0 0 0 32 0 0 0 0 2 0 0 12 0 0 0 4 49

2032 0 0 0 0 0 0 0 0 0 32 0 0 0 0 1 0 0 12 0 0 0 4 49

2033 0 0 0 0 0 0 0 0 0 32 0 0 0 0 1 0 0 12 0 0 0 4 49

2034 0 0 0 0 0 0 0 0 0 32 0 0 0 0 1 0 0 12 0 0 0 4 49

2035 0 0 0 0 0 0 0 0 0 32 0 0 0 0 1 0 0 12 0 0 0 4 49

2036 0 0 0 0 0 0 0 0 0 32 0 0 0 0 1 0 0 12 0 0 0 4 49

2037 0 0 0 0 0 0 0 0 0 32 0 0 0 0 1 0 0 12 0 0 0 4 49

TOTAL 0 6 0 10 1 2 1 0 0 699 0 0 0 8 49 0 1 264 1 0 0 85 1,127

Production Total (Costruction + Drilling + Completion 

+ Production)

xylenes [tpy]

Pollutant Year

Construction Drilling Completion

0

182

364

546

728

910

1,092

1,274

1,456

1,638

1,820

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well Xylenes Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-206

Table 266. New Project Wells CO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 29. New Project Wells CO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction DustConstruction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 13,961 395 85,304 6,893 18,798 4,287 5,795 0 52 115,106 0 0 776 0 113,731 215 153 0 0 0 0 365,467

2010 0 18,731 529 114,450 9,243 25,221 5,748 7,775 0 122 269,541 0 0 1,814 0 306,150 505 359 0 0 0 1 760,187

2011 0 18,614 525 113,739 9,175 25,064 5,706 7,727 0 192 423,016 0 0 2,834 0 469,747 792 564 0 0 0 1 1,077,695

2012 0 18,265 514 111,606 8,992 24,594 5,591 7,582 0 260 573,614 0 0 3,821 0 607,749 1,074 765 601,322 96,112 0 1 2,061,863

2013 0 18,614 523 113,739 9,149 25,064 5,688 7,727 0 329 727,089 0 0 4,810 0 743,693 1,361 970 601,322 96,112 0 2 2,356,191

2014 0 18,440 517 112,672 9,049 24,829 5,625 7,654 0 398 879,125 0 0 5,776 0 864,155 1,646 1,172 601,322 96,112 0 2 2,628,494

2015 0 19,021 532 116,227 9,317 25,612 5,791 7,896 0 469 1,035,958 0 0 6,752 0 982,666 1,939 1,381 601,322 96,112 0 3 2,910,999

2016 0 14,862 415 90,813 7,266 20,012 4,516 6,169 0 525 1,158,498 0 0 7,490 0 1,071,923 2,169 1,545 601,322 96,112 0 3 3,083,640

2017 0 19,516 543 119,248 9,524 26,278 5,918 8,101 0 598 1,319,407 0 0 8,463 0 1,183,750 2,470 1,759 601,322 96,112 0 3 3,403,012

2018 0 21,465 596 131,155 10,457 28,902 6,497 8,910 0 678 1,496,383 0 0 9,523 0 1,353,971 2,801 1,995 601,322 96,112 0 4 3,770,769

2019 0 17,276 478 105,564 8,403 23,263 5,220 7,171 0 742 1,638,827 0 0 10,356 0 1,457,627 3,068 2,185 601,322 96,112 0 4 3,977,619

2020 0 17,291 478 105,653 8,397 23,282 5,216 7,177 0 807 1,781,391 0 0 11,179 0 1,553,372 3,335 2,375 601,322 96,112 0 5 4,217,392

2021 0 19,516 538 119,248 9,464 26,278 5,878 8,101 0 880 1,942,301 0 0 12,113 0 1,653,623 3,636 2,590 601,322 96,112 0 5 4,501,605

2022 0 18,512 508 113,117 8,945 24,927 5,555 7,684 0 949 2,094,936 0 0 12,855 0 1,779,182 3,922 2,793 601,322 96,112 0 5 4,771,325

2023 0 6,210 171 37,943 3,007 8,361 1,868 2,578 0 972 2,146,135 0 0 13,303 0 1,782,508 4,018 2,862 601,322 96,112 0 6 4,707,374

2024 0 0 0 0 0 0 0 0 0 972 2,146,135 0 0 13,235 0 1,702,123 4,018 2,862 601,322 96,112 0 6 4,566,784

2025 0 0 0 0 0 0 0 0 0 972 2,146,135 0 0 13,111 0 1,649,632 4,018 2,862 601,322 96,112 0 6 4,514,168

2026 0 0 0 0 0 0 0 0 0 972 2,146,135 0 0 13,054 0 1,612,301 4,018 2,862 601,322 96,112 0 6 4,476,781

2027 0 0 0 0 0 0 0 0 0 972 2,146,135 0 0 13,010 0 1,582,070 4,018 2,862 601,322 96,112 0 6 4,446,505

2028 0 0 0 0 0 0 0 0 0 972 2,146,135 0 0 12,967 0 1,556,255 4,018 2,862 601,322 96,112 0 6 4,420,648

2029 0 0 0 0 0 0 0 0 0 972 2,146,135 0 0 12,930 0 1,533,629 4,018 2,862 601,322 96,112 0 6 4,397,986

2030 0 0 0 0 0 0 0 0 0 972 2,146,135 0 0 12,896 0 1,513,378 4,018 2,862 601,322 96,112 0 6 4,377,700

2031 0 0 0 0 0 0 0 0 0 972 2,146,135 0 0 12,866 0 1,495,075 4,018 2,862 601,322 96,112 0 6 4,359,367

2032 0 0 0 0 0 0 0 0 0 972 2,146,135 0 0 12,837 0 1,478,250 4,018 2,862 601,322 96,112 0 6 4,342,513

2033 0 0 0 0 0 0 0 0 0 972 2,146,135 0 0 12,812 0 1,462,728 4,018 2,862 601,322 96,112 0 6 4,326,966

2034 0 0 0 0 0 0 0 0 0 972 2,146,135 0 0 12,788 0 1,448,276 4,018 2,862 601,322 96,112 0 6 4,312,490

2035 0 0 0 0 0 0 0 0 0 972 2,146,135 0 0 12,768 0 1,434,654 4,018 2,862 601,322 96,112 0 6 4,298,848

2036 0 0 0 0 0 0 0 0 0 972 2,146,135 0 0 12,750 0 1,421,772 4,018 2,862 601,322 96,112 0 6 4,285,949

2037 0 0 0 0 0 0 0 0 0 972 2,146,135 0 0 12,734 0 1,409,575 4,018 2,862 601,322 96,112 0 6 4,273,734

TOTAL 0 260,294 7,262 1,590,477 127,280 350,485 79,101 108,046 0 21,585 47,647,215 0 0 292,622 0 37,223,568 89,198 63,534 15,634,373 2,498,906 0 124 105,994,072

Production Total (Costruction + Drilling + Completion 

+ Production)

CO2 [tpy]

Pollutant Year

Construction Drilling Completion

0

716,000

1,432,000

2,148,000

2,864,000

3,580,000

4,296,000

5,012,000

5,728,000

6,444,000

7,160,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well CO2 Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-207

Table 267. New Project Wells CO2e - from CH4 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 30. New Project Wells CO2e - from CH4 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction DustConstruction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 8 0 14 6 3 4 36 0 11,134 46 0 0 1 409 662 0 36,530 0 0 0 1 48,857

2010 0 11 1 19 9 4 5 48 0 26,072 108 0 0 3 1,259 1,765 0 85,541 0 0 0 2 114,849

2011 0 11 1 19 9 4 6 48 0 40,918 170 0 0 5 1,895 2,712 0 134,248 0 0 0 4 180,049

2012 0 11 1 19 9 4 6 47 0 55,485 231 0 0 6 2,349 3,520 0 182,041 1,908 210 0 5 245,851

2013 0 11 1 19 10 4 6 48 0 70,330 293 0 0 8 2,777 4,318 0 230,748 1,908 210 0 6 310,695

2014 0 11 1 19 10 4 6 48 0 85,036 354 0 0 9 3,093 5,032 0 278,998 1,908 210 0 8 374,745

2015 0 11 1 20 10 4 6 49 0 100,206 417 0 0 10 3,376 5,738 0 328,770 1,908 210 0 9 440,744

2016 0 9 0 15 8 3 5 38 0 112,059 466 0 0 11 3,572 6,271 0 367,659 1,908 210 0 10 492,245

2017 0 12 1 20 10 4 6 50 0 127,624 531 0 0 13 3,788 6,943 0 418,725 1,908 210 0 11 559,856

2018 0 13 1 22 11 4 7 56 0 144,743 602 0 0 14 4,382 7,936 0 474,889 1,908 210 0 13 634,811

2019 0 10 1 18 9 4 6 45 0 158,521 660 0 0 15 4,609 8,556 0 520,095 1,908 210 0 14 694,679

2020 0 10 1 18 9 4 6 45 0 172,311 717 0 0 16 4,776 9,133 1 565,339 1,908 210 0 15 754,517

2021 0 12 1 20 10 4 6 50 0 187,875 782 0 0 17 4,905 9,743 1 616,405 1,908 210 0 17 821,965

2022 0 11 1 19 10 4 6 48 0 202,640 843 0 0 18 5,257 10,485 1 664,845 1,908 210 0 18 886,322

2023 0 4 0 6 3 1 2 16 0 207,592 864 0 0 19 5,083 10,525 1 681,093 1,908 210 0 18 907,345

2024 0 0 0 0 0 0 0 0 0 207,592 864 0 0 19 4,476 10,094 1 681,093 1,908 210 0 18 906,274

2025 0 0 0 0 0 0 0 0 0 207,592 864 0 0 19 4,080 9,812 1 681,093 1,908 210 0 18 905,595

2026 0 0 0 0 0 0 0 0 0 207,592 864 0 0 19 3,798 9,611 1 681,093 1,908 210 0 18 905,113

2027 0 0 0 0 0 0 0 0 0 207,592 864 0 0 19 3,570 9,449 1 681,093 1,908 210 0 18 904,723

2028 0 0 0 0 0 0 0 0 0 207,592 864 0 0 19 3,375 9,310 1 681,093 1,908 210 0 18 904,389

2029 0 0 0 0 0 0 0 0 0 207,592 864 0 0 19 3,204 9,188 1 681,093 1,908 210 0 18 904,097

2030 0 0 0 0 0 0 0 0 0 207,592 864 0 0 18 3,051 9,080 1 681,093 1,908 210 0 18 903,835

2031 0 0 0 0 0 0 0 0 0 207,592 864 0 0 18 2,913 8,981 1 681,093 1,908 210 0 18 903,598

2032 0 0 0 0 0 0 0 0 0 207,592 864 0 0 18 2,786 8,891 1 681,093 1,908 210 0 18 903,381

2033 0 0 0 0 0 0 0 0 0 207,592 864 0 0 18 2,669 8,808 1 681,093 1,908 210 0 18 903,180

2034 0 0 0 0 0 0 0 0 0 207,592 864 0 0 18 2,560 8,730 1 681,093 1,908 210 0 18 902,993

2035 0 0 0 0 0 0 0 0 0 207,592 864 0 0 18 2,457 8,657 1 681,093 1,908 210 0 18 902,817

2036 0 0 0 0 0 0 0 0 0 207,592 864 0 0 17 2,360 8,588 1 681,093 1,908 210 0 18 902,651

2037 0 0 0 0 0 0 0 0 0 207,592 864 0 0 17 2,268 8,522 1 681,093 1,908 210 0 18 902,493

TOTAL 0 157 8 269 132 54 83 673 0 4,608,832 19,178 0 0 420 95,098 221,057 14 15,121,233 49,600 5,451 0 410 20,122,669

Production Total (Costruction + Drilling + Completion 

+ Production)

CO2e-from CH4 [tpy]

Pollutant Year

Construction Drilling Completion

0

278,000

556,000

834,000

1,112,000

1,390,000

1,668,000

1,946,000

2,224,000

2,502,000

2,780,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well CO2e - from CH4 Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-208

Table 268. New Project Wells CO2e - from N2O Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 31. New Project Wells CO2e - from N2O Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction DustConstruction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 110 3 671 41 148 26 19 0 0 654 0 0 10 0 271 2 0 0 0 0 0 1,954

2010 0 148 3 901 52 198 33 26 0 0 1,532 0 0 21 0 696 4 0 0 0 0 0 3,613

2011 0 147 3 895 48 197 30 26 0 0 2,404 0 0 30 0 1,075 6 0 0 0 0 0 4,862

2012 0 144 3 878 43 194 28 25 0 0 3,260 0 0 38 0 1,413 8 0 4,209 792 0 0 11,035

2013 0 147 3 895 41 197 26 26 0 0 4,132 0 0 44 0 1,749 11 0 4,209 792 0 0 12,272

2014 0 146 2 887 38 195 24 25 0 0 4,996 0 0 49 0 2,061 13 0 4,209 792 0 0 13,437

2015 0 150 2 915 36 202 23 26 0 0 5,888 0 0 53 0 2,373 15 0 4,209 792 0 0 14,685

2016 0 117 2 715 26 157 17 20 0 0 6,584 0 0 55 0 2,612 17 0 4,209 792 0 0 15,324

2017 0 154 2 938 32 207 20 27 0 0 7,499 0 0 58 0 2,917 19 0 4,209 792 0 0 16,875

2018 0 170 2 1,032 33 227 21 30 0 0 8,504 0 0 61 0 3,326 22 0 4,209 792 0 0 18,429

2019 0 137 2 831 25 183 16 24 0 0 9,314 0 0 62 0 3,604 24 0 4,209 792 0 0 19,221

2020 0 137 1 831 23 183 15 24 0 0 10,124 0 0 63 0 3,869 26 0 4,209 792 0 0 20,298

2021 0 154 2 938 25 207 16 27 0 0 11,039 0 0 64 0 4,156 29 0 4,209 792 0 0 21,657

2022 0 146 1 890 20 196 13 25 0 0 11,906 0 0 57 0 4,476 31 0 4,209 792 0 0 22,764

2023 0 49 0 299 7 66 5 9 0 0 12,197 0 0 66 0 4,523 32 0 4,209 792 0 0 22,254

2024 0 0 0 0 0 0 0 0 0 0 12,197 0 0 62 0 4,399 32 0 4,209 792 0 0 21,691

2025 0 0 0 0 0 0 0 0 0 0 12,197 0 0 55 0 4,317 32 0 4,209 792 0 0 21,603

2026 0 0 0 0 0 0 0 0 0 0 12,197 0 0 52 0 4,260 32 0 4,209 792 0 0 21,542

2027 0 0 0 0 0 0 0 0 0 0 12,197 0 0 50 0 4,213 32 0 4,209 792 0 0 21,493

2028 0 0 0 0 0 0 0 0 0 0 12,197 0 0 48 0 4,173 32 0 4,209 792 0 0 21,450

2029 0 0 0 0 0 0 0 0 0 0 12,197 0 0 45 0 4,138 32 0 4,209 792 0 0 21,413

2030 0 0 0 0 0 0 0 0 0 0 12,197 0 0 44 0 4,106 32 0 4,209 792 0 0 21,380

2031 0 0 0 0 0 0 0 0 0 0 12,197 0 0 42 0 4,078 32 0 4,209 792 0 0 21,350

2032 0 0 0 0 0 0 0 0 0 0 12,197 0 0 41 0 4,052 32 0 4,209 792 0 0 21,323

2033 0 0 0 0 0 0 0 0 0 0 12,197 0 0 40 0 4,028 32 0 4,209 792 0 0 21,298

2034 0 0 0 0 0 0 0 0 0 0 12,197 0 0 40 0 4,005 32 0 4,209 792 0 0 21,275

2035 0 0 0 0 0 0 0 0 0 0 12,197 0 0 39 0 3,984 32 0 4,209 792 0 0 21,254

2036 0 0 0 0 0 0 0 0 0 0 12,197 0 0 39 0 3,964 32 0 4,209 792 0 0 21,233

2037 0 0 0 0 0 0 0 0 0 0 12,197 0 0 38 0 3,946 32 0 4,209 792 0 0 21,214

TOTAL 0 2,057 31 12,516 491 2,758 312 358 0 0 270,795 0 0 1,367 0 96,783 702 0 109,443 20,588 0 0 518,201

Production Total (Costruction + Drilling + Completion 

+ Production)

CO2e-from N2O [tpy]

Pollutant Year

Construction Drilling Completion

0

3,900

7,800

11,700

15,600

19,500

23,400

27,300

31,200

35,100

39,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well CO2e - from N2O Emissions 

By Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Project Emissions Inventory for Future Wells

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-209

Table 269. New Project Wells CO2e - total Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 32. New Project Wells CO2e - total Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction DustConstruction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial Completions DehydratorsFugitive Devices HeatersPneumatic DevicesPneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 14,079 398 85,990 6,940 18,949 4,317 5,850 0 11,186 115,807 0 0 787 409 114,664 217 36,683 0 0 0 1 416,278

2010 0 18,890 533 115,370 9,303 25,423 5,786 7,849 0 26,194 271,181 0 0 1,838 1,259 308,611 509 85,900 0 0 0 3 878,649

2011 0 18,773 529 114,653 9,232 25,265 5,742 7,800 0 41,109 425,590 0 0 2,869 1,895 473,535 798 134,812 0 0 0 5 1,262,606

2012 0 18,421 518 112,503 9,045 24,791 5,624 7,654 0 55,744 577,104 0 0 3,865 2,349 612,682 1,082 182,806 607,439 97,113 0 6 2,318,749

2013 0 18,773 526 114,653 9,199 25,265 5,720 7,800 0 70,659 731,514 0 0 4,862 2,777 749,760 1,372 231,717 607,439 97,113 0 8 2,679,158

2014 0 18,597 520 113,578 9,096 25,028 5,655 7,727 0 85,435 884,475 0 0 5,835 3,093 871,247 1,659 280,170 607,439 97,113 0 10 3,016,677

2015 0 19,183 535 117,161 9,363 25,818 5,820 7,971 0 100,676 1,042,262 0 0 6,816 3,376 990,777 1,955 330,151 607,439 97,113 0 12 3,366,428

2016 0 14,989 417 91,543 7,301 20,173 4,537 6,228 0 112,584 1,165,548 0 0 7,557 3,572 1,080,806 2,186 369,204 607,439 97,113 0 13 3,591,210

2017 0 19,682 546 120,207 9,566 26,489 5,945 8,178 0 128,222 1,327,437 0 0 8,534 3,788 1,193,610 2,490 420,484 607,439 97,113 0 15 3,979,743

2018 0 21,647 598 132,209 10,501 29,134 6,525 8,995 0 145,420 1,505,490 0 0 9,597 4,382 1,365,233 2,824 476,885 607,439 97,113 0 17 4,424,010

2019 0 17,423 481 106,412 8,437 23,449 5,242 7,240 0 159,263 1,648,801 0 0 10,433 4,609 1,469,786 3,093 522,280 607,439 97,113 0 18 4,691,519

2020 0 17,438 480 106,502 8,430 23,469 5,237 7,246 0 173,118 1,792,233 0 0 11,258 4,776 1,566,374 3,362 567,714 607,439 97,113 0 20 4,992,207

2021 0 19,682 540 120,207 9,499 26,489 5,900 8,178 0 188,755 1,954,121 0 0 12,194 4,905 1,667,523 3,665 618,995 607,439 97,113 0 22 5,345,228

2022 0 18,670 510 114,026 8,975 25,127 5,573 7,758 0 203,589 2,107,686 0 0 12,930 5,257 1,794,143 3,953 667,639 607,439 97,113 0 23 5,680,411

2023 0 6,262 172 38,248 3,018 8,428 1,874 2,602 0 208,564 2,159,196 0 0 13,388 5,083 1,797,557 4,050 683,955 607,439 97,113 0 24 5,636,974

2024 0 0 0 0 0 0 0 0 0 208,564 2,159,196 0 0 13,316 4,476 1,716,616 4,050 683,955 607,439 97,113 0 24 5,494,749

2025 0 0 0 0 0 0 0 0 0 208,564 2,159,196 0 0 13,184 4,080 1,663,761 4,050 683,955 607,439 97,113 0 24 5,441,366

2026 0 0 0 0 0 0 0 0 0 208,564 2,159,196 0 0 13,125 3,798 1,626,172 4,050 683,955 607,439 97,113 0 24 5,403,436

2027 0 0 0 0 0 0 0 0 0 208,564 2,159,196 0 0 13,078 3,570 1,595,731 4,050 683,955 607,439 97,113 0 24 5,372,721

2028 0 0 0 0 0 0 0 0 0 208,564 2,159,196 0 0 13,033 3,375 1,569,738 4,050 683,955 607,439 97,113 0 24 5,346,488

2029 0 0 0 0 0 0 0 0 0 208,564 2,159,196 0 0 12,994 3,204 1,546,956 4,050 683,955 607,439 97,113 0 24 5,323,496

2030 0 0 0 0 0 0 0 0 0 208,564 2,159,196 0 0 12,958 3,051 1,526,564 4,050 683,955 607,439 97,113 0 24 5,302,915

2031 0 0 0 0 0 0 0 0 0 208,564 2,159,196 0 0 12,926 2,913 1,508,135 4,050 683,955 607,439 97,113 0 24 5,284,315

2032 0 0 0 0 0 0 0 0 0 208,564 2,159,196 0 0 12,896 2,786 1,491,193 4,050 683,955 607,439 97,113 0 24 5,267,217

2033 0 0 0 0 0 0 0 0 0 208,564 2,159,196 0 0 12,870 2,669 1,475,564 4,050 683,955 607,439 97,113 0 24 5,251,444

2034 0 0 0 0 0 0 0 0 0 208,564 2,159,196 0 0 12,845 2,560 1,461,012 4,050 683,955 607,439 97,113 0 24 5,236,759

2035 0 0 0 0 0 0 0 0 0 208,564 2,159,196 0 0 12,825 2,457 1,447,295 4,050 683,955 607,439 97,113 0 24 5,222,918

2036 0 0 0 0 0 0 0 0 0 208,564 2,159,196 0 0 12,806 2,360 1,434,324 4,050 683,955 607,439 97,113 0 24 5,209,832

2037 0 0 0 0 0 0 0 0 0 208,564 2,159,196 0 0 12,789 2,268 1,422,042 4,050 683,955 607,439 97,113 0 24 5,197,441

TOTAL 0 262,508 7,301 1,603,261 127,903 353,297 79,496 109,078 0 4,630,417 47,937,188 0 0 294,409 95,098 37,541,408 89,914 15,184,767 15,793,416 2,524,945 0 534 126,634,942

Production Total (Costruction + Drilling + Completion 

+ Production)

CO2e-total 

[tpy]

Pollutant Year

Construction Drilling Completion

0

998,400

1,996,800

2,995,200

3,993,600

4,992,000

5,990,400

6,988,800

7,987,200

8,985,600

9,984,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well CO2e - total Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-210

Total Project Emissions Summary
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-211

Table 270. Total New and Existing Wells NOx Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 33. Total New and Existing Wells NOx Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 293 5 1,166 52 169 32 0 0 0 570 0 0 29 0 62 20 0 568 621 0 0 3,587

2009 0 177 3 802 51 161 31 3 0 0 660 0 0 33 0 120 22 0 568 621 0 0 3,250

2010 0 237 3 1,076 61 216 38 4 0 0 783 0 0 38 0 214 24 0 568 621 0 0 3,884

2011 0 236 3 1,069 55 215 34 4 0 0 905 0 0 42 0 298 26 0 568 621 0 0 4,075

2012 0 231 3 1,049 48 211 30 4 0 0 1,025 0 0 44 0 372 29 0 951 675 0 0 4,672

2013 0 236 2 1,069 43 215 27 4 0 0 1,147 0 0 46 0 445 31 0 951 675 0 0 4,893

2014 0 234 2 1,059 38 213 23 4 0 0 1,269 0 0 48 0 509 33 0 951 675 0 0 5,058

2015 0 241 2 1,093 35 219 21 5 0 0 1,394 0 0 49 0 572 35 0 951 675 0 0 5,292

2016 0 188 1 854 24 171 15 4 0 0 1,491 0 0 48 0 620 37 0 951 675 0 0 5,079

2017 0 247 2 1,121 28 225 17 5 0 0 1,619 0 0 49 0 680 40 0 951 675 0 0 5,659

2018 0 272 2 1,233 27 247 16 5 0 0 1,762 0 0 49 0 771 42 0 951 675 0 0 6,052

2019 0 219 1 992 19 199 12 4 0 0 1,875 0 0 48 0 827 44 0 951 675 0 0 5,867

2020 0 219 1 993 17 199 10 4 0 0 1,989 0 0 47 0 879 46 0 951 675 0 0 6,032

2021 0 247 1 1,121 17 225 11 5 0 0 2,118 0 0 47 0 934 49 0 951 675 0 0 6,402

2022 0 235 1 1,063 12 213 8 4 0 0 2,240 0 0 43 0 1,002 51 0 951 675 0 0 6,499

2023 0 79 0 357 5 72 3 1 0 0 2,278 0 0 47 0 1,004 52 0 951 675 0 0 5,524

2024 0 0 0 0 0 0 0 0 0 0 2,273 0 0 45 0 964 52 0 951 675 0 0 4,960

2025 0 0 0 0 0 0 0 0 0 0 2,268 0 0 42 0 937 52 0 951 675 0 0 4,925

2026 0 0 0 0 0 0 0 0 0 0 2,263 0 0 40 0 917 51 0 951 675 0 0 4,899

2027 0 0 0 0 0 0 0 0 0 0 2,258 0 0 39 0 902 51 0 951 675 0 0 4,877

2028 0 0 0 0 0 0 0 0 0 0 2,249 0 0 38 0 888 51 0 951 675 0 0 4,852

2029 0 0 0 0 0 0 0 0 0 0 2,245 0 0 37 0 876 51 0 951 675 0 0 4,835

2030 0 0 0 0 0 0 0 0 0 0 2,240 0 0 37 0 865 51 0 951 675 0 0 4,819

2031 0 0 0 0 0 0 0 0 0 0 2,236 0 0 36 0 855 50 0 951 675 0 0 4,804

2032 0 0 0 0 0 0 0 0 0 0 2,231 0 0 35 0 847 50 0 951 675 0 0 4,789

2033 0 0 0 0 0 0 0 0 0 0 2,227 0 0 35 0 838 50 0 951 675 0 0 4,776

2034 0 0 0 0 0 0 0 0 0 0 2,222 0 0 34 0 831 50 0 951 675 0 0 4,763

2035 0 0 0 0 0 0 0 0 0 0 2,218 0 0 34 0 823 50 0 951 675 0 0 4,751

2036 0 0 0 0 0 0 0 0 0 0 2,213 0 0 33 0 817 50 0 951 675 0 0 4,739

2037 0 0 0 0 0 0 0 0 0 0 2,209 0 0 33 0 810 49 0 951 675 0 0 4,728

TOTAL 0 3,591 32 16,118 531 3,170 329 62 0 0 54,476 0 0 1,225 0 21,480 1,289 0 27,002 20,035 0 0 149,340

Production Total (Costruction + 

Drilling + Completion 

+ Production)

NOx [tpy]

Pollutant Year

Construction Drilling Completion

0

680

1,360

2,040

2,720

3,400

4,080

4,760

5,440

6,120

6,800

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well NOx Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-212

Table 271. Total New and Existing Wells VOC Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 34. Total New and Existing Wells VOC Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 44 1 106 6 0 4 130 27,096 1,904 31 0 12,422 7 197 79 2 2,133 198 221 14,072 20 58,672

2009 0 26 0 45 6 9 4 4 26,548 2,206 36 0 12,295 8 246 154 2 2,470 198 221 13,311 21 57,811

2010 0 35 0 61 8 12 5 6 25,484 2,617 43 0 12,169 9 347 276 2 2,930 198 221 11,585 22 56,030

2011 0 35 0 60 7 12 4 6 24,751 3,025 50 0 12,042 10 427 384 2 3,387 198 221 10,624 22 55,269

2012 0 35 0 59 6 12 4 6 24,463 3,427 56 0 11,925 11 492 479 3 3,837 271 224 10,438 23 55,770

2013 0 35 0 60 6 12 4 6 24,206 3,836 63 0 11,808 12 554 573 3 4,296 271 224 10,307 24 56,300

2014 0 35 0 60 5 12 3 6 23,736 4,242 70 0 11,692 13 594 655 3 4,750 271 224 9,821 25 56,215

2015 0 36 0 62 5 12 3 6 23,244 4,661 77 0 11,575 13 628 737 3 5,220 271 224 9,316 26 56,118

2016 0 28 0 48 4 10 2 5 22,781 4,985 82 0 11,458 13 651 798 3 5,582 271 224 8,875 27 55,845

2017 0 37 0 63 4 13 3 6 22,347 5,415 89 0 11,341 13 677 876 3 6,064 271 224 8,490 28 55,964

2018 0 41 0 69 4 14 3 7 21,938 5,890 97 0 11,224 14 761 992 3 6,596 271 224 8,150 29 56,326

2019 0 33 0 56 3 11 2 5 21,545 6,269 103 0 11,108 14 790 1,064 3 7,020 271 224 7,840 30 56,391

2020 0 33 0 56 3 11 2 5 21,179 6,650 109 0 11,000 14 811 1,131 3 7,447 271 224 7,555 31 56,534

2021 0 37 0 63 3 13 2 6 20,830 7,082 116 0 10,893 14 826 1,202 4 7,931 271 224 7,298 32 56,846

2022 0 35 0 60 2 12 1 6 20,403 7,491 123 0 10,786 13 873 1,289 4 8,389 271 224 6,951 33 56,965

2023 0 12 0 20 1 4 1 2 20,072 7,617 125 0 10,679 14 844 1,293 4 8,530 271 224 6,729 33 56,473

2024 0 0 0 0 0 0 0 0 19,751 7,601 125 0 10,572 13 751 1,240 4 8,512 271 224 6,521 33 55,616

2025 0 0 0 0 0 0 0 0 19,449 7,584 125 0 10,465 12 690 1,205 4 8,493 271 224 6,340 33 54,894

2026 0 0 0 0 0 0 0 0 19,149 7,568 124 0 10,358 12 645 1,181 4 8,475 271 224 6,162 32 54,203

2027 0 0 0 0 0 0 0 0 18,858 7,551 124 0 10,251 12 609 1,160 4 8,456 271 224 5,996 32 53,547

2028 0 0 0 0 0 0 0 0 18,445 7,520 124 0 10,046 11 578 1,143 4 8,421 271 224 5,837 32 52,655

2029 0 0 0 0 0 0 0 0 18,076 7,505 123 0 9,949 11 548 1,127 4 8,405 271 224 5,580 32 51,853

2030 0 0 0 0 0 0 0 0 17,816 7,490 123 0 9,852 10 524 1,113 4 8,388 271 224 5,440 32 51,286

2031 0 0 0 0 0 0 0 0 17,564 7,475 123 0 9,754 10 501 1,101 4 8,371 271 224 5,310 31 50,739

2032 0 0 0 0 0 0 0 0 17,314 7,460 123 0 9,657 10 481 1,089 4 8,354 271 224 5,184 31 50,201

2033 0 0 0 0 0 0 0 0 17,066 7,445 122 0 9,560 10 462 1,079 4 8,338 271 224 5,060 31 49,670

2034 0 0 0 0 0 0 0 0 16,826 7,431 122 0 9,462 10 444 1,069 4 8,321 271 224 4,945 31 49,157

2035 0 0 0 0 0 0 0 0 16,591 7,416 122 0 9,365 9 427 1,060 4 8,304 271 224 4,836 31 48,658

2036 0 0 0 0 0 0 0 0 16,367 7,401 122 0 9,268 9 411 1,051 4 8,288 271 224 4,738 31 48,183

2037 0 0 0 0 0 0 0 0 16,146 7,386 121 0 9,170 9 396 1,042 4 8,271 271 224 4,643 30 47,714

TOTAL 0 537 5 948 75 169 47 210 620,038 182,149 2,996 0 322,148 341 17,184 27,640 98 203,978 7,828 6,695 227,956 867 1,621,907

Production Total (Costruction + 

Drilling + Completion 

+ Production)

VOC [tpy]

Pollutant Year

Construction Drilling Completion

0

6,160

12,320

18,480

24,640

30,800

36,960

43,120

49,280

55,440

61,600

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well VOC Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-213

Table 272. Total New and Existing Wells SO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 35. Total New and Existing Wells SO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 5 0 71 0 56 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 135

2009 0 3 0 19 0 4 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 29

2010 0 2 0 12 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 19

2011 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 5

2012 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2013 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2014 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2015 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2016 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2017 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2018 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2019 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2020 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2021 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2022 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2023 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2024 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2025 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2026 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2027 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2028 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2029 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2030 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2031 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2032 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2033 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2034 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2035 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2036 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2037 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

TOTAL 0 12 0 112 1 65 1 0 0 0 0 0 0 7 0 0 2 0 18 61 0 0 279

Production Total (Costruction + 

Drilling + Completion 

+ Production)

SO2 [tpy]

Pollutant Year

Construction Drilling Completion

0.0

14.0

28.0

42.0

56.0

70.0

84.0

98.0

112.0

126.0

140.0

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well SO2 Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-214

Table 273. Total New and Existing Wells PM10 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 36. Total New and Existing Wells PM10 Emissions (tons/year) Contribution by Source Category and by Project Year. Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 194 18 32 56 298 12 188 0 0 0 43 0 0 379 0 0 1 0 32 49 0 0 1,302

2009 117 11 19 27 309 5 196 0 0 0 50 0 0 439 0 0 1 0 32 49 0 0 1,255

2010 157 14 26 36 414 7 262 0 0 0 59 0 0 521 0 0 2 0 32 49 0 0 1,579

2011 156 14 26 36 411 7 261 0 0 0 69 0 0 602 0 0 2 0 32 49 0 0 1,663

2012 153 14 25 35 403 7 255 0 0 0 78 0 0 682 0 0 2 0 67 55 0 0 1,776

2013 156 14 26 36 411 7 260 0 0 0 87 0 0 763 0 0 2 0 67 55 0 0 1,884

2014 154 14 26 36 406 7 257 0 0 0 96 0 0 844 0 0 2 0 67 55 0 0 1,964

2015 159 15 26 37 419 7 265 0 0 0 106 0 0 927 0 0 2 0 67 55 0 0 2,085

2016 124 11 21 29 327 6 207 0 0 0 113 0 0 991 0 0 2 0 67 55 0 0 1,953

2017 163 15 27 38 429 7 272 0 0 0 123 0 0 1,076 0 0 2 0 67 55 0 0 2,275

2018 179 16 30 41 472 8 299 0 0 0 134 0 0 1,171 0 0 2 0 67 55 0 0 2,475

2019 144 13 24 33 380 7 241 0 0 0 142 0 0 1,246 0 0 2 0 67 55 0 0 2,354

2020 144 13 24 33 380 7 241 0 0 0 151 0 0 1,321 0 0 2 0 67 55 0 0 2,439

2021 163 15 27 38 429 7 272 0 0 0 161 0 0 1,407 0 0 2 0 67 55 0 0 2,643

2022 155 14 26 36 406 7 257 0 0 0 170 0 0 1,488 0 0 2 0 67 55 0 0 2,683

2023 52 5 9 12 136 2 86 0 0 0 173 0 0 1,513 0 0 3 0 67 55 0 0 2,113

2024 0 0 0 0 0 0 0 0 0 0 173 0 0 1,510 0 0 2 0 67 55 0 0 1,807

2025 0 0 0 0 0 0 0 0 0 0 172 0 0 1,506 0 0 2 0 67 55 0 0 1,803

2026 0 0 0 0 0 0 0 0 0 0 172 0 0 1,503 0 0 2 0 67 55 0 0 1,799

2027 0 0 0 0 0 0 0 0 0 0 172 0 0 1,499 0 0 2 0 67 55 0 0 1,796

2028 0 0 0 0 0 0 0 0 0 0 171 0 0 1,493 0 0 2 0 67 55 0 0 1,789

2029 0 0 0 0 0 0 0 0 0 0 171 0 0 1,490 0 0 2 0 67 55 0 0 1,785

2030 0 0 0 0 0 0 0 0 0 0 170 0 0 1,487 0 0 2 0 67 55 0 0 1,782

2031 0 0 0 0 0 0 0 0 0 0 170 0 0 1,484 0 0 2 0 67 55 0 0 1,779

2032 0 0 0 0 0 0 0 0 0 0 170 0 0 1,481 0 0 2 0 67 55 0 0 1,775

2033 0 0 0 0 0 0 0 0 0 0 169 0 0 1,478 0 0 2 0 67 55 0 0 1,772

2034 0 0 0 0 0 0 0 0 0 0 169 0 0 1,475 0 0 2 0 67 55 0 0 1,769

2035 0 0 0 0 0 0 0 0 0 0 169 0 0 1,472 0 0 2 0 67 55 0 0 1,765

2036 0 0 0 0 0 0 0 0 0 0 168 0 0 1,469 0 0 2 0 67 55 0 0 1,762

2037 0 0 0 0 0 0 0 0 0 0 168 0 0 1,466 0 0 2 0 67 55 0 0 1,759

TOTAL 2,369 217 393 558 6,030 112 3,820 0 0 0 4,140 0 0 36,185 0 0 65 0 1,883 1,615 0 0 57,386

Production Total (Costruction + 

Drilling + Completion 

+ Production)

PM10 [tpy]

Pollutant Year

Construction Drilling Completion

0

282

564

846

1,128

1,410

1,692

1,974

2,256

2,538

2,820

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well PM10 Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-215

Table 274. Total New and Existing Wells PM2.5 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 37. Total New and Existing Wells PM2.5 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 50 17 3 54 32 12 20 0 0 0 43 0 0 39 0 0 1 0 32 49 0 0 353

2009 30 10 2 26 33 5 21 0 0 0 50 0 0 45 0 0 1 0 32 49 0 0 305

2010 40 14 3 35 44 7 28 0 0 0 59 0 0 53 0 0 1 0 32 49 0 0 366

2011 40 14 3 35 44 7 28 0 0 0 69 0 0 62 0 0 2 0 32 49 0 0 382

2012 39 14 3 34 42 7 27 0 0 0 78 0 0 70 0 0 2 0 67 55 0 0 437

2013 40 14 3 35 43 7 27 0 0 0 87 0 0 78 0 0 2 0 67 55 0 0 457

2014 40 14 3 35 42 7 27 0 0 0 96 0 0 86 0 0 2 0 67 55 0 0 473

2015 41 14 3 36 43 7 27 0 0 0 106 0 0 94 0 0 2 0 67 55 0 0 495

2016 32 11 2 28 34 6 21 0 0 0 113 0 0 100 0 0 2 0 67 55 0 0 471

2017 42 14 3 37 44 7 28 0 0 0 123 0 0 109 0 0 2 0 67 55 0 0 531

2018 46 16 3 40 48 8 30 0 0 0 134 0 0 118 0 0 2 0 67 55 0 0 568

2019 37 13 2 32 39 6 24 0 0 0 142 0 0 126 0 0 2 0 67 55 0 0 547

2020 37 13 2 32 38 6 24 0 0 0 151 0 0 133 0 0 2 0 67 55 0 0 563

2021 42 14 3 37 43 7 27 0 0 0 161 0 0 142 0 0 2 0 67 55 0 0 601

2022 40 14 3 35 41 7 26 0 0 0 170 0 0 149 0 0 2 0 67 55 0 0 609

2023 13 5 1 12 14 2 9 0 0 0 173 0 0 152 0 0 2 0 67 55 0 0 505

2024 0 0 0 0 0 0 0 0 0 0 173 0 0 152 0 0 2 0 67 55 0 0 449

2025 0 0 0 0 0 0 0 0 0 0 172 0 0 151 0 0 2 0 67 55 0 0 448

2026 0 0 0 0 0 0 0 0 0 0 172 0 0 151 0 0 2 0 67 55 0 0 447

2027 0 0 0 0 0 0 0 0 0 0 172 0 0 150 0 0 2 0 67 55 0 0 447

2028 0 0 0 0 0 0 0 0 0 0 171 0 0 150 0 0 2 0 67 55 0 0 445

2029 0 0 0 0 0 0 0 0 0 0 171 0 0 149 0 0 2 0 67 55 0 0 444

2030 0 0 0 0 0 0 0 0 0 0 170 0 0 149 0 0 2 0 67 55 0 0 444

2031 0 0 0 0 0 0 0 0 0 0 170 0 0 149 0 0 2 0 67 55 0 0 443

2032 0 0 0 0 0 0 0 0 0 0 170 0 0 148 0 0 2 0 67 55 0 0 442

2033 0 0 0 0 0 0 0 0 0 0 169 0 0 148 0 0 2 0 67 55 0 0 442

2034 0 0 0 0 0 0 0 0 0 0 169 0 0 148 0 0 2 0 67 55 0 0 441

2035 0 0 0 0 0 0 0 0 0 0 169 0 0 148 0 0 2 0 67 55 0 0 440

2036 0 0 0 0 0 0 0 0 0 0 168 0 0 147 0 0 2 0 67 55 0 0 440

2037 0 0 0 0 0 0 0 0 0 0 168 0 0 147 0 0 2 0 67 55 0 0 439

TOTAL 610 210 41 541 625 109 395 0 0 0 4,140 0 0 3,644 0 0 63 0 1,883 1,615 0 0 13,875

Production Total (Costruction + 

Drilling + Completion 

+ Production)

PM2.5 [tpy]

Pollutant Year

Construction Drilling Completion

0

64

128

192

256

320

384

448

512

576

640

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well PM2.5 Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-216

Table 275. Total New and Existing Wells CO Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 38. Total New and Existing Wells CO Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 362 6 504 56 132 36 0 0 0 478 0 0 79 0 335 8 0 741 449 0 0 3,185

2009 0 218 4 470 55 93 35 18 0 0 554 0 0 90 0 651 9 0 741 449 0 0 3,386

2010 0 293 5 630 71 125 45 24 0 0 657 0 0 105 0 1,167 11 0 741 449 0 0 4,322

2011 0 291 4 626 67 124 43 24 0 0 760 0 0 118 0 1,622 12 0 741 449 0 0 4,881

2012 0 286 4 615 62 122 40 24 0 0 861 0 0 130 0 2,024 13 0 1,244 511 0 0 5,936

2013 0 291 4 626 60 124 38 24 0 0 964 0 0 141 0 2,423 15 0 1,244 511 0 0 6,465

2014 0 288 4 621 56 123 36 24 0 0 1,066 0 0 150 0 2,771 16 0 1,244 511 0 0 6,910

2015 0 297 4 640 55 127 35 25 0 0 1,171 0 0 159 0 3,115 18 0 1,244 511 0 0 7,400

2016 0 232 3 500 40 99 26 19 0 0 1,252 0 0 163 0 3,373 19 0 1,244 511 0 0 7,483

2017 0 305 3 657 51 130 32 25 0 0 1,360 0 0 171 0 3,703 20 0 1,244 511 0 0 8,214

2018 0 336 3 722 53 143 34 28 0 0 1,480 0 0 180 0 4,195 22 0 1,244 511 0 0 8,952

2019 0 270 3 581 41 115 26 22 0 0 1,575 0 0 186 0 4,500 23 0 1,244 511 0 0 9,099

2020 0 270 3 582 40 115 26 23 0 0 1,671 0 0 192 0 4,784 24 0 1,244 511 0 0 9,485

2021 0 305 3 657 44 130 28 25 0 0 1,779 0 0 199 0 5,085 26 0 1,244 511 0 0 10,036

2022 0 289 3 623 39 123 25 24 0 0 1,882 0 0 200 0 5,450 27 0 1,244 511 0 0 10,440

2023 0 97 1 209 14 41 9 8 0 0 1,914 0 0 208 0 5,465 28 0 1,244 511 0 0 9,749

2024 0 0 0 0 0 0 0 0 0 0 1,909 0 0 204 0 5,243 28 0 1,244 511 0 0 9,140

2025 0 0 0 0 0 0 0 0 0 0 1,905 0 0 197 0 5,097 28 0 1,244 511 0 0 8,983

2026 0 0 0 0 0 0 0 0 0 0 1,901 0 0 194 0 4,992 28 0 1,244 511 0 0 8,870

2027 0 0 0 0 0 0 0 0 0 0 1,897 0 0 191 0 4,906 28 0 1,244 511 0 0 8,778

2028 0 0 0 0 0 0 0 0 0 0 1,889 0 0 188 0 4,833 27 0 1,244 511 0 0 8,693

2029 0 0 0 0 0 0 0 0 0 0 1,885 0 0 185 0 4,766 27 0 1,244 511 0 0 8,619

2030 0 0 0 0 0 0 0 0 0 0 1,882 0 0 183 0 4,707 27 0 1,244 511 0 0 8,555

2031 0 0 0 0 0 0 0 0 0 0 1,878 0 0 181 0 4,655 27 0 1,244 511 0 0 8,496

2032 0 0 0 0 0 0 0 0 0 0 1,874 0 0 179 0 4,606 27 0 1,244 511 0 0 8,442

2033 0 0 0 0 0 0 0 0 0 0 1,870 0 0 176 0 4,562 27 0 1,244 511 0 0 8,391

2034 0 0 0 0 0 0 0 0 0 0 1,867 0 0 174 0 4,520 27 0 1,244 511 0 0 8,343

2035 0 0 0 0 0 0 0 0 0 0 1,863 0 0 172 0 4,480 27 0 1,244 511 0 0 8,298

2036 0 0 0 0 0 0 0 0 0 0 1,859 0 0 171 0 4,443 27 0 1,244 511 0 0 8,256

2037 0 0 0 0 0 0 0 0 0 0 1,855 0 0 169 0 4,408 27 0 1,244 511 0 0 8,214

TOTAL 0 4,431 55 9,264 804 1,864 512 339 0 0 45,760 0 0 5,036 0 116,879 674 0 35,313 15,092 0 0 236,021

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO [tpy]

Pollutant Year

Construction Drilling Completion

0

1,096

2,192

3,288

4,384

5,480

6,576

7,672

8,768

9,864

10,960

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well CO Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-217

Table 276. Total New and Existing Wells Formaldehyde Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 39. Total New and Existing Wells Formaldehyde Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 4 0 9 0 0 0 0 0 0 3 0 0 0 0 32 0 0 85 148 0 0 282

2009 0 2 0 4 0 1 0 2 0 0 3 0 0 0 0 62 0 0 85 148 0 0 308

2010 0 3 0 5 1 1 0 2 0 0 3 0 0 0 0 110 0 0 85 148 0 0 360

2011 0 3 0 5 0 1 0 2 0 0 4 0 0 0 0 153 0 0 85 148 0 0 404

2012 0 3 0 5 0 1 0 2 0 0 5 0 0 0 0 191 0 0 110 151 0 0 469

2013 0 3 0 5 0 1 0 2 0 0 5 0 0 0 0 229 0 0 110 151 0 0 508

2014 0 3 0 5 0 1 0 2 0 0 6 0 0 0 0 262 0 0 110 151 0 0 541

2015 0 3 0 5 0 1 0 2 0 0 6 0 0 0 0 295 0 0 110 151 0 0 574

2016 0 2 0 4 0 1 0 2 0 0 7 0 0 0 0 319 0 0 110 151 0 0 597

2017 0 3 0 5 0 1 0 2 0 0 7 0 0 1 0 350 0 0 110 151 0 0 631

2018 0 3 0 6 0 1 0 3 0 0 8 0 0 1 0 397 0 0 110 151 0 0 680

2019 0 3 0 5 0 1 0 2 0 0 8 0 0 1 0 426 0 0 110 151 0 0 706

2020 0 3 0 5 0 1 0 2 0 0 9 0 0 1 0 453 0 0 110 151 0 0 734

2021 0 3 0 5 0 1 0 2 0 0 9 0 0 1 0 481 0 0 110 151 0 0 764

2022 0 3 0 5 0 1 0 2 0 0 10 0 0 0 0 516 0 0 110 151 0 0 798

2023 0 1 0 2 0 0 0 1 0 0 10 0 0 1 0 517 0 0 110 151 0 0 792

2024 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 496 0 0 110 151 0 0 767

2025 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 482 0 0 110 151 0 0 754

2026 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 472 0 0 110 151 0 0 744

2027 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 464 0 0 110 151 0 0 735

2028 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 457 0 0 110 151 0 0 728

2029 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 451 0 0 110 151 0 0 722

2030 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 445 0 0 110 151 0 0 716

2031 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 440 0 0 110 151 0 0 711

2032 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 436 0 0 110 151 0 0 707

2033 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 431 0 0 110 151 0 0 703

2034 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 428 0 0 110 151 0 0 699

2035 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 424 0 0 110 151 0 0 695

2036 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 420 0 0 110 151 0 0 691

2037 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 417 0 0 110 151 0 0 688

TOTAL 0 46 0 81 5 14 3 32 0 0 240 0 0 13 0 11,056 8 0 3,200 4,511 0 0 19,209

Production Total (Costruction + 

Drilling + Completion 

+ Production)

formaldehyde 

[tpy]

Pollutant Year

Construction Drilling Completion

0

84

168

252

336

420

504

588

672

756

840

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well Formaldehyde Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-218

Table 277. Total New and Existing Wells n-hexane Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 40. Total New and Existing Wells n-hexane Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 3 708 80 0 0 589 0 7 0 0 42 0 1 547 0 1,978

2009 0 0 0 0 0 0 0 0 694 93 0 0 583 0 8 0 0 49 0 1 517 0 1,947

2010 0 0 0 0 0 0 0 0 666 110 0 0 577 0 12 0 0 58 0 1 450 0 1,875

2011 0 0 0 0 0 0 0 0 647 128 0 0 571 0 15 0 0 67 0 1 412 0 1,841

2012 0 0 0 0 0 0 0 0 639 145 0 0 566 0 17 0 0 76 1 1 405 0 1,849

2013 0 0 0 0 0 0 0 0 633 162 0 0 560 0 19 0 0 85 1 1 400 0 1,860

2014 0 0 0 0 0 0 0 0 620 179 0 0 555 0 20 0 0 94 1 1 381 0 1,851

2015 0 0 0 0 0 0 0 0 607 197 0 0 549 0 21 0 0 104 1 1 361 0 1,841

2016 0 0 0 0 0 0 0 0 595 210 0 0 544 0 22 0 0 111 1 1 344 0 1,828

2017 0 0 0 0 0 0 0 0 584 228 0 0 538 0 23 0 0 120 1 1 328 0 1,824

2018 0 0 0 0 0 0 0 0 573 248 0 0 532 0 26 0 0 131 1 1 315 0 1,828

2019 0 0 0 0 0 0 0 0 563 264 0 0 527 0 27 0 0 139 1 1 303 0 1,826

2020 0 0 0 0 0 0 0 0 553 280 0 0 522 0 28 0 0 148 1 1 292 0 1,825

2021 0 0 0 0 0 0 0 0 544 299 0 0 517 0 28 0 0 157 1 1 282 0 1,829

2022 0 0 0 0 0 0 0 0 533 316 0 0 512 0 30 0 0 166 1 1 268 0 1,827

2023 0 0 0 0 0 0 0 0 525 321 0 0 507 0 29 0 0 169 1 1 260 0 1,812

2024 0 0 0 0 0 0 0 0 516 321 0 0 502 0 26 0 0 169 1 1 252 0 1,786

2025 0 0 0 0 0 0 0 0 508 320 0 0 496 0 23 0 0 169 1 1 244 0 1,763

2026 0 0 0 0 0 0 0 0 500 319 0 0 491 0 22 0 0 168 1 1 237 0 1,741

2027 0 0 0 0 0 0 0 0 493 318 0 0 486 0 21 0 0 168 1 1 231 0 1,719

2028 0 0 0 0 0 0 0 0 482 317 0 0 477 0 20 0 0 167 1 1 225 0 1,689

2029 0 0 0 0 0 0 0 0 472 317 0 0 472 0 19 0 0 167 1 1 215 0 1,663

2030 0 0 0 0 0 0 0 0 466 316 0 0 467 0 18 0 0 166 1 1 209 0 1,644

2031 0 0 0 0 0 0 0 0 459 315 0 0 463 0 17 0 0 166 1 1 204 0 1,626

2032 0 0 0 0 0 0 0 0 452 315 0 0 458 0 16 0 0 166 1 1 199 0 1,609

2033 0 0 0 0 0 0 0 0 446 314 0 0 453 0 16 0 0 165 1 1 195 0 1,591

2034 0 0 0 0 0 0 0 0 440 313 0 0 449 0 15 0 0 165 1 1 190 0 1,574

2035 0 0 0 0 0 0 0 0 434 313 0 0 444 0 15 0 0 165 1 1 186 0 1,558

2036 0 0 0 0 0 0 0 0 428 312 0 0 440 0 14 0 0 164 1 1 182 0 1,542

2037 0 0 0 0 0 0 0 0 422 312 0 0 435 0 13 0 0 164 1 1 178 0 1,526

TOTAL 0 0 0 0 0 0 0 3 16,202 7,682 0 0 15,282 2 584 0 0 4,047 14 43 8,812 1 52,675

Production Total (Costruction + 

Drilling + Completion 

+ Production)

n-hexane [tpy]

Pollutant Year

Construction Drilling Completion

0

208

416

624

832

1,040

1,248

1,456

1,664

1,872

2,080

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well n-hexane Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-219

Table 278. Total New and Existing Wells Benzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 41. Total New and Existing Wells Benzene Emissions (tons/year) Contribution by Source Category and by Project Year. Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 1 0 0 0 1 2,610 13 1 0 50 0 1 0 0 9 2 1 112 3 2,804

2009 0 0 0 0 0 0 0 0 2,557 15 1 0 50 0 1 0 0 10 2 1 106 3 2,747

2010 0 0 0 1 0 0 0 0 2,454 18 2 0 49 0 2 0 0 12 2 1 92 3 2,636

2011 0 0 0 1 0 0 0 0 2,384 21 2 0 49 0 2 0 0 14 2 1 84 3 2,563

2012 0 0 0 1 0 0 0 0 2,356 24 2 0 48 0 2 0 0 16 3 1 82 3 2,539

2013 0 0 0 1 0 0 0 0 2,331 27 3 0 48 0 3 0 0 18 3 1 81 3 2,518

2014 0 0 0 1 0 0 0 0 2,286 29 3 0 47 0 3 0 0 20 3 1 77 3 2,474

2015 0 0 0 1 0 0 0 0 2,239 32 3 0 47 0 3 0 0 22 3 1 73 4 2,427

2016 0 0 0 1 0 0 0 0 2,194 34 3 0 46 0 3 0 0 23 3 1 70 4 2,383

2017 0 0 0 1 0 0 0 0 2,152 37 4 0 46 0 3 0 0 25 3 1 67 4 2,343

2018 0 0 0 1 0 0 0 0 2,113 41 4 0 45 0 4 0 0 27 3 1 64 4 2,307

2019 0 0 0 1 0 0 0 0 2,075 43 4 0 45 0 4 0 0 29 3 1 61 4 2,271

2020 0 0 0 1 0 0 0 0 2,040 46 4 0 44 0 4 0 0 31 3 1 59 4 2,237

2021 0 0 0 1 0 0 0 0 2,006 49 5 0 44 0 4 0 0 33 3 1 57 4 2,207

2022 0 0 0 1 0 0 0 0 1,965 52 5 0 43 0 4 0 0 35 3 1 54 5 2,168

2023 0 0 0 0 0 0 0 0 1,933 53 5 0 43 0 4 0 0 35 3 1 52 5 2,134

2024 0 0 0 0 0 0 0 0 1,902 53 5 0 43 0 4 0 0 35 3 1 51 5 2,100

2025 0 0 0 0 0 0 0 0 1,873 52 5 0 42 0 3 0 0 35 3 1 49 5 2,069

2026 0 0 0 0 0 0 0 0 1,844 52 5 0 42 0 3 0 0 35 3 1 48 4 2,038

2027 0 0 0 0 0 0 0 0 1,816 52 5 0 41 0 3 0 0 35 3 1 46 4 2,007

2028 0 0 0 0 0 0 0 0 1,776 52 5 0 40 0 3 0 0 35 3 1 45 4 1,965

2029 0 0 0 0 0 0 0 0 1,741 52 5 0 40 0 3 0 0 35 3 1 43 4 1,927

2030 0 0 0 0 0 0 0 0 1,716 52 5 0 40 0 3 0 0 35 3 1 42 4 1,900

2031 0 0 0 0 0 0 0 0 1,691 52 5 0 39 0 2 0 0 35 3 1 41 4 1,874

2032 0 0 0 0 0 0 0 0 1,667 52 5 0 39 0 2 0 0 35 3 1 40 4 1,848

2033 0 0 0 0 0 0 0 0 1,644 51 5 0 39 0 2 0 0 34 3 1 39 4 1,822

2034 0 0 0 0 0 0 0 0 1,620 51 5 0 38 0 2 0 0 34 3 1 38 4 1,798

2035 0 0 0 0 0 0 0 0 1,598 51 5 0 38 0 2 0 0 34 3 1 37 4 1,773

2036 0 0 0 0 0 0 0 0 1,576 51 5 0 37 0 2 0 0 34 3 1 36 4 1,750

2037 0 0 0 0 0 0 0 0 1,555 51 5 0 37 0 2 0 0 34 3 1 36 4 1,728

TOTAL 0 6 0 10 1 2 1 1 59,713 1,259 120 0 1,299 11 82 0 1 843 84 21 1,783 120 65,356

Production Total (Costruction + 

Drilling + Completion 

+ Production)

benzene [tpy]

Pollutant Year

Construction Drilling Completion

0

294

589

883

1,178

1,472

1,766

2,061

2,355

2,650

2,944

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well Benzene Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-220

Table 279. Total New and Existing Wells Ethylbenzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 42. Total New and Existing Wells Ethylbenzene Emissions (tons/year) Contribution by Source Category and by Project Year. Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 160 0 0 0 2 0 0 0 0 0 0 0 2 0 166

2009 0 0 0 0 0 0 0 0 157 0 0 0 2 0 0 0 0 0 0 0 2 0 163

2010 0 0 0 0 0 0 0 0 151 0 0 0 2 0 0 0 0 1 0 0 2 0 156

2011 0 0 0 0 0 0 0 0 146 0 0 0 2 0 0 0 0 1 0 0 2 0 152

2012 0 0 0 0 0 0 0 0 145 1 0 0 2 0 0 0 0 1 0 0 2 0 150

2013 0 0 0 0 0 0 0 0 143 1 0 0 2 0 0 0 0 1 0 0 2 0 149

2014 0 0 0 0 0 0 0 0 140 1 0 0 2 0 0 0 0 1 0 0 1 0 146

2015 0 0 0 0 0 0 0 0 137 1 0 0 2 0 0 0 0 1 0 0 1 0 144

2016 0 0 0 0 0 0 0 0 135 1 0 0 2 0 0 0 0 1 0 0 1 0 141

2017 0 0 0 0 0 0 0 0 132 1 0 0 2 0 0 0 0 1 0 0 1 0 138

2018 0 0 0 0 0 0 0 0 130 1 0 0 2 0 0 0 0 1 0 0 1 0 136

2019 0 0 0 0 0 0 0 0 127 1 0 0 2 0 0 0 0 1 0 0 1 0 134

2020 0 0 0 0 0 0 0 0 125 1 0 0 2 0 0 0 0 1 0 0 1 0 132

2021 0 0 0 0 0 0 0 0 123 1 0 0 2 0 0 0 0 1 0 0 1 0 130

2022 0 0 0 0 0 0 0 0 121 1 0 0 2 0 0 0 0 2 0 0 1 0 127

2023 0 0 0 0 0 0 0 0 119 1 0 0 2 0 0 0 0 2 0 0 1 1 125

2024 0 0 0 0 0 0 0 0 117 1 0 0 2 0 0 0 0 2 0 0 1 0 123

2025 0 0 0 0 0 0 0 0 115 1 0 0 2 0 0 0 0 2 0 0 1 0 121

2026 0 0 0 0 0 0 0 0 113 1 0 0 2 0 0 0 0 2 0 0 1 0 120

2027 0 0 0 0 0 0 0 0 112 1 0 0 2 0 0 0 0 2 0 0 1 0 118

2028 0 0 0 0 0 0 0 0 109 1 0 0 2 0 0 0 0 2 0 0 1 0 115

2029 0 0 0 0 0 0 0 0 107 1 0 0 2 0 0 0 0 2 0 0 1 0 113

2030 0 0 0 0 0 0 0 0 105 1 0 0 2 0 0 0 0 2 0 0 1 0 111

2031 0 0 0 0 0 0 0 0 104 1 0 0 2 0 0 0 0 2 0 0 1 0 110

2032 0 0 0 0 0 0 0 0 102 1 0 0 2 0 0 0 0 2 0 0 1 0 108

2033 0 0 0 0 0 0 0 0 101 1 0 0 2 0 0 0 0 2 0 0 1 0 107

2034 0 0 0 0 0 0 0 0 100 1 0 0 2 0 0 0 0 2 0 0 1 0 105

2035 0 0 0 0 0 0 0 0 98 1 0 0 2 0 0 0 0 2 0 0 1 0 104

2036 0 0 0 0 0 0 0 0 97 1 0 0 2 0 0 0 0 2 0 0 1 0 103

2037 0 0 0 0 0 0 0 0 96 1 0 0 2 0 0 0 0 2 0 0 1 0 101

TOTAL 0 1 0 2 0 0 0 0 3,667 29 0 0 54 4 1 0 0 38 2 2 34 13 3,849

Production Total (Costruction + 

Drilling + Completion 

+ Production)

ethylbenzene 

[tpy]

Pollutant Year

Construction Drilling Completion

0.0

17.4

34.8

52.2

69.6

87.0

104.4

121.8

139.2

156.6

174.0

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well Ethylbenzene Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-221

Table 280. Total New and Existing Wells Toluene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 43. Total New and Existing Wells Toluene Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 1 0 2 0 0 0 1 4,310 18 1 0 69 1 1 0 0 12 1 0 159 4 4,579

2009 0 0 0 1 0 0 0 0 4,222 21 1 0 68 1 2 0 0 14 1 0 151 4 4,486

2010 0 1 0 1 0 0 0 0 4,053 25 1 0 68 1 2 0 0 17 1 0 130 4 4,304

2011 0 1 0 1 0 0 0 0 3,937 29 1 0 67 1 3 0 0 19 1 0 119 4 4,183

2012 0 1 0 1 0 0 0 0 3,891 33 1 0 66 1 3 0 0 22 1 0 117 4 4,142

2013 0 1 0 1 0 0 0 0 3,850 37 1 0 66 1 3 0 0 24 1 0 116 4 4,106

2014 0 1 0 1 0 0 0 0 3,775 41 1 0 65 1 4 0 0 27 1 0 110 5 4,033

2015 0 1 0 1 0 0 0 0 3,697 45 2 0 64 1 4 0 0 30 1 0 104 5 3,955

2016 0 0 0 1 0 0 0 0 3,623 48 2 0 64 1 4 0 0 32 1 0 99 5 3,881

2017 0 1 0 1 0 0 0 0 3,554 53 2 0 63 1 4 0 0 35 1 0 95 5 3,815

2018 0 1 0 1 0 0 0 0 3,489 57 2 0 62 1 5 0 0 38 1 0 91 5 3,754

2019 0 0 0 1 0 0 0 0 3,427 61 2 0 62 1 5 0 0 40 1 0 87 5 3,693

2020 0 0 0 1 0 0 0 0 3,368 65 2 0 61 1 5 0 0 42 1 0 84 6 3,637

2021 0 1 0 1 0 0 0 0 3,313 69 2 0 60 1 5 0 0 45 1 0 81 6 3,586

2022 0 1 0 1 0 0 0 0 3,245 73 2 0 60 1 5 0 0 48 1 0 77 6 3,520

2023 0 0 0 0 0 0 0 0 3,192 74 3 0 59 1 5 0 0 49 1 0 74 6 3,466

2024 0 0 0 0 0 0 0 0 3,141 74 3 0 59 1 5 0 0 48 1 0 72 6 3,410

2025 0 0 0 0 0 0 0 0 3,093 74 2 0 58 1 4 0 0 48 1 0 70 6 3,359

2026 0 0 0 0 0 0 0 0 3,046 73 2 0 58 1 4 0 0 48 1 0 68 6 3,308

2027 0 0 0 0 0 0 0 0 2,999 73 2 0 57 1 4 0 0 48 1 0 66 6 3,258

2028 0 0 0 0 0 0 0 0 2,934 73 2 0 56 1 4 0 0 48 1 0 64 6 3,189

2029 0 0 0 0 0 0 0 0 2,875 73 2 0 55 1 3 0 0 48 1 0 61 6 3,126

2030 0 0 0 0 0 0 0 0 2,833 73 2 0 55 1 3 0 0 48 1 0 59 6 3,082

2031 0 0 0 0 0 0 0 0 2,793 73 2 0 54 1 3 0 0 48 1 0 58 6 3,040

2032 0 0 0 0 0 0 0 0 2,754 72 2 0 54 1 3 0 0 48 1 0 56 6 2,997

2033 0 0 0 0 0 0 0 0 2,714 72 2 0 53 1 3 0 0 47 1 0 55 6 2,956

2034 0 0 0 0 0 0 0 0 2,676 72 2 0 53 1 3 0 0 47 1 0 54 6 2,915

2035 0 0 0 0 0 0 0 0 2,639 72 2 0 52 1 3 0 0 47 1 0 53 6 2,876

2036 0 0 0 0 0 0 0 0 2,603 72 2 0 51 1 3 0 0 47 1 0 51 6 2,838

2037 0 0 0 0 0 0 0 0 2,568 72 2 0 51 1 2 0 0 47 1 0 50 5 2,801

TOTAL 0 8 0 14 2 3 2 1 98,614 1,767 60 0 1,789 27 108 0 1 1,162 39 11 2,530 156 106,295

Production Total (Costruction + 

Drilling + Completion 

+ Production)

toluene [tpy]

Pollutant Year

Construction Drilling Completion

0

481

962

1,443

1,924

2,405

2,886

3,367

3,848

4,329

4,810

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well Toluene Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-222

Table 281. Total New and Existing Wells Xylenes Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 44. Total New and Existing Wells Xylenes Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 1 0 1 0 0 0 0 1,587 10 0 0 40 0 1 0 0 4 0 0 86 5 1,735

2009 0 0 0 1 0 0 0 0 1,555 12 0 0 39 0 1 0 0 4 0 0 81 5 1,700

2010 0 0 0 1 0 0 0 0 1,493 14 0 0 39 0 1 0 0 5 0 0 70 5 1,630

2011 0 0 0 1 0 0 0 0 1,450 16 0 0 39 0 1 0 0 6 0 0 64 5 1,584

2012 0 0 0 1 0 0 0 0 1,433 18 0 0 38 1 2 0 0 7 0 0 63 6 1,569

2013 0 0 0 1 0 0 0 0 1,418 20 0 0 38 1 2 0 0 8 0 0 62 6 1,556

2014 0 0 0 1 0 0 0 0 1,390 22 0 0 37 1 2 0 0 8 0 0 59 6 1,529

2015 0 0 0 1 0 0 0 0 1,361 25 0 0 37 1 2 0 0 9 0 0 56 6 1,500

2016 0 0 0 1 0 0 0 0 1,334 26 0 0 37 1 2 0 0 10 0 0 53 7 1,472

2017 0 0 0 1 0 0 0 0 1,309 29 0 0 36 1 2 0 0 11 0 0 51 7 1,447

2018 0 0 0 1 0 0 0 0 1,285 31 0 0 36 1 3 0 0 12 0 0 49 7 1,425

2019 0 0 0 1 0 0 0 0 1,262 33 0 0 36 1 3 0 0 12 0 0 47 7 1,403

2020 0 0 0 1 0 0 0 0 1,240 35 0 0 35 1 3 0 0 13 0 0 45 7 1,382

2021 0 0 0 1 0 0 0 0 1,220 37 0 0 35 1 3 0 0 14 0 0 44 8 1,363

2022 0 0 0 1 0 0 0 0 1,195 39 0 0 35 1 3 0 0 15 0 0 41 8 1,339

2023 0 0 0 0 0 0 0 0 1,176 40 0 0 34 1 3 0 0 15 0 0 40 8 1,318

2024 0 0 0 0 0 0 0 0 1,157 40 0 0 34 1 3 0 0 15 0 0 39 8 1,296

2025 0 0 0 0 0 0 0 0 1,139 40 0 0 34 1 2 0 0 15 0 0 38 8 1,277

2026 0 0 0 0 0 0 0 0 1,121 40 0 0 33 1 2 0 0 15 0 0 37 8 1,257

2027 0 0 0 0 0 0 0 0 1,104 40 0 0 33 1 2 0 0 15 0 0 36 8 1,239

2028 0 0 0 0 0 0 0 0 1,080 40 0 0 32 1 2 0 0 15 0 0 35 8 1,213

2029 0 0 0 0 0 0 0 0 1,059 40 0 0 32 1 2 0 0 15 0 0 33 8 1,189

2030 0 0 0 0 0 0 0 0 1,043 39 0 0 32 0 2 0 0 15 0 0 32 8 1,172

2031 0 0 0 0 0 0 0 0 1,029 39 0 0 31 0 2 0 0 15 0 0 31 8 1,156

2032 0 0 0 0 0 0 0 0 1,014 39 0 0 31 0 2 0 0 15 0 0 31 8 1,140

2033 0 0 0 0 0 0 0 0 999 39 0 0 31 0 2 0 0 15 0 0 30 8 1,124

2034 0 0 0 0 0 0 0 0 985 39 0 0 30 0 2 0 0 15 0 0 29 8 1,109

2035 0 0 0 0 0 0 0 0 972 39 0 0 30 0 1 0 0 15 0 0 28 8 1,094

2036 0 0 0 0 0 0 0 0 959 39 0 0 30 0 1 0 0 15 0 0 28 7 1,080

2037 0 0 0 0 0 0 0 0 946 39 0 0 29 0 1 0 0 15 0 0 27 7 1,066

TOTAL 0 6 0 11 2 2 1 0 36,314 960 0 0 1,032 16 60 0 1 362 9 9 1,367 211 40,362

Production Total (Costruction + 

Drilling + Completion 

+ Production)

xylenes [tpy]

Pollutant Year

Construction Drilling Completion

0

182

364

546

728

910

1,092

1,274

1,456

1,638

1,820

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well Xylenes Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-223

Table 282. Total New and Existing Wells CO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 45. Total New and Existing Wells CO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 23,168 655 44,407 6,637 35,396 4,128 54 5,232 310 683,444 0 5,160 4,616 0 110,507 1,275 911 582,056 809,692 540 7 2,318,196

2009 0 13,961 395 85,304 6,893 18,798 4,287 5,795 5,143 359 791,588 0 5,108 5,345 0 217,975 1,477 1,056 582,056 809,692 509 7 2,555,747

2010 0 18,731 529 114,450 9,243 25,221 5,748 7,775 4,996 425 939,059 0 5,055 6,335 0 396,100 1,754 1,252 582,056 809,692 438 8 2,928,866

2011 0 18,614 525 113,739 9,175 25,064 5,706 7,727 4,894 492 1,085,571 0 5,003 7,308 0 551,763 2,028 1,448 582,056 809,692 399 8 3,231,211

2012 0 18,265 514 111,606 8,992 24,594 5,591 7,582 4,842 557 1,229,741 0 4,954 8,252 0 688,281 2,298 1,640 1,183,378 905,804 391 8 4,207,292

2013 0 18,614 523 113,739 9,149 25,064 5,688 7,727 4,793 624 1,376,789 0 4,905 9,198 0 823,193 2,573 1,836 1,183,378 905,804 386 9 4,493,991

2014 0 18,440 517 112,672 9,049 24,829 5,625 7,654 4,722 690 1,522,398 0 4,857 10,120 0 939,673 2,846 2,030 1,183,378 905,804 367 9 4,755,680

2015 0 19,021 532 116,227 9,317 25,612 5,791 7,896 4,651 758 1,672,803 0 4,808 11,052 0 1,054,049 3,127 2,231 1,183,378 905,804 346 9 5,027,413

2016 0 14,862 415 90,813 7,266 20,012 4,516 6,169 4,584 810 1,788,916 0 4,760 11,746 0 1,139,698 3,345 2,385 1,183,378 905,804 328 10 5,189,818

2017 0 19,516 543 119,248 9,524 26,278 5,918 8,101 4,519 880 1,943,398 0 4,711 12,675 0 1,248,379 3,634 2,591 1,183,378 905,804 313 10 5,499,422

2018 0 21,465 596 131,155 10,457 28,902 6,497 8,910 4,458 958 2,113,947 0 4,663 13,691 0 1,415,831 3,953 2,819 1,183,378 905,804 299 10 5,857,792

2019 0 17,276 478 105,564 8,403 23,263 5,220 7,171 4,398 1,019 2,249,964 0 4,614 14,481 0 1,516,971 4,208 3,000 1,183,378 905,804 287 11 6,055,511

2020 0 17,291 478 105,653 8,397 23,282 5,216 7,177 4,343 1,081 2,386,636 0 4,570 15,264 0 1,610,399 4,464 3,182 1,183,378 905,804 275 11 6,286,902

2021 0 19,516 538 119,248 9,464 26,278 5,878 8,101 4,290 1,151 2,541,653 0 4,525 16,158 0 1,708,574 4,754 3,389 1,183,378 905,804 265 11 6,562,978

2022 0 18,512 508 113,117 8,945 24,927 5,555 7,684 4,232 1,218 2,688,397 0 4,481 16,860 0 1,831,299 5,029 3,585 1,183,378 905,804 251 12 6,823,794

2023 0 6,210 171 37,943 3,007 8,361 1,868 2,578 4,181 1,238 2,733,704 0 4,436 17,269 0 1,832,835 5,114 3,645 1,183,378 905,804 242 12 6,751,996

2024 0 0 0 0 0 0 0 0 4,130 1,236 2,727,812 0 4,392 17,161 0 1,750,780 5,103 3,637 1,183,378 905,804 234 12 6,603,679

2025 0 0 0 0 0 0 0 0 4,082 1,233 2,721,921 0 4,347 16,996 0 1,696,837 5,092 3,629 1,183,378 905,804 227 12 6,543,558

2026 0 0 0 0 0 0 0 0 4,033 1,230 2,716,029 0 4,303 16,900 0 1,658,081 5,081 3,622 1,183,378 905,804 220 12 6,498,692

2027 0 0 0 0 0 0 0 0 3,986 1,228 2,710,137 0 4,258 16,816 0 1,626,527 5,070 3,614 1,183,378 905,804 213 11 6,461,042

2028 0 0 0 0 0 0 0 0 3,904 1,223 2,698,889 0 4,173 16,697 0 1,599,498 5,049 3,599 1,183,378 905,804 207 11 6,422,432

2029 0 0 0 0 0 0 0 0 3,854 1,220 2,693,533 0 4,133 16,624 0 1,574,784 5,039 3,592 1,183,378 905,804 197 11 6,392,169

2030 0 0 0 0 0 0 0 0 3,811 1,218 2,688,177 0 4,093 16,553 0 1,553,423 5,029 3,584 1,183,378 905,804 192 11 6,365,273

2031 0 0 0 0 0 0 0 0 3,769 1,215 2,682,821 0 4,052 16,487 0 1,534,089 5,019 3,577 1,183,378 905,804 187 11 6,340,409

2032 0 0 0 0 0 0 0 0 3,727 1,213 2,677,465 0 4,012 16,422 0 1,516,264 5,009 3,570 1,183,378 905,804 182 11 6,317,057

2033 0 0 0 0 0 0 0 0 3,685 1,211 2,672,108 0 3,971 16,360 0 1,499,764 4,999 3,563 1,183,378 905,804 177 11 6,295,032

2034 0 0 0 0 0 0 0 0 3,644 1,208 2,666,752 0 3,931 16,300 0 1,484,406 4,989 3,556 1,183,378 905,804 173 11 6,274,153

2035 0 0 0 0 0 0 0 0 3,603 1,206 2,661,396 0 3,890 16,245 0 1,469,929 4,979 3,549 1,183,378 905,804 168 11 6,254,159

2036 0 0 0 0 0 0 0 0 3,563 1,203 2,656,040 0 3,850 16,191 0 1,456,286 4,969 3,542 1,183,378 905,804 165 11 6,235,001

2037 0 0 0 0 0 0 0 0 3,523 1,201 2,650,684 0 3,810 16,138 0 1,443,349 4,959 3,534 1,183,378 905,804 161 11 6,216,552

TOTAL 0 283,462 7,917 1,634,884 133,917 385,882 83,229 108,100 127,593 29,615 65,371,774 0 133,827 412,260 0 38,949,545 122,262 87,168 33,096,054 26,789,679 8,340 308 167,765,816

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2 [tpy]

Pollutant Year

Construction Drilling Completion

0

716,000

1,432,000

2,148,000

2,864,000

3,580,000

4,296,000

5,012,000

5,728,000

6,444,000

7,160,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well CO2 Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-224

Table 283. Total New and Existing Wells CO2e - from CH4 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 46. Total New and Existing Wells CO2e - from CH4 Emissions (tons/year) Contribution by Source Category and by Project Year. Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 14 1 34 6 0 4 12,830 454,768 66,108 275 0 1,228,142 8 1,321 665 1 216,897 7,391 18,182 57,368 24 2,064,038

2009 0 8 0 14 6 3 4 36 449,981 76,569 319 0 1,215,630 9 1,655 1,292 1 251,217 7,391 18,182 54,394 24 2,076,735

2010 0 11 1 19 9 4 5 48 444,904 90,834 378 0 1,203,117 11 2,331 2,318 1 298,018 7,391 18,182 47,684 25 2,115,290

2011 0 11 1 19 9 4 6 48 440,014 105,005 437 0 1,190,605 12 2,871 3,221 1 344,515 7,391 18,182 43,932 26 2,156,310

2012 0 11 1 19 9 4 6 47 435,718 118,951 495 0 1,179,055 14 3,307 4,021 1 390,268 9,298 18,391 43,186 28 2,202,829

2013 0 11 1 19 10 4 6 48 431,440 133,174 554 0 1,167,505 15 3,722 4,813 1 436,935 9,298 18,391 42,650 29 2,248,627

2014 0 11 1 19 10 4 6 48 427,042 147,259 613 0 1,155,955 17 3,990 5,505 1 483,146 9,298 18,391 40,741 30 2,292,086

2015 0 11 1 20 10 4 6 49 422,632 161,807 673 0 1,144,405 18 4,223 6,188 1 530,878 9,298 18,391 38,762 31 2,337,408

2016 0 9 0 15 8 3 5 38 418,238 173,039 720 0 1,132,855 19 4,375 6,701 1 567,727 9,298 18,391 37,027 32 2,368,502

2017 0 12 1 20 10 4 6 50 413,861 187,982 782 0 1,121,305 20 4,553 7,355 1 616,753 9,298 18,391 35,508 33 2,415,946

2018 0 13 1 22 11 4 7 56 409,497 204,478 851 0 1,109,756 21 5,114 8,333 1 670,878 9,298 18,391 34,164 34 2,470,930

2019 0 10 1 18 9 4 6 45 405,142 217,635 906 0 1,098,206 22 5,311 8,938 1 714,044 9,298 18,391 32,937 35 2,510,958

2020 0 10 1 18 9 4 6 45 401,147 230,855 961 0 1,087,618 23 5,449 9,503 1 757,418 9,298 18,391 31,808 36 2,552,601

2021 0 12 1 20 10 4 6 50 397,162 245,850 1,023 0 1,077,031 25 5,553 10,101 1 806,614 9,298 18,391 30,790 37 2,601,979

2022 0 11 1 19 10 4 6 48 393,132 260,044 1,082 0 1,066,443 25 5,871 10,827 1 853,185 9,298 18,391 29,421 38 2,647,858

2023 0 4 0 6 3 1 2 16 389,157 264,426 1,100 0 1,055,856 26 5,675 10,857 1 867,563 9,298 18,391 28,537 39 2,650,960

2024 0 0 0 0 0 0 0 0 385,187 263,857 1,098 0 1,045,268 26 5,048 10,416 1 865,694 9,298 18,391 27,709 38 2,632,031

2025 0 0 0 0 0 0 0 0 381,229 263,287 1,096 0 1,034,681 25 4,635 10,125 1 863,824 9,298 18,391 26,982 38 2,613,612

2026 0 0 0 0 0 0 0 0 377,271 262,717 1,093 0 1,024,094 26 4,336 9,916 1 861,954 9,298 18,391 26,267 38 2,595,402

2027 0 0 0 0 0 0 0 0 373,318 262,147 1,091 0 1,013,506 25 4,092 9,746 1 860,084 9,298 18,391 25,601 38 2,577,339

2028 0 0 0 0 0 0 0 0 365,852 261,059 1,086 0 993,294 25 3,883 9,600 1 856,514 9,298 18,391 24,937 37 2,543,979

2029 0 0 0 0 0 0 0 0 362,200 260,541 1,084 0 983,669 25 3,687 9,467 1 854,815 9,298 18,391 23,919 37 2,527,134

2030 0 0 0 0 0 0 0 0 358,609 260,023 1,082 0 974,044 25 3,520 9,351 1 853,115 9,298 18,391 23,357 37 2,510,853

2031 0 0 0 0 0 0 0 0 355,023 259,505 1,080 0 964,419 24 3,370 9,247 1 851,415 9,298 18,391 22,830 37 2,494,640

2032 0 0 0 0 0 0 0 0 351,438 258,986 1,078 0 954,794 24 3,231 9,151 1 849,715 9,298 18,391 22,318 37 2,478,463

2033 0 0 0 0 0 0 0 0 347,854 258,468 1,076 0 945,169 24 3,102 9,061 1 848,015 9,298 18,391 21,817 37 2,462,313

2034 0 0 0 0 0 0 0 0 344,274 257,950 1,073 0 935,544 24 2,982 8,978 1 846,316 9,298 18,391 21,349 36 2,446,217

2035 0 0 0 0 0 0 0 0 340,697 257,432 1,071 0 925,919 24 2,869 8,900 1 844,616 9,298 18,391 20,905 36 2,430,160

2036 0 0 0 0 0 0 0 0 337,127 256,914 1,069 0 916,294 24 2,763 8,826 1 842,916 9,298 18,391 20,503 36 2,414,162

2037 0 0 0 0 0 0 0 0 333,558 256,396 1,067 0 906,669 23 2,662 8,756 1 841,216 9,298 18,391 20,113 36 2,398,187

TOTAL 0 171 9 302 138 54 87 13,504 11,747,471 6,323,298 26,312 0 31,850,850 632 115,499 232,178 31 20,746,266 271,315 550,896 957,515 1,020 72,837,549

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2e-from 

CH4 [tpy]

Pollutant Year

Construction Drilling Completion

0

278,000

556,000

834,000

1,112,000

1,390,000

1,668,000

1,946,000

2,224,000

2,502,000

2,780,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well CO2e - from CH4 Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-225

Table 284. Total New and Existing Wells CO2e - from N2O Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 47. Total New and Existing Wells CO2e - from N2O Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 183 5 2,490 41 1,984 26 0 0 0 3,884 0 0 60 0 182 10 0 4,096 5,974 0 0 18,935

2009 0 110 3 671 41 148 26 19 0 0 4,499 0 0 69 0 443 12 0 4,096 5,974 0 0 16,110

2010 0 148 3 901 52 198 33 26 0 0 5,337 0 0 80 0 847 14 0 4,096 5,974 0 0 17,708

2011 0 147 3 895 48 197 30 26 0 0 6,170 0 0 88 0 1,215 16 0 4,096 5,974 0 0 18,905

2012 0 144 3 878 43 194 28 25 0 0 6,989 0 0 95 0 1,550 18 0 8,305 6,766 0 0 25,039

2013 0 147 3 895 41 197 26 26 0 0 7,825 0 0 101 0 1,885 20 0 8,305 6,766 0 0 26,237

2014 0 146 2 887 38 195 24 25 0 0 8,652 0 0 105 0 2,190 22 0 8,305 6,766 0 0 27,359

2015 0 150 2 915 36 202 23 26 0 0 9,507 0 0 109 0 2,497 25 0 8,305 6,766 0 0 28,562

2016 0 117 2 715 26 157 17 20 0 0 10,167 0 0 110 0 2,730 26 0 8,305 6,766 0 0 29,159

2017 0 154 2 938 32 207 20 27 0 0 11,045 0 0 113 0 3,030 29 0 8,305 6,766 0 0 30,668

2018 0 170 2 1,032 33 227 21 30 0 0 12,014 0 0 115 0 3,435 31 0 8,305 6,766 0 0 32,181

2019 0 137 2 831 25 183 16 24 0 0 12,787 0 0 115 0 3,709 33 0 8,305 6,766 0 0 32,932

2020 0 137 1 831 23 183 15 24 0 0 13,564 0 0 116 0 3,971 35 0 8,305 6,766 0 0 33,971

2021 0 154 2 938 25 207 16 27 0 0 14,445 0 0 116 0 4,255 37 0 8,305 6,766 0 0 35,293

2022 0 146 1 890 20 196 13 25 0 0 15,279 0 0 109 0 4,570 40 0 8,305 6,766 0 0 36,361

2023 0 49 0 299 7 66 5 9 0 0 15,537 0 0 117 0 4,615 40 0 8,305 6,766 0 0 35,815

2024 0 0 0 0 0 0 0 0 0 0 15,503 0 0 113 0 4,488 40 0 8,305 6,766 0 0 35,215

2025 0 0 0 0 0 0 0 0 0 0 15,470 0 0 105 0 4,404 40 0 8,305 6,766 0 0 35,090

2026 0 0 0 0 0 0 0 0 0 0 15,436 0 0 102 0 4,344 40 0 8,305 6,766 0 0 34,993

2027 0 0 0 0 0 0 0 0 0 0 15,403 0 0 99 0 4,295 40 0 8,305 6,766 0 0 34,907

2028 0 0 0 0 0 0 0 0 0 0 15,339 0 0 96 0 4,253 40 0 8,305 6,766 0 0 34,798

2029 0 0 0 0 0 0 0 0 0 0 15,308 0 0 93 0 4,215 40 0 8,305 6,766 0 0 34,727

2030 0 0 0 0 0 0 0 0 0 0 15,278 0 0 91 0 4,182 40 0 8,305 6,766 0 0 34,661

2031 0 0 0 0 0 0 0 0 0 0 15,247 0 0 89 0 4,152 40 0 8,305 6,766 0 0 34,598

2032 0 0 0 0 0 0 0 0 0 0 15,217 0 0 87 0 4,124 39 0 8,305 6,766 0 0 34,538

2033 0 0 0 0 0 0 0 0 0 0 15,186 0 0 86 0 4,098 39 0 8,305 6,766 0 0 34,481

2034 0 0 0 0 0 0 0 0 0 0 15,156 0 0 85 0 4,074 39 0 8,305 6,766 0 0 34,426

2035 0 0 0 0 0 0 0 0 0 0 15,126 0 0 84 0 4,052 39 0 8,305 6,766 0 0 34,372

2036 0 0 0 0 0 0 0 0 0 0 15,095 0 0 83 0 4,031 39 0 8,305 6,766 0 0 34,319

2037 0 0 0 0 0 0 0 0 0 0 15,065 0 0 82 0 4,011 39 0 8,305 6,766 0 0 34,267

TOTAL 0 2,240 36 15,005 533 4,742 338 358 0 0 371,530 0 0 2,914 0 99,846 963 0 232,314 199,806 0 0 930,626

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2e-from 

N2O [tpy]

Pollutant Year

Construction Drilling Completion

0

3,900

7,800

11,700

15,600

19,500

23,400

27,300

31,200

35,100

39,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well CO2e - from N2O Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
APPENDIX H – CONTINENTAL DIVIDE – CRESTON PROPOSED ACTION 

PROJECT EMISSIONS INVENTORY

Total Project Emissions Summary

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 H-226

Table 285. Total New and Existing Wells CO2e - total Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 48. Total New and Existing Wells CO2e - total Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 23,365 661 46,930 6,685 37,381 4,158 12,884 460,000 66,418 687,604 0 1,233,303 4,684 1,321 111,354 1,286 217,808 593,542 833,848 57,908 31 4,401,169

2009 0 14,079 398 85,990 6,940 18,949 4,317 5,850 455,124 76,928 796,405 0 1,220,738 5,423 1,655 219,711 1,490 252,272 593,542 833,848 54,903 32 4,648,592

2010 0 18,890 533 115,370 9,303 25,423 5,786 7,849 449,900 91,259 944,774 0 1,208,173 6,426 2,331 399,265 1,768 299,270 593,542 833,848 48,122 33 5,061,864

2011 0 18,773 529 114,653 9,232 25,265 5,742 7,800 444,908 105,497 1,092,178 0 1,195,608 7,409 2,871 556,199 2,045 345,962 593,542 833,848 44,331 34 5,406,425

2012 0 18,421 518 112,503 9,045 24,791 5,624 7,654 440,560 119,508 1,237,225 0 1,184,009 8,362 3,307 693,852 2,317 391,908 1,200,981 930,961 43,577 36 6,435,160

2013 0 18,773 526 114,653 9,199 25,265 5,720 7,800 436,233 133,798 1,385,168 0 1,172,411 9,314 3,722 829,891 2,594 438,771 1,200,981 930,961 43,037 37 6,768,855

2014 0 18,597 520 113,578 9,096 25,028 5,655 7,727 431,765 147,949 1,531,663 0 1,160,812 10,242 3,990 947,368 2,869 485,176 1,200,981 930,961 41,108 39 7,075,124

2015 0 19,183 535 117,161 9,363 25,818 5,820 7,971 427,283 162,565 1,682,984 0 1,149,214 11,179 4,223 1,062,733 3,153 533,108 1,200,981 930,961 39,108 40 7,393,383

2016 0 14,989 417 91,543 7,301 20,173 4,537 6,228 422,822 173,849 1,799,803 0 1,137,615 11,875 4,375 1,149,128 3,372 570,113 1,200,981 930,961 37,355 41 7,587,479

2017 0 19,682 546 120,207 9,566 26,489 5,945 8,178 418,380 188,862 1,955,225 0 1,126,017 12,808 4,553 1,258,765 3,664 619,345 1,200,981 930,961 35,821 43 7,946,037

2018 0 21,647 598 132,209 10,501 29,134 6,525 8,995 413,955 205,436 2,126,812 0 1,114,418 13,828 5,114 1,427,599 3,985 673,697 1,200,981 930,961 34,463 44 8,360,903

2019 0 17,423 481 106,412 8,437 23,449 5,242 7,240 409,540 218,654 2,263,657 0 1,102,820 14,619 5,311 1,529,618 4,242 717,044 1,200,981 930,961 33,224 46 8,599,401

2020 0 17,438 480 106,502 8,430 23,469 5,237 7,246 405,490 231,936 2,401,161 0 1,092,188 15,403 5,449 1,623,872 4,500 760,601 1,200,981 930,961 32,083 47 8,873,474

2021 0 19,682 540 120,207 9,499 26,489 5,900 8,178 401,452 247,001 2,557,121 0 1,081,556 16,299 5,553 1,722,929 4,793 810,004 1,200,981 930,961 31,055 49 9,200,250

2022 0 18,670 510 114,026 8,975 25,127 5,573 7,758 397,364 261,262 2,704,759 0 1,070,924 16,994 5,871 1,846,696 5,070 856,770 1,200,981 930,961 29,672 50 9,508,012

2023 0 6,262 172 38,248 3,018 8,428 1,874 2,602 393,338 265,665 2,750,341 0 1,060,292 17,412 5,675 1,848,307 5,155 871,208 1,200,981 930,961 28,779 50 9,438,770

2024 0 0 0 0 0 0 0 0 389,318 265,092 2,744,413 0 1,049,660 17,299 5,048 1,765,684 5,144 869,331 1,200,981 930,961 27,943 50 9,270,925

2025 0 0 0 0 0 0 0 0 385,311 264,520 2,738,486 0 1,039,028 17,127 4,635 1,711,366 5,133 867,453 1,200,981 930,961 27,209 50 9,192,259

2026 0 0 0 0 0 0 0 0 381,304 263,947 2,732,558 0 1,028,396 17,028 4,336 1,672,341 5,122 865,576 1,200,981 930,961 26,487 50 9,129,087

2027 0 0 0 0 0 0 0 0 377,304 263,375 2,726,630 0 1,017,765 16,940 4,092 1,640,569 5,111 863,698 1,200,981 930,961 25,814 49 9,073,289

2028 0 0 0 0 0 0 0 0 369,756 262,281 2,715,314 0 997,467 16,818 3,883 1,613,351 5,090 860,113 1,200,981 930,961 25,145 49 9,001,209

2029 0 0 0 0 0 0 0 0 366,054 261,761 2,709,925 0 987,802 16,742 3,687 1,588,465 5,080 858,406 1,200,981 930,961 24,117 49 8,954,030

2030 0 0 0 0 0 0 0 0 362,420 261,240 2,704,537 0 978,137 16,669 3,520 1,566,956 5,070 856,699 1,200,981 930,961 23,548 48 8,910,787

2031 0 0 0 0 0 0 0 0 358,792 260,720 2,699,148 0 968,471 16,600 3,370 1,547,487 5,059 854,992 1,200,981 930,961 23,017 48 8,869,647

2032 0 0 0 0 0 0 0 0 355,165 260,199 2,693,759 0 958,806 16,534 3,231 1,529,539 5,049 853,285 1,200,981 930,961 22,500 48 8,830,058

2033 0 0 0 0 0 0 0 0 351,539 259,679 2,688,370 0 949,140 16,471 3,102 1,512,924 5,039 851,578 1,200,981 930,961 21,994 48 8,791,827

2034 0 0 0 0 0 0 0 0 347,918 259,158 2,682,982 0 939,475 16,409 2,982 1,497,459 5,029 849,872 1,200,981 930,961 21,521 47 8,754,795

2035 0 0 0 0 0 0 0 0 344,300 258,638 2,677,593 0 929,810 16,353 2,869 1,482,881 5,019 848,165 1,200,981 930,961 21,073 47 8,718,690

2036 0 0 0 0 0 0 0 0 340,690 258,117 2,672,204 0 920,144 16,297 2,763 1,469,143 5,009 846,458 1,200,981 930,961 20,668 47 8,683,482

2037 0 0 0 0 0 0 0 0 337,081 257,597 2,666,815 0 910,479 16,243 2,662 1,456,116 4,999 844,751 1,200,981 930,961 20,274 47 8,649,006

TOTAL 0 285,873 7,962 1,650,191 134,588 390,678 83,654 121,962 11,875,065 6,352,913 65,769,616 0 31,984,677 415,806 115,499 39,281,569 123,256 20,833,434 33,599,683 27,540,381 965,855 1,328 241,533,990

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2e-total 

[tpy]

Pollutant Year

Construction Drilling Completion

0

998,400

1,996,800

2,995,200

3,993,600

4,992,000

5,990,400

6,988,800

7,987,200

8,985,600

9,984,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well CO2e - total Emissions By Source 

Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016

Appendix I

2008 Baseline Modeling for the Continental Divide-Creston (CD-C) Project and 

Assessment of the Estimated Regional Air Quality and AQRV Impacts
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-1

1.0. INTRODUCTION

1.1. BACKGROUND AND PROJECT DESCRIPTION

Gary Holsan Environmental Planning is preparing an Environmental Impact Statement (EIS) for 

the Continental Divide-Creston (CD-C) Natural Gas Development Project located in Sweetwater 

and Carbon Counties in southwestern Wyoming. The EIS is being prepared for the Bureau of 

Land Management (BLM). The operators propose to drill approximately 8,950 natural gas wells 

in addition to the 2,454 wells that currently exist in the Project Area. 

As part of the EIS, Carter Lake Consulting (Carter Lake) and ENVIRON International Corporation 

(ENVIRON) are performing an air quality analysis to assess potential impacts on ambient air 

quality (AQ) and air quality-related values (AQRVs) from air emissions that could occur from 

development and production emissions within the CD-C Project Area and from other 

documented regional emissions sources within a defined study area. AQRVs refer to those 

resources identified by a federal land management agency that may be adversely affected by a 

change in air quality and typically include visibility, flora, fauna, water, and soils. Changes in 

concentrations of air pollutants are analyzed to determine if visibility may be impaired or if 

increases in atmospheric deposition may cause damage to vegetation or affect soil or surface 

water chemistry at federally mandated Class I areas or identified sensitive Class II areas. 

The methods to be used in the CD-C air impact analysis were documented in a Air Quality 

Impact Assessment Modeling Protocol (Carter Lake and ENVIRON, 2010) that was provided 

prior to the air impact assessment to ensure that the approach, input data, and computation 

methods are acceptable to the Wyoming Department of Environmental Quality – Air Quality 

Division (WDEQ-AQD), the Bureau of Land Management (BLM) and other air quality 

stakeholders, and that all air quality stakeholders have the opportunity to review the Protocol 

and provide input before the impact assessment is performed. 

1.2. OVERVIEW OF AIR QUALITY MODELING APPROACH

The air quality impact assessment for the CD-C EIS is being performed with the photochemical 

grid model CAMx (Comprehensive Air quality Model with Extensions; ENVIRON, 2010; 

www.camx.com). The basic modeling strategy used in any EIS that employs a photochemical 

grid model, such as CAMx, is to first evaluate the ability of the model to reproduce ambient 

observations of trace pollutants during a recent historical episode (the “current year”); then, 

once confidence in the model is established, a future year case can be run and the potential 

project impacts evaluated. 

A current year base case is simulated using a comprehensive regional emission inventory of 

actual emissions from all sources (including motor vehicles, power plants, oil and gas 

exploration and production sources, biogenic sources, etc.). It is preferable to run the model 

for more than one year so that as many different meteorological regimes as possible are 

simulated. Pollutants emitted from Project sources may only influence a particular sensitive 

receptor under certain conditions (wind direction, atmospheric stability) and a conservative 

estimate of AQ and AQRV impacts requires that those conditions be simulated. While it is not 

possible to ensure that all possible meteorological conditions that might lead to transport of 
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-2

pollutants from Project sources to sensitive receptors are simulated, modeling two full years 

increases the likelihood that the relevant conditions will occur. 

The base case simulation is evaluated with respect to ambient air quality measurements. If the 

base case simulation reproduces concentrations of observed species with reasonable accuracy, 

then the model can be used in the future year impact assessment. The next step is to prepare a 

baseline model for use in future year projections. The only difference between the base case 

model and the baseline model is that the baseline model uses typical emissions while the base 

case model uses actual emissions. An example of an emissions source category for which the 

base case and baseline emissions are different is electrical generating units (EGUs). The base 

case emission inventory uses hourly EGU emissions derived from continuous emissions 

monitoring data because the base case model is evaluated against observations to determine 

whether the model provides a realistic simulation of atmospheric processes. The purpose of 

the baseline model, on the other hand, is to serve as the base year from which future year 

projections are made. The baseline EGU emissions are used to represent typical conditions (no 

shutdowns for maintenance, for example) in order to be consistent with the future year 

emissions, which also represent typical conditions. The baseline emission inventory, therefore, 

is usually identical to the base case emission inventory, except for the difference in emissions 

from EGUs and other source categories with large variability in time, such as drill rigs.

The future year modeling involves development of a future year Project emission inventory as 

well as a future year regional emission inventory. In the future year regional emission 

inventory, the emissions from human activities are projected from the base year to the future 

year and changes such as population growth and planned emissions controls (such as controls 

on motor vehicle emissions) are accounted for. Emissions that are not controllable, such as 

biogenics and wildfire emissions, are held fixed. The Project emissions are included in the 

future year emission inventory. The model is run using the future year regional emission 

inventory with the rest of the model (meteorological fields, boundary conditions, model 

settings, etc.) in the same configuration as in the base case. If multiple years were simulated in 

the base case, then the meteorological conditions for those same years are used together with 

the future year emissions scenario in the future year modeling. Project AQ and AQRV impacts 

are determined from the future year simulations.

1.2.1. CD-C 2005 and 2006 Base Case Modeling and Evaluation

For the CD-C EIS, a base case simulation has been completed. CAMx was applied for the 

calendar years 2005 and 2006 using a nested-grid modeling domain with horizontal spatial 

resolution 36/12/4 km (Figures 1-1 through 1-3). The 2005 and 2006 base case model runs 

used actual emissions of NOx, SO2, PM10, PM2.5, VOC and CO from all sources for those years 

and included a comprehensive inventory of oil and gas (O&G) emissions sources within 

Southwest Wyoming developed by Carter Lake and BP as well as the WRAP Phase III O&G 

emissions for the Denver-Julesburg, Piceance, and Uinta Basins. The model used 2005-6 MM5 

meteorology. The CAMx gas phase and particle phase model estimates were compared against 

observed ambient values for those two years and a model performance evaluation was 

conducted (ENVIRON and Carter Lake, 2010). Model performance was determined to be 

satisfactory and the base case modeling was approved by the CD-C stakeholders at their April 
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-3

15, 2010 meeting. The next step in the CD-C analysis was to apply CAMx for a baseline 

emissions scenario.

36/12/4 km Modeling Domain

36 km: 148 x 112 (-2736, -2088) to (2592, 1944)

12 km: 89 x 68 (-1452, -84) to (-384, 732) 

 4 km: 119 x 101 (-1192, 68) to (-716, 472)

Figure 1-1. 36/12/4 km CAMx air quality modeling domains to be used in the CD-C Project 

ozone and far-field modeling AQ and AQRV analysis. 
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-4

12/4 km Modeling Domain

12 km: 89 x 68 (-1452, -84) to (-384, 732)

 4 km: 119 x 101 (-1192, 68) to (-716, 472)

Figure 1-2. 12/4 km CAMx air quality modeling domains to be used in the CD-C Project ozone 

and far-field AQ and AQRV modeling analysis. 
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-5

Figure 1-3. 4 km CAMx modeling domain used in the CD-C Project ozone and far-field AQ and 

AQRV modeling analysis.

1.2.2. CD-C 2008 Baseline Modeling

At their January 7, 2010 meeting, the CD-C stakeholders determined that the baseline year to 

be used in performing future year modeling and impact analyses would be 2008. Originally, 

2006 was to have been the baseline year, but extensive development of oil and gas resources in 

southwest Wyoming occurred during the 2006-2008 period, and emissions of criteria pollutants 

and ozone precursors from this source category were significantly larger in 2008 than in 2006. 

The economic slowdown in 2008-9 leads to a reduction in the pace of development such that 

2009 emissions are expected to be smaller than 2008 emissions. 2008 is a National Emission 

Inventory Year, in which states submit emission inventories to the EPA. Because emission 
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-6

inventories for 2008 for the state of Wyoming are now available, and 2008 is the year of peak 

emissions from the energy sector in Wyoming, the stakeholders selected 2008 as the baseline 

year for the impact analysis modeling. Another important factor is that more ambient 

monitoring was available in 2008 than in 2006. Carter Lake Consulting and ENVIRON have 

developed a regional emission inventory for the year 2008 for use in CAMx baseline modeling, 

and the 2008 inventory is described briefly below.

The CD-C 2008 baseline run consisted of two annual runs. Both annual simulations were 

performed with 2008 emissions; one year was run with 2005 meteorology and the other year 

was run with 2006 meteorology. CAMx was applied using a 36/12/4 km nested-grid modeling 

domain as shown in Figure 1-1. The main study area was within the 12/4 km modeling domain 

shown in Figure 1-2 and includes all sources and receptor areas of interest in the far-field air 

quality and AQRV assessment of the CD-C Project alternatives and regional emissions. The 

primary function of the 36 km grid domain is to provide lateral boundary conditions to the 12 

km grid domain. The 4 km grid encompasses the CD-C project area and nearby Class I and 

sensitive Class II areas (Figure 1-3). 

In addition to its use as the current year on which future year CD-C modeling will be based, the 

2008 baseline modeling is also being used to assess the impacts of the existing CD-C Project on 

regional air quality. The CD-C Project area contains existing development which must be 

accounted for in the CD-C modeling in addition to the wells proposed as part of the CD-C 

Project. The purpose of this assessment was to evaluate the state of regional air quality under 

the baseline emission scenario and determine whether mitigation measures may need to be 

considered for the CD-C Project area in advance of the future year modeling. The CAMx output 

concentration fields were used for the evaluation of regional air quality, and the CAMx probing 

tools were used to isolate the contribution of existing 2008 CD-C Project area emissions sources 

to the total modeled concentrations. 

1.2.3. Use of CAMx Probing Tools in the 2008 Baseline Modeling

CAMx Particulate Matter (PM) Source Apportionment Technology (PSAT) and the 

Anthropogenic Precursor Culpability Assessment (APCA) version of the Ozone Source 

Apportionment Technology (OSAT; ENVIRON, 2010) probing tools were used to obtain the 

ozone and PM contributions due to different emissions source groups in the 2008 baseline run. 

APCA is a source apportionment tool similar to OSAT that focuses on determining the 

contribution to ozone concentrations from human (i.e. controllable) activities. Below, we 

describe ozone source apportionment in CAMx using OSAT and then discuss how APCA differs 

from the standard OSAT tool.

OSAT uses multiple tracer species to track the fate of ozone precursor emissions (VOC and NOX) 

and the ozone formation caused by these emissions within a simulation. The tracers operate as 

spectators to the normal CAMx calculations so that the underlying CAMx predicted 

relationships between emission groups (sources) and ozone concentrations at specific locations 

(receptors) are not perturbed. Tracers of this type are conventionally referred to as “passive 

tracers,” however it is important to realize that the tracers in the OSAT track the effects of 

chemical reaction, transport, diffusion, emissions and deposition within CAMx. In recognition 

of this, they are described as “ozone reaction tracers.” The ozone reaction tracers allow ozone 
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-7

formation from multiple “source groupings” to be tracked simultaneously within a single 

simulation. A source grouping can be defined in terms of geographical area and/or emission 

category. So that all sources of ozone precursors are accounted for, the CAMx boundary 

conditions and initial conditions are always tracked as separate source groupings. This allows 

an assessment of the role of transported ozone and precursors in contributing to high ozone 

episodes within the CD-C modeling domain.

The methodology is designed so that all ozone and precursor concentrations are attributed 

among the selected source groupings at all times. Thus, for all receptor locations and times, 

the ozone (or ozone precursor concentrations) predicted by CAMx is attributed among the 

source groupings selected for OSAT. The methodology also estimates the fractions of ozone 

arriving at the receptor that were formed en-route under VOC- or NOx-limited conditions. This 

information indicates how ozone concentrations at the receptor will respond to reductions in 

VOC and NOX precursor emissions, and can be useful in the event that an exploration of 

mitigation strategies is required.

APCA differs from the standard CAMx Ozone Source Apportionment Tool in recognizing that 

certain emission groups are not controllable (e.g., biogenic emissions) and that apportioning 

ozone production to these groups does not provide information that is relevant to development 

of control strategies. To address this, in situations where OSAT would attribute ozone 

production to non-controllable (i.e., biogenic) emissions, APCA re-allocates that ozone 

production to the controllable portion of precursors that participated in ozone formation with 

the non-controllable precursor. For example, when ozone formation is due to biogenic VOC 

and anthropogenic NOX under VOC-limited conditions (a situation in which OSAT would 

attribute ozone production to biogenic VOC), APCA re-directs that attribution to the 

anthropogenic NOX precursors present. The use of APCA instead of OSAT results in more ozone 

formation attributed to anthropogenic NOX sources and less ozone formation attributed to 

biogenic VOC sources, but generally does not change the partitioning of ozone attributed to 

local sources and the transported background for a given receptor. 

The PM Source Apportionment Technology (PSAT) uses reactive tracers to apportion primary 

PM, secondary PM and gaseous precursors to secondary PM among different source categories 

and source regions. The PSAT methodology is described below. PSAT was developed from the 

related ozone source apportionment method (OSAT) already implemented in CAMx (Dunker at 

al., 2002b). PSAT is designed to source apportion the following PM species modeled in CAMx:

 Sulfate (SO4)

 Particulate nitrate (NO3)

 Ammonium (NH4)

 Particulate mercury (Hg(p))

 Secondary organic aerosol (SOA)

 Six categories of primary PM

- Elemental carbon (EC) 

- Primary organic aerosol (POA)

- Crustal fine
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-8

- Other fine

- Crustal coarse

- Other coarse

PSAT “reactive tracers” are added to the model for each source category/region. In general, a 

single tracer can track primary PM species whereas secondary PM species require several 

tracers to track the relationship between gaseous precursors and the resulting PM. 

At the direction of the WDEQ-AQD (Personal communication from Kelly Bott, WDEQ-AQD, July 

23, 2010), the 2008 baseline emission inventory modeling was carried out so that the following 

emissions source categories were processed separately and tracked as separate emissions 

source groups using the CAMx APCA and PSAT probing tools:

1. CD-C Project-related oil and gas sources within the physical boundary of the CD-C Project 

area;

2. Non- CD-C Project -related oil and gas sources within the physical boundary of the CD-C 

Project area. Note that this category includes gas plants and compressor stations which 

are located within the CD-C Project area, but do not process gas produced by CD-C Project 

wells.

3. Biogenic sources;

4. All other sources.

1.2.4. 2008 Emissions Development

In this section, we briefly describe the 2008 emission inventory. The 2005-6 base case 

inventory uses actual measured electric generating unit (EGU) emissions and monthly drill rig 

emissions because the base case model is evaluated against observations to determine whether 

the model provides a realistic simulation of the atmospheric processes related to ozone and PM 

formation, transport, and removal. The purpose of the 2008 baseline model, on the other 

hand, is to serve as the base year from which future year projections are made and against 

which future year project alternative and cumulative emissions impacts will be evaluated. The 

2008 inventory, therefore, uses typical rather than actual emissions for some source categories 

in order to be consistent with the future year emission inventories. For example, baseline EGU 

emissions represent typical conditions (no shutdowns for maintenance, for example) in order to 

be consistent with the future year emissions, which also represent typical conditions and would 

have no maintenance shutdowns. The base case emission inventory would have a period of 

zero emissions during a maintenance shutdown. If base case EGU emissions were used rather 

than typical emissions, a period when a plant was shut down for maintenance would show up 

as an impact due to an apparent emissions increase in the future year, which would use a 

typical inventory and would not contain the period of zero emissions from the shutdown. The 

two source categories for which 2008 typical emissions were developed are EGUs and drilling 

rigs. The method for calculating emissions from these source categories is described below.

Several source categories of the 2008 regional inventory (e.g. non-O&G area sources, non-road 

mobile) were linearly interpolated from the latest WRAP 2002 and WRAP 2018 emission 

inventories. The most recent WRAP emission databases currently available are the “2002 Plan 
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-9

D” and “2018 PRP18b” emissions databases. The 2018 PRP18b database recently developed for 

Preliminary Reasonable Progress was built from the WRAP 2002 inventory by projecting the 

impacts of activity growth and emission controls. As noted above, the methodology for 

projecting emissions is described in the WRAP PRP Technical Memorandum (Fields and Wolf, 

2007), and information on the WRAP 2002 emission inventory can be found in Tonnesen et al. 

(2006). 

ENVIRON and Carter Lake developed a detailed inventory of point source emissions for the 

2008 year for Wyoming. Year 2008 is a national emissions inventory reporting year and 

emission inventories for Wyoming major and minor point sources have recently been made 

available by the State. These inventories had not been quality-assured by the WDEQ, but were 

quality-assured by ENVIRON and Carter lake and then prepared for processing through SMOKE 

to create CAMx-ready emissions inputs.

For Wyoming and other states, Continuous Emissions Monitor (CEM) data from the U.S. EPA’s 

Clean Air Markets Division (CAMD) was used to supply hourly emissions for electric generating 

utilities (EGUs). The hourly emissions were then be used to form quarterly averages for each of 

the 24 hours in a day. These quarterly averages constitute typical emissions for a particular 

EGU; they are averages that retain information about the typical temporal profile of emissions 

for that facility during a given season. Use of typical EGU emissions is one important difference 

between the base case and baseline inventories. 

For on-road mobile source emissions within the 36/12/4 km domains, 2008 Vehicle Miles 

Travelled (VMT) were developed by interpolating between the 2006 VMT developed for the 

base case modeling and VISTAS 2009 VMT. 2005 and 2006 MM5 meteorological data were 

used with the SMOKE-MOBILE6 processor to generate the gridded speciated day-of-week 

emissions required as input to CAMx. For each month, emissions were generated for a 

representative weekday, Saturday and Sunday in 2008. Holidays were treated as Sundays.

Carter Lake and ENVIRON developed a 2008 emission inventory for Wyoming oil and gas 

sources. A detailed emission inventory was prepared for the 5-county area of southwest 

Wyoming that is similar in scope to the 2005-6 southwest Wyoming oil and gas inventory. The 

2008 5-county southwest Wyoming inventory was developed using the oil and gas emissions 

information available from the Wyoming 2008 inventory and from operator provided emissions 

assumptions. For oil and gas sources in Wyoming outside the 5-county area of southwest 

Wyoming emissions were developed from the Wyoming 2008 point source inventory and from 

available WRAP inventories. In order to be consistent with future year emission inventories, 

drill rig emissions were annualized rather than reported by month, as was done for the 2005-6 

base case emission inventory. Emissions for oil and gas sources within the 12 km domain but 

outside Wyoming were estimated through interpolation of the 2006 and 2012 WRAP Phase III 

inventory where possible and through interpolation of the 2005 and 2018 WRAP Phase II 

inventories elsewhere.

For the 2008 baseline simulations using 2005 and 2006 meteorology, the corresponding 2005 

and 2006 emission inventories for wildfires, wind-blown dust, biogenics, and ammonia were 

used. As noted above, the 2008 baseline emission inventory modeling was carried out so that 
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emissions source categories selected by the WDEQ AQD were processed separately so that they 

could be run as separate emissions source groups in the CAMx probing tools.

The WDEQ-AQD reviewed the 2008 baseline emission inventory and approved the use of the 

inventory for the CD-C 2008 baseline modeling (Personal Communication from Kelly Bott, 

WDEQ-AQD, July 7, 2010). 

1.2.5. Model Configuration

CAMx was configured for the 2008 baseline runs in a manner essentially similar to the 2005-6 

base case modeling. The model was run on the 36/12/4 km domains shown in Figures 1-1 

through 1-3 and the same 34 layer vertical structure (with no collapsing of meteorological 

model layers) used in the base case model was used again in the baseline modeling. An 

important difference from the base case modeling is that a new version of CAMx was used that 

corrects a model error introduced when the vertical velocity algorithm was updated in 2009 to 

reduce excessive vertical transport. This error did not affect the core model results that were 

relied upon in the model performance evaluation, but made the source apportionment results 

unreliable. The problem was resolved in CAMx v5.30, which was used in the 2008 baseline 

modeling. The model configuration for the 2008 baseline modeling is summarized in Table 1-1 

below.

Table 1-1. CAMx air quality model configuration for the CD-C 2008 baseline simulation.

Science Options CD-C Baseline Configuration

Model Code CAMx V5.30 with Vertical Velocity Update

Horizontal Grid Mesh 36/12/4 km

 36 km grid 148 x 112 cells

 12 km grid 89 x 68 cells

 4 km grid 119 x 101 cells

Vertical Grid Mesh 34 Layers

Grid Interaction

One-way 36/12 km

Two-Way 12/4 km

Initial Conditions ~10 days full spin-up

Boundary Conditions

Day-specific 2005 and 2006 3-hourly GEOS-CHEM w/ 2002 GEOSChem monthly average for PM species

Emissions

 Baseline Emissions Processing SMOKE V2.4 

 NH3 Inventory WRAP Ammonia Model with updated seasonal adjustments

Chemistry

 Gas Phase Chemistry CB05

 Aerosol Chemistry ISORROPIA

 Mineral Nitrate Yes

 Secondary Organic Aerosols SOAP

 Aqueous Chemistry RADM

Meteorological Processor MM5CAMx

Horizontal Transport

 Eddy Diffusivity Scheme K-theory with Kh grid size dependence

Vertical Transport

 Advection Scheme Vertical Velocity Update

 Eddy Diffusivity Scheme CMAQ-like
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Science Options CD-C Baseline Configuration

 Diffusivity Lower Limit Kzmin = 0.1 to 2.0 w/ kv100

Dry Deposition Scheme Zhang

Numerics

 Gas Phase Chemistry Solver Euler Backward Iterative (EBI) solver

 Horizontal Advection Scheme PPM)

Simulation Periods 2005 and 2006 using 2008 emissions

Integration Time Step Determined by met conditions

1.3. APPENDIX ORGANIZATION

This Appendix presents results of the CD-C 2008 baseline CAMx runs. In Section 2, we evaluate 

regional ozone levels under a 2008 emissions scenario with 2005 and 2006 meteorology and 

quantify the ozone contribution of CD-C Project Area emissions sources. In Section 3, we 

summarize the impacts at the distant Prevention of Significant (PSD) Class I areas and sensitive 

Class II areas, which include AQRV impacts, (visibility, nitrogen and sulfur deposition and 

sensitive lake acidity), and impacts to PSD increments. In Section 4, we present an evaluation of 

the modeling results for criteria pollutants other than ozone: NO2, SO2, CO, PM2.5, and PM10. In 

Section 5, we provide a summary of the results of the CD-C 2008 baseline modeling.
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2.0. OZONE IMPACT ANALYSIS

2.1. INTRODUCTION

The CAMx modeling outputs from the two annual simulations using 2008 emissions and 2005 

and 2006 meteorology were post-processed to derive ozone concentrations for comparison to 

the ambient air quality standards (WAAQS, CAAQS and NAAQS) across the 4 km domain, 

including each far-field sensitive area. In Section 2, we present CAMx modeling results for 

comparison with the applicable air quality standards in two ways: 

1. following EPA’s modeling guidance for projecting current-year Design Values for criteria 

pollutants that are compared against the NAAQS, WAAQS and CAAQS (EPA, 2007); and

2. using the absolute modeling results that are averaged in accordance with the form of the 

standard and then compared directly with NAAQS, WAAQS and CAAQS. 

EPA has developed guidance for modeled attainment tests for both ozone and PM2.5. CAMx 

2008 baseline run ozone was analyzed using the EPA (2007) guidance, but insufficient 

monitoring data were available within the 4 km domain for projection of PM2.5, so PM2.5 was 

not evaluated using method (1). Method (2), the evaluation of absolute modeling results 

against the ambient air quality standards, was carried out for the following criteria air 

pollutants: NO2, SO2, PM2.5, PM10, ozone and CO. The evaluation of ozone is presented in this 

section, and the evaluation of the remaining criteria pollutants is presented in Section 4.

In method (1), 2008 ozone concentrations for the 2005 and 2006 meteorological years were 

projected using procedures in EPA’s latest modeling guidance (EPA, 2007c). An overview of the 

EPA method is given in the next section. These procedures use the modeling results together 

with observed ozone design values to derive an interpolated current year ozone design value 

field which can then be compared to the NAAQS, which are identical to or more stringent than 

the CAAQS and WAAQS for 8-hour ozone.” Wyoming has not revised the standard for 8-hour 

ozone, and still retains the standard of 0.08 ppm. In method (2), the 4th high daily maximum 8-

hour ozone was calculated for each grid cell for both 2005 and 2006, and then the 2005 and 

2006 results were averaged and compared to the results of method (1) and the NAAQS.

For days and locations in which the absolute model-estimated daily maximum 8-hour ozone 

concentrations or observed 2005-6 daily maximum 8-hour ozone concentrations exceeded a 

threshold, the CAMx APCA ozone source apportionment contributions were used to estimate 

the contribution of emissions from 2008 existing CD-C project emissions sources to the 

exceedances of that threshold. Several thresholds were used to examine the CD-C Project 

contribution to high modeled and observed ozone: the 2008 ozone standard (75 ppb) and two 

values (60 ppb and70 ppb) that bracket the 60-70 ppb range of the NAAQS proposed by EPA in 

January, 2010. The modeling results were evaluated in light of the 2008 NAAQS of 75 ppb that 

was in effect at the time of the CD-C Baseline simulation.

2.2. EPA GUIDANCE OZONE PROJECTION APPROACH 

The ozone NAAQS are formulated in terms of a Design Value, which is calculated as the 3-year 

average of the fourth highest monitored daily maximum 8-hour concentration at each 

monitoring site. To attain the 2008 ozone standard, the Design Value for a given monitor must 
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not exceed 75 ppb. EPA’s modeling guidance (EPA, 2007) for projecting future year 8-hour 

ozone Design Values recommends the use of modeling results in a relative sense to scale the 

observed current year 8-hour ozone Design Value (DVC) to obtain a future year 8-hour ozone 

Design Value (DVF). The model-derived scaling factors are referred to as Relative Response 

Factors (RRF) and are defined as the ratio of daily maximum 8-hour ozone concentrations near 

a monitor averaged over several days of modeling results for the future year emissions scenario 

to the current year base case:

 

 









days

current year

days

future year

monitor i

daily hour ozone

daily hour ozone

RRF

max 8

max 8

DVFmonitor i = DVCmonitor ix RRFmonitor i

This technique is used to minimize the effect of model uncertainty on future year ozone 

projections. For example, if the model has a bias toward underestimating ozone at a given 

monitor, using the raw future year ozone predictions may result in an underestimate of future 

year ozone at that monitor. However, if the ratio of the future year to base year modeled 

ozone values at that monitor is multiplied by the observed base year design value to produce a 

predicted future year value, that future year value will better reflect the change in ozone due to 

changes in emissions between base and future year cases, and the effect of the model’s bias 

toward lower ozone values will have been reduced.

For the CD-C 2008 baseline modeling, DVCs were calculated for comparison with the 2008 

NAAQS of 75 ppb and these results are presented later in this Section. The 2008 DVCs will also 

be used as the basis for the CD-C Project impact analysis once the CD-C future year modeling 

runs are completed. The model output from the future year CAMx runs that include the CD-C 

Project will be used to construct the RRFs, which will then be used with the DVCs calculated 

using the 2008 baseline run to produce DVFs for the future. The DVFs will be used to evaluate 

future year compliance with the 2008 ozone NAAQS. Below, we describe the EPA guidance for 

performing these DVC and future year calculations as well as the procedure for calculating the 

2008 DVC across the entire modeling domain based on the DVCs at the monitors.

The basic steps in performing future year 8-hour ozone projections using EPA’s recommended 

projection approach are summarized as follows:

1. Develop observed current year 8-hour ozone Design Values (DVC) at each monitoring site 

as the starting point for the ozone projections. EPA guidance recommends using a three 

year average of three consecutive years of Design Values centered on the modeling year. 

For the CD-C modeling, this means Design Values from the five year period of 2006-2010 

are required to calculate the observed DVCs for the 2008 modeling year. 

2. Select the maximum modeled 8-hour ozone concentrations near a monitor for several 

days from the base year and future year emission scenarios and take the ratio of their 

averages to construct the monitor-specific RRFs:
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a. EPA guidance defines “near a monitor” to be an array of 7 x 7 grid cells centered on 

the monitoring location for modeling that uses a 4 km grid resolution as in the CD-C 

modeling.

b. EPA recommends that RRFs be based on at least 10 modeled days and recommends 

selecting days in which the base year base case maximum daily (i.e. 2005-6 for the CDC modeling) maximum 8-hour ozone concentrations near a monitor are greater than 

an ozone threshold (cut off). This is done so that the model response to future 

changes in emissions is considered only on high ozone days with conditions 

comparable to those days that produced the design values. Initially, an ozone 

threshold of 85 ppb is used. If less than 10 modeling days are obtained the threshold is 

reduced by 1 ppb until at least 10 days are obtained for the RRF. When the 70 ppb 

threshold floor is reached and there are at least 5 days then the RRF is used. In the 

CD-C 4 km modeling domain, many sites did not meet this 5 day minimum. To ensure 

that the greatest number of monitors possible were used to constrain the DVC field, 

this requirement was relaxed so that the minimum number of days above the 

threshold was 1 day.

- Note that this modeling day selection approach for the RRFs automatically 

eliminates using modeling days in which the model is greatly underestimating 

the observed ozone concentrations when constructing the RRFs.

3. The RRF is applied to the DVC to obtain the projected DVF at each monitoring site for the 

future year emission scenarios. The projected DVF is truncated to the nearest ppb.

4. If the future year ozone projections are carried out as part of an attainment 

demonstration, DVFs are compared with the NAAQS for ozone. If the DVFs at all 

monitoring sites are less than or equal to the ozone NAAQS, then the modeled attainment 

demonstration test is passed. If a DVF at any monitor exceeds the ozone NAAQS, the 

modeled attainment test is not passed. [Note that the current EPA guidance (EPA, 2007) 

addresses the 84 ppb 8-hour ozone NAAQS and we address the 2008 8-hour ozone NAAQS 

of 75 ppb that was in effect at the time of the CD-C baseline modeling].

5. The method of projecting future year design values discussed above applies only to grid 

cells containing monitors, and it is necessary to project future ozone values for areas in 

the domain that lie between the monitors. This is known as an unmonitored area analysis 

and is performed by interpolating DVCs from monitoring sites to each grid cell in the 

modeling domain using the Voronoi Neighbor Averaging technique. The modeled ozone 

gradients are taken into account in the interpolation in order to reflect modeled higher 

and lower ozone areas in the interpolated DVC field. 

An unmonitored area analysis was performed that interpolates the 2008 DVCs across the 

modeling domain and performs ozone projections in each grid cell using the procedures 

given above, except using the modeling results within each grid cell only rather than using 

the surrounding grid cells in addition to the grid cell itself. For the CD-C 2008 DVC ozone 

calculations, the unmonitored area analysis is important given the paucity of ozone 

observations in the region. EPA provides two caveats to be considered when interpreting 

an unmonitored area analysis:
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a. EPA believes that the unmonitored area analysis is more uncertain than the 

monitor-based ozone projections. EPA indicates that additional emissions reductions 

are likely required to eliminate any projected monitored ozone exceedances, while the 

same is not true in the unmonitored area test.

b. EPA recommends that the reasons behind any unmonitored area test exceedances 

be understood and explained.

To facilitate the implementation of EPA’s recommended ozone projections approach, EPA has 

developed the Modeled Attainment Test Software (MATS; Abt, 2009) that codifies the EPA 

recommended projection approach. EPA’s MATS tool includes observed ozone data from which 

DVCs can be calculated along with several options that can be specified in making the ozone 

projections. 

2.2.1. Issues Associated with Applying EPA’s MATS Procedures to Southwest Wyoming

There are several issues associated with using the EPA-recommended ozone projection 

procedure for making future year projections in southwestern (SW) Wyoming. These issues are 

primarily related to the fact that EPA’s procedures were designed for making projections for 

ozone State Implementation Planning (SIP) modeling that in the past occurred primarily in 

urban areas where there are relatively dense monitoring networks for ozone. The MATS 

software includes ozone design value data that is used to construct DVCs for monitors in the 

region of interest. The monitoring network is relatively sparse in SW Wyoming (see Table 2-1 

and Figure 2-1) and for many of these monitors, the monitoring history is relatively short. For 

example, many of the WDEQ SW Wyoming industrial monitoring sites started operation from 

late 2004 through 2007 and therefore may not have the five year record needed to construct 

the EPA default DVCs. For CD-C, the EPA projection procedure was therefore adapted to use 

additional available data to construct the DVC field for the 2008 baseline modeling. 

In addition to the scarcity of monitoring data and the short data record for some SW Wyoming 

monitors, another issue that needs to be addressed in making the DVC calculations projections 

is the portion of the calendar year to be included in the analysis. The WDEQ-AQD has 

determined that the simulation of winter ozone is a research area that is not appropriate for 

inclusion in a NEPA analysis. Therefore, winter ozone will not be analyzed as part of the CD-C 

EIS. However, ozone Design Values are based on the three-year average of the annual fourth 

highest daily maximum 8-hour ozone concentrations that, by definition, include the high winter 

ozone concentrations for the affected monitors. In developing the 2008 DVC values, we have 

used data for the full year in calculating the DVCs at the monitors. This ensures that the 

calculations for the enhanced MATS (EMATS) sites are consistent with those from the base 

MATS (BMATS) sites (which are included with the EPA MATS tool and which use data for the full 

year). However, for the unmonitored areas (i.e. grid cells that do not contain a monitor), the 

model output-based gradients that were used to interpolate ozone design values between 

monitors use data from the April 1-October 31 ozone season only.
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2.2.2. Enhanced Ozone Projection Approach

In order to address the issues noted in the previous section, the following approach was used to 

develop 2008 DVCs in the 4 km CD-C domain for evaluation against the NAAQS. The DVC was 

calculated in two ways: the first method uses only the DVC data included with the MATS tool 

(BMATS sites in Table 2-1) and the second method relaxes requirements regarding length of 

data record and includes additional WDEQ industrial monitors and CASTNet monitoring sites in 

the analysis. These additional monitors are listed as EMATS sites in Table 2-1. In the discussion 

to follow, we refer to these two methods as the BMATS and EMATS methods. Note that the 

EMATS method uses both BMATS and EMATS monitors listed in Table 2-1, while the BMATS 

method uses only the BMATS monitors shaded in blue in Table 2-1. Both the EMATS and BMATS 

site DVCs are calculated using data from the full year, but in unmonitored grid cells, both 

methods use modeling results from April 1-October 31 in the to derive DVCs based on the

MATS interpolation procedure that uses gradients in the modeled ozone output.

Table 2-1. Monitors used in the 2008 CD-C Baseline modeling analysis. Three-year average 

design value (DVC) data used in base MATS (BMATS; blue color) and enhanced MATS (EMATS;

green color) for the CD-C 4 km modeling domain.

Note DV year represents the middle year, e.g. 2008 representing 2007-2009.

The Sun Dog monitor was not used in the EMATS analysis due to its short 2009 data record that included only winter months, 

but is included in this table because it is used in the source apportionment analysis discussed later in this section.

2007 2008

080690007 Rocky MTN NP CO Larimer 40.277 -105.545 76 74 2006-2009

560350098 Jonah W Y Sublette 42.429 -109.696 73 75 2006-2007 and Jan 1- Sep 30, 2008

560350099 Boulder W Y Sublette 42.721 -109.753 80 78 2006-2009

560350100 Daniel W Y Sublette 42.793 -110.056 71 67 2006-2009

560370200 Wamsutter W Y Sweetwater 41.678 -108.068 65 63 Mar 7 - Dec 31, 2006 and 2007-2009

560410101 Murphy Ridge W Y Uinta 41.373 -111.042 67 64 2007-2009

CNT169 Centennial W Y Albany 41.364 -106.240 68 67 2006-2009

PND165 Pinedale W Y Sublette 42.929 -109.788 66 64 2006-2009

ROM206 Rocky Mtn NP Collocated CO Larimer 40.278 -105.545 77 71 2006-2009

ROM406 Rocky Mtn NP CO Larimer 40.278 -105.545 76 74 2006-2009

560130099 South Pass W Y Fremont 42.528 -108.720 68 72 Mar 15 - Dec 31, 2007 and 2008 - 2009

560070099 Atlantic Rim W Y Carbon 41.536 -107.546 73 61 2008 and Jan 1 - Feb 24, 2009

560070100 Sun Dog W Y Carbon 41.397 -107.619 No Data 46 Nov 1 - Dec 31, 2009-Site not used in MATS

560130232 Spring Creek W Y Fremont 43.082 -107.549 No Data 59 Feb 6 - Dec 31, 2009

560370898 OCI W Y Sweetwater 41.737 -109.639 69 66 2007-2008 and Jan 1 - Sep 30, 2009

Site ID SiteName State County LAT LONG

3-year average DV

Data Available for DV Calculcation
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Figure 2-1. Southwest Wyoming ozone monitors used in the Enhanced and Base MATS 

analyses.

2.3. MATS MODELING RESULTS

In this section, we present MATS current year Design Values (DVC) using CAMx results for the 

2008 emissions scenario with 2005 and 2006 meteorology in order to compare with the 2008 

ozone NAAQS of 0.075 ppm (75 ppb). An 8-hour ozone Design Value attains the NAAQS if it is 

75 ppb or lower. As 8-hour ozone Design Values are expressed to the nearest ppb and the EPA 

convention is to truncate to the nearest ppb, then exceedances of the 8-hour ozone NAAQS 

occur when ozone is 76.0 ppb or higher and attainment is achieved with 8-hour ozone Design 

Values of 75.9 ppb or lower. We also evaluate the MATS results in light of EPA’s January 2010 

announcement that they plan to lower the NAAQS to be within the 60-70 ppb range. 

Figure 2-2 shows the BMATS design values for all grid cells in the 4 km domain for the 2005 

meteorological year. In the BMATS configuration, there are very few monitoring stations within 

the 4 km domain. The BMATS results show values higher than the 2008 NAAQS (75 ppb) in a 

region extending from the Salt Lake City metropolitan area northward through Uinta, Lincoln 

and Sweetwater Counties up into in Sublette and Fremont Counties. This broad region of high 

DVCs is in part due to the interpolation of high ozone of the Salt Lake City area to the northeast 

into SW Wyoming. The DVC values also exceed 75 ppb in the southeastern corner of the 

domain in the Fort Collins, Colorado metropolitan area that lies within the Denver/North Front 

Range ozone nonattainment area. DVCs exceed 60 ppb everywhere within the 4 km domain, 
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and the DVCs exceed 70 ppb across most of the western half of the domain as well as in the 

Fort Collins area.

When additional EMATS sites are used in the analysis (Figure 2-3), they supply additional data 

and prevent high urban ozone values from being interpolated into rural areas of SW Wyoming. 

Generally lower ozone is projected in EMATS as compared to BMATS. Only a few grid cells in 

the Fort Collins, CO area exceed the 75 ppb ozone standard in the BMATS figure. The EMATS 

figure shows that the design values for parts of Sublette, Sweetwater, Fremont, Uinta and 

Lincoln Counties exceed 65 ppb and/or 70 ppb and that most of SW Wyoming exceeds 60 ppb. 

The region where the 70 ppb threshold is exceeded is far smaller in the EMATS case than in the 

BMATS case.

The BMATS plot for the 2006 meteorological year (Figure 2-4) shows lower ozone over the Salt 

Lake City area and in Lincoln, Sweetwater and Uinta Counties compared to the 2005 BMATS 

plot. The 2006 BMATS design values exceed the 75 ppb NAAQS in the Fort Collins, CO area and 

in Sublette, Fremont, and Lincoln Counties in Wyoming. In the 2006 EMATS plot, ozone is 

generally lower across the domain than in the 2006 BMATS plot. Comparison of the 2006 and 

2005 EMATS plots shows that design values were generally higher domain-wide in 2006 and 

that peak ozone design values were higher in Sublette County in 2006 than in 2005. Parts of 

Sublette, Uinta, Sweetwater, Fremont and Lincoln Counties exceed 65 ppb and/or 70 ppb in the 

2006 EMATS case, and design values across much of SW Wyoming exceed 60 ppb.
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Figure 2-2. Base MATS (BMATS) DVCs for the 2008 emissions scenario using 2005 

meteorology.

Figure 2-3. Enhanced MATS (EMATS) DVCs for the 2008 emissions scenario using 2005 

meteorology.
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Figure 2-4. Base MATS (BMATS) DVCs for the 2008 emissions scenario using 2006 

meteorology.

Figure 2-5. Enhanced MATS (EMATS) DVCs for the 2008 emissions scenario using 2006 

meteorology.
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2.4. ABSOLUTE MODELING RESULTS

In the previous section, the modeled ozone results were used together with the EPA MATS tool 

to calculate current year Design Values based on observed ozone at SW Wyoming monitors and 

gradients in the modeled ozone fields. In this section, we present the absolute (raw) modeling 

results. The 4th highest daily maximum 8-hour average was computed for each grid cell from 

the CAMx runs for both the 2005 and 2006 meteorological years. Only data from the Wyoming 

ozone season (April 1-October 31) were used in this calculation, per the WDEQ-AQD. This is 

consistent with the processing of the MATS results. Figure 2-6 shows the average of the results 

for the 2008 emissions scenario for 2005 and 2006 meteorological years. Figures 2-7 and 2-8 

show the results for the individual 2005 and 2006 meteorological years, respectively. The 2005-

6 average is an approximation to a Design Value produced with the absolute modeling results 

and is compared with the EMATS design values in Figures 2-3 and 2-5.

The absolute modeling results show two-year design values that are generally higher than the 

2005 and 2006 EMATS DVCs across a larger swath of SW Wyoming, but peak values in Sublette 

County are lower in the absolute modeling results than in the EMATS DVCs. Values in the Fort

Collins area agree reasonably well, but the absolute modeling results are higher than the 

EMATS DVCs over the Salt Lake City area. The 2005-6 average absolute modeling results show 

that the 2008 NAAQS (75 ppb) are exceeded only in the Fort Collins and Salt Lake City areas. 

The full range of the proposed NAAQS of 60-70 ppb is exceeded throughout the 4 km domain in 

the absolute modeling results in Figure 2-6, while in the EMATS results for both 2005 and 2006, 

the northeastern portion of the domain has regions where the DVC falls below 60 ppb.

Observed ozone concentrations were generally higher in the 4 km domain during the 2006 

meteorological year than in 2005, and this is reflected in the model results shown in Figures 2-7 

and 2-8. Comparison of Figure 2-7 with Figure 2-2 and Figure 2-8 with Figure 2-4 shows the role 

that modeled gradients play in determining the BMATS DVC values, as the overall patterns of 

high and low ozone are similar in these figures. In the absolute modeling results shown in 

Figure 2-7 and 2-8, the 2008 NAAQS (75 ppb) are exceeded only in the Fort Collins and Salt Lake 

City areas in 2005 while in 2006, the 2008 NAAQS (75 ppb) is exceeded over broad areas of SW 

Wyoming. In both 2005 and 2006 meteorological years, the proposed range of the NAAQS of 

60-70 ppb is exceeded everywhere within the 4 km domain in the absolute modeling results.
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Figure 2-6. Two-year (2005-6) average of 4th highest daily max 8-hour average ozone 

concentration from the absolute CAMx modeling results. 

Figure 2-7. 4th highest daily max 8-hour average ozone concentration from the absolute 

CAMx modeling results for the 2005 meteorological year. 
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Figure 2-8. 4th highest daily max 8-hour average ozone concentration from the absolute 

CAMx modeling results for the 2006 meteorological year. 

2.5. CD-C PROJECT OZONE CONTRIBUTIONS ON HIGH DAYS

Having analyzed the MATS ozone DV results and the absolute modeling results across the 4 km 

modeling domain, we now isolate the contribution of emissions from the CD-C Project to high 

ozone during the two year CAMx simulation. On days during the April 1-October 31 ozone 

season that had high observed and/or modeled 8-hour ozone at monitors within the 4 km 

domain, the contribution of CD-C Project area sources to 8-hour ozone at the monitors was 

determined. 

We analyze results for days with high observed ozone at the monitors (Tables 2-2 through 2-4) 

as well as for days with high modeled ozone at the monitors (Tables 2-5 through 2-7). If model 

performance were perfect, so that the modeled ozone always matched the observed ozone, 

and all monitoring sites were operating during both meteorological years, there would be a 

need for only one set of tables. However, we include results for both high modeled and high 

observed days to account for the fact that the model may under- or overpredict ozone. Looking 

at the results for days with high modeled ozone also allows us to expand the analysis to sites 

where no monitor was present during that meteorological year (e.g. Wamsutter during 2005). 

We include results for both high observed and modeled ozone days in order to present a more 

complete view of the modeling results for CD-C project impacts.

The CAMx APCA ozone source apportionment results were used to isolate the CD-C Project area 

contribution to 8-hour ozone at each monitor and time. The contributions of both CD-C 
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-24

Project and non-CD-C Project sources within the CD-C Project area were analyzed. The APCA 

ozone source apportionment results were also used to calculate the contribution of CD-C 

Project sources to the MATS design values shown in Figures 2-2 through 2-5. 

2.5.1. Contribution of CD-C Project Area Sources to High Ozone at Monitors in the 4 km 

Domain

Table 2-2 shows the maximum ozone season 8-hour ozone impact at each 4 km domain 

monitor both as an absolute figure in ppb and as a percentage of the total daily maximum 8-

hour average ozone (DM8) at that monitor on days when the observed DM8 > 60 ppb. For each 

monitor, the maximum value during the 2005 and 2006 meteorological years is shown, and the 

CD-C Project area contributions are broken down into contributions from CD-C Project and nonCD-C Project sources within the CD-C Project area. The upper left hand panel of Figure 2-9 

shows the maximum value of the CD-C Project contribution to high ozone as a percentage of 

the DM8 during the 2005 and 2006 meteorological years. The percentages are identical to the 

data in Table 2-2 and are displayed on the map of the 4 km domain in order to illustrate 

graphically the spatial extent and magnitude of the CD-C Project ozone contribution on high 

ozone days. The maximum 8-hour ozone impact from CD-C project sources is 1.5 ppb at the 

Wamsutter monitor in 2006; this value is 2.7% of daily max 8-hour ozone (DM8) at Wamsutter. 

The maximum impact from non-CD-C sources within the CD-C Project area is 0.09 ppb, 

corresponding to 0.14% of the DM8 at Centennial during 2006. The largest CD-C impacts 

occurred within and east (generally downwind) of Project area, while impacts were far smaller 

in Sublette County, which was infrequently downwind of CD-C during 2006 (see 2006 modeled 

and observed wind roses for the Wamsutter monitor in the lower right panel of Figure 2-9). 

On days when the DM8 at the monitors was higher than 70 ppb (Table 2-3; upper right panel of 

Figure 2-9), the maximum CD-C Project contributions were 0.08 at the Boulder monitor (0.11% 

of the modeled DM8) and 0.08 ppb at the Wamsutter monitor (0.13% of the modeled DM8), 

and the maximum contribution from non-CD-C Project sources within the CD-C Project area was 

less than 0.01 ppb (0.01% of the modeled DM8). 

Only the Centennial, Pinedale and Jonah monitors had days in 2005 or 2006 where the DM8 at 

the monitors exceeded 75 ppb (Table 2-4; lower left hand panel of Figure 2-9). On these days, 

the maximum CD-C Project contribution was less than 0.01 ppb at all monitors and less than 

0.01% of the modeled DM8 at all monitors. 

Table 2-5 shows the maximum ozone season CD-C Project area impact on 8-hour ozone impact 

at each monitor both as an absolute figure in ppb and as a percentage of the total DM8 at that 

monitor on days when the modeled DM8 > 60 ppb. For each monitor, the maximum value 

during the 2005 and 2006 meteorological years is shown. The upper left hand panel of Figure 

2-10 shows the maximum value of the CD-C Project contribution to high ozone as a percentage 

of the DM8 during the 2005 and 2006 meteorological years. The maximum 8-hour ozone 

impact from CD-C project sources is 2.3 ppb at the Spring Creek monitor in 2006; this value is 

3.2% of the DM8 at Spring Creek. This impact occurred on April 22, 2006, and is the result of a 

southerly wind event which brought ozone from the CD-C Project northward into Fremont and 

Natrona Counties. HYSPLIT back trajectories using EDAS 40 km resolution meteorology indicate 

that there was southerly flow on this day (Figure 2-15; this event is discussed in more detail in 
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-25

the next section). Animations of the modeled ozone results (not shown) indicate that, during 

April 2006, there were several episodes of southerly winds that brought ozone and precursors 

from the CD-C Project area northward into Fremont and Natrona Counties. There were no 

similar periods during the rest of the ozone season in 2006 or during the 2005 ozone season. 

Note that the maximum CD-C Project impact at Spring Creek is less than 0.4 ppb in 2005.

The other monitors that showed impacts greater than 1 ppb when modeled DM8 > 60 ppb were 

Wamsutter (1.1 ppb; 1.7% of the DM8), Atlantic Rim (1.4 ppb; 2.2% of the DM8), and Sun Dog 

(1.6 ppb; 2.3% of the DM8). These three sites are located in the vicinity of the CD-C Project 

area (Figure 2-10). The CD-C Project contribution to high 8-hour ozone at Sublette County 

monitors was <0.1 ppb. Aside from the April 22, 2006 event, the largest CD-C impacts occurred 

within and east (generally downwind) of Project area; impacts were far smaller in Sublette 

County and in the Lincoln and Uinta Counties to the west of the Project area. The maximum 

impact from non-CDC sources within the CD-C Project area is 0.18 ppb, corresponding to 0.26% 

of the DM8 at Atlantic Rim during 2006. 

On days when the modeled daily max 8-hour average ozone at the monitors was higher than 70 

ppb (Table 2-6; upper right hand panel of Figure 2-10), the maximum CD-C Project contribution 

was 1.1 ppb at the Wamsutter monitor (1.4% of the modeled DM8), and the maximum 

contribution from non-CD-C Project sources within the CD-C Project area was 0.06 ppb (0.07% 

of the modeled DM8) at Sun Dog. Modeled and observed ozone were higher in 2006 than in 

2005. Table 2-7 shows that there were no days in 2005 in which the DM8>75 ppb at any of the 

sites. The maximum CD-C Project contribution when modeled DM8>75 ppb was 1.1 ppb at the 

Wamsutter monitor (1.4% of the modeled DM8), and the maximum contribution from non-CDC Project sources within the CD-C Project area was 0.06 ppb (0.07% of the modeled DM8) at 

Sun Dog. 

Figures 2-9 and 2-10 show that the CD-C Project emissions sources contribute less than 3% to 

the DM8 on any modeled or observed high ozone day during the 2005-6 meteorological years 

and that aside from the April 22, 2006 event, the largest contributions occur at sites near the 

Project area. The CD-C Project has its highest contribution when the observed or modeled DM8 

is less than 70 ppb. On the days when the observed or modeled ozone exceeded the 2008 75 

ppb standard, the highest CD-C Project contribution was 1.4% of the DM8 at Wamsutter. 

Contributions from the CD-C Project to ozone in Sublette County have a maximum of 0.83% of 

the DM8 at Boulder when DM8 > 60 ppb. As the DM8 threshold is increased to 70 ppb, this 

peak contribution drops to 0.11% of the DM8, and then as the threshold moves to 75 ppb, the 

peak CD-C contribution is less than 0.01% for all Sublette County monitors.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-26

Table 2-2. Contribution to modeled daily max 8-hour average ozone (DM8) at SW Wyoming 

monitors from CD-C Project and non-CDC Project sources of emissions within the CD-C Project 

Area on days when the observed DM8 > 60 ppb. Wamsutter was not operating in 2005.

Table 2-3. Contribution to modeled daily max 8-hour average ozone (DM8) at SW Wyoming 

monitors from CD-C Project and non-CDC Project sources of emissions within the CD-C Project 

Area on days when the observed DM8 > 70 ppb. Sites that did not have DM8 > 70 ppb or 

were not operating during a given year are indicated by “-“. Data for sites that had impacts < 

0.00005 ppb or % impacts <0.00005% are shown in gray type.

Table 2-4. Contribution to modeled daily max 8-hour average ozone (DM8) at SW Wyoming 

monitors from CD-C Project and non-CDC Project sources of emissions within the CD-C Project 

Area on days when the observed DM8 > 75 ppb. Sites that did not have DM8 > 75 ppb or 

were not operating during a given year are indicated by “-“. Data for sites that had impacts < 

0.00005 ppb or % impacts <0.00005% are shown in gray type.

Max CDC Max CDC Max non-CDC Max non-CDC Max CDC Max CDC Max non-CDC Max non-CDC

Absolute (ppb) % Absolute (ppb) % Absolute (ppb) % Absolute (ppb) %

Pinedale 0.0398 0.0687 0.0024 0.0038 0.0757 0.1171 0.0022 0.0033

Centennial 0.5974 1.0749 0.0355 0.0639 1.0750 1.8368 0.0922 0.1433

Jonah 0.2660 0.4362 0.0130 0.0213 0.1481 0.2281 0.0019 0.0033

Boulder 0.1945 0.3411 0.0104 0.0183 0.4456 0.8286 0.0242 0.0450

Daniel 0.1435 0.2544 0.0084 0.0148 0.0912 0.1437 0.0024 0.0037

Wamsutter -- -- -- -- 1.5410 2.6468 0.0708 0.1216

Max Overall 0.5974 1.0749 0.0355 0.0639 1.5410 2.6468 0.0922 0.1433

Monitor

2008met2005 2008met2006

Max CDC Max CDC Max non-CDC Max non-CDC Max CDC Max CDC Max non-CDC Max non-CDC

Absolute (ppb) % Absolute (ppb) % Absolute (ppb) % Absolute (ppb) %

Pinedale 0.0000 0.0000 0.0000 0.0000 0.0001 0.0002 0.0000 0.0000

Centennial 0.0026 0.0046 0.0008 0.0013 0.0215 0.0360 0.0072 0.0120

Jonah 0.0003 0.0007 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

Boulder 0.0000 0.0000 0.0000 0.0000 0.0751 0.1108 0.0003 0.0005

Daniel -- -- -- -- 0.0001 0.0002 0.0000 0.0000

Wamsutter -- -- -- -- 0.0750 0.1329 0.0000 0.0001

Max Overall 0.0026 0.0046 0.0008 0.0013 0.0751 0.1329 0.0072 0.0120

Monitor

2008met2005 2008met2006

Max CDC Max CDC Max non-CDC Max non-CDC Max CDC Max CDC Max non-CDC Max non-CDC

Absolute (ppb) % Absolute (ppb) % Absolute (ppb) % Absolute (ppb) %

Pinedale 0.0000 0.0000 0.0000 0.0000 0.0001 0.0002 0.0000 0.0000

Centennial 0.0026 0.0046 0.0008 0.0013 -- -- -- --

Jonah -- -- -- -- -- -- -- --

Boulder -- -- -- -- 0.0001 0.0002 0.0000 0.0000

Daniel -- -- -- -- -- -- -- --

Wamsutter -- -- -- -- -- -- -- --

Max Overall 0.0026 0.0046 0.0008 0.0013 0.0001 0.0002 0.0000 0.0000

Monitor

2008met2005 2008met2006
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-27

60 ppb Threshold 70 ppb Threshold

75 ppb Threshold

Figure 2-9. Maximum ozone season impact at each monitor as a percentage of total DM8 at the monitor 

when observed DM8 > 60 ppb during 2005-6. Values less than 0.01% of the DM8 are not shown. If no 

values are shown on the map, then no monitor had a contribution from the CD-C Project that exceeded 

0.01% of the DM8. Lower right hand panel: Modeled MM5 Wind rose for 2006 for the grid cell 

containing the Wamsutter monitor (top) and observed wind rose for 2006 for the Wamsutter monitor 

(bottom). 
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-28

Table 2-5. Contribution to modeled daily max 8-hour average ozone (DM8) at SW Wyoming 

monitors from CD-C Project and non-CDC Project sources of emissions within the CD-C Project 

Area on days when the modeled DM8 > 60 ppb. Sites that did not have DM8 > 60 ppb during 

a given year are indicated by “-“. Data for sites that had impacts < 0.00005 ppb or % impacts 

<0.00005% are shown in gray type.

Table 2-6. Contribution to modeled daily max 8-hour average ozone (DM8) at SW Wyoming 

monitors from CD-C Project and non-CDC Project sources of emissions within the CD-C Project 

Area on days when the modeled DM8 > 70 ppb. Sites that did not have DM8 > 70 ppb during 

a given year are indicated by “-“. Data for sites that had impacts < 0.00005 ppb or % impacts 

<0.00005% are shown in gray type.

Max CDC Max CDC Max non-CDC Max non-CDC Max CDC Max CDC Max non-CDC Max non-CDC

Absolute (ppb) % Absolute (ppb) % Absolute (ppb) % Absolute (ppb) %

Pinedale 0.0373 0.0595 0.0024 0.0038 0.0757 0.1171 0.0022 0.0033

Centennial 0.4866 0.7884 0.0486 0.0733 0.6907 1.0351 0.0956 0.1433

OCI 0.2428 0.3886 0.0120 0.0191 0.3131 0.4874 0.0034 0.0054

Jonah 0.0000 0.0000 0.0000 0.0000 0.1481 0.2281 0.0007 0.0010

Boulder 0.0001 0.0001 0.0000 0.0000 0.0751 0.1108 0.0003 0.0005

Daniel 0.0001 0.0001 0.0000 0.0000 0.0912 0.1437 0.0024 0.0037

Wamsutter 0.8866 1.3506 0.0196 0.0299 1.1485 1.7117 0.0364 0.0527

Murphy Ridge 0.0564 0.0920 0.0043 0.0070 0.1169 0.1866 0.0124 0.0198

Caribou 0.0343 0.0558 0.0024 0.0039 0.1009 0.1454 0.0019 0.0027

Fremont 0.4060 0.5992 0.0075 0.0111 0.3519 0.5591 0.0040 0.0065

South Pass 0.0012 0.0016 0.0000 0.0000 0.2219 0.3319 0.0039 0.0058

Atlantic Rim 1.4208 2.1536 0.0830 0.1355 1.4353 2.0503 0.1763 0.2585

Moxa Arch 0.0491 0.0789 0.0028 0.0045 0.1961 0.3127 0.0092 0.0146

Hiawatha 0.0605 0.0867 0.0020 0.0031 0.3922 0.6237 0.0090 0.0140

Sun Dog 1.5657 2.3154 0.1407 0.2080 1.0177 1.6403 0.1587 0.2520

Spring Creek 0.3069 0.4637 0.0128 0.0194 2.2781 3.2388 0.0375 0.0532

Max Overall 1.5657 2.3154 0.1407 0.2080 2.2781 3.2388 0.1763 0.2585

Monitor

2008met2005 2008met2006

Max CDC Max CDC Max non-CDC Max non-CDC Max CDC Max CDC Max non-CDC Max non-CDC

Absolute (ppb) % Absolute (ppb) % Absolute (ppb) % Absolute (ppb) %

Pinedale 0.0000 0.0000 0.0000 0.0000 0.0064 0.0089 0.0004 0.0005

Centennial 0.0769 0.1081 0.0041 0.0058 0.2279 0.3075 0.0359 0.0485

OCI 0.0000 0.0000 0.0000 0.0000 0.0002 0.0003 0.0000 0.0000

Jonah 0.0000 0.0000 0.0000 0.0000 0.0047 0.0063 0.0002 0.0002

Boulder 0.0000 0.0000 0.0000 0.0000 0.0028 0.0037 0.0002 0.0003

Daniel 0.0000 0.0000 0.0000 0.0000 0.0028 0.0037 0.0002 0.0003

Wamsutter 0.1198 0.1584 0.0034 0.0045 1.0588 1.3920 0.0193 0.0253

Murphy Ridge 0.0000 0.0000 0.0000 0.0000 0.0001 0.0001 0.0000 0.0000

Caribou 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

Fremont -- -- -- -- 0.0039 0.0053 0.0003 0.0005

South Pass 0.0000 0.0000 0.0000 0.0000 0.0045 0.0061 0.0001 0.0002

Atlantic Rim 0.1419 0.1967 0.0203 0.0279 0.5525 0.7282 0.0368 0.0485

Moxa Arch 0.0000 0.0000 0.0000 0.0000 0.0061 0.0080 0.0000 0.0001

Hiawatha 0.0153 0.0215 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

Sun Dog 0.0611 0.0836 0.0089 0.0125 0.0561 0.0733 0.0555 0.0724

Spring Creek -- -- -- -- 0.0020 0.0028 0.0005 0.0007

Max Overall 0.1419 0.1967 0.0203 0.0279 1.0588 1.3920 0.0555 0.0724

Monitor

2008met2005 2008met2006
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-29

Table 2-7. Contribution to modeled daily max 8-hour average ozone (DM8) at SW Wyoming 

monitors from CD-C Project and non-CDC Project sources of emissions within the CD-C Project 

Area on days when the modeled DM8 > 75 ppb. Sites that did not have DM8 > 75 ppb during 

a given year are indicated by “-“. Data for sites that had impacts < 0.00005 ppb or % impacts 

<0.00005% are shown in gray type.

Max CDC Max CDC Max non-CDC Max non-CDC Max CDC Max CDC Max non-CDC Max non-CDC

Absolute (ppb) % Absolute (ppb) % Absolute (ppb) % Absolute (ppb) %

Pinedale -- -- -- -- 0.0003 0.0004 0.0002 0.0003

Centennial -- -- -- -- -- -- -- --

OCI -- -- -- -- 0.0002 0.0003 0.0000 0.0000

Jonah -- -- -- -- 0.0012 0.0016 0.0002 0.0002

Boulder -- -- -- -- 0.0005 0.0007 0.0002 0.0003

Daniel -- -- -- -- 0.0011 0.0014 0.0002 0.0003

Wamsutter -- -- -- -- 1.0588 1.3920 0.0193 0.0253

Murphy Ridge 0.0000 0.0000 0.0000 0.0000 0.0001 0.0001 0.0000 0.0000

Caribou -- -- -- -- -- -- -- --

Fremont -- -- -- -- -- -- -- --

South Pass -- -- -- -- 0.0009 0.0012 0.0001 0.0002

Atlantic Rim -- -- -- -- -- -- -- --

Moxa Arch 0.0000 0.0000 0.0000 0.0000 0.0061 0.0080 0.0000 0.0001

Hiawatha -- -- -- -- -- -- -- --

Sun Dog -- -- -- -- 0.0561 0.0733 0.0555 0.0724

Spring Creek -- -- -- -- -- -- -- --

Max Overall 0.0000 0.0000 0.0000 0.0000 1.0588 1.3920 0.0555 0.0724

Monitor

2008met2005 2008met2006
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-30

60 ppb Threshold 70 ppb Threshold

75 ppb Threshold

Figure 2-10. Maximum ozone season impact at each monitor as a percentage of total DM8 at the monitor 

when modeled DM8 > 60 ppb during 2005-6. Values less than 0.01% of the DM8 are not shown. If no 

values are shown on the map, then no monitor had a contribution from the CD-C Project that exceeded 

0.01% of the DM8.

0.12

0.14 0.11

0.23 0.33

3.24

0.19

0.49

1.71

2.15

1.04

0.62

0.31

2.32

Hiawatha

Moxa Arch

Sun Dog

Fremont

0.15 0.60

0.01

0.01 0.01

1.39

0.73

0.31

0.02

0.01

0.08

Hiawatha

Moxa Arch

Sun Dog

Fremont

0.01

1.39

0.07

Hiawatha

Sun Dog

Fremont

0.01

Moxa Arch
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-31

2.6. CONTRIBUTION OF CD-C PROJECT SOURCES TO MATS 2008 DVC RESULTS

Next, we assess the effect of CD-C Project area emissions sources on 2008 ozone Design Values 

within the 4 km domain using EPA’s MATS tool. The base case EMATS and BMATS results 

obtained using all sources of emissions within the 4 km domain are shown in Figures 2-2 

through 2-5. A second set of MATS results was generated by subtracting the CD-C Project APCA 

contribution from the CAMx output 8-hour ozone averages and then running MATS on the 

resulting ozone field. If we subtract the MATS results without the CD-C Project contribution 

from the MATS results in the base cases shown in Figures 2-2 through 2-5, we obtain the CD-C 

contribution to the 2008 DVC. This procedure was carried out for both the EMATS and BMATS 

results, and the results are shown in Figures 2-11 through 2-14.

The CD-C Project 2008 DVC contribution for the BMATS case run with 2005 meteorology is 

shown in Figure 2-11. The ozone DVCs increase within the CD-C Project area and in its 

immediate vicinity due to the contribution of CD-C Project emissions. The maximum increase in 

the Design Value due to CD-C Project emissions is 0.4 ppb. In the EMATS case run with 2005 

meteorology (Figure 2-12), increases in the DVC due to CD-C Project emissions occur within and 

near the CD-C Project area, with maximum value of 0.4 ppb, as in the 2005 BMATS case. In the 

EMATS case, some apparent ozone Design Value reductions occur in Sweetwater and Carbon 

counties and south of the Wyoming-Colorado border. These negative values are likely a 

numerical artifact introduced via the interpolation procedure and their peak value, -0.2 ppb, 

may serve as an estimate of uncertainty in the CD-C Project MATS design value impact analysis. 

Therefore, we estimate that there is noise of approximately 0.1-0.2 ppb introduced into this 

procedure by the interpolation, so that a more realistic estimate of the CD-C ozone design value 

contribution would be ~0.1-0.2 ppb during the 2005 meteorological year.

For the 2006 meteorological year, the CD-C Project ozone DVC impacts calculated using the 

BMATS differences are shown in Figure 2-13. The largest increase in the Design Value due to 

CD-C Project emissions is 0.6 ppb. The highest values occur in the CD-C Project area and in a 

plume extending to the east of the Project area as well as two maxima in Fremont and Natrona 

Counties. The Fremont and Natrona maxima are due to the April 22, 2006 event in which 

southerly winds transported air from the CD-C Project area northward into these counties. 

Note that there are no such maxima in the 2005 results shown in Figures 2-11 and 2-12. Figure 

2-15 displays the 2006 BMATS DVCs alongside the absolute 1-hour CAMx ozone concentrations 

for 3 pm on April 22, 2006 the CD-C Project APCA ozone contribution for this time. The 

correspondence between the APCA contribution and the DVC signal is clear. In the lower panel 

of Figure 2-15, we show trajectory analyses generated using NOAA’s HYSPLIT model (Draxler et 

al., 1997) run with 40 km EDAS meteorological data. Forward trajectories beginning at the 

Wamsutter monitor on the morning of April 22, 2006 show northward flow toward 

Fremont/Natrona. Longer back trajectories ending in the Spring Creek area on the afternoon of 

April 22, 2006 indicate that the wind flow was from the south-southwest. While these 

trajectories must be interpreted with caution given the limitations of the HYSPLIT model and 

the coarse resolution of the EDAS meteorology, they suggest that the model’s transport of 

ozone/precursors from the CD-C project northward to Fremont/Natrona Counties is not 

unreasonable. Animations of the CAMx ozone outputs show that ozone precursors were 

transported northward overnight and that high ozone formed in situ in Fremont Natrona after 
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-32

sunrise on April 22; this fact, together with the fact the MATS isolates high ozone values, is why 

the high DVCs in Fremont and Natrona appear isolated and are not associated with a plume 

extending northward from the CD-C Project area.

As in 2005, there are apparent decreases in the 2006 DVC that are likely to be numerical 

artifacts; the peak negative value is 0.2 ppb, indicating an uncertainty of 0.2 ppb, so that the 

increase in design values due to CD-C Project sources within the 4 km domain can be taken to 

be ~0.4 ppb or less. The 2006 EMATS DVCs are similar in pattern to the 2006 BMATS DVCs, with 

slightly smaller magnitude; the peak increase is 0.5 ppb for the EMATS case. In summary, the 

peak increase in design value during the 2005-6 meteorological years due to the CD-C Project 

emissions is approximately 0.4 ppb.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-33

Figure 2-11. 2005 meteorological year MATS ozone DVC contribution from the CD-C Project 

emissions sources within the CD-C Project area (Base BMATS – Base BMATS without CD-C).

Figure 2-12. 2005 meteorological year MATS ozone DVC contribution from the CD-C Project 

emissions sources within the CD-C Project area (Base EMATS – Base EMATS without CD-C).
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-34

Figure 2-13. 2006 meteorological year MATS ozone DVC contribution from the CD-C Project 

emissions sources within the CD-C Project area (Base BMATS – Base BMATS without CD-C).

Figure 2-14. 2006 meteorological year MATS ozone DVC contribution from the CD-C Project 

emissions sources within the CD-C Project area (Base EMATS – Base EMATS without CD-C).
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-35

Figure 2-15. Upper left panel: as in Figure 2-13. Upper right panel: 1 hour absolute CAMx 

ozone at 3 pm (LST), April 22, 2006. Middle panel: CAMx APCA ozone contribution from CD-C 

Project emission sources at 3 pm (LST), April 22, 2006. Lower left panel: HYSPLIT 12-hour 

forward trajectories for 250 m, 500 m and 1000 m beginning at Wamsutter monitor at 3 am 

(LST) April 22, 2006. Lower right panel: HYSPLIT 24-hour backward trajectories for 500 m, 

1000 m and 2000 m ending at the Spring Creek monitor at 3 pm (LST) April 22, 2006. 

Wamsutter

Spring Creek
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-36

2.7. SUMMARY OF OZONE SOURCE APPORTIONMENT RESULTS

Analysis of the APCA ozone source apportionment results from the CD-C 2008 baseline CAMx 

runs indicates that the impact of emissions from existing CD-C Project is 0.4 ppb or less to 8-

hour ozone Design Values across the 4 km domain. The CD-C contribution to 8-hour ozone at 

monitors on observed and modeled DM8 > 75 ppb days and DM8 > 70 ppb days is 1.1 ppb or 

less and 1.4% or less of the DM8 value. The CD-C contribution to 8-hour ozone at monitors on 

observed and modeled DM8 > 60 ppb days is 2.3 ppb or less and 3.2% or less of the DM8 value. 

The largest CD-C ozone impacts occur at monitors near and generally downwind of the CD-C 

Project area; these are Wamsutter, Atlantic Rim, Sun Dog, and Centennial. In 2006 only, there 

is a comparable impact at the Spring Creek monitor due to an episode of southerly winds on 

April 22, 2006 that brought ozone and precursors northward from the CD-C Project area to 

Fremont and Natrona Counties.

The non-CD-C project contribution to high observed and modeled 8-hour ozone at Sublette 

County monitors was 0.2 ppb or less and less than 0.3% of the DM8. The contribution of CD-C 

Project sources was larger than that of non-CD-C Project sources within the CD-C Project area.
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3.0. FAR FIELD ANALYSIS

3.1. INTRODUCTION

The results of the 2008 Baseline CAMx model simulations were evaluated to assess the air 

quality (AQ) and air quality-related values (AQRVs) impacts of the 2008 CD-C Project area 

emissions and the cumulative impacts of the 2008 CD-C Project area emissions taken together 

with the impacts of all other 2008 regional emissions. In Section 3, the CAMx-estimated AQRV 

impacts due to existing 2008 CD-C Project area emissions sources are compared with

Prevention of Significant Deterioration (PSD; described below in Section 3.2) Class I and II area 

increments, visibility thresholds, and deposition analysis thresholds. 

The PSD Class I areas and sensitive Class II areas analyzed are:

 Bridger Wilderness Area, Wyoming (Class I);

 Fitzpatrick Wilderness Area, Wyoming (Class I);

 Savage Run Wilderness Area, Wyoming (Federal Class II, Wyoming Class I)

 Mount Zirkel Wilderness Area, Colorado (Class I);

 Rawah Wilderness Area, Colorado (Class I);

 Popo Agie Wilderness Area , Wyoming (Class II);

 Wind River Roadless Area, Wyoming (Class II); and

 Dinosaur National Monument, Colorado-Utah (Federal Class II, Colorado Class I (SO2 only).

In addition, 12 lakes that are designated as acid sensitive and are located within the sensitive 

PSD Class I and Class II Wilderness areas are assessed for potential lake acidification from 

atmospheric deposition impacts. These lakes are:

 Deep Lake in the Bridger Wilderness Area, Wyoming;

 Black Joe Lake in the Bridger Wilderness Area, Wyoming;

 Hobbs Lake in the Bridger Wilderness Area, Wyoming;

 Upper Frozen Lake in the Bridger Wilderness Area, Wyoming;

 Lazy Boy Lake in the Bridger Wilderness Area, Wyoming;

 Ross Lake in the Fitzpatrick Wilderness Area, Wyoming; 

 Lower Saddlebag Lake in the Popo Agie Wilderness Area, Wyoming;

 Lake Elbert in the Mount Zirkel Wilderness Area, Colorado;

 Seven Lakes in the Mount Zirkel Wilderness Area, Colorado;

 Summit Lake in the Mount Zirkel Wilderness Area, Colorado;

 Island Lake in the Rawah Wilderness Area, Colorado; and

 Rawah Lake #4 in the Rawah Wilderness Area, Colorado.

The grid cell locations of the far-field Class I and II receptor areas analyzed are shown in Figure 

3-1 below. The maximum incremental concentration, deposition or visibility impact in any 

CAMx grid cell that intersects with the Class I or II receptor area of interest was used to 
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represent the impact at that receptor area. The CAMx incremental concentration and 

deposition output was post-processed in order to:

 Compare against the PSD Class I and II increments at the Class I and II receptor areas, 

respectively.

 Determine total nitrogen and sulfur deposition impacts and compare to deposition 

analysis thresholds.

 Analyze for changes in Acid Neutralizing Capacity (ANC) at sensitive lakes in the region.

 Analyze for visibility impacts and compare against visibility thresholds.

Figure 3-1. Locations of CAMx grid cells within the 4 km grid that contain Class I and sensitive 

Class II receptors. Blue circles indicate the locations of sensitive lakes.

3.2. PSD CLASS I AREA CONCENTRATION INCREMENTS

Areas regulated to ensure the preservation of certain levels of AQRVs are called “Prevention of 

Significant Deterioration (PSD)” Class I or sensitive Class II areas. Such areas are granted special 

air quality protections under Section 162(a) of the federal Clean Air Act. PSD Class I areas 

include federal lands such as national parks, national wilderness areas, and national 
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monuments. PSD Class I and sensitive Class II areas allow additional, well-controlled industrial 

growth through the incremental addition of some area-specific pollutants. Specific increments 

exist for NOx, SO2, and PM. The increments vary depending upon the pollutant and 

classification of an area. The PSD Class I and II Increments are shown in Table 3-1. 

Table 3-1. NAAQS, CAAQS, WAAQS, and PSD Class I and Class II Increments for comparison to 

far-field analysis results (μg m-3).

Pollutant/Averaging Time NAAQS CAAQS WAAQS

PSD Class I

Increment1

PSD Class II 

Increment1

CO

1-hour240,000 40,000 40,000 --

3

--

3

8-hour210,000 10,000 10,000 -- --

NO2

1-hour8188

Annual4100 100 100 2.5 25

O3

8-hour6147 147 157 -- --

PM10

24-hour2150 150 150 8 30

Annual4--

5

50 50 4 17

PM2.5

24-hour735 35 35 --

3

--

3

Annual415 15 15 -- --

SO2

1-hour9196

3-hour21,300 700 1,300 25 512

24-hour2365 365 260 5 91

Annual480 60 60 2 20

1

The PSD demonstrations serve information purposes only and do not constitute a regulatory PSD increment consumption 

analysis.

2

No more than one exceedance per year.

3

No PSD increments have been established for this pollutant.

4

Annual arithmetic mean.

5

The NAAQS for this averaging time for this pollutant has been revoked by EPA.

6

An area is in compliance with the standard if the fourth-highest daily maximum 8-hour ozone concentrations in a year, 

averaged over 3 years, is less than or equal to the level of the standard.

7

An area is in compliance with the standard if the 98th percentile of 24-hour PM2.5 concentrations in a year, averaged over 

3 years, is less than or equal to the level of the standard.

8

An area is in compliance with the standard if the 98th percentile of daily maximum 1-hour NO2 concentrations in a year, 

averaged over 3 years, is less than or equal to the level of the standard.

9

An area is in compliance with the standard if the 99th percentile of daily maximum 1-hour SO2 concentrations in a year, 

averaged over 3 years, is less than or equal to the level of the standard.

The CAMx estimates of incremental concentrations attributable to the CD-C Project were 

compared against PSD Class I and II area increments for the 2008 emissions scenario using the 

2005 and 2006 meteorological years. These demonstrations are for informational purposes 

only and are not regulatory PSD Increment consumption analyses, which are completed as 

necessary during the permitting process by the state of Wyoming.

Tables 3-2 and 3-3 compare the maximum CD-C Project impacts against the Class I PSD 

increments for NO2 and PM10 (Table 3-2) and SO2, (Table 3-3) within the Class I areas in the 4 
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km domain. 2005 and 2006 results were calculated for each pollutant and averaging time and 

the higher of the 2005 and 2006 results is presented in Tables 3-2 and 3-3. Note that although 

PSAT does not track NO2, it does track NOx (NO2+NO). We have compared the CD-C Project 

NOx contribution with the NO2 PSD; if the CD-C NOx contribution is smaller than the PSD 

increment, then the CD-C NO2 contribution must also be less than the PSD increment. 

For all Class I and sensitive Class II areas, the maximum 2008 CD-C Project impacts are less than 

the relevant PSD increments for all pollutants and averaging times. For NO2, all Class I and Class 

II areas are many orders of magnitude less than the applicable PSD increment. For annual 

average PM10, the Class I area with the largest impact is Savage Run WA, for which the CD-C 

Project impact is 0.05% of the PSD increment. The Class II area with the largest annual average 

PM10 impact is Dinosaur NM, with 0.01% of the Class II annual average PM10 increment. For 24-

hour average PM10, the Class I area with the largest impact is Mount Zirkel WA, for which the 

CD-C Project impacts is 0.48% of the PSD increment; the largest 24-hour PM10 impact at any 

Class II area occurs at Dinosaur NM and is 0.14% of the PSD increment. For SO2, all CD-C 

Project impacts at Class I and sensitive Class II areas are many orders of magnitude lower than 

the relevant PSD Class I and Class II PSD increments.

Table 3-2. CD-C Project Class I Area Maximum PSD increments for the 2005-6 meteorological 

years for NO2 and PM (μg m-3).

Table 3-3. CD-C Project Class I Area Maximum PSD increments for the 2005-6 meteorological 

years for SO2 (μg m-3).

*Dinosaur National Monument is a Federal Class II area and a Colorado Class I area for SO2 only.

Class I 

Areas Class I PSD Max CD-C NOx Class I PSD Max CD-C Class I PSD Max CD-C

Bridger WA 2.5 2.96E-07 4 1.86E-04 8 7.99E-03

Fitzpatrick WA 2.5 6.41E-08 4 1.15E-04 8 5.99E-03

Mount Zirkel WA 2.5 3.74E-06 4 1.63E-03 8 3.82E-02

Rawah WA 2.5 1.84E-06 4 1.04E-03 8 1.20E-02

Savage Run WA 2.5 5.54E-06 4 2.00E-03 8 2.35E-02

Annual Average NO2/NOx Annual Average PM10 24-hr Average PM10 Class I 

Areas Class I PSD Max CD-C Class I PSD Max CD-C Class I PSD Max CD-C

Bridger WA 2 2.28E-08 5 7.58E-07 25 3.14E-06

Dinosaur NM* 2 2.44E-07 5 3.52E-06 25 1.07E-05

Fitzpatrick WA 2 8.88E-09 5 5.91E-07 25 1.85E-06

Mount Zirkel WA 2 2.10E-07 5 2.01E-06 25 9.33E-06

Rawah WA 2 1.06E-07 5 7.96E-07 25 2.88E-06

Savage Run WA 2 3.06E-07 5 2.17E-06 25 7.80E-06

Annual Average SO2 24-hr Average SO2 3-hr Average SO2
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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-41

Table 3-4. CD-C Project Class II Area Maximum PSD increments for the 2005-6 meteorological 

years for NO2 and PM (μg m-3).

Table 3-5. CD-C Project Class II Area Maximum PSD increments for the 2005-6 meteorological 

years for SO2 (μg m-3).

Tables 3-2 through 3-5 show that the estimated potential air quality impacts due to existing 

2008 development of CD-C Project emissions sources within the CD-C Project area would not 

exceed any PSD Class I increment at any Class I area or PSD Class II increment at any sensitive 

Class II area using 2005 or 2006 meteorology.

3.3. AIR QUALITY RELATED VALUES (AQRVS)

3.3.1. Visibility

3.3.1.1. Overview of Approach

The assessment of potential visibility impacts due to the existing CD-C Project area emission 

sources used incremental concentrations due to CD-C Project area emissions as quantified by 

the CAMx PSAT tool. Changes in light extinction from CAMx model concentration increments 

due to emissions from existing CD-C Project emissions sources were calculated for each day at 

all grid cells that intersect Class I and sensitive Class II areas within the 4 km modeling domain. 

Change in atmospheric light extinction relative to background conditions is used to measure 

visibility impairment. The visual range (VR) in km is related to the atmospheric light extinction 

(bext) in Mm-1by the following relationship:

VR = 3912 / bext.

Model results are post-processed so that they are reported in percent change in light extinction 

and change in deciview over background. The visibility evaluation metric is the change in 

extinction (bext) expressed as a percentage or as change in Deciview Haze Index (DHI) over a 

visibility background (bext(background)) as follows:

Sensitive

Class II Areas Class II PSD Max CD-C NOx Class II PSD Max CD-C Class II PSD Max CD-C

Dinosaur NM 25 4.19E-06 17 1.69E-03 30 4.17E-02

Popo Agie WA 25 3.11E-07 17 1.99E-04 30 8.58E-03

Wind River RA 25 8.24E-08 17 1.31E-04 30 5.11E-03

Annual Average NO2/NOx Annual Average PM10 24-hr Average PM10 Sensitive

Class II Areas Class II PSD Max CD-C Class II PSD Max CD-C Class II PSD Max CD-C

Popo Agie WA 20 2.22E-08 91 6.46E-07 512 3.51E-06

Wind River RA 20 9.27E-09 91 5.71E-07 512 1.53E-06

Annual Average SO2 24-hr Average SO2 3-hr Average SO2
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bext = 100 x (bext(source+background) -bext(background)/ bext(background))

Deciview Haze Index = 10 ln (bext/10Mm-1)

Change in DHI = 10 ln[(bext(source + background))/bext(background)]

Visibility impact assessments are typically based on the maximum predicted daily average 

visibility impacts across all receptors in a Class I or sensitive Class II area evaluated on an annual 

basis. The maximum number of days above threshold values and the maximum predicted 

impacts are reported. Following FLAG (2010) guidance for a first level (screening) analysis, the 

visibility impact assessment is reported in terms of the annual 98th percentile maximum 

predicted daily values (8th highest daily value in a year). The threshold value below which a 

source is presumed to have no adverse impact is a 5% change in light extinction over the 

reference background visibility [which is approximately equal to a 0.5 change in deciview (dv)] 

from project alone emissions. Note that there are no applicable local, state, tribal, or Federal 

regulatory visibility standards. 

For visibility, the incremental daily average concentrations due to CD-C Project area emissions 

sources for grid cells containing the far-field Class I and sensitive Class II area receptors were 

processed using the new IMPROVE reconstructed mass extinction equation (FLAG 2010) to 

obtain maximum incremental daily visibility impacts at each far-field receptor area. The 

visibility results were then tabulated using the FLAG (2010) visibility screening method 

discussed below. The incremental contributions of existing CD-C Project emissions sources to 

changes in light extinction were compared to the 0.5 dv change threshold. When the BLM has 

completed development of required visibility analysis software, a refined visibility analysis will 

be conducted for project and cumulative sources using the method discussed in 3.3.1.4 and 

results will be compared to an analysis threshold of 1.0 dv. 

3.3.1.2. New IMPROVE Equation for Evaluating Light Extinction

The FLAG procedures for evaluating visibility impacts at Class I areas use the new IMPROVE 

reconstructed mass extinction equation to convert PM species in μg m-3to light extinction (bext) 

in Mm-1as follows:

bext = bSO4 + bNO3 + bEC + bOCM + bSoil + bPMC+ bSeaSalt+ bRayleigh+ bNO2

where

bSO4 = 2.2 × fS(RH) × [Small Sulfate] + 4.8 × fL(RH) × [Large Sulfate] 

bNO3 = 2.4 × fS(RH) × [Small Nitrate] + 5.1 × fL(RH) × [Large Nitrate] 

bOCM = 2.8 × [Small Organic Mass] + 6.1 × [Large Organic Mass] 

bEC = 10 × [Elemental Carbon] 

bSoil = 1 × [Fine Soil]

bCM = 0.6 × [Coarse Mass]

bSeaSalt = 1.7 × fSS(RH) × [Sea Salt] 

bRayleigh = Rayleigh Scattering (Site Specific) 

bNO2 = 0.33 × [NO2 (ppb)] {or as: 0.1755 × [NO2 (μg/m3)]} .
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Here, f(RH) are relative humidity adjustment factors that account for the fact that sulfate and 

nitrate aerosols are hygroscopic and are more effective at scattering radiation at higher relative 

humidities. For refined modeling calculations, FLAG (2010) recommends using monthly average 

f(RH) values rather than the hourly averages recommended in the previous FLAG (2000) 

guidance document in order to moderate the effects of extreme weather events on the 

visibility results. 

The new IMPROVE equation treats "large sulfate" and "small sulfate" separately because large 

and small aerosols affect an incoming beam of light differently. However, the IMPROVE 

measurements do not separately measure large and small sulfate; they measure only the total 

PM2.5 sulfate. Similarly, CAMx writes out a single concentration of particulate sulfate for each 

grid cell. Part of the definition of the new IMPROVE equation is a procedure for calculating the 

large and small sulfate contributions based on the magnitude of the model output sulfate 

concentrations; the procedure is documented in FLAG (2010). The sulfate concentration 

magnitude is used as a surrogate for distinguishing between large and small sulfate 

concentrations. For a given grid cell, the large and small sulfate contributions are calculated 

from the model output sulfate (which is the "Total Sulfate" referred to in the FLAG 2010 

guidance) as:

For Total Sulfate < 20 μg/m3: 

[Large Sulfate] = ([Total Sulfate] / 20 μg/m3) × [Total Sulfate]

For Total Sulfate ≥ 20 μg/m3: 

[Large Sulfate] = [Total Sulfate] 

For all values of Total Sulfate:

[Small Sulfate] = [Total Sulfate] – [Large Sulfate]

The procedure is identical for nitrate and organic mass. For the incremental visibility impact for 

an oil and gas development project in Wyoming, the sulfate and nitrate concentrations will be 

relatively small (<< 20 μg/m3), so we would expect most of the nitrate and sulfate to be found 

in the small sulfate size regime. 

3.3.1.3. FLAG Screening Method for Visibility Impact Analysis

The FLAG Screening Method uses the new IMPROVE equation together with annual average 

natural conditions (Table 6; FLAG, 2010) and monthly relative humidity factors for each Class I 

area (Table 7-9; FLAG, 2010). Change in deciview haze index was calculated for each day of each 

annual CAMx run. The number of days in each annual run for CD-C Project sources alone with 

deciview haze values greater than 0.5 dv and 1.0 dv were counted, and the 98th percentile (8th 

highest day) values were compared to the 0.5 dv threshold for all grid cells that overlap a Class 

I area. If any impacts are greater than 0.5 dv, then a cumulative analysis would be performed 

that considers the impacts of CD-C Project emissions sources taken together with impacts of all 

other sources in the region. 
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3.3.1.4. Refined Method for Visibility Impact Analysis

The Refined Method uses the revised IMPROVE equation and area monitoring station data 

together with modeled concentration data to estimate changes in extinction values for each 

simulation day. Daily relative humidity factors based on relative humidity data from the 

nearest representative monitoring station and the revised IMPROVE relative humidity factors 

for small and large size distribution sulfate, nitrate, and sea salt are used along with 24-hour 

aerosol concentrations for the period of record at the nearest IMPROVE monitoring site. 

Because IMPROVE monitoring data are available for Federal Class I areas only, data from the 

nearest Federal Class I area must be used for the sensitive Class II areas. In this refined analysis, 

analysis results are compared to the 0.5 dv threshold as recommended in FLAG 2010 and to a 

1.0 dv threshold which represents a just noticeable change in visibility when compared to 

background conditions.

The 98th percentile (8th highest day) for the CD-C Project sources alone would be compared to 

the 0.5 dv threshold and 1.0 dv threshold for all grid cells that overlap a Class I area. In order to 

assess cumulative impacts as required under NEPA for this project, a cumulative analysis would 

be performed that considers the impacts of CD-C Project emissions sources taken together with 

impacts of all other sources in the region. Cumulative visibility impacts from all sources would 

then be compared to the 1.0 dv threshold. The number of days exceeding the 1.0 dv threshold 

in the cumulative analysis would be reported. 

As of the writing of this report, software for implementing the BLM Refined Method was under 

development by the BLM and not yet available (Melissa Hovey, personal communication, 

January, 2010), so the analysis was performed using only the FLAG (2010) method. However, in 

subsequent drafts of this report, the BLM Method results can be added once the software 

becomes available.

Table 3-6. Summary of visibility impact assessment methods used in the CD-C 2008 baseline 

modeling.

Method Background Data

Relative Humidity Factor 

f(RH) Calculation Method

Refined Observed Daily Hourly Revised IMPROVE Equation

Screening Annual Average Monthly Revised IMPROVE Equation

Data from Tables 6-10 of FLAG (2010) were used to calculate the light extinction under natural 

conditions (bext(background)) for each Class I area. For sensitive Class II areas, data from the nearest 

Class I area were used. FLAG (2010) annual average natural conditions visibility data from the 

Bridger Wilderness Area were used for the Popo Agie Wilderness Areas and the Wind River 

Roadless Area. Data from the Mount Zirkel Wilderness Area were also used for the Savage Run 

Wilderness Area and Dinosaur National Monument Monthly relative humidity factors are 

available for the Bridger, Fitzpatrick, Rawah, and Mount Zirkel Wilderness Areas. FLAG (2010) 

relative humidity data for the Bridger Wilderness Area were used for the Popo Agie Wilderness 

Area and for the Wind River Roadless Area analyses. Relative humidity data for the Mountain 

Zirkel Wilderness Area were also used for the Savage Run Wilderness and Dinosaur National 

Monument.
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3.3.1.5. CAMx Species Used in Visibility Analysis

Table 3-7 gives the species mapping between the CAMx modeled species and those in the 

IMPROVE reconstructed mass extinction equation given above. The IMPROVE equation 

assumes that sufficient ammonium is present to completely neutralize sulfate and nitrate. This 

means that if a quantity of sulfate, SO4, is present in a grid cell, we assume there is enough 

ammonium present to completely convert the sulfate to ammonium sulfate ([NH4]2SO4). The 

ratio of the molecular weights of SO4 to [NH4]2SO4 is 1.375, so the sulfate concentration output 

of CAMx must be scaled by 1.375 to produce the sulfate input to the IMPROVE equation in the 

visibility impact assessment. A similar procedure is performed for nitrate, in which NO3 is 

assumed to be neutralized to ammonium nitrate (NH4NO3), and the CAMx nitrate (NO3) 

concentration is scaled by the factor 1.290 prior to use in the IMPROVE equation. Although 

CAMx explicitly models ammonium (NH4), the NH4 concentration is not considered in the 

visibility impact analysis. This may overstate the visibility degradation because sulfate and 

nitrate are not always completely neutralized by ammonium. 

The NO2 concentration is approximated by using the CAMx NOX species. This is a conservative 

assumption equivalent to saying that all NOx is composed entirely of NO2 for the purposes of 

the visibility calculation. Although sodium and particulate chloride are treated in the CAMx 

core model, these species are not carried in the CAMx PSAT tool; neglecting sea salt in the 

visibility calculations in the 4 km domain does not compromise the accuracy of the analysis as 

IMPROVE measurements show that sea salt concentrations are extremely small in this inland 

area and there would be no sea salt associated with the CD-C project emissions.

Table 3-7. Mappings of species from the CAMx model to the IMPROVE visibility equation.

IMPROVE

Component Name CAMx Species

[SO4] (as [NH4]2SO4) Sulfate (as [NH4]2SO4) PS4*1.375

[NO3] (as NH4NO3) Nitrate (as NH4NO3) PN3*1.290

[EC] Elemental Carbon PEC

[OCM] Organic Mass POA

[Soil] Fine Soil PFC+PFN

[CM] Coarse Mass PCC+PCS

[NO2] Nitrogen Dioxide NOX

Sea Salt Sea Salt None

3.3.1.6. FLAG Screening Method Visibility Impact Results

Table 3-8 presents the visibility impacts for the incremental visibility changes due to the CD-C 

Project emissions scenarios using the FLAG (2010) screening method for the 2005 

meteorological year. The largest 98th percentile impact occurs at Dinosaur NM (98th percentile 

dv = 0.165; 0 days > 0.5 dv), Savage Run WA (98th percentile dv = 0.087; 0 days > 0.5 dv), and 

Mount Zirkel WA (98th percentile dv = 0.086; 0 days > 0.5 dv). The size of the bNO3 extinction 

term relative to the sulfate (bSO4) and other (bother= bEC + bOCM + bSoil + bPMC+ bSeaSalt+ bNO2) terms 

indicates that nitrate makes the largest contribution toward visibility impairment from the CD-C 

project sources. For Non-CD-C emissions sources within the CD-C Project area, visibility impacts 

are far lower during 2005 (Table 3-9), with all 98th percentile impacts <0.03 dv. As for CD-C 

Project sources, nitrate is the largest contributor to the overall change in visibility.
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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-46

Table 3-8. 2005 CDC project visibility impacts using FLAG (2010) screening method.

Table 3-9. 2005 Non-CDC project visibility impacts using FLAG (2010) screening method.

Table 3-10 compares the visibility impacts for the incremental visibility changes due to the CD-C 

Project emissions scenarios using the FLAG (2010) screening method for the 2006 

meteorological year. The largest 98th percentile impacts occur at the Dinosaur NM (98th

percentile dv = 0.105; 0 days > 0.5 dv), Savage Run WA (98th percentile dv = 0.091; 0 days > 0.5 

dv) and Mount Zirkel (98th percentile dv = 0.093; 0 days > 0.5 dv). Nitrate makes the largest 

contribution to the overall 98th percentile change in extinction for all areas. For Non-CD-C 

emissions sources within the CD-C Project area, visibility impacts are far lower than for the CD-C 

Project sources during 2006 (Table 3-11), with all 98th percentile impacts <0.02 dv. 

Table 3-10. 2006 CDC project visibility impacts using FLAG (2010) screening method.

Class I or Class II Area #days > 1.0 #days > 0.5 98th percentile dv day frh_l frh_s b_src back_bext b_so4 b_no3 b_other

Bridger WA 0 0 0.010 1/5/05 2.2 2.8 0.014 13.969 0.004 0.009 0.001

Fitzpatrick WA 0 0 0.006 5/15/05 1.9 2.4 0.008 13.787 0.003 0.003 0.002

Mount Zirkel WA 0 0 0.086 12/3/05 2.0 2.4 0.114 13.203 0.007 0.091 0.016

Rawah WA 0 0 0.043 12/3/05 1.9 2.3 0.057 13.163 0.002 0.049 0.005

Dinosaur NM 0 0 0.165 2/23/05 2.0 2.4 0.221 13.238 0.066 0.121 0.034

Popo Agie WA 0 0 0.010 3/24/05 2.0 2.6 0.014 13.847 0.002 0.012 0.000

Savage Run WA 0 0 0.087 3/22/05 1.9 2.3 0.115 13.173 0.011 0.092 0.012

Wind River RA 0 0 0.010 3/24/05 2.0 2.6 0.014 13.847 0.002 0.012 0.000

CDC Project Met 2005

Class I or Class II Area #days > 1.0 #days > 0.5 98th percentile dv day frh_l frh_s b_src back_bext b_so4 b_no3 b_other

Bridger WA 0 0 0.001 5/14/05 2.0 2.5 0.001 13.792 0.000 0.000 0.001

Fitzpatrick WA 0 0 0.001 1/5/05 2.2 2.8 0.001 13.969 0.000 0.001 0.000

Mount Zirkel WA 0 0 0.014 3/9/05 1.9 2.3 0.019 13.173 0.003 0.011 0.005

Rawah WA 0 0 0.006 2/8/05 2.0 2.4 0.007 13.213 0.001 0.004 0.002

Dinosaur NM 0 0 0.023 1/22/05 2.0 2.4 0.030 13.233 0.004 0.021 0.006

Popo Agie WA 0 0 0.001 5/14/05 2.0 2.5 0.001 13.792 0.000 0.000 0.001

Savage Run WA 0 0 0.011 11/12/05 2.0 2.4 0.014 13.223 0.003 0.006 0.005

Wind River RA 0 0 0.001 9/24/05 1.7 2.0 0.001 13.572 0.000 0.000 0.000

CDC non-Project Met 2005

Class I or Class II Area #days > 1.0 #days > 0.5 98th percentile dv day frh_l frh_s b_src back_bext b_so4 b_no3 b_other

Bridger WA 0 0 0.013 3/12/06 2.0 2.6 0.017 13.847 0.006 0.009 0.002

Fitzpatrick WA 0 0 0.014 2/19/06 2.1 2.6 0.020 13.875 0.002 0.016 0.001

Mount Zirkel WA 0 0 0.093 2/19/06 2.0 2.4 0.123 13.238 0.007 0.108 0.008

Rawah WA 0 0 0.041 12/3/06 1.9 2.3 0.053 13.163 0.001 0.050 0.002

Dinosaur NM 0 0 0.105 12/17/06 2.0 2.4 0.139 13.203 0.009 0.103 0.028

Popo Agie WA 0 0 0.015 3/12/06 2.0 2.6 0.021 13.847 0.006 0.013 0.001

Savage Run WA 0 0 0.091 2/2/06 2.0 2.4 0.121 13.238 0.030 0.071 0.020

Wind River RA 0 0 0.016 3/12/06 2.0 2.6 0.022 13.847 0.006 0.014 0.001

CDC Project Met 2006
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-47

Table 3-11. 2006 Non- CDC project visibility impacts using FLAG (2010) screening method.

In summary, there are no days for which the emissions from either CD-C Project or non-CD-C 

Project sources within the CD-C Project area cause visibility impairment greater than 0.5 dv at 

any Class I or sensitive Class II receptor. Nitrate impacts dominate the total visibility 

impairment in both years for CD-C Project sources.

The FLAG 2010 document states that a cumulative visibility analysis is not required if project 

along impacts are less than 0.5 dv. Given that the CD-C Project visibility impacts are all less 

than 0.5 dv, a cumulative analysis is not required following the FLAG guidance. 

3.4. DEPOSITION 

The effects of atmospheric deposition of nitrogen and sulfur compounds on terrestrial and 

aquatic ecosystems are well documented and have been shown to cause leaching of nutrients 

from soils, acidification of surface waters, injury to high elevation vegetation, and changes in 

nutrient cycling and species composition. FLAG (2010) recommends that applicable sources 

assess impacts of nitrogen and sulfur deposition at Class I areas. Although the CD-C Project is 

not an “applicable source” under New Source Review, BLM is analyzing nitrogen and sulfur 

deposition impacts attributable to this project at Class I areas and identified sensitive Class II 

areas within the Project study area.

3.4.1. Overview of Approach

CAMx-predicted wet and dry fluxes of sulfur- and nitrogen-containing species were processed 

to estimate total annual sulfur (S) and nitrogen (N) deposition values at each PSD Class I and 

sensitive PSD Class II area and at each acid sensitive lake. The maximum annual S and N 

deposition values from any grid cell that intersects a Class I or Class II receptor area were used 

to represent deposition for that area, in addition to the average annual deposition values of all 

grid cells that intersect a Class I or Class II receptor area. Maximum and average predicted S 

and N deposition impacts were estimated for existing emissions sources within the CD-C Project 

area. 

Nitrogen deposition impacts were calculated by taking the sum of the nitrogen contained in the 

fluxes of all nitrogen species modeled by CAMx. CAMx species used in the nitrogen deposition 

flux calculation are: reactive gaseous nitrate species, RGN (NOX, NO3, HONO, N2O5), TPN (PAN, 

PANX, PNA), organic nitrates (NTR), particulate nitrate formed from primary emissions plus 

secondarily formed nitrate (PN3), gaseous nitric acid (HN3), gaseous ammonia (NH3) and 

particulate ammonium (PN4). CAMx species used in the sulfur deposition calculation are 

primary sulfur dioxide emissions (SO2) and particulate sulfate ion from primary emissions plus 

secondarily formed sulfate (PS4).

Class I or Class II Area #days > 1.0 #days > 0.5 98th percentile dv day frh_l frh_s b_src back_bext b_so4 b_no3 b_other

Bridger WA 0 0 0.001 9/8/06 1.7 2.0 0.002 13.572 0.001 0.000 0.001

Fitzpatrick WA 0 0 0.001 2/19/06 2.1 2.6 0.001 13.875 0.000 0.000 0.000

Mount Zirkel WA 0 0 0.016 4/30/06 1.9 2.4 0.021 13.203 0.004 0.009 0.008

Rawah WA 0 0 0.006 12/2/06 1.9 2.3 0.008 13.163 0.001 0.006 0.001

Dinosaur NM 0 0 0.015 8/19/06 1.7 2.0 0.019 13.026 0.006 0.001 0.012

Popo Agie WA 0 0 0.001 5/22/06 2.0 2.5 0.002 13.792 0.001 0.000 0.001

Savage Run WA 0 0 0.011 2/2/06 2.0 2.4 0.014 13.238 0.003 0.006 0.005

Wind River RA 0 0 0.001 3/19/06 2.0 2.6 0.002 13.847 0.000 0.001 0.000

CDC non-Project Met 2006
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-48

FLAG 2010 recommends that applicable sources assess impacts of nitrogen and sulfur 

deposition at Class I areas. This guidance recognizes the importance of establishing critical 

deposition loading values (“critical loads”) for each specific Class I area as these critical loads 

are completely dependent on local atmospheric, aquatic and terrestrial conditions and 

chemistry. Critical load thresholds are essentially a level of atmospheric pollutant deposition 

below which negative ecosystem effects are not likely to occur. FLAG 2010 does not include 

any critical load levels for specific Class I areas and refers to site-specific critical load 

information on FLM websites for each area of concern. This guidance does, however 

recommend the use of deposition analysis thresholds (DATs) developed by the National Park 

Service and the Fish and Wildlife Service. The DATs represent screening level values for 

nitrogen and sulfur deposition from project alone emission sources below which estimated 

impacts are considered negligible. The DAT established for both nitrogen and sulfur in western 

Class I areas is 0.005 kilograms per hectare per year (kg/ha/yr). 

BLM has compiled currently available research data on critical load values for Class I areas in 

the vicinity of this project. Critical load thresholds published by Fox et al. (Fox 1989) 

established pollutant loadings for total nitrogen of 3-5 kilograms per hectare per year 

(kg/ha/yr) and for total sulfur of 5 kg/ha/yr for Bob Marshall Wilderness Area in Montana and 

Bridger Wilderness Area in Wyoming. Research conducted by Jill Baron (Baron 2006) using 

hindcasting of diatom communities suggests 1.5 kg/ha/yr as a critical loading value for wet 

nitrogen deposition for high elevation lakes in Rocky Mountain National Park, Colorado. Recent 

research conducted by Saros et al. (2010) using fossil diatom assemblages suggests that a 

critical load value of 1.4 kg/ha/yr for wet nitrogen is applicable to the eastern Sierra Nevada 

and Greater Yellowstone ecosystems.

As a screening analysis, N and S maximum deposition from CD-C project sources were 

compared to the DATs. As a refined analysis, project alone N and S deposition were compared 

to the following critical load values: 3.0 kg/ha/yr was used as for total N deposition and 5 

kg/ha/yr was used for total S deposition for the Class I areas evaluated in this analysis. For N 

and S, we report both the average deposition as well as the maximum deposition, although only 

the maximum deposition is compared with the applicable level of concern. 

3.4.2. Nitrogen Deposition Impacts: 

Table 3-12 shows the incremental nitrogen deposition impacts of the CD-C Project sources 

within the CD-C Project area for the 2005 meteorological year. Nitrogen deposition impacts 

exceed the DAT at three Class I areas for project alone sources; therefore, a refined approach 

was used to compare impacts to more representative values. No Class I or sensitive Class II 

area exceeds the 3.0 kg/ha/yr critical load value. The largest impacts are at the Savage Run 

WA, Dinosaur NM, Mount Zirkel WA, and Rawah WA, all with maximum impacts that are less 

than 0.3% of the critical load. Impacts at the Bridger WA, Fitzpatrick WA, Popo Agie WA and 

Wind River Roadless Area are lower still, and are all less than 0.03% of the critical load; these 

sites are further from the CD-C Project area and are generally upwind. 

Table 3-13 displays the total nitrogen deposition impacts for the 2005 meteorological year for 

the non-CDC Project emissions sources within the CD-C Project area. Impacts are smaller than 

for CD-C Project sources within the Project area and do not exceed the DAT. No Class I or Class 
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-49

II areas exceed the 3.0 kg/ha/yr critical load. As with the CD-C Project sources, the largest 

impacts are at Savage Run, Mount Zirkel, Dinosaur and Rawah, with maximum impacts that are 

all 0.03% or less of the critical load. 

Table 3-12. 2005 meteorological year nitrogen deposition impacts for the CD-C Project 

sources within the CD-C Project area. 

Table 3-13. 2005 meteorological year nitrogen deposition impacts for the non-CD-C Project 

sources within the CD-C Project area. 

Table 3-14 shows the incremental nitrogen deposition impacts of the CD-C Project sources 

within the CD-C Project area for the 2006 meteorological year. Nitrogen deposition impacts 

exceed the DAT at four Class I areas for project alone sources; therefore, a refined approach 

was used to compare impacts to more representative values. No Class I or sensitive Class II 

area exceeds the 3.0 kg/ha/yr critical load. The largest impacts are at the Savage Run WA, 

Mount Zirkel WA, Rawah WA and Dinosaur NM, all with maximum impacts that are less than 

0.4% of the critical load. As in the 2005 meteorological year, impacts at the Bridger WA, Fitzpatrick 

WA, Popo Agie WA and Wind River Roadless Area are lower, and are all less than 0.05% of the critical 

load. 

Table 3-15 displays the total nitrogen deposition impacts for the 2006 meteorological year for 

the non-CDC Project emissions sources within the CD-C Project area. Impacts are smaller than 

for CD-C Project sources within the Project area and do not exceed the DAT. There are no Class 

I or Class II areas that exceed the 3.0 kg/ha/yr critical load. As with the CD-C Project sources, 

the largest impacts are at Savage Run, Mount Zirkel, Dinosaur and Rawah, with maximum 

impacts that are all 0.05% or less of the critical load. 

CAMx N Species CAMx N Species CAMx N Species CAMx N Species

Max % of Critical Load % of DAT Average

 (kgN/ha) (3 kg N /ha ) (0.005 kg N /ha ) (kgN/ha)

Bridger WA 0.0006 0.0208% 12.46% 0.0003

Fitzpatrick WA 0.0003 0.0111% 6.69% 0.0002

Mount Zirkel WA 0.0057 0.1885% 113.08% 0.0039

Rawah WA 0.0040 0.1327% 79.63% 0.0029

Dinosaur NM 0.0058 0.1931% 115.86% 0.0031

Popo Agie WA 0.0008 0.0265% 15.89% 0.0004

Savage Run WA 0.0075 0.2486% 149.15% 0.0066

Wind River RA 0.0004 0.0129% 7.73% 0.0003

Class I or Class II Area

CD-C Project Deposition 2008Met2005

CAMx N Species CAMx N Species CAMx N Species CAMx N Species

Max % of Critical Load % of DAT Average

 (kgN/ha) (3 kg N /ha ) (0.005 kg N /ha ) (kgN/ha)

Bridger WA 0.0000 0.0011% 0.65% 0.0000

Fitzpatrick WA 0.0000 0.0007% 0.41% 0.0000

Mount Zirkel WA 0.0007 0.0230% 13.78% 0.0005

Rawah WA 0.0004 0.0148% 8.90% 0.0003

Dinosaur NM 0.0005 0.0178% 10.70% 0.0003

Popo Agie WA 0.0000 0.0013% 0.76% 0.0000

Savage Run WA 0.0009 0.0300% 18.03% 0.0008

Wind River RA 0.0000 0.0009% 0.51% 0.0000

Class I or Class II Area

CD-C Non-Project Deposition 2008Met2005
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-50

Table 3-14. 2006 meteorological year nitrogen deposition impacts for the CD-C Project 

sources within the CD-C Project area.

Table 3-15. 2006 meteorological year nitrogen deposition impacts for the non-CD-C Project 

sources within the CD-C Project area.

3.4.3. Sulfur Deposition Impacts

Table 3-16 shows the total sulfur deposition impacts of CD-C Project sources within the CD-C 

Project area for the 2005 and 2006 meteorological years. No Class I or Class II area exceeds the 

DAT. All areas have sulfur deposition less than 0.03% of the critical load of 5.0 kg/ha/yr. Areas 

with the highest deposition due to CD-C Project sources are Mount Zirkel (0.03% of the critical 

load in 2006) and Rawah (0.02% of the critical load in 2006). Impacts are higher overall in 2006 

than in 2005. For non-CDC Project sources within the CD-C Project area (Table 3-17) impacts 

are even lower, with no area exceeding the DAT and all areas with impacts less than 0.003% of 

the critical load.

CAMx N Species CAMx N Species CAMx N Species CAMx N Species

Max % of Critical Load % of DAT Average

 (kgN/ha) (3 kg N /ha ) (0.005 kg N /ha ) (kgN/ha)

Bridger WA 0.0011 0.0358% 21.5% 0.0006

Fitzpatrick WA 0.0007 0.0217% 13.0% 0.0005

Mount Zirkel WA 0.0074 0.2482% 148.9% 0.0054

Rawah WA 0.0066 0.2198% 131.9% 0.0045

Dinosaur NM 0.0064 0.2125% 127.5% 0.0036

Popo Agie WA 0.0015 0.0491% 29.4% 0.0009

Savage Run WA 0.0100 0.3340% 200.4% 0.0086

Wind River RA 0.0006 0.0207% 12.4% 0.0005

CD-C Project Deposition 2008Met2006

Class I or Class II Area

CAMx N Species CAMx N Species CAMx N Species CAMx N Species

Max % of Critical Load % of DAT Average

 (kgN/ha) (3 kg N /ha ) (0.005 kg N /ha ) (kgN/ha)

Bridger WA 0.0001 0.0022% 1.35% 0.0000

Fitzpatrick WA 0.0000 0.0013% 0.80% 0.0000

Mount Zirkel WA 0.0010 0.0327% 19.64% 0.0007

Rawah WA 0.0007 0.0248% 14.87% 0.0005

Dinosaur NM 0.0006 0.0190% 11.38% 0.0003

Popo Agie WA 0.0001 0.0030% 1.80% 0.0001

Savage Run WA 0.0012 0.0406% 24.35% 0.0010

Wind River RA 0.0000 0.0013% 0.76% 0.0000

CD-C Non-Project Deposition 2008Met2006

Class I or Class II Area
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-51

Table 3-16. 2005-2006 meteorological year sulfur deposition impacts for CD-C Project 

sources. CAMx species used in the sulfur deposition flux calculation are: SO2 and PS4.

Table 3-17. 2005-6 meteorological year sulfur deposition impacts for non-CDC sources within 

the CD-C Project area. CAMx species used in the sulfur deposition flux calculation are: SO2 

and PS4.

3.4.3.1. Summary of Deposition Impacts

The deposition analysis indicates total nitrogen deposition impacts from CD-C Project emission 

sources are estimated to be above the DAT at four Class I areas. Total nitrogen and sulfur 

deposition impacts were estimated to be well below the critical load values as a result of 

existing 2008 CD-C Project emissions sources. Total N and S deposition impacts from non-CD-C 

sources were estimated to be even lower than for project sources. 

3.4.4 Sensitive Lakes Analysis

3.4.4.1. Sensitive Lakes Acid Neutralizing Capacity (ANC)

The CAMx-predicted annual deposition fluxes of S and N at sensitive lake receptors listed in 

Section 3.1 were used to estimate the impact on the acid neutralizing capacity (ANC) of each 

lake due to the existing CD-C project emissions and regional emissions. The changes in ANC 

were calculated following the January 2000, USFS Rocky Mountain Region's Screening 

Methodology for Calculating ANC Change to High Elevation Lakes, User's Guide (USFS, 2000). 

The most recent lake chemistry background ANC data were obtained from the BLM for each 

sensitive lake to be analyzed. The 10th percentile lowest ANC values were calculated for each 

lake following procedures provided by the USFS. The ANC values used in this analysis and the 

number of samples used in the calculation of the 10th percentile lowest ANC values are 

provided in Tables 3-18 - 3-21. Two lakes listed in Tables 3-18 through 3-21 are considered by 

the USFS to be extremely sensitive to atmospheric deposition (background ANC values are less 

than 25 microequivalents per liter (μeq/l)); these are Lazy Boy Lake and Upper Frozen Lake in 

the Bridger Wilderness. 

The predicted changes in ANC are compared below with the USFS’s Level of Acceptable Change 

(LAC) thresholds of 10% of the 10th percentile lowest ANC value for lakes with ANC values 

greater than 25 μeq/l. For lakes with background ANC values of 25 μeq/l and less the USFS LAC 

threshold is that no further decrease is acceptable. Lake impacts must be assessed with 

Sulfur- Max % of Critical Load % of DAT Sulfur- Avg Sulfur- Max % of Critical Load % of DAT Sulfur- Avg

Class I or Class II Area (kgS/ha) (5 kg S /ha ) (0.005 kg S/ha ) (kgS/ha) (kgS/ha) (5 kg S /ha ) (0.005 kg S/ha ) (kgS/ha)

Bridger WA 0.0001 0.0016% 1.56% 0.0000 0.0002 0.0031% 3.15% 0.0001

Fitzpatrick WA 0.0001 0.0016% 1.61% 0.0000 0.0001 0.0026% 2.61% 0.0001

Mount Zirkel WA 0.0005 0.0103% 10.27% 0.0003 0.0014 0.0272% 27.20% 0.0007

Rawah WA 0.0005 0.0092% 9.23% 0.0003 0.0012 0.0233% 23.26% 0.0006

Dinosaur NM 0.0006 0.0110% 11.02% 0.0002 0.0008 0.0162% 16.19% 0.0003

Popo Agie WA 0.0001 0.0019% 1.93% 0.0001 0.0002 0.0045% 4.51% 0.0002

Savage Run WA 0.0006 0.0113% 11.35% 0.0005 0.0007 0.0147% 14.70% 0.0005

Wind River RA 0.0001 0.0021% 2.13% 0.0001 0.0001 0.0025% 2.54% 0.0001

CDC Project 2008Met2005 CDC Project 2008Met2006

Sulfur- Max % of Critical Load % of DAT Sulfur- Avg Sulfur- Max % of Critical Load % of DAT Sulfur- Avg

Class I or Class II Area (kgS/ha) (5 kg S /ha ) (0.005 kg S/ha ) (kgS/ha) (kgS/ha) (5 kg S /ha ) (0.005 kg S/ha ) (kgS/ha)

Bridger WA 0.0000 0.0000% 0.04% 0.0000 0.0000 0.0001% 0.15% 0.0000

Fitzpatrick WA 0.0000 0.0001% 0.08% 0.0000 0.0000 0.0001% 0.13% 0.0000

Mount Zirkel WA 0.0000 0.0009% 0.94% 0.0000 0.0001 0.0027% 2.72% 0.0001

Rawah WA 0.0000 0.0010% 0.97% 0.0000 0.0001 0.0018% 1.79% 0.0000

Dinosaur NM 0.0000 0.0006% 0.60% 0.0000 0.0001 0.0012% 1.19% 0.0000

Popo Agie WA 0.0000 0.0001% 0.07% 0.0000 0.0000 0.0002% 0.21% 0.0000

Savage Run WA 0.0001 0.0012% 1.21% 0.0000 0.0001 0.0014% 1.36% 0.0001

Wind River RA 0.0000 0.0001% 0.11% 0.0000 0.0000 0.0001% 0.14% 0.0000

CDC Non-Project 2008Met2005 CDC Non-Project 2008Met2006
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-52

consideration of limited data points available for several analyzed lakes. ANC calculations are 

shown for CD-C Project and non-CD-C Project sources of emissions located within the CD-C 

Project area. 

3.4.4.2. CD-C Project Area Source ANC Impacts

Tables 3-18 through 3-21 show that in 2005 and 2006, none of the Lakes undergoes a change in 

ANC that exceeds the LAC threshold of 10% due to the impacts of CD-C Project or non-CD-C 

Project sources within the CD-C Project area. The predicted change in ANC due to non-CD-C 

Project sources impacts or CD-C Project source impacts is very small.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) PROJECT 

AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-53

Table 3-18. Modeled changes in ANC from CD-C Project sources for the 2005 meteorological year.

Table 3-19. Modeled changes in ANC from non-CD-C Project sources for the 2005 meteorological year.

Wilderness 

Area Lake

Latitude 

(Deg N, 

NAD27)

Longitude 

(Deg W, 

NAD27)

Elevation 

(m)

10th 

Percentile 

Lowest ANC 

Value 

(μeq/L)

Number of 

Samples

Period of 

Monitoring

Total S Dep 

(kg-S/ha-yr)

Total N Dep 

(kg-N/ha-yr) PPT (m) Delta ANC (%)

Delta ANC 

(ueq/l)

Bridger Black Joe Lake 42o44'22" 109o10'16" 3126.6 69.7 78 1984-2009 0.00004 0.00040 0.91186 0.01 n/a

Bridger Deep Lake 42o43'10" 109o10'15" 3201.0 60.4 75 1984-2009 0.00005 0.00043 0.91186 0.01 n/a

Bridger Hobbs Lake 43o02'08" 109o40'20" 3066.3 70.1 85 1984-2009 0.00004 0.00030 0.91186 0.01 n/a

Bridger Lazy Boy Lake 43o19'57" 109o43'47" 3535.7 12.4 5 1997-2009 0.00003 0.00024 0.91186 0.03 0.00

Bridger Upper Frozen Lake 42o41'13" 109o09'39" 3486.9 7.4 12 1997-2009 0.00006 0.00053 0.91186 0.09 0.01

Fitzpatrick Ross Lake 43o22'41" 109o39'30" 2948.9 54.1 60 1988-2009 0.00003 0.00022 0.91186 0.01 n/a

Mount Zirkel Lake Elbert 40o38'03" 106o42'25" 3291.8 53.6 67 1985-2007 0.00037 0.00378 1.08966 0.07 n/a

Mount Zirkel Seven Lakes (LG East) 40o53'45" 106o40'55" 3271.4 40.5 24 1985-2007 0.00041 0.00487 1.08966 0.13 n/a

Mount Zirkel Summit Lake 40o32'43" 106o40'55" 3144.3 48.0 108 1985-2007 0.00039 0.00367 1.08966 0.08 n/a

Popo Agie Lower Saddlebag Lake 42o37'24" 108o59'38" 3432.7 55.6 59 1989-2009 0.00008 0.00059 0.91186 0.01 n/a

Rawah Island Lake 40o37'38" 105o56'28" 3391.8 71.4 21 1996-2009 0.00028 0.00274 0.84582 0.05 n/a

Rawah Rawah Lake #4 40o40'16" 105o57'28" 3497.3 41.6 26 1996-2009 0.00029 0.00295 0.84582 0.10 n/a

CDC Project 2008 Met 2005

Wilderness 

Area Lake

Latitude 

(Deg N, 

NAD27)

Longitude 

(Deg W, 

NAD27)

Elevation 

(m)

10th 

Percentile 

Lowest ANC 

Value 

(μeq/L)

Number of 

Samples

Period of 

Monitoring

Total S Dep 

(kg-S/ha-yr)

Total N Dep 

(kg-N/ha-yr) PPT (m) Delta ANC (%)

Delta ANC 

(ueq/l)

Bridger Black Joe Lake 42o44'22" 109o10'16" 3126.6 69.7 78 1984-2009 0.00000 0.00002 0.91186 0.00 n/a

Bridger Deep Lake 42o43'10" 109o10'15" 3201.0 60.4 75 1984-2009 0.00000 0.00002 0.91186 0.00 n/a

Bridger Hobbs Lake 43o02'08" 109o40'20" 3066.3 70.1 85 1984-2009 0.00000 0.00002 0.91186 0.00 n/a

Bridger Lazy Boy Lake 43o19'57" 109o43'47" 3535.7 12.4 5 1997-2009 0.00000 0.00001 0.91186 0.00 0.00

Bridger Upper Frozen Lake 42o41'13" 109o09'39" 3486.9 7.4 12 1997-2009 0.00000 0.00003 0.91186 0.00 0.00

Fitzpatrick Ross Lake 43o22'41" 109o39'30" 2948.9 54.1 60 1988-2009 0.00000 0.00001 0.91186 0.00 n/a

Mount Zirkel Lake Elbert 40o38'03" 106o42'25" 3291.8 53.6 67 1985-2007 0.00003 0.00042 1.08966 0.01 n/a

Mount Zirkel Seven Lakes (LG East) 40o53'45" 106o40'55" 3271.4 40.5 24 1985-2007 0.00004 0.00058 1.08966 0.01 n/a

Mount Zirkel Summit Lake 40o32'43" 106o40'55" 3144.3 48.0 108 1985-2007 0.00003 0.00040 1.08966 0.01 n/a

Popo Agie Lower Saddlebag Lake 42o37'24" 108o59'38" 3432.7 55.6 59 1989-2009 0.00000 0.00003 0.91186 0.00 n/a

Rawah Island Lake 40o37'38" 105o56'28" 3391.8 71.4 21 1996-2009 0.00002 0.00028 0.84582 0.01 n/a

Rawah Rawah Lake #4 40o40'16" 105o57'28" 3497.3 41.6 26 1996-2009 0.00002 0.00031 0.84582 0.01 n/a

CDC Non-Project 2008 Met 2005
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) PROJECT 

AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-54

Table 3-20. Modeled changes in ANC from CD-C Project source for the 2006 meteorological year.

Table 3-21. Modeled changes in ANC from non-CD-C Project sources for the 2006 meteorological year.

Wilderness 

Area Lake

Latitude 

(Deg N, 

NAD27)

Longitude 

(Deg W, 

NAD27)

Elevation 

(m)

10th 

Percentile 

Lowest ANC 

Value 

(μeq/L)

Number of 

Samples

Period of 

Monitoring

Total S Dep 

(kg-S/ha-yr)

Total N Dep 

(kg-N/ha-yr) PPT (m) Delta ANC (%)

Delta ANC 

(ueq/l)

Bridger Black Joe Lake 42o44'22" 109o10'16" 3126.6 69.7 78 1984-2009 0.00019 0.00085 0.91186 0.02 n/a

Bridger Deep Lake 42o43'10" 109o10'15" 3201.0 60.4 75 1984-2009 0.00020 0.00097 0.91186 0.02 n/a

Bridger Hobbs Lake 43o02'08" 109o40'20" 3066.3 70.1 85 1984-2009 0.00010 0.00067 0.91186 0.01 n/a

Bridger Lazy Boy Lake 43o19'57" 109o43'47" 3535.7 12.4 5 1997-2009 0.00006 0.00040 0.91186 0.04 0.01

Bridger Upper Frozen Lake 42o41'13" 109o09'39" 3486.9 7.4 12 1997-2009 0.00016 0.00104 0.91186 0.19 0.01

Fitzpatrick Ross Lake 43o22'41" 109o39'30" 2948.9 54.1 60 1988-2009 0.00007 0.00038 0.91186 0.01 n/a

Mount Zirkel Lake Elbert 40o38'03" 106o42'25" 3291.8 53.6 67 1985-2007 0.00095 0.00575 1.08966 0.12 n/a

Mount Zirkel Seven Lakes (LG East) 40o53'45" 106o40'55" 3271.4 40.5 24 1985-2007 0.00108 0.00698 1.08966 0.19 n/a

Mount Zirkel Summit Lake 40o32'43" 106o40'55" 3144.3 48.0 108 1985-2007 0.00052 0.00467 1.08966 0.10 n/a

Popo Agie Lower Saddlebag Lake 42o37'24" 108o59'38" 3432.7 55.6 59 1989-2009 0.00018 0.00118 0.91186 0.03 n/a

Rawah Island Lake 40o37'38" 105o56'28" 3391.8 71.4 21 1996-2009 0.00069 0.00427 0.84582 0.09 n/a

Rawah Rawah Lake #4 40o40'16" 105o57'28" 3497.3 41.6 26 1996-2009 0.00075 0.00465 0.84582 0.16 n/a

CDC Project 2008 Met 2006

Wilderness 

Area Lake

Latitude 

(Deg N, 

NAD27)

Longitude 

(Deg W, 

NAD27)

Elevation 

(m)

10th 

Percentile 

Lowest ANC 

Value 

(μeq/L)

Number of 

Samples

Period of 

Monitoring

Total S Dep 

(kg-S/ha-yr)

Total N Dep 

(kg-N/ha-yr) PPT (m) Delta ANC (%)

Delta ANC 

(ueq/l)

Bridger Black Joe Lake 42o44'22" 109o10'16" 3126.6 69.7 78 1984-2009 0.00001 0.00005 0.91186 0.00 n/a

Bridger Deep Lake 42o43'10" 109o10'15" 3201.0 60.4 75 1984-2009 0.00001 0.00006 0.91186 0.00 n/a

Bridger Hobbs Lake 43o02'08" 109o40'20" 3066.3 70.1 85 1984-2009 0.00000 0.00004 0.91186 0.00 n/a

Bridger Lazy Boy Lake 43o19'57" 109o43'47" 3535.7 12.4 5 1997-2009 0.00000 0.00002 0.91186 0.00 0.00

Bridger Upper Frozen Lake 42o41'13" 109o09'39" 3486.9 7.4 12 1997-2009 0.00001 0.00006 0.91186 0.01 0.00

Fitzpatrick Ross Lake 43o22'41" 109o39'30" 2948.9 54.1 60 1988-2009 0.00000 0.00002 0.91186 0.00 n/a

Mount Zirkel Lake Elbert 40o38'03" 106o42'25" 3291.8 53.6 67 1985-2007 0.00009 0.00066 1.08966 0.01 n/a

Mount Zirkel Seven Lakes (LG East) 40o53'45" 106o40'55" 3271.4 40.5 24 1985-2007 0.00011 0.00089 1.08966 0.02 n/a

Mount Zirkel Summit Lake 40o32'43" 106o40'55" 3144.3 48.0 108 1985-2007 0.00004 0.00052 1.08966 0.01 n/a

Popo Agie Lower Saddlebag Lake 42o37'24" 108o59'38" 3432.7 55.6 59 1989-2009 0.00001 0.00007 0.91186 0.00 n/a

Rawah Island Lake 40o37'38" 105o56'28" 3391.8 71.4 21 1996-2009 0.00005 0.00046 0.84582 0.01 n/a

Rawah Rawah Lake #4 40o40'16" 105o57'28" 3497.3 41.6 26 1996-2009 0.00005 0.00050 0.84582 0.02 n/a

Non-CDC Project 2008 Met 2006
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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-55

4.0. CRITERIA AIR POLLUTANT RESULTS

4.1. INTRODUCTION

During the fall of 2010, ENVIRON completed an initial 2008 baseline modeling run. Evaluation 

of the PSAT results indicated that a model error had been introduced when the new vertical 

velocity algorithm was added to the model in 2009. This error did not affect the CAMx host 

model results, only the APCA/PSAT source apportionment results. The error was identified and 

corrected, but insufficient time remained before the November 18, 2010 CD-C stakeholder 

meeting to rerun CAMx with PSAT, which is very computationally demanding. The model was 

rerun for ozone only with APCA to produce criteria pollutant and ozone results, and the criteria 

pollutant results were presented to the CD-C stakeholders at their November 18 meeting. A 

new 2008 baseline run with PSAT using the corrected version CAMx was then performed to 

calculate 2008 CD-C AQRV impacts. This run was completed in late December, 2010; in Section 

4, we present results for criteria air pollutants from this run.

Criteria air pollutants (CAPs) are pollutants regulated under the Clean Air Act and for which 

National Ambient Air Quality Standards have been set. The CAPs are: ozone, NO2, CO, PM10, 

PM2.5 and SO2. ENVIRON processed the 2008 model output surface layer concentrations for the 

4 km modeling domain for the two years of meteorology (2005 and 2006) for the required 

averaging periods so that the results for each of the CAPS could be compared to the relevant 

NAAQS. The purpose of this analysis was to determine whether the existing 2008 CD-C Project 

sources contribute to modeled exceedances of the NAAQS in the 4 km domain which will be the 

focus of the future year CD-C Project impact analysis.

The ozone modeling results were processed for comparison with the 8-hour ozone NAAQS 

using two different methods. The first method was to use the absolute modeling 

concentrations to calculate the 4th high daily maximum 8-hour ozone concentration for each 

grid cell in the 4 km domain for each modeled year. Then, the results for 2005 and 2006 were 

averaged to approximate a design value for each grid cell; these values were then compared 

with the NAAQS. The second method was to use EPA’s Modeled Attainment Software (MATS; 

Abt, 2009) to project the 2008 design values starting from observed 2008 ozone design values 

and using the modeling results via the calculation of relative reduction response factors (RRFs). 

The EPA projection procedures used in MATS are described further in the CD-C Modeling 

Protocol and in Abt (2009) and the results of the ozone analysis are presented in Section 2. 

Although MATS has the capability to project PM2.5 values, the EPA MATS projection method for 

PM2.5 could not be used due to insufficient ambient data in the CD-C 4 km domain.

For the CAPs other than ozone (NO2, SO2, PM2.5, PM10, and CO), the raw model results were 

processed for comparison with the relevant NAAQS for 2005 and 2006, and then the results for 

2005 and 2006 were averaged together. Note that for these five pollutants, 2005 and 2006 

results were similar enough that taking an average of the results for the two years was a 

reasonable strategy.

The CAPs analysis showed exceedances of the NAAQS for 1-hour SO2, 24-hour and annual 

average PM10 and 8-hour average CO within the 4 km domain. Note that the 8-hour average 
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CO exceedance was caused by a fire that occurred in 2005. This fire is an exceptional event and 

will not affect the outcome of the CD-C impact analysis. 

Air in the vicinity of large point sources may fall within the fenceline of the facility and so would 

not be considered ambient air regulated by the NAAQS. It is not clear how to define “ambient 

air” when the air quality model is running at 4 km grid resolution. Near-field air impacts within 

and in the vicinity of the fenceline of industrial facilities are typically evaluated with a plume 

model such as AERMOD. Near-field modeling of CAPs from the CD-C Project will be performed 

using AERMOD.

4.2. RESULTS FOR PM, NO2, SO2 AND CO

In this section, the 2008 baseline run results are displayed for each pollutant. Note that the CDC Project-only contribution (lower panels of Figures 4-1 through 4-10) would not have been 

visible on the scale used to plot the absolute model results from all regional emissions sources 

(upper panel of Figures 4-1 through 4-10) so the CD-C Project contributions are plotted on 

different scales with much lower maxima. The NAAQS for each of the criteria pollutants is 

shown in Table 4-1. For species that show an exceedance of the NAAQS (1-hour SO2, 24-hour 

and annual average PM10 and 8-hour average CO), the size and spatial scale of the CD-C Project 

contribution make it clear that the CD-C Project is not a significant contributor to the 

exceedance. For 8-hour CO, the exceedance is caused by a fire in Lincoln County and is not 

related to CD-C Project emissions.

Table 4-1. Ambient Air Quality Standards (μg/m3).

Pollutant/Averaging Time NAAQS WAAQS

CO

1-hour140,000 40,000

8-hour110,000 10,000

NO2

1-hour5188 --

Annual2100 100

PM10

24-hour1150 150

Annual2--

3

50

PM2.5

24-hour435 35

Annual215 15

SO2

 1-hour6196

3-hour11,300 1,300

24-hour1365 260

Annual280 60

1

No more than one exceedance per year.

2

Annual arithmetic mean.

3

The annual NAAQS for pollutant has been revoked by EPA.

4

An area is in compliance with the standard if the 98th percentile of 24-hour PM2.5 concentrations in a year, averaged over 

3 years, is less than or equal to the level of the standard.

5

An area is in compliance with the standard if the 98th percentile of daily maximum 1-hour NO2 concentrations in a year, 

averaged over 3 years, is less than or equal to the level of the standard.

6

An area is in compliance with the standard if the 99th percentile of daily maximum 1-hour SO2 concentrations in a year, 

averaged over 3 years, is less than or equal to the level of the standard.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-57

Tables 4-2 and 4-3 summarize the maximum CD-C Project impacts for NO2, PM (Table 4-2) and 

SO2, (Table 4-3) respectively within the Class I and sensitive Class II areas. 2005 and 2006 

results were calculated for each CAP and averaging time and the higher of the 2005 and 2006 

results is presented in Tables 4-2 and 4-3. Note that although PSAT does not track NO2, it does 

track NOx (NO2+NO). 

Tables 4-2 and 4-3 show that the areas with largest impacts across all pollutants are: Dinosaur 

NM, Rawah WA, Savage Run WA, and Mount Zirkel WA. Bridger WA, Fitzpatrick WA and the 

Wind River Roadless Area tended to have lower impacts as they are further from the Project 

and are located generally upwind.

Table 4-2. Maximum CD-C Project contribution during 2005 and 2006 meteorological years 

across all Class I and sensitive Class II Areas. 

Table 4-3. Maximum CD-C Project contribution during 2005 and 2006 meteorological years 

across all Class I and sensitive Class II Areas. 

Class I and Sensitive

Class II Areas

Bridger WA 2.96E-07 1.86E-04 7.99E-03 1.86E-04 2.64E-03

Dinosaur NM 4.19E-06 1.69E-03 4.17E-02 1.69E-03 1.78E-02

Fitzpatrick WA 6.41E-08 1.15E-04 5.99E-03 1.15E-04 2.47E-03

Mount Zirkel WA 3.74E-06 1.63E-03 3.82E-02 1.63E-03 1.09E-02

Popo Agie WA 3.11E-07 1.99E-04 8.58E-03 1.99E-04 2.28E-03

Rawah WA 1.84E-06 1.04E-03 1.20E-02 1.04E-03 7.46E-03

Savage Run WA 5.54E-06 2.00E-03 2.35E-02 2.00E-03 1.34E-02

Wind River RA 8.24E-08 1.31E-04 5.11E-03 1.31E-04 2.51E-03

Annual Average 

NO2/NOx

Annual Average 

PM10 24-hr Average PM10

Annual Average 

PM2.5 24-hr Average PM2.5

Class I and Sensitive

Class II Areas

Bridger WA 2.28E-08 7.58E-07 3.14E-06

Dinosaur NM 2.44E-07 3.52E-06 1.07E-05

Fitzpatrick WA 8.88E-09 5.91E-07 1.85E-06

Mount Zirkel WA 2.10E-07 2.01E-06 9.33E-06

Popo Agie WA 2.22E-08 6.46E-07 3.51E-06

Rawah WA 1.06E-07 7.96E-07 2.88E-06

Savage Run WA 3.06E-07 2.17E-06 7.80E-06

Wind River RA 9.27E-09 5.71E-07 1.53E-06

Annual Average SO2 24-hr Average SO2 3-hr Average SO2
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-58

1-hour SO2: Contribution from All Regional Sources 

Including CD-C Project

CD-C Project 1-hour SO2 Contribution: 2008met2005 CD-C Project 1-hour SO2 Contribution: 2008met2006

Figure 4-1. CAMx 2008 baseline model results for 1-hour SO2. Upper panel: Absolute model 

results for 1-hour SO2 from all regional emissions sources, including CD-C Project and nonProject sources within the CD-C Project area. 1-hour SO2 results from the 2005 and 2006 

meteorological years using 2008 emissions were averaged together to produce this figure. 

Lower panels: 1-hour SO2 contribution from the CD-C Project sources only for the 2005 (left 

panel) and 2006 (right panel) meteorological years, respectively. Note difference in scales 

between upper and lower panels.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-59

3-hour SO2: Contribution from All Regional Sources 

Including CD-C Project

CD-C Project 3-hour SO2 Contribution: 2008met2005 CD-C Project 3-hour SO2 Contribution: 2008met2006

Figure 4-2. CAMx 2008 baseline model results for 3-hour SO2. Upper panel: Absolute model 

results for 3-hour SO2 from all regional emissions sources, including CD-C Project and nonProject sources within the CD-C Project area. 3-hour SO2 results from the 2005 and 2006 

meteorological years using 2008 emissions were averaged together to produce this figure. 

Lower panels: 3-hour SO2 contribution from the CD-C Project sources only for the 2005 (left 

panel) and 2006 (right panel) meteorological years, respectively. Note difference in scales 

between upper and lower panels.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-60

24-hour SO2: Contribution from All Regional Sources 

Including CD-C Project

CD-C Project 24-hour SO2 Contribution: 2008met2005 CD-C Project 24-hour SO2 Contribution: 2008met2006

Figure 4-3. CAMx 2008 baseline model results for 24-hour SO2. Upper panel: Absolute model 

results for 24-hour SO2 from all regional emissions sources, including CD-C Project and nonProject sources within the CD-C Project area. 24-hour SO2 results from the 2005 and 2006 

meteorological years using 2008 emissions were averaged together to produce this figure. 

Lower panels: 24-hour SO2 contribution from the CD-C Project sources only for the 2005 (left 

panel) and 2006 (right panel) meteorological years, respectively. Note difference in scales 

between upper and lower panels.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-61

Annual Average SO2: Contribution from All Regional 

Sources Including CD-C Project

CD-C Project Annual Average SO2 Contribution: 

2008met2005

CD-C Project Annual Average SO2 Contribution: 

2008met2006

Figure 4-4. CAMx 2008 baseline model results for annual average SO2. Upper panel: 

Absolute model results for annual average SO2 from all regional emissions sources, including 

CD-C Project and non-Project sources within the CD-C Project area. Annual average SO2

results from the 2005 and 2006 meteorological years using 2008 emissions were averaged 

together to produce this figure. Lower panels: annual average SO2 contribution from the CDC Project sources only for the 2005 (left panel) and 2006 (right panel) meteorological years, 

respectively. Note difference in scales between upper and lower panels.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-62

24-hour PM2.5: Contribution from All Regional Sources 

Including CD-C Project

CD-C Project 24-hour PM2.5 Contribution: 

2008met2005

CD-C Project 24-hour PM2.5 Contribution: 

2008met2006

Figure 4-5. CAMx 2008 baseline model results for 24-hour PM2.5. Upper panel: Absolute 

model results for 24-hour PM2.5 from all regional emissions sources, including CD-C Project 

and non-Project sources within the CD-C Project area. 24-hour PM2.5 results from the 2005 

and 2006 meteorological years using 2008 emissions were averaged together to produce this 

figure. Lower panels: 24-hour PM2.5 contribution from the CD-C Project sources only for the 

2005 (left panel) and 2006 (right panel) meteorological years, respectively. Note difference in 

scales between upper and lower panels.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-63

Annual Average PM2.5: Contribution from All Regional 

Sources Including CD-C Project

CD-C Project Annual Average PM2.5 Contribution: 

2008met2005

CD-C Project Annual Average PM2.5 Contribution: 

2008met2006

Figure 4-6. CAMx 2008 baseline model results for annual average PM2.5. Upper panel: 

Absolute model results for annual average PM2.5 from all regional emissions sources, 

including CD-C Project and non-Project sources within the CD-C Project area. Annual average 

PM2.5 results from the 2005 and 2006 meteorological years using 2008 emissions were 

averaged together to produce this figure. Lower panels: annual average PM2.5 contribution 

from the CD-C Project sources only for the 2005 (left panel) and 2006 (right panel) 

meteorological years, respectively. Note difference in scales between upper and lower 

panels.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-64

24-hour PM10: Contribution from All Regional Sources 

Including CD-C Project

CD-C Project 24-hour PM10 Contribution: 2008met2005 CD-C Project 24-hour PM10 Contribution: 2008met2006

Figure 4-7. CAMx 2008 baseline model results for 24-hour PM10. Upper panel: Absolute 

model results for 24-hour PM10 from all regional emissions sources, including CD-C Project 

and non-Project sources within the CD-C Project area. 24-hour PM10 results from the 2005 

and 2006 meteorological years using 2008 emissions were averaged together to produce this 

figure. . Lower panels: 24-hour PM10 contribution from the CD-C Project sources only for the 

2005 (left panel) and 2006 (right panel) meteorological years, respectively. Note difference in 

scales between upper and lower panels.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-65

Annual Average PM10: Contribution from All Regional 

Sources Including CD-C Project

CD-C Project Annual Average PM10 Contribution: 

2008met2005

CD-C Project Annual Average PM10 Contribution: 

2008met2006

Figure 4-8. CAMx 2008 baseline model results for annual average PM10. Upper panel: 

Absolute model results for annual average PM10 from all regional emissions sources, including 

CD-C Project and non-Project sources within the CD-C Project area. Annual average PM10

results from the 2005 and 2006 meteorological years using 2008 emissions were averaged 

together to produce this figure. Lower panels: annual average PM10 contribution from the CDC Project sources only for the 2005 (left panel) and 2006 (right panel) meteorological years, 

respectively. Note difference in scales between upper and lower panels.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-66

1-hour Average NO2: Contribution from All Regional 

Sources Including CD-C Project

Annual Average NO2: Contribution from All Regional 

Sources Including CD-C Project

Figure 4-9. CAMx 2008 baseline model results for NO2. Left panel: Absolute model results for 1-

hour average NO2 from all regional emissions sources, including CD-C Project and non-Project 

sources within the CD-C Project area. 1-hour average NO2 results from the 2005 and 2006 

meteorological years using 2008 emissions were averaged together to produce this figure. Right 

panel: as in left panel, but for annual average NO2.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-67

1-hour Average CO: Contribution from All Regional Sources 

Including CD-C Project

8-hour Average CO: Contribution from All Regional Sources 

Including CD-C Project

Figure 4-10. CAMx 2008 baseline model results for CO. Right panel: Absolute model results for 1-

hour average CO from all regional emissions sources, including CD-C Project and non-Project sources 

within the CD-C Project area. 1-hour average CO results from the 2005 and 2006 meteorological 

years using 2008 emissions were averaged together to produce this figure. Left panel: as in right 

panel, but for 8-hour average CO.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-68

Figure 4-11. CAMx 4 km modeling domain, showing location of Class I and sensitive Class II 

areas and the CD-C Project area.

4.3. SUMMARY

Examination of the spatial scale and magnitude of the CD-C Project contribution to criteria 

pollutant concentrations within the 4 km grid show that exceedances of the NAAQS in the 2008 

baseline modeling are not related to emissions from the existing CD-C Project.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-69

5.0. CONCLUSIONS 

Baseline year CAMx modeling was carried out for the CD-C EIS. A 2008 typical emissions 

scenario was modeled using 2005 and 2006 meteorology. This model run was performed to 

establish a baseline against which future year runs containing CD-C Project emissions will be 

evaluated. A second purpose of the baseline modeling was to assess 2008 AQ and AQRV 

impacts from existing CD-C Project area emissions sources.

Criteria pollutant levels within the 4 km domain were evaluated and the contributions of the 

CD-C Project emissions sources were quantified using the CAMx APCA and PSAT probing tools. 

Modeled ozone levels and CD-C Project area ozone impacts are reported in this document, and 

results for criteria pollutants other than ozone (NO2, SO2, PM10, PM2.5 and CO) have been 

reported to the CD-C stakeholders in a separate memorandum (ENVIRON and Carter Lake, 

2011).

The regional ozone modeling results were analyzed using the EPA MATS tool as well as through 

examination of the absolute modeling results. Both methods showed exceedances of the 2008 

ozone NAAQS (75 ppb) in the 4 km domain as well as exceedances of the full range of NAAQS 

proposed by the EPA in January 2010 (60 ppb-70 ppb). However, none of the exceedances of 

the 75 ppb NAAQS occurs in the vicinity of the CD-C Project area, which is distant from and has 

much lower ozone than the high ozone regions that include the Salt Lake City and Fort 

Collins/Denver metropolitan areas and Sublette County, WY.

The ozone source apportionment results from the CAMx APCA tool showed that CD-C Project 

emissions sources contributed 0.4 ppb or less to 8-hour ozone Design Values across the 4 km 

domain. The CD-C contribution to 8-hour ozone at monitors on observed and modeled 

DM8>75 ppb days and DM8>70 ppb days was 1.1 ppb or less and 1.4% or less of the DM8 value. 

The CD-C contribution to 8-hour ozone at monitors on observed and modeled DM8>60 ppb 

days was 2.3 ppb or less and 3.2% or less of the DM8 value. The largest CD-C ozone impacts 

occurred at monitors near and generally downwind of the CD-C Project area; these are 

Wamsutter, Atlantic Rim, Sun Dog, and Centennial. In 2006 only, there is a comparable impact 

at the Spring Creek monitor due to an episode of southerly winds on April 22, 2006 that 

brought ozone and precursors northward from the CD-C Project area to Fremont and Natrona 

Counties.

The non-CD-C project contribution to high observed and modeled 8-hour ozone at Sublette 

County monitors was 0.2 ppb or less and less than 0.3% of the DM8. The contribution of CD-C 

Project sources was larger than that of non-CD-C Project sources within the CD-C Project area.

The AQRV impact analysis evaluated CD-C project impacts on visibility, deposition and 

acidification of sensitive lakes. The visibility impact assessment showed that there were no 

days during the 2005 or 2006 meteorological years when the 0.5 dv visibility impact threshold 

was exceeded at any Class I or sensitive Class II area within the 4 km domain. The deposition 

analysis showed that there were no nitrogen or sulfur deposition impacts from CD-C Project 

area emissions sources that exceeded the BLM levels of concern at any Class I or Class II 
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-70

sensitive area; impacts on ANC from CD-C Project area sources at sensitive lakes were less than 

the levels of acceptable change.

Finally, examination of the spatial scale and magnitude of the CD-C Project contribution to 

criteria pollutant concentrations within the 4 km grid showed that exceedances of the NAAQS 

in the 2008 baseline modeling are not related to emissions from the existing CD-C Project.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-71

6.0 REFERENCES

Abt Associates Inc. 2009. Modeled Attainment Test Software User’s Guide. Prepared for the 

U.S. EPA, Office of Air Quality Planning and Standards U.S. Environmental Protection 

Agency, Research Triangle Park, NC. March.

Baron, J.S. 2006. Hindcasting nitrogen deposition to determine an ecological critical load. 

Ecological Applications, 16(2), 433–439. 

BLM. 2008. Pinedale Anticline Supplemental EIS, Air Quality Technical Support Document. 

http://www.blm.gov/wy/st/en/info/NEPA/documents/pfo/anticline/seis.html

Carter Lake and ENVIRON. 2010. Air Quality Impact Assessment Protocol for the Continental 

Divide-Creston Project Environmental Impact Statement. Revised Draft. Carter Lake 

Consulting, Laramie, Wyoming. ENVIRON International Corporation, Novato, California. 

March. 

Dunker, A. M. G. Yarwood, J.P. Ortmann and G.M. Wilson. 2002. Comparison of source 

apportionment and source sensitivity of ozone in a three-dimensional air quality model. 

Environ. Sci. Technol., 36, 2953-2964.

Draxler, R.R. and G.D. Hess. 1997. Description of the Hysplit_4 modeling system. NOAA Tech 

Memo ERL ARL-224, Dec, 24 pp.

Environmental Protection Agency. 2007. Guidance on the Use of Models and Other Analyses 

for Demonstrating Attainment of Air Quality Goals for ozone, PM2.5, and Regional Haze. 

U.S. Environmental Protection Agency, Office of Air Quality and Planning Standards, 

Research Triangle Park, North Carolina. (EPA-454/B-07-002). April.

ENVIRON. 2010. User’s Guide Comprehensive Air Quality Model With Extensions (CAMx) 

Version 5.30. ENVIRON International Corporation, Novato, California. (www.camx.com). 

December.

ENVIRON and Carter Lake. 2010. Model Performance Evaluation of the CAMx 2005 and 2006 

Base Case Simulation Performed Under the Continental Divide-Creston Environmental 

Impact Statement Study. Prepared for the Wyoming Department of Environmental 

Quality, Air Quality Division, the BLM Rawlins Field Office, and BLM State Office. March.

ENVIRON and Carter Lake. 2011. Methods for Presentation of 2008 Baseline CAMx Modeling 

Results for Criteria Air Pollutants. Memorandum to Kelly Bott, Wyoming Department of 

Environmental Quality, Air Quality Division.

Federal Land Managers' Air Quality Related Values Workgroup. 2010. Federal Land Managers' 

Air Quality Related Values Workgroup (FLAG) Phase I Report-Revised 2010. U.S. Forest 

Service-Air Quality Program, National Park Service-Air Resources Division, U.S. Fish and 

Wildlife Service-Air Quality Branch. October.

Federal Land Managers' Air Quality Related Values Workgroup. 2000. Federal Land Managers' 

Air Quality Related Values Workgroup (FLAG) Phase I Report. U.S. Forest Service-Air 

Quality Program, National Park Service-Air Resources Division, U.S. Fish and Wildlife 

Service-Air Quality Branch. December.
APPENDIX I – 2008 BASELINE MODELING FOR THE CONTINENTAL DIVIDE-CRESTON (CD-C) 

PROJECT AND ASSESSMENT OF THE ESTIMATED REGIONAL AIR QUALITY AND AQRV IMPACTS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 I-72

Field, P. and M. Wolf. 2007. Technical Memorandum, WRAP 2018 Preliminary Reasonable 

Progress Emissions Inventory – Final. June 18.

http://www.wrapair.org/forums/ssjf/documents/eictts/projections.html

http://www.wrapair.org/forums/ssjf/documents/eictts/projections.html

Fox, Douglas, Ann M. Bartuska, James G. Byrne, Ellis Cowling, Rich Fisher, Gene E. Likens, Steven 

E. Lindberg, Rick A. Linthurst, Jay Messer and Dale S. Nichols. 1989. A Screening 

Procedure to Evaluate Air Pollution Effects on Class I Wilderness Areas. General 

Technical Report RM-168. U.S.D.A. Forest Service, Rocky Mountain Forest and Range 

Experiment Station, Fort Collins, Colorado. 36 pp.

Interagency Workgroup on Air Quality Modeling. 1998. Interagency Workgroup on Air Quality 

Modeling (IWAQM) Phase 2 Summary Report and Recommendations for Modeling Long 

Range Transport Impacts. EPA-454/R-98-019. Office of Quality Planning and Standards. 

U.S. EPA, Research Triangle Park, North Carolina. December.

Morris R. 2009. The Uinta Basin Air Quality Study (UBAQS). Prepared for Kathleen Sgamma, 

Independent Petroleum Association of the Mountain States (IPAMS), Denver, CO. June.

National Park Service. 2001. Guidance on Nitrogen and Sulfur Deposition Analysis Thresholds. 

National Park Service and U.S. Fish and Wildlife Service. National Park Service Air 

Resources Division. (http://www.aqd.nps.gov/ard/flagfree/2001), Data accessed July 

2003.

Saros, J.E., Clow, D.W., Blett, T. & A.P. Wolfe. 2010. “Critical nitrogen deposition loads in highelevation lakes of the western U.S. inferred from paleolimnological records”. Water, Air 

& Soil Pollution, DOI 10.1007/s11270-010-0526-6. 

Tonnesen, G. et al., 2006. Final Report for the Western Regional Air Partnership (WRAP) 2002 

Visibility Model Performance Evaluation. Prepared for the Western Governors 

Association. February. 

http://pah.cert.ucr.edu/aqm/308/reports/final/2002_MPE_report_main_body_FINAL.pdf

U.S.D.A. Forest Service. 2000. Screening Methodology for Calculating ANC Change to High 

Elevation Lakes, User's Guide. U.S. Department of Agriculture (USDA) Forest Service, 

Rocky Mountain Region. January.

______. 2008. Lake water chemistry data provided by the USDA Forest Service, December 

2008. www.fs.fed.us/armdata.

Yarwood, G., S. Rao, M. Yocke and G. Whitten. 2005. Updates to the Carbon Bond Chemical 

Mechanism: CB05. ENVIRON International Corporation, Novato, California. December. 
Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016

Appendix J

Criteria Pollutant Plots for the 4 km Grid for the 2022 Future Year Modeling
APPENDIX J – CRITERIA POLLUTANT PLOTS FOR THE 4 KM GRID 

FOR THE 2022 FUTURE YEAR MODELING

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 J-1

1.0. INTRODUCTION

In Section 4.5.3, we presented the CAMx modeling results for Criteria Air Pollutants (CAPs) in 

the 4 km domain. The results shown in Section 4.5.3 are two year averages over the 2005 and 

2006 meteorological years. The two year averages are presented as an approximation to the 

form of the NAAQS, many of which are defined in terms of a multi-year averaging period. In 

Appendix J, we present plots of the CAPs for both the 2005 and 2006 meteorological years 

separately in order to show the year-to-year variability of the CAPs results. 
APPENDIX J – CRITERIA POLLUTANT PLOTS FOR THE 4 KM GRID 

FOR THE 2022 FUTURE YEAR MODELING

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 J-2

2022-2008 1-Hour 

Average NO2 All Sources

2022 1-Hour Average 

NO2 All Sources

2008 1-Hour Average 

NO2 All Sources

CD-C No Action 

NOX Contribution

CD-C Proposed Action 

NOX Contribution

2022 1-Hour Average 

NO2 All Sources

Figure J-1a. CAMx model results for 1-hour NO2. Left and center panels: 2008 and 2022 

absolute model results for 1-hour NO2 from all regional emissions sources, including CD-C 

Project. Right panel: 2022-2008 difference in 1-hour NO2. Upper panels show 2005 

meteorological year. Lower panels show 2006 meteorological year.

Figure J-1b. Left panel: 2022 absolute model results for 1-hour NO2 from all regional 

emissions sources, including CD-C Project. Center panel: CD-C Proposed Action contribution 

to 2022 1-hour NOX. Right panel: CD-C No Action (existing wells) contribution to the 2022 1-

hour NOX. Upper panels show 2005 meteorological year. Lower panels show 2006 

meteorological year.
APPENDIX J – CRITERIA POLLUTANT PLOTS FOR THE 4 KM GRID 

FOR THE 2022 FUTURE YEAR MODELING

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 J-3

Figure J-2a. CAMx model results for annual average NO2. Left and center panels: 2008 and 

2022 absolute model results for annual average NO2 from all regional emissions sources, 

including CD-C Project. Right panel: 2022-2008 difference in annual average NO2. Upper 

panels show 2005 meteorological year. Lower panels show 2006 meteorological year.

Figure J-2b. Left panel: 2022 absolute model results for annual average NO2 from all regional 

emissions sources, including CD-C Project. Center panel: CD-C Proposed Action contribution 

to 2022 annual average NOX. Right panel: CD-C No Action (existing wells) contribution to the 

2022 annual average NOX. Upper panels show 2005 meteorological year. Lower panels show 

2006 meteorological year.

2022-2008 Annual 

Average NO2 All Sources

2022 Annual Average 

NO2 All Sources

2008 Annual Average 

NO2 All Sources

CD-C No Action 

NOX Contribution

CD-C Proposed Action 

NOX Contribution

2022 Annual Average 

NO2 All Sources
APPENDIX J – CRITERIA POLLUTANT PLOTS FOR THE 4 KM GRID 

FOR THE 2022 FUTURE YEAR MODELING

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 J-4

Figure J-3a. CAMx model results for 1-hour SO2. Left and center panels: 2008 and 2022 

absolute model results for 1-hour SO2 from all regional emissions sources, including CD-C 

Project. Right panel: 2022-2008 difference in 1-hour SO2. Upper panels show 2005 

meteorological year. Lower panels show 2006 meteorological year.

Figure J-3b. Left panel: 2022 absolute model results for 1-hour SO2 from all regional 

emissions sources, including CD-C Project. Center panel: CD-C Proposed Action contribution 

to 2022 1-hour SO2. Right panel: CD-C No Action (existing wells) contribution to the 2022 1-

hour SO2. Upper panels show 2005 meteorological year. Lower panels show 2006 

meteorological year.

2022-2008 1-Hour 

Average SO2 All Sources

2022 1-Hour Average 

SO2 All Sources

2008 1-Hour Average 

SO2 All Sources

CD-C No Action 

SO2 Contribution

CD-C Proposed Action 

SO2 Contribution

2022 1-Hour Average 

SO2 All Sources
APPENDIX J – CRITERIA POLLUTANT PLOTS FOR THE 4 KM GRID 

FOR THE 2022 FUTURE YEAR MODELING

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 J-5

Figure J-4a. CAMx model results for 3-hour SO2. Left and center panels: 2008 and 2022 

absolute model results for 3-hour SO2 from all regional emissions sources, including CD-C 

Project. Right panel: 2022-2008 difference in 3-hour SO2. Upper panels show 2005 

meteorological year. Lower panels show 2006 meteorological year.

Figure J-4b. Left panel: 2022 absolute model results for 3-hour SO2 from all regional 

emissions sources, including CD-C Project. Center panel: CD-C Proposed Action contribution 

to 2022 3-hour SO2. Right panel: CD-C No Action (existing wells) contribution to the 2022 3-

hour SO2. Upper panels show 2005 meteorological year. Lower panels show 2006 

meteorological year.

2022-2008 3-Hour 

Average SO2 All Sources

2022 3-Hour Average 

SO2 All Sources

2008 3-Hour Average 

SO2 All Sources

CD-C No Action 

SO2 Contribution

CD-C Proposed Action 

SO2 Contribution

2022 3-Hour Average 

SO2 All Sources
APPENDIX J – CRITERIA POLLUTANT PLOTS FOR THE 4 KM GRID 

FOR THE 2022 FUTURE YEAR MODELING

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 J-6

Figure J-5a. CAMx model results for 24-hour SO2. Left and center panels: 2008 and 2022 

absolute model results for 24-hour SO2 from all regional emissions sources, including CD-C 

Project. Right panel: 2022-2008 difference in 24-hour SO2. Upper panels show 2005 

meteorological year. Lower panels show 2006 meteorological year.

Figure J-5b. Left panel: 2022 absolute model results for 24-hour SO2 from all regional 

emissions sources, including CD-C Project. Center panel: CD-C Proposed Action contribution 

to 2022 24-hour SO2. Right panel: CD-C No Action (existing wells) contribution to the 2022 24-

hour SO2. Upper panels show 2005 meteorological year. Lower panels show 2006 

meteorological year.

2022-2008 24-Hour 

Average SO2 All Sources

2022 24-Hour Average 

SO2 All Sources

2008 24-Hour Average 

SO2 All Sources

CD-C No Action 

SO2 Contribution

CD-C Proposed Action 

SO2 Contribution

2022 24-Hour Average 

SO2 All Sources
APPENDIX J – CRITERIA POLLUTANT PLOTS FOR THE 4 KM GRID 

FOR THE 2022 FUTURE YEAR MODELING

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 J-7

Figure J-6a. CAMx model results for annual average SO2. Left and center panels: 2008 and 

2022 absolute model results for annual average SO2 from all regional emissions sources, 

including CD-C Project. Right panel: 2022-2008 difference in annual average SO2. Upper 

panels show 2005 meteorological year. Lower panels show 2006 meteorological year.

Figure J-6b. Left panel: 2022 absolute model results for annual average SO2 from all regional 

emissions sources, including CD-C Project. Center panel: CD-C Proposed Action contribution 

to 2022 annual average SO2. Right panel: CD-C No Action (existing wells) contribution to the 

2022 annual average SO2. Upper panels show 2005 meteorological year. Lower panels show 

2006 meteorological year.

2022-2008 Annual 

Average SO2 All Sources

2022 Annual Average 

SO2 All Sources

2008 Annual Average 

SO2 All Sources

CD-C No Action 

SO2 Contribution

CD-C Proposed Action 

SO2 Contribution

2022 Annual Average 

SO2 All Sources
APPENDIX J – CRITERIA POLLUTANT PLOTS FOR THE 4 KM GRID 

FOR THE 2022 FUTURE YEAR MODELING

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 J-8

Figure J-7a. CAMx model results for 98th percentile 24-hour average PM2.5. Left and center 

panels: 2008 and 2022 absolute model results for 98th percentile 24-hour average PM2.5 from 

all regional emissions sources, including CD-C Project. Right panel: 2022-2008 difference in 

98th percentile 24-hour average PM2.5. Upper panels show 2005 meteorological year. Lower 

panels show 2006 meteorological year.

Figure J-7b. Left panel: 2022 absolute model results for 98th percentile 24-hour average PM2.5 

from all regional emissions sources, including CD-C Project. Center panel: CD-C Proposed 

Action contribution to 2022 98th percentile 24-hour average PM2.5. Right panel: CD-C No 

Action (existing wells) contribution to the 2022 98th percentile 24-hour average PM2.5. Upper 

panels show 2005 meteorological year. Lower panels show 2006 meteorological year.

2022-2008 98th Percentile 24-

Hour Average PM2.5 All Sources

2022 98th Percentile 24-Hour 

Average PM2.5 All Sources

2008 98th Percentile 24-Hour 

Average PM2.5 All Sources

CD-C No Action 

PM2.5 Contribution

CD-C Proposed Action 

PM2.5 Contribution

2022 98thPercentile 24-Hour 

Average PM2.5 All Sources
APPENDIX J – CRITERIA POLLUTANT PLOTS FOR THE 4 KM GRID 

FOR THE 2022 FUTURE YEAR MODELING

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 J-9

Figure J-8a. CAMx model results for highest 24-hour average PM2.5. Left and center panels: 

2008 and 2022 absolute model results for highest 24-hour average PM2.5 from all regional 

emissions sources, including CD-C Project. Right panel: 2022-2008 difference in highest 24-

hour average PM2.5. Upper panels show 2005 meteorological year. Lower panels show 2006

meteorological year.

Figure J-8b. Left panel: 2022 absolute model results for highest 24-hour average PM2.5 from 

all regional emissions sources, including CD-C Project. Center panel: CD-C Proposed Action 

contribution to 2022 highest 24-hour average PM2.5. Right panel: CD-C No Action (existing 

wells) contribution to the 2022 highest 24-hour average PM2.5. Upper panels show 2005

meteorological year. Lower panels show 2006 meteorological year.

2022-2008 Highest 24-Hour 

Average PM2.5 All Sources

2022 Highest 24-Hour 

Average PM2.5 All Sources

2008 Highest 24-Hour 

Average PM2.5 All Sources

CD-C No Action 

PM2.5 Contribution

CD-C Proposed Action 

PM2.5 Contribution

2022 Highest 24-Hour 

Average PM2.5 All Sources
APPENDIX J – CRITERIA POLLUTANT PLOTS FOR THE 4 KM GRID 

FOR THE 2022 FUTURE YEAR MODELING

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 J-10

Figure J-9a. CAMx model results for annual average PM2.5. Left and center panels: 2008 and 

2022 absolute model results for annual average PM2.5 from all regional emissions sources, 

including CD-C Project. Right panel: 2022-2008 difference in annual average PM2.5. Upper 

panels show 2005 meteorological year. Lower panels show 2006 meteorological year.

Figure J-9b. Left panel: 2022 absolute model results for annual average PM2.5 from all 

regional emissions sources, including CD-C Project. Center panel: CD-C Proposed Action 

contribution to 2022 annual average PM2.5. Right panel: CD-C No Action (existing wells) 

contribution to the 2022 annual average PM2.5. Upper panels show 2005 meteorological year. 

Lower panels show 2006 meteorological year.

2022-2008 Annual 

Average PM2.5All Sources

2022 Annual Average 

PM2.5All Sources

2008 Annual Average 

PM2.5 All Sources

CD-C No Action 

PM2.5 Contribution

CD-C Proposed Action 

PM2.5 Contribution

2022 Annual Average 

PM2.5All Sources
APPENDIX J – CRITERIA POLLUTANT PLOTS FOR THE 4 KM GRID 

FOR THE 2022 FUTURE YEAR MODELING

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 J-11

Figure J-10a. CAMx model results for 24-hour average PM10. Left and center panels: 2008 

and 2022 absolute model results for 24-hour average PM10 from all regional emissions 

sources, including CD-C Project. Right panel: 2022-2008 difference in 24-hour average PM10. 

Upper panels show 2005 meteorological year. Lower panels show 2006 meteorological year.

Figure J-10b. Left panel: 2022 absolute model results for 24-hour average PM10 from all 

regional emissions sources, including CD-C Project. Center panel: CD-C Proposed Action 

contribution to 2022 24-hour average PM10. Right panel: CD-C No Action (existing wells) 

contribution to the 2022 24-hour average PM10. Upper panels show 2005 meteorological 

year. Lower panels show 2006 meteorological year.

2022-2008 24-Hour

Average PM10All Sources

2022 24-Hour Average 

PM10All Sources

2008 24-Hour Average 

PM10 All Sources

CD-C No Action 

PM10 Contribution

CD-C Proposed Action 

PM10 Contribution

2022 24-Hour Average 

PM10All Sources
APPENDIX J – CRITERIA POLLUTANT PLOTS FOR THE 4 KM GRID 

FOR THE 2022 FUTURE YEAR MODELING

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 J-12

Figure J-11a. CAMx model results for annual average PM10. Left and center panels: 2008 and 

2022 absolute model results for annual average PM10 from all regional emissions sources, 

including CD-C Project. Right panel: 2022-2008 difference in annual average PM10. Upper 

panels show 2005 meteorological year. Lower panels show 2006 meteorological year.

Figure J-11b. Left panel: 2022 absolute model results for annual average PM10 from all 

regional emissions sources, including CD-C Project. Center panel: CD-C Proposed Action 

contribution to 2022 annual average PM10. Right panel: CD-C No Action (existing wells) 

contribution to the 2022 annual average PM10. Upper panels show 2005 meteorological year. 

Lower panels show 2006 meteorological year.

2022-2008 Annual 

Average PM10All Sources

2022 Annual Average 

PM10 All Sources

2008 Annual Average 

PM10 All Sources

CD-C No Action 

PM10 Contribution

CD-C Proposed Action 

PM10 Contribution

2022 Annual Average 

PM10 All Sources
APPENDIX J – CRITERIA POLLUTANT PLOTS FOR THE 4 KM GRID 

FOR THE 2022 FUTURE YEAR MODELING

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 J-13

Figure J-12. CAMx model results for 1-hour CO. Left and center panels: 2008 and 2022 

absolute model results for 1-hour CO from all regional emissions sources, including CD-C 

Project. Right panel: 2022-2008 difference in 1-hour CO. Upper panels show 2005 

meteorological year. Lower panels show 2006 meteorological year.

Figure J-13. CAMx model results for 8-hour CO. Left and center panels: 2008 and 2022 

absolute model results for 8-hour CO from all regional emissions sources, including CD-C 

Project. Right panel: 2022-2008 difference in 8-hour CO. Upper panels show 2005 

meteorological year. Lower panels show 2006 meteorological year.

2022-2008 1-Hour

Average COAll Sources

2022 1-Hour Average 

COAll Sources

2008 1-Hour Average 

CO All Sources

2022-2008 8-Hour

Average COAll Sources

2022 8-Hour Average 

COAll Sources

2008 8-Hour Average

CO All Sources
Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016

Appendix K

Modeled Activity Assumptions and Emissions Controls
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-1

1.0. INTRODUCTION

In Appendix K, we summarize the activity assumptions made in estimating emissions for the CDC Project Emissions Inventory. The origin of the emission factors and speciation used is noted, 

as well as fuel type and the activity surrogate used to calculate field-wide emissions. We also 

show the emissions control measures that were modeled for the CD-C Project. Detailed 

information on CD-C Project emissions calculations and are provided in Appendix H.
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-2

Source 

Category

Activity Data 

Provided By Operator

Emission Factors/Speciation

Fuel Type

Engine 

Technology or 

Control Device

Type of 

Control 

Applied

Control 

Applied to 

Pollutants

Activity 

Criteria Air Pollutants Greenhouse Gases Surrogate

Hazardous Air 

Pollutants

Well Pad Const 

Equip (diesel 

ICE)

Engine Type, 

Number of Units,

Fuel Type,

Engine Technology,

Rated Horsepower,

Time Used,

Load Factor

Emission factors from EPA 

Federal Diesel Engine 

Standards. Where EPA 

Federal emission factors 

were not available, used 

EPA NONROAD model 

fully deteriorated Tier 

emission factors.

CO2 and CH4 emission 

factors based on EPA 

NONROAD model 

methodology and N2O 

emission factor from The 

Climate Registry, General 

Reporting Protocol v1.1, 

Table 13.6.

SPECIATE4, 

Profile 4674 Diesel Tier 1 Change in fuel sulfur content SOx Well Pads

Completion 

Equipment

(diesel ICE)

Engine Type, 

Number of Units,

Fuel Type,

Rated Horsepower,

Time Used,

Load Factor

Emission factors from EPA 

Federal Diesel Engine 

Standards. Where EPA 

Federal emission factors 

were not available, used 

EPA NONROAD model 

fully deteriorated Tier 

emission factors.

CO2 and CH4 emission 

factors based on EPA 

NONROAD model 

methodology and N2O 

emission factor from The 

Climate Registry, General 

Reporting Protocol v1.1, 

Table 13.6.

SPECIATE4, 

Profile 4674 Diesel Tier 2 Change in fuel sulfur content SOx Spuds

Construction 

Traffic, Road 

and Well pad Vehicle Type (Light or 

Heavy),

Mean Vehicle Speed, 

Round Trip Off-Road 

Trip Distance, Number 

of Round Trips Per 

Well

Emission factors estimated 

based on EPA MOVES 

model runs.

Emission factors estimated 

based on EPA MOVES 

model runs.

Heavy Duty 

Vehicles:

EPA profiles 

based on CRC 

E-55/E-59 

Study

Light Duty 

Vehicles:

Profiles 

provided by 

EPA and 

MOVES

MOVES 

default 

fuel 

fractions 

for each 

vehicle 

type

-

Change in 

emissions due 

to fleet turnover

NOx, CO, 

CO2, VOC, 

SOx, PM10, 

PM2.5, CH4, 

N2O

Well Pads

Construction 

Traffic, Road 

and Well padFugitive Dust

Emissions estimated using 

the equation from EPA,AP42, Section 13.2.2 Unpaved 

Roads (11/06). Assumed 

Heavy truck weight of 

70000 pounds, assumed 

Light truck weight of 7000 

lbs.

N/A N/A N/A - Watering

Fugitive 

Road Dust 

PM10,

Fugitive 

Road Dust 

PM2.5

Well Pads
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-3

Source 

Category

Activity Data 

Provided By Operator

Emission Factors/Speciation

Fuel Type

Engine 

Technology or 

Control Device

Type of 

Control 

Applied

Control 

Applied to 

Pollutants

Activity 

Criteria Air Pollutants Greenhouse Gases Surrogate

Hazardous Air 

Pollutants

Drilling 

Equipment 

(diesel ICE)

Engine Type, 

Number of Units,

Fuel Type,

Engine Technology,

Rated Horsepower

Time Used,

Load Factor,

Brake Specific Fuel 

Consumption

Emission factors from EPA 

Federal Diesel Engine 

Standards. Where EPA 

Federal emission factors 

were not available, used 

EPA NONROAD model 

fully deteriorated Tier 

emission factors.

CO2 and CH4 emission 

factors based on EPA 

NONROAD model 

methodology and N2O 

emission factor from The 

Climate Registry, General 

Reporting Protocol v1.1, 

Table 13.6.

SPECIATE4, 

Profile 4674 Diesel

Drilling by three 

diesel 1476 HP 

IC engines and 

one diesel 125 

HP IC engine. All 

diesel engines, 

assumed to be 

Tier 2

Change in fuel 

sulfur content SOx Spuds

Drilling Traffic 

Vehicle Type (Light or 

Heavy),

Mean Vehicle Speed, 

Round Trip Off-Road 

Trip Distance, Number 

of Round Trips Per 

Spud

Emission factors estimated 

based on EPA MOVES 

model runs.

Emission factors estimated 

based on EPA MOVES 

model runs.

Heavy Duty 

Vehicles:

EPA profiles 

based on CRC 

E-55/E-59 

Study

Light Duty 

Vehicles:

EPA and 

MOVES

Profiles

MOVES 

default 

fuel 

fractions 

for each 

vehicle 

type

-

Change in 

emissions due 

to fleet turnover

NOx, CO, 

CO2, VOC, 

SOx, PM10, 

PM2.5, CH4, 

N2O

Spuds

Drilling TrafficFugitive Dust

Emissions estimated using 

the equation from EPA,AP42, Section 13.2.2 Unpaved 

Roads (11/06). Assumed 

Heavy truck weight of 

70000 pounds, assumed 

Light truck weight of 7000 

lbs.

N/A N/A N/A - Watering

Fugitive 

Road Dust 

PM10, 

Fugitive 

Road Dust 

PM2.5

Spuds

Completion 

Traffic 

Vehicle Type (Light or 

Heavy),

Mean Vehicle Speed, 

Round Trip Off-Road 

Trip Distance, Number 

of Round Trips Per 

Spud

Emission factors estimated 

based on EPA MOVES 

model runs.

Emission factors estimated 

based on EPA MOVES 

model runs.

Heavy Duty 

Vehicles:

EPA profiles 

based on CRC 

E-55/E-59 

Study

Light Duty 

Vehicles:

EPA and 

MOVES

profiles

MOVES 

default 

fuel 

fractions 

for each 

vehicle 

type

-

Change in 

emissions due 

to fleet turnover

NOx, CO, 

CO2, VOC, 

SOx, PM10, 

PM2.5, CH4, 

N2O

Spuds
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-4

Source 

Category

Activity Data 

Provided By Operator

Emission Factors/Speciation

Fuel Type

Engine 

Technology or 

Control Device

Type of 

Control 

Applied

Control 

Applied to 

Pollutants

Activity 

Criteria Air Pollutants Greenhouse Gases Surrogate

Hazardous Air 

Pollutants

Completion 

Traffic- Fugitive 

Dust

Emissions estimated using 

the equation from EPA,AP42, Section 13.2.2 Unpaved 

Roads (11/06). Assumed 

Heavy truck weight of 

70000 pounds, assumed 

Light truck weight of 7000 

lbs.

N/A N/A N/A - Watering

Fugitive 

Road Dust 

PM10,

Fugitive 

Road Dust 

PM2.5

Spuds

Completion 

Venting

Gas Composition 

Analysis,

Gas Flow, 

Heat Content of Flared

gas ,

Green Completion and 

Conventional 

Completion Fraction,

Fraction of Gas Flared,

Fraction of Gas Vented, 

Fraction of Flared Gas 

Controlled per Well,

Volume of Gas Vented 

Zero uncontrolled venting 

emissions due to flaring 

and green completion 

controls.

Zero uncontrolled venting 

emissions due to flaring 

and green completion 

controls.

Wamsutter Wet 

Gas 

Composition

- -

96% of Gas to 

Green 

Completions 

and 4% of Gas 

will be Flared

VOC, CO2, 

CH4

Spuds

Completion 

Flaring

Heat Content of Flared 

Gas, 

Wet Gas Composition,

Fraction of Gas Flared,

Volume Flared per day, 

Volume Flared per 

Spud, 

Average Days per 

Completion

NOx, and CO emission 

factors were obtained from 

EPA AP-42, Table 13.5-1. 

Emission Factors for Flare 

Operations (9/95). VOC 

emission factor based on 

the fraction of THC as VOC 

and THC emission factor 

from EPA AP-42, Table 

13.5-1. Emission Factors 

for Flare Operations (9/95). 

CO2 emissions are based 

on the estimation of CO2

potential of the entire gas 

from the wet gas 

composition. N2O emission 

factor from API 

Compendium of 

Greenhouse Gas 

Emissions Methodologies 

for the Oil and Natural Gas 

Industry, 2009 Table 4-11, 

GHG Emission Factors for 

Gas Flares in Developed 

Countries. CH4 emission 

factor based on the fraction 

of THC as CH4 and THC 

emission factor from EPA 

AP-42, Table 13.5-1. 

Emission Factors for Flare 

Operations (9/95). 

SPECIATE4, 

Profile 0051

Natural 

Gas - N/A - Spuds
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-5

Source 

Category

Activity Data 

Provided By Operator

Emission Factors/Speciation

Fuel Type

Engine 

Technology or 

Control Device

Type of 

Control 

Applied

Control 

Applied to 

Pollutants

Activity 

Criteria Air Pollutants Greenhouse Gases Surrogate

Hazardous Air 

Pollutants

Well Pad and 

Access Road 

ConstructionFugitive Dust

Equipment Type,

Number of Units,

Time Used per Pad

Fugitive Construction Dust 

PM10 and PM2.5 emissions 

were estimated using 

equations from EPA, AP-42 

Table 11.9-1 for Bulldozing 

Overburden Emissions, 

Western Surface Coal 

Mining. Parameters used in 

emission equations were 

from EPA AP-42, Table 

11.9-3.

N/A N/A N/A - Watering

Fugitive 

Dust PM10,

Fugitive 

Dust PM2.5

Well Pads

Construction 

Wind ErosionFugitive Dust

Disturbed Area per 

Well Pad

Fugitive Wind Erosion Dust 

PM10 and PM2.5 emissions 

were estimated using 

methodology described in 

EPA, AP-42 Section 

13.2.5.3. Exposed surface 

type assumed to be flat. 

2007, 2008, and 2009 Wind 

Speed data from the 

Wamsutter Station.

N/A N/A N/A - None - Well Pads

Workover Equip 

(diesel ICE)

Engine Type, 

Number of Units,

Fuel Type,

Engine Technology,

Rated Horsepower,

Time Used,

Workover Equipment 

Use Frequency,

Workover Equipment 

Yearly Requirement,

Load Factor

Emission factors from EPA 

Federal Diesel Engine 

Standards. Where EPA 

Federal emission factors 

were not available, used 

EPA NONROAD model 

fully deteriorated Tier 2

emission factors.

CO2 and CH4 emission 

factors based on EPA 

NONROAD model 

methodology and N2O

emission factor from The 

Climate Registry, General 

Reporting Protocol v1.1, 

Table 13.6.

SPECIATE4, 

Profile 4674 Diesel Tier 2 Change in fuel sulfur content SOx Active Well Counts

Workover Rig 

Traffic 

Vehicle Type (Light or 

Heavy),

Mean Vehicle Speed, 

Round Trip Off-Road 

Trip Distance, Number 

of Round Trips Per 

Well

Emission factors estimated 

based on EPA MOVES 

model runs.

Emission factors estimated 

based on EPA MOVES 

model runs.

Heavy Duty 

Vehicles:

EPA profiles 

based on CRC 

E-55/E-59 

Study

Light Duty 

Vehicles:

EPA and 

MOVES 

profiles

MOVES 

default 

fuel 

fractions 

for each 

vehicle 

type

-

Change in 

emissions due 

to fleet turnover

NOx, CO, 

CO2, VOC, 

SOx, PM10, 

PM2.5, CH4, 

N2O

Active Well 

Counts
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-6

Source 

Category

Activity Data 

Provided By Operator

Emission Factors/Speciation

Fuel Type

Engine 

Technology or 

Control Device

Type of 

Control 

Applied

Control 

Applied to 

Pollutants

Activity 

Criteria Air Pollutants Greenhouse Gases Surrogate

Hazardous Air 

Pollutants

Workover Rig 

Traffic- Fugitive 

Dust

Emissions estimated using 

the equation from EPA, AP42, Section 13.2.2 Unpaved 

Roads (11/06). Assumed 

Heavy truck weight of 

70000 pounds, assumed 

Light truck weight of 7000 

lbs.

N/A N/A N/A - Watering

Fugitive 

Road Dust 

PM10,

Fugitive 

Road Dust 

PM2.5

Active Well 

Counts

Heaters

Equipment Type,

Heat Input,

Local Heating Value,

Number of Units,

Time Used Per Unit,

Heating Cycle Fraction

Emission factors from EPA, 

AP-42, Tables 1.4-1 

Emission Factors for 

Nitrogen Oxides and 

Carbon Monoxide from 

Natural Gas Combustion 

and 1.4-2 Emission Factors 

for Criteria Pollutants and 

Greenhouse Gases from 

Natural Gas Combustion.

Emission factors from EPA, 

AP-42, Table 1.4-2 

Emission Factors for 

Criteria Pollutants and 

Greenhouse Gases from 

Natural Gas Combustion.

SPECIATE4, 

Profile 0003

Natural 

Gas - None -

Active Well 

Counts

Fugitives

Gas Composition 

Analysis,

Component Counts by 

Media Type

VOC emissions estimated 

using TOC emission factor 

(kg/hr/component) from 

EPA, 1995 AP-42 Table 2-

4. "Oil and Gas Production 

Operations Average 

Emission Factors", and 

VOC/THC weight fraction 

from gas composition 

analysis.

To obtain CO2 and CH4

emissions, the CO2 and 

CH4 to VOC weight ratio 

from the natural gas 

composition were applied to 

VOC emissions.

Wamsutter 

Produced Gas 

Composition 

and Wamsutter 

Fugitive Post 

Flash Gas 

Composition

- - None -

Active Well 

Counts

Pneumatic 

Devices As per Operator's input there will be all "no bleed" devices and hence zero emissions from this category

Pneumatic 

Pump

Type of Pump,

Gallons Used per 

Pump,

SCF/Gallon ,

Number of Pumps,

Days of Use per Year,

SCF/Pump/Minute, 

Vented Volume Per 

Year, 

Molar Composition of 

Sales Gas

Zero uncontrolled venting 

emissions due to flaring 

control.

Zero uncontrolled venting 

emissions due to flaring 

control.

Wamsutter 

Produced Gas 

Composition

- Flare WYDEQ BACT VOC, CH4, 

CO2

Active Well 

Counts
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-7

Source 

Category

Activity Data 

Provided By Operator

Emission Factors/Speciation

Fuel Type

Engine 

Technology or 

Control Device

Type of 

Control 

Applied

Control 

Applied to 

Pollutants

Activity 

Criteria Air Pollutants Greenhouse Gases Surrogate

Hazardous Air 

Pollutants

Dehydrator 

Venting

Average Gas 

Production Per Year 

Per Well,

Number of dehydrators 

per Well, Regenerator 

Overhead Vent Stream 

Composition

Zero uncontrolled venting 

emissions due to flaring 

control.

Zero uncontrolled venting 

emissions due to flaring 

control.

Regenerator 

Overhead Vent 

Stream 

Composition

- Flare WYDEQ BACT VOC, CH4, 

CO2

Active Well 

Counts

Tank Loadout 

(vapor losses)

Type of Petroleum 

Liquid Loaded,

Saturation Factor,

True Vapor Pressure of 

Liquid Loaded ,

Molecular Weight of 

Vapors ,

Temperature of Bulk 

Liquid ,

Mode of Operation,

Capacity of Truck

VOC loading losses 

determined using EPA,AP42, Section 5.2.2.1.1 

Equation 1.

To obtain CO2 and CH4

emissions, the CO2 and 

CH4 to VOC weight ratio 

from the natural gas 

composition were applied to 

VOC emissions.

Wamsutter 

Condensate 

Composition 

(Post Flash)

- - None -

Annual 

Condensate 

Production

Well Venting

VOC Venting Emission 

Factor,

Wet Gas Composition 

VOC emission factor from 

operator .

To obtain CO2 and CH4

emissions, the CO2 and 

CH4 to VOC weight ratio 

from the natural gas 

composition were applied to 

VOC emissions.

Wamsutter Wet 

Gas 

Composition

- - None -

Active Well 

Counts

Production 

Traffic Vehicle Type (Light or 

Heavy),

Mean Vehicle Speed, 

Round Trip Off-Road 

Trip Distance, Number 

of Round Trips Per 

Well or Central 

Facilities 

Emission factors estimated 

based on EPA MOVES 

model runs.

Emission factors estimated 

based on EPA MOVES 

model runs.

Heavy Duty 

Vehicles:

EPA profiles 

based on CRC 

E-55/E-59 

Study

Light Duty 

Vehicles:

EPA and 

MOVES 

profiles

MOVES 

default 

fuel 

fractions 

for each 

vehicle 

type

-

Change in 

emissions due 

to fleet turnover

NOx, CO, 

CO2, VOC, 

SOx, PM10, 

PM2.5, CH4, 

N2O

Active Well 

Counts,

None for 

Central 

Facilities

Production 

Traffic- Fugitive 

Dust

Emissions estimated using 

the equation from EPA,AP42, Section 13.2.2 Unpaved 

Roads (11/06). Assumed 

Heavy truck weight of 

70000 pounds, assumed 

Light truck weight of 7000 

lbs.

N/A N/A N/A - Watering

Fugitive 

Road Dust 

PM10,

Fugitive 

Road Dust 

PM2.5

Active Well 

Counts,

None for 

Central 

Facilities
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-8

Source 

Category

Activity Data 

Provided By Operator

Emission Factors/Speciation

Fuel Type

Engine 

Technology or 

Control Device

Type of 

Control 

Applied

Control 

Applied to 

Pollutants

Activity 

Criteria Air Pollutants Greenhouse Gases Surrogate

Hazardous Air 

Pollutants

Condensate 

Tank Flashing 

Losses

Uncontrolled VOC, CH4

emission factors

Zero uncontrolled venting 

emissions due to flaring 

control.

Zero uncontrolled venting 

emissions due to flaring 

control.

Wamsutter 

Condensate 

Composition 

(Flash)

- Flare WYDEQ BACT VOC, CH4, 

CO2

Annual 

Condensate 

Production

Condensate 

Tank Working 

Losses

Uncontrolled VOC, CH4

emission factors

Zero uncontrolled venting 

emissions due to flaring 

control.

Zero uncontrolled venting 

emissions due to flaring 

control.

Wamsutter 

Condensate 

Composition 

(Post Flash)

- Flare WYDEQ BACT VOC, CH4, 

CO2

Total 

Turnovers per 

Year

Condensate 

Tank Breathing 

Losses

Uncontrolled VOC, CH4

emission factors

Zero uncontrolled venting 

emissions due to flaring 

control.

Zero uncontrolled venting 

emissions due to flaring 

control.

Wamsutter 

Condensate 

Composition 

(Post Flash)

- Flare WYDEQ BACT VOC, CH4, 

CO2

Active Well 

Counts

Production 

Flaring

Total Process Gas,

Gas Composition 

Analysis

NOx, and CO emission 

factors were obtained from 

EPA AP-42, Table 13.5-1. 

Emission Factors for Flare 

Operations (9/95). VOC 

emission factor based on 

the fraction of THC as VOC 

and THC emission factor 

from EPA AP-42, Table 

13.5-1. Emission Factors 

for Flare Operations (9/95). 

CO2 emissions based on 

CO2 potential of the entire 

gas based on gas 

composition. N2O emission 

factor from API 

Compendium of 

Greenhouse Gas 

Emissions Methodologies 

for the Oil and Natural Gas 

Industry, 2009 Table 4-11, 

GHG Emission Factors for 

Gas Flares in Developed 

Countries. CH4 emission 

factor based on the fraction 

of THC as CH4 and THC 

emission factor from EPA 

AP-42, Table 13.5-1. 

Emission Factors for Flare 

Operations (9/95). 

SPECIATE4, 

Profile 0051

Natural 

Gas - - -

Annual 

Condensate 

Production,

Total 

Turnovers per 

Year,

Active Well 

Counts
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-9

Source 

Category

Activity Data 

Provided By Operator

Emission Factors/Speciation

Fuel Type

Engine 

Technology or 

Control Device

Type of 

Control 

Applied

Control 

Applied to 

Pollutants

Activity 

Criteria Air Pollutants Greenhouse Gases Surrogate

Hazardous Air 

Pollutants

Compressor 

Station

Existing Capacity ,

Capacity to be Added,

Additional Horsepower 

Needed ,

Compressor Type -

Reciprocating or 

Turbines

Turbines:

All criteria pollutants 

emission factors except 

NOx, VOC, and CO were 

from EPA, AP-42, Table 

3.1-2a, Emission Factors 

for Criteria Pollutants and 

Greenhouse Gasses from 

Stationary Gas Turbines. 

The NOx, VOC and CO 

emission factors were 

obtained from minimum 

emission factors provided in 

existing sources by 

operator.

Turbines:

CO2 and N2O emission 

factors from EPA, AP-42, 

Table 3.1-2a, Emission 

Factors for Criteria 

Pollutants and Greenhouse 

Gases from Stationary Gas 

Turbines . CH4 from 

SPECIATE PROFILE.

SPECIATE4, 

Profile 0007

Natural 

Gas

As per the 

operator, 

additional 24,936 

horsepower is 

required. 

Assumed 2.7% of 

horsepower 

added is 

reciprocating 

engines and 

97.3% of 

horsepower 

added is turbines. 

These fractions 

were assumed 

based on the 

fraction of 

horsepower by 

engine type at 

existing stations.

None -

None

Reciprocating Engines:

All criteria pollutants 

emission factors except 

NOx, VOC and CO were 

from Table3-2.3, 

Uncontrolled Emission 

Factors for 4-Stroke Richburn Engines. Assumed 

BACT level NOx and CO 

emission factors and VOC 

emission factor was 

obtained from minimum 

emission factors provided in 

existing sources by 

operator.

Reciprocating Engines:

CO2 emission factor from 

Table3-2.3, Uncontrolled 

Emission Factors for 4-

Stroke Rich-burn Engines. 

CH4 from SPECIATE 

PROFILE. N2O emission 

factor from API 

Compendium of 

greenhouse gas emissions 

methodologies for the oil 

and natural gas 

industry,2009 .

SPECIATE4, 

Profile 1001

Natural 

Gas

BACT was 

assumed to 

limit NOx and 

CO emissions.

NOx , CO
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-10

Source 

Category

Activity Data 

Provided By Operator

Emission Factors/Speciation

Fuel Type

Engine 

Technology or 

Control Device

Type of 

Control 

Applied

Control 

Applied to 

Pollutants

Activity 

Criteria Air Pollutants Greenhouse Gases Surrogate

Hazardous Air 

Pollutants

Gas Plant

Total Engine Capacity,

Existing Plant Capacity 

,

NOx, CO and VOC 

Emissions for the 

Existing Plant 

Turbines:

All criteria pollutants 

emission factors except 

NOx, VOC, and CO were 

from EPA, AP-42, Table 

3.1-2a, Emission Factors 

for Criteria Pollutants and 

Greenhouse Gasses from 

Stationary Gas Turbines. 

The NOx, VOC and CO 

emission factors were 

obtained from minimum 

emission factors provided in 

existing sources by 

operator.

Turbines:

CO2 and N2O emission 

factors from EPA, AP-42, 

Table 3.1-2a, Emission 

Factors for Criteria 

Pollutants and Greenhouse 

Gases from Stationary Gas 

Turbines . CH4 from 

SPECIATE PROFILE.

SPECIATE4, 

Profile 0007

Natural 

Gas

As per the 

operator, 

additional 760 

mmscfd capacity 

is required to 

handle the 

additional gas 

volumes 

anticipated from 

the proposed 

wells. 

None -

None

Reciprocating Engines:

All criteria pollutants 

emission factors except 

NOx, VOC and CO were 

from Table3-2.3, 

Uncontrolled Emission 

Factors for 4-Stroke Richburn Engines. Assumed 

BACT level NOx and CO 

emission factors and VOC 

emission factor was 

obtained from minimum 

emission factors provided in 

existing sources by 

operator.

Reciprocating Engines:

CO2 emission factor from 

Table3-2.3, Uncontrolled 

Emission Factors for 4-

Stroke Rich-burn Engines. 

CH4 from SPECIATE 

PROFILE. N2O emission 

factor from API 

Compendium of 

greenhouse gas emissions 

methodologies for the oil 

and natural gas industry,

2009 .

SPECIATE4, 

Profile 1001

Natural 

Gas

BACT was 

assumed to 

limit NOx and 

CO emissions.

NOx , CO
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-11

Source 

Category

Activity Data 

Provided By Operator

Emission Factors/Speciation

Fuel Type

Engine 

Technology or 

Control Device

Type of 

Control 

Applied

Control 

Applied to 

Pollutants

Activity 

Criteria Air Pollutants Greenhouse Gases Surrogate

Hazardous Air 

Pollutants

Heaters/Process/Duct 

Burner:

All criteria pollutants except 

NOx, VOC and CO 

emission factors were from 

EPA AP-42, Table 1.4-2 

Emission Factors for 

Criteria Pollutants and 

Greenhouse Gases from 

Natural Gas Combustion. 

The NOx, CO and VOC 

emission factor were 

obtained from minimum or 

average

emission factors provided in 

existing sources by 

operator.

Heaters/Process/Duct 

Burner:

CO2, CH4 and N2O 

Emission Factors from EPA 

AP-42 Table 1.4-2 

Emission Factors for 

Criteria Pollutants and 

Greenhouse Gases from 

Natural Gas Combustion.

SPECIATE4, 

Profile 0003

Natural 

Gas

None -

Flaring:

NOx, VOC and CO 

emissions of the existing 

plant were scaled by the 

ratio of new plant capacity 

to existing plant capacity.

Flaring:

CO2/CH4/N2O to NOx 

emission factor ratio was 

applied to NOx emissions 

to obtain CO2, CH4 and 

N2O emissions. The NOx, 

CO2 and CH4 emission 

factors were obtained from 

EPA AP-42, Table 13.5-1. 

Emission Factors for Flare 

Operations. N2O emission 

factor from API 

Compendium of 

greenhouse gas emissions 

methodologies for the oil 

and natural gas 

industry,2009 Table 4-11, 

GHG Emission Factors for 

Gas Flares in Developed 

Countries.

SPECIATE4, 

Profile 0051

Natural 

Gas

Fugitives:

Operator has assumed that 

emissions do not scale by 

plant capacity. It was 

assumed that the existing 

and new plant will have 

LDAR.

Fugitives:

To obtain CO2 and CH4

emissions, CO2 and CH4 to 

VOC weight ratios from the 

gas composition analysis 

were applied to VOC 

emissions.

Wamsutter 

Produced Gas 

Composition

-
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-12

Source 

Category

Activity Data 

Provided By Operator

Emission Factors/Speciation

Fuel Type

Engine 

Technology or 

Control Device

Type of 

Control 

Applied

Control 

Applied to 

Pollutants

Activity 

Criteria Air Pollutants Greenhouse Gases Surrogate

Hazardous Air 

Pollutants

Evaporation 

Ponds

Emissions (tpy) based 

on Water 9 model 

Output, Produced 

Water Working and 

Breathing Analysis

Assumed that the HPAs 

estimates from Water 9 

model output to be the only 

VOCs emitted from the 

ponds.

To obtain CO2 and CH4

emissions, CO2 and CH4 to 

VOC weight ratios from the 

gas composition analysis 

were applied to VOC 

emissions.

Produced 

Water Working 

and Breathing 

Analysis

- - None -

Active Well 

Counts
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-13

Source 

Category

Control Percentage (%)

Uncontrolled 

Case Engine 

Technology 

or control

Uncontrolled 

Case Type of 

NOx CO VOC PM10 PM2.5 SOx Control

Well Pad 

Const Equip 

(diesel ICE)

0% 0% 0% 0% 0%

Prior to 2010 - 0%

2010 - 53%

2011 - 91%

After 2011 - 97%

no change

fuel sulfur 

content 

changes 

removed

Completion 

Equipment 

(diesel ICE)

0% 0% 0% 0% 0%

Prior to 2010 - 0%

2010 - 53%

2011 - 91%

After 2011 - 97%

no change

fuel sulfur 

content 

changes 

removed

Construction 

Traffic, 

Road and 

Well pad 

Control percentage in the selected years

 Heavy Duty Light Duty

2010 10% 5% 

2015 51% 33%

2020 74% 54%

2025 84% 66%

2030 88% 73%

2037 89% 77%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 4% 3%

2015 28% 22%

2020 44% 34%

2025 52% 41%

2030 56% 46%

2037 60% 50%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 3% 4%

2015 38% 33%

2020 62% 52%

2025 76% 65%

2030 83% 73%

2037 87% 78%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 7% 6%

2015 53% 35%

2020 79% 54%

2025 90% 63%

2030 94% 69%

2037 96% 72%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 7% 6%

2015 53% 36%

2020 79% 54%

2025 90% 64%

2030 94% 69%

2037 96% 73%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 45% 11%

2015 76% 30%

2020 77% 36%

2025 77% 40%

2030 77% 42%

2037 78% 44%

-

Emission rates 

held constant at 

2009 levels

Construction 

Traffic, 

Road and 

Well padFugitive 

Dust

0% 0% 0% 50% 50% 0% -

Removed 

watering 

control

Drilling 

Equipment 

(diesel ICE)

0% 0% 0% 0% 0%

Prior to 2010 - 0%

2010 - 53%

2011 - 91%

After 2011 - 97%

no change.

fuel sulfur 

content 

changes 

removed

Drilling 

Traffic 

Control percentage in the selected years

 Heavy Duty Light Duty

2010 10% 5% 

2015 51% 33%

2020 74% 54%

2025 84% 66%

2030 88% 73%

2037 89% 77%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 4% 3% 

2015 28% 22%

2020 44% 34%

2025 52% 41%

2030 56% 46%

2037 60% 50%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 3% 4% 

2015 38% 33%

2020 62% 52%

2025 76% 65%

2030 83% 73%

2037 87% 78%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 7% 6% 

2015 53% 35%

2020 79% 54%

2025 90% 63%

2030 94% 69%

2037 96% 72%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 7% 6% 

2015 53% 36%

2020 79% 54%

2025 90% 64%

2030 94% 69%

2037 96% 73%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 45% 11% 

2015 76% 30%

2020 77% 36%

2025 77% 40%

2030 77% 42%

2037 78% 44%

-

Emission 

rates held 

constant at 

2009 levels
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-14

Source 

Category

Control Percentage (%)

Uncontrolled 

Case Engine 

Technology 

or control

Uncontrolled 

Case Type of 

NOx CO VOC PM10 PM2.5 SOx Control

Drilling 

TrafficFugitive 

Dust

0% 0% 0% 50% 50% 0% -

Removed 

watering 

control

Control percentage in the selected years

 Heavy Duty Light Duty

2010 10% 5% 

2015 51% 33%

2020 74% 54%

2025 84% 66%

2030 88% 73%

2037 89% 77%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 4% 3% 

2015 28% 22%

2020 44% 34%

2025 52% 41%

2030 56% 46%

2037 60% 50%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 3% 4% 

2015 38% 33%

2020 62% 52%

2025 76% 65%

2030 83% 73%

2037 87% 78%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 7% 6% 

2015 53% 35%

2020 79% 54%

2025 90% 63%

2030 94% 69%

2037 96% 72%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 7% 6% 

2015 53% 36%

2020 79% 54%

2025 90% 64%

2030 94% 69%

2037 96% 73%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 45% 11% 

2015 76% 30%

2020 77% 36%

2025 77% 40%

2030 77% 42%

2037 78% 44%

Completion 

Traffic -

Emission 

rates held 

constant at 

2009 levels

Completion 

TrafficFugitive 

Dust

0% 0% 0% 50% 50% 0% -

Removed 

watering 

control

Completion 

Venting 0% 0%

Zero vented emissions are 

estimated due to flaring control. 

100% of the gas stream is assumed 

combusted in the flare; flare 

combustion VOC emissions are 

estimated to be approximately 1% of 

the VOC emissions if no controls 

were implemented.

0% 0% 0% -

Assumed that 

all completion 

emission are 

vented to the 

atmosphere
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-15

Source 

Category

Control Percentage (%)

Uncontrolled 

Case Engine 

Technology 

or control

Uncontrolled 

Case Type of 

NOx CO VOC PM10 PM2.5 SOx Control

Completion 

Flaring N/A N/A N/A N/A N/A N/A - -

Well Pad 

and Access 

Road 

Construction

- Fugitive 

Dust

0% 0% 0% 50% 50% 0% -

Removed 

watering 

control

Construction 

Wind 

ErosionFugitive 

Dust

0% 0% 0% 0% 0% 0% - no change

Workover 

Equip 

(diesel ICE)

0% 0% 0% 0% 0%

Prior to 2010 - 0%

2010 - 53%

2011 - 91%

After 2011 - 97%

-

fuel sulfur 

content 

changes 

removed

Workover 

Rig Traffic 

Control percentage in the selected years

 Heavy Duty Light Duty

2010 10% 5% 

2015 51% 33%

2020 74% 54%

2025 84% 66%

2030 88% 73%

2037 89% 77%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 4% 3% 

2015 28% 22%

2020 44% 34%

2025 52% 41%

2030 56% 46%

2037 60% 50%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 3% 4% 

2015 38% 33%

2020 62% 52%

2025 76% 65%

2030 83% 73%

2037 87% 78%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 7% 6% 

2015 53% 35%

2020 79% 54%

2025 90% 63%

2030 94% 69%

2037 96% 72%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 7% 6% 

2015 53% 36%

2020 79% 54%

2025 90% 64%

2030 94% 69%

2037 96% 73%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 45% 11% 

2015 76% 30%

2020 77% 36%

2025 77% 40%

2030 77% 42%

2037 78% 44%

-

Emission 

rates held 

constant at 

2009 levels

Workover 

Rig TrafficFugitive 

Dust

0% 0% 0% 50% 50% 0% -

Removed 

watering 

control
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-16

Source 

Category

Control Percentage (%)

Uncontrolled 

Case Engine 

Technology 

or control

Uncontrolled 

Case Type of 

NOx CO VOC PM10 PM2.5 SOx Control

Heaters 0% 0% 0% 0% 0% 0% - no change

Fugitives 0% 0% 0% 0% 0% 0% - no change

Pneumatic 

Devices

- - - - - -

- no change

Pneumatic 

Pump 0% 0%

Zero vented emissions are 

estimated due to flaring control. 

100% of the gas stream is assumed 

combusted in the flare; flare 

combustion VOC emissions are 

estimated to be approximately 1% of 

the VOC emissions if no controls 

were implemented.

0% 0% 0% none

assumed no 

BACT 

installed, 

100% 

uncontrolled 

emissions

Dehydrator 

Venting 0% 0%

Zero vented emissions are 

estimated due to flaring control. 

100% of the gas stream is assumed 

combusted in the flare; flare 

combustion VOC emissions are 

estimated to be approximately 1% of 

the VOC emissions if no controls 

were implemented.

0% 0% 0% none

assumed no 

BACT 

installed, 

100% 

uncontrolled 

emissions

Tank 

Loadout 

(vapor 

losses)

0% 0% 0% 0% 0% 0% - no change
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-17

Source 

Category

Control Percentage (%)

Uncontrolled 

Case Engine 

Technology 

or control

Uncontrolled 

Case Type of 

NOx CO VOC PM10 PM2.5 SOx Control

Well Venting 0% 0% 0% 0% 0% 0% - no change

Production 

Traffic 

Control percentage in the selected years

 Heavy Duty Light Duty

2010 10% 5% 

2015 51% 33%

2020 74% 54%

2025 84% 66%

2030 88% 73%

2037 89% 77%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 4% 3% 

2015 28% 22%

2020 44% 34%

2025 52% 41%

2030 56% 46%

2037 60% 50%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 3% 4% 

2015 38% 33%

2020 62% 52%

2025 76% 65%

2030 83% 73%

2037 87% 78%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 7% 6% 

2015 53% 35%

2020 79% 54%

2025 90% 63%

2030 94% 69%

2037 96% 72%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 7% 6% 

2015 53% 36%

2020 79% 54%

2025 90% 64%

2030 94% 69%

2037 96% 73%

Control percentage in the selected years

 Heavy Duty Light Duty

2010 45% 11% 

2015 76% 30%

2020 77% 36%

2025 77% 40%

2030 77% 42%

2037 78% 44%

-

Emission 

rates held 

constant at 

2009 levels

Production 

TrafficFugitive 

Dust

0% 0% 0% 50% 50% 0% -

Removed 

watering 

control

Condensate 

Tank 

Flashing 

Losses

0% 0%

Zero vented emissions are 

estimated due to flaring control. 

100% of the gas stream is assumed 

combusted in the flare; flare 

combustion VOC emissions are 

estimated to be approximately 1% of 

the VOC emissions if no controls 

were implemented.

0% 0% 0% none

assumed no 

BACT 

installed, 

100% 

uncontrolled 

emissions

Condensate 

Tank 

Working 

Losses

0% 0%

Zero vented emissions are 

estimated due to flaring control. 

100% of the gas stream is assumed 

combusted in the flare; flare 

combustion VOC emissions are 

estimated to be approximately 1% of 

the VOC emissions if no controls 

were implemented.

0% 0% 0% none

assumed no 

BACT 

installed, 

100% 

uncontrolled 

emissions

Condensate 

Tank 

Breathing 

Losses

0% 0%

Zero vented emissions are 

estimated due to flaring control. 

100% of the gas stream is assumed 

combusted in the flare; flare 

combustion VOC emissions are 

estimated to be approximately 1% of 

the VOC emissions if no controls 

were implemented.

0% 0% 0% none

assumed no 

BACT 

installed, 

100% 

uncontrolled 

emissions
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-18

Source 

Category

Control Percentage (%)

Uncontrolled 

Case Engine 

Technology 

or control

Uncontrolled 

Case Type of 

NOx CO VOC PM10 PM2.5 SOx Control

Production 

Flaring N/A N/A N/A N/A N/A N/A - -

Compressor 

Station

0% 0% 0% 0% 0% 0% none no change

92% 84% 0% 0% 0% 0% none

assumed 

AP-42 

uncontrolled 

NOx and CO 

emission rates

Gas Plant

0% 0% 0% 0% 0% 0% none no change

92% 84% 0% 0% 0% 0% none

assumed AP42 

uncontrolled 

NOx and CO 

emission rates

0% 0% 0% 0% 0% 0% - no change
APPENDIX K – MODELED ACTIVITY ASSUMPTIONS AND EMISSIONS CONTROLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 K-19

Source 

Category

Control Percentage (%)

Uncontrolled 

Case Engine 

Technology 

or control

Uncontrolled 

Case Type of 

NOx CO VOC PM10 PM2.5 SOx Control

0% 0% 0% 0% 0% 0% - no change

0% 0% 0% 0% 0% 0% - no change

Evaporation 

Ponds 0% 0% 0% 0% 0% 0% - no change
Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016

Appendix L

Continental Divide-Creston No Action Alternative Scenario Emissions Inventory
APPENDIX L – CONTINENTAL DIVIDE – CRESTON NO ACTION ALTERNATIVE

SCENARIO EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016

LIST OF ACRONYMS

Note: Central Facility refers to gas plants and compressor stations.

B Billion

BACT Best Available Control Technology

bpd Barrel Per Day

BSFC Brake Specific Fuel Consumption

BTU British Thermal Unit

CD-C Continental Divide-Creston

CH4 Methane

CO Carbon Monoxide

CO2 Carbon Dioxide

d Day

EC Elemental Carbon

EF Emission Factor

G Gram

HC Hydrocarbons

HD Heavy Duty

HHV Higher Heating Value

HP Horsepower

hp-hr Horsepower-Hour

hr Hour

ICE Internal Combustion Engine

Lb Pound

LD Light Duty

M Thousand

mi Miles

MM Million

mph Miles Per Hour

N2O Nitrous Oxide

NG Natural Gas

NMHC Non-Methane Hydrocarbon

NOx Oxides Of Nitrogen

PM Particulate Matter

PM_cond Condensable Particulate Matter

PM_filt Filterable Particulate Matter

Scf Standard Cubic Feet

SOA Secondary Organic Aerosols

SO2 Sulfur Dioxide

THC Total Hydrocarbons

TOC Total Organic Carbon

tpy Tons Per Year

TSP Total Suspended Particles

VMT Vehicle Miles Traveled

VOC Volatile Organic Compounds

Wt% Weight Percentage

WtFraction Weight Fraction

yr Year
APPENDIX L – CONTINENTAL DIVIDE – CRESTON NO ACTION ALTERNATIVE

SCENARIO EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-1

Continental Divide-Creston No Action Project Emissions Inventory

In Appendix L, we present the detailed emissions calculations used to develop the CD-C Project 

Emission Inventory for the No Action Alternative.
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-2

Existing Wells Emissions Inventory
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-3

Table 1. Summary of Existing Wells Activity Data by Project Year.

Year

Project 

Yr

Well Pads 

Constructed Spuds

Active Well 

Count

Annual 

Condensate 

Production 

(Mbbl/yr)

Annual Gas 

Production 

(MMSCF/yr)

Cumulative 

Well Pads 

Constructed

Cumulative 

Spuds

Cumulative 

Condensate 

Production 

(Mbbl)

Cumulative 

Gas 

Production 

(BSCF)

2008 1 462 462 2,850 2,726 193,570 462 462 2,726 194

2009 2 0 0 2,821 2,569 182,685 462 462 5,295 376

2010 3 0 0 2,792 2,211 157,216 462 462 7,507 533

2011 4 0 0 2,763 2,013 143,095 462 462 9,519 677

2012 5 0 0 2,736 1,976 140,480 462 462 11,495 817

2013 6 0 0 2,709 1,950 138,671 462 462 13,445 956

2014 7 0 0 2,682 1,851 131,597 462 462 15,296 1,087

2015 8 0 0 2,656 1,748 124,251 462 462 17,044 1,212

2016 9 0 0 2,629 1,657 117,844 462 462 18,701 1,329

2017 10 0 0 2,602 1,579 112,265 462 462 20,280 1,442

2018 11 0 0 2,575 1,510 107,356 462 462 21,790 1,549

2019 12 0 0 2,548 1,447 102,899 462 462 23,237 1,652

2020 13 0 0 2,524 1,389 98,793 462 462 24,627 1,751

2021 14 0 0 2,499 1,338 95,116 462 462 25,964 1,846

2022 15 0 0 2,475 1,267 90,091 462 462 27,232 1,936

2023 16 0 0 2,450 1,223 86,926 462 462 28,454 2,023

2024 17 0 0 2,426 1,181 83,975 462 462 29,635 2,107

2025 18 0 0 2,401 1,145 81,413 462 462 30,780 2,188

2026 19 0 0 2,376 1,110 78,899 462 462 31,890 2,267

2027 20 0 0 2,352 1,077 76,569 462 462 32,967 2,344

2028 21 0 0 2,305 1,047 74,456 462 462 34,014 2,418

2029 22 0 0 2,283 995 70,757 462 462 35,009 2,489

2030 23 0 0 2,260 968 68,803 462 462 35,977 2,558

2031 24 0 0 2,238 942 66,989 462 462 36,919 2,625

2032 25 0 0 2,216 917 65,232 462 462 37,836 2,690

2033 26 0 0 2,193 893 63,513 462 462 38,730 2,753

2034 27 0 0 2,171 871 61,923 462 462 39,601 2,815

2035 28 0 0 2,149 850 60,426 462 462 40,450 2,876

2036 29 0 0 2,126 831 59,091 462 462 41,282 2,935

2037 30 0 0 2,104 813 57,799 462 462 42,094 2,993

Total 462 462
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-4

Table 2. Projection Parameters Used in Future Year Emission Inventory Development for 

Existing Wells by Source Category.

Source Category Projection Parameter

Completion Equipment (diesel ICE) totals for year with spuds

Condensate Tank Flashing Losses annual condensate production

Dehydrator Venting - Well Site active well counts

Heaters active well counts

Initial Completion Venting totals for year with spuds

Pneumatic Devices active well counts

Pneumatic Pumps active well counts

Tank Loadout (vapor losses) annual condensate production

Well Stream Fugitive Devices active well counts

Gas Stream Fugitive Devices active well counts

Condensate Fugitive Devices active well counts

Well Venting active well counts

Condensate Tank Working Losses total turnovers per year

Condensate Tank Breathing Losses active well counts

Drilling Equip (diesel ICE) totals for year with spuds

Drilling Traffic (LD) total spuds

Drilling Traffic (HD) total spuds

Completion Traffic (LD) total spuds

Completion Traffic (HD) total spuds

Well Pad Const Equip (diesel ICE) new pads

Construction Dust, Fugitive new pads

Construction Dust, Wind Erosion new pads

Construction Traffic, Road and Well pad (LD) new pads

Construction Traffic, Road and Well pad (HD) new pads

Production Traffic (LD) active well counts

Production Traffic (HD) active well counts

Drilling Traffic (LD) Dust total spuds

Drilling Traffic (HD) Dust total spuds

Completion Traffic (LD) Dust total spuds

Completion Traffic (HD) Dust total spuds

Construction Traffic, Road and Well pad (LD) Dust new pads

Construction Traffic, Road and Well pad (HD) Dust new pads

Production Traffic (LD) Dust active well counts

Production Traffic (HD) Dust active well counts

Workover Equipment (diesel ICE) active well counts

WorkoverTraffic (LD) active well counts

WorkoverTraffic (HD) active well counts

WorkoverTraffic (LD) Dust active well counts

WorkoverTraffic (HD) Dust active well counts
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-5

Source Category Projection Parameter

Compressor Station (Reciprocating Engine Rich Burn) totals for year with compressor station

Compressor Station (Reciprocating Engine Lean Burn) totals for year with compressor station

Compressor Station (Turbine) totals for year with compressor station

Compressor Station (Venting) totals for year with compressor station

Compressor Station (External NG Combustion) totals for year with compressor station

Compressor Station (Flashing) totals for year with compressor station

Compressor Station (Working/Breathing) totals for year with compressor station

Compressor Station (Flaring) totals for year with compressor station

Gas Plant (Reciprocating Engine) totals for year with gas plant

Gas Plant (Turbine) totals for year with gas plant

Gas Plant (flaring) totals for year with gas plant

Gas Plant (natural gas external combustion (boiler/heater)) totals for year with gas plant

Gas Plant (venting) totals for year with gas plant

Condensate Tank Flashing Flaring annual condensate production

Condensate Tank Working Flaring total turnovers per year

Condensate Tank Breathing Flaring active well counts

Production Traffic, Central Facility (HD) None

Production Traffic, Central Facility (HD) Dust None

Evaporation Ponds active well counts
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-6

Table 3. Summary of Projection Factors Used in Future Year Emission Inventory Development for Existing Wells.

Projection New pads 

per Year

Active Well 

Counts per Year

Total Spuds 

per Year

Annual Gas 

Production

(MMSCF/yr)

Annual 

Condensate 

Production

(bbl/yr)

Total 

Turnovers per 

Year

Totals for Year 

with Spuds

Totals for Year 

with 

Compressor 

Station

Totals for 

Year with 

Gas Plant

None

2008 462 2,850 462 193,570 2,726,059 2,850 1 1 1 1

2009 0 2,821 0 182,685 2,569,379 2,821 0 1 1 1

2010 0 2,792 0 157,216 2,211,169 2,792 0 1 1 1

2011 0 2,763 0 143,095 2,012,559 2,763 0 1 1 1

2012 0 2,736 0 140,480 1,975,782 2,736 0 1 1 1

2013 0 2,709 0 138,671 1,950,348 2,709 0 1 1 1

2014 0 2,682 0 131,597 1,850,855 2,682 0 1 1 1

2015 0 2,656 0 124,251 1,747,525 2,656 0 1 1 1

2016 0 2,629 0 117,844 1,657,424 2,629 0 1 1 1

2017 0 2,602 0 112,265 1,578,959 2,602 0 1 1 1

2018 0 2,575 0 107,356 1,509,910 2,575 0 1 1 1

2019 0 2,548 0 102,899 1,447,219 2,548 0 1 1 1

2020 0 2,524 0 98,793 1,389,480 2,524 0 1 1 1

2021 0 2,499 0 95,116 1,337,765 2,499 0 1 1 1

2022 0 2,475 0 90,091 1,267,081 2,475 0 1 1 1

2023 0 2,450 0 86,926 1,222,568 2,450 0 1 1 1

2024 0 2,426 0 83,975 1,181,063 2,426 0 1 1 1

2025 0 2,401 0 81,413 1,145,037 2,401 0 1 1 1

2026 0 2,376 0 78,899 1,109,676 2,376 0 1 1 1

2027 0 2,352 0 76,569 1,076,911 2,352 0 1 1 1

2028 0 2,305 0 74,456 1,047,183 2,305 0 1 1 1

2029 0 2,283 0 70,757 995,158 2,283 0 1 1 1

2030 0 2,260 0 68,803 967,685 2,260 0 1 1 1

2031 0 2,238 0 66,989 942,173 2,238 0 1 1 1

2032 0 2,216 0 65,232 917,459 2,216 0 1 1 1

2033 0 2,193 0 63,513 893,285 2,193 0 1 1 1

2034 0 2,171 0 61,923 870,920 2,171 0 1 1 1

2035 0 2,149 0 60,426 849,856 2,149 0 1 1 1

2036 0 2,126 0 59,091 831,090 2,126 0 1 1 1

2037 0 2,104 0 57,799 812,920 2,104 0 1 1 1
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-7

Gas Composition Analysis

Table 4. Summary of Gas Composition Analysis as Provided in Table 5 through Table 11.
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-8

Assumptions 

Data obtained from operators in blue text

Table 5. Sales Gas Composition Analysis.
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-9

Table 6. Fugitive Post-Flash Gas Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 2.79% 2.79% 44.0 1.2 3.0190% N

Nitrogen 0.02% 0.02% 28.0 0.0 0.0151% N

Methane 34.37% 34.37% 16.0 5.5 13.5728% N

Ethane 13.30% 13.30% 30.1 4.0 9.8429% N

Propane 17.80% 17.80% 44.1 7.9 19.3288% Y 26.28% 11.59

Isobutane 6.84% 6.84% 58.1 4.0 9.7798% Y 13.30% 7.73

n-Butane 9.37% 9.37% 58.1 5.4 13.4078% Y 18.23% 10.60

Isopentane 4.55% 4.55% 72.2 3.3 8.0782% Y 10.98% 7.92

n-Pentane 3.97% 3.97% 72.2 2.9 7.0578% Y 9.60% 6.92

Cyclopentane 0.00% 0.00% 70.1 0.0 0.0000% Y 0.00% 0.00

n-Hexane 1.37% 1.37% 86.2 1.2 2.9160% Y 3.96% 3.42

Cyclohexane 0.30% 0.30% 84.2 0.3 0.6178% Y 0.84% 0.71

2,2-Dimethylbutane 0.09% 0.09% 86.2 0.1 0.1907% Y 0.26% 0.22

2,3-Dimethylbutane 0.35% 0.35% 86.2 0.3 0.7423% Y 1.01% 0.87

2-Methylpentane 1.06% 1.06% 86.2 0.9 2.2383% Y 3.04% 2.62

3-Methylpentane 0.54% 0.54% 86.2 0.5 1.1373% Y 1.55% 1.33

n-Heptane 1.85% 1.85% 100.2 1.9 4.5651% Y 6.21% 6.22

Methylcyclohexane 0.18% 0.18% 98.2 0.2 0.4350% Y 0.59% 0.58

2,2,4-Trimethylpentane 0.07% 0.07% 114.2 0.1 0.1980% Y 0.27% 0.31

Benzene 0.32% 0.32% 78.1 0.2 0.6104% Y 0.83% 0.65

Toluene 0.38% 0.38% 92.1 0.3 0.8601% Y 1.17% 1.08

Ethylbenzene 0.00% 0.00% 106.2 0.0 0.0114% Y 0.02% 0.02

m-Xylene 0.16% 0.16% 106.2 0.2 0.4206% Y 0.57% 0.61

o-Xylene 0.02% 0.02% 106.2 0.0 0.0399% Y 0.05% 0.06

n-Octane 0.22% 0.22% 114.2 0.3 0.6172% Y 0.84% 0.96

n-Nonane 0.05% 0.05% 128.3 0.1 0.1582% Y 0.22% 0.28

n-Decane 0.04% 0.04% 142.3 0.1 0.1395% Y 0.19% 0.27

Total 100.00% 100.00% 40.6 100.00% 65.0
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-10

Table 7. Flash Gas Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 2.80% 2.80% 44.0 1.2 3.0392% N

Nitrogen 0.02% 0.02% 28.0 0.0 0.0149% N

Methane 34.25% 34.25% 16.0 5.5 13.5394% N

Ethane 13.42% 13.42% 30.1 4.0 9.9421% N

Propane 17.98% 17.98% 44.1 7.9 19.5446% Y 26.60% 11.73

Isobutane 6.85% 6.85% 58.1 4.0 9.8099% Y 13.35% 7.76

n-Butane 9.34% 9.34% 58.1 5.4 13.3756% Y 18.21% 10.58

Isopentane 4.48% 4.48% 72.2 3.2 7.9707% Y 10.85% 7.83

n-Pentane 3.91% 3.91% 72.2 2.8 6.9497% Y 9.46% 6.83

Cyclopentane 0.00% 0.00% 70.1 0.0 0.0000% Y 0.00% 0.00

n-Hexane 1.36% 1.36% 86.2 1.2 2.8850% Y 3.93% 3.38

Cyclohexane 0.30% 0.30% 84.2 0.2 0.6125% Y 0.83% 0.70

2,2-Dimethylbutane 0.09% 0.09% 86.2 0.1 0.1877% Y 0.26% 0.22

2,3-Dimethylbutane 0.34% 0.34% 86.2 0.3 0.7319% Y 1.00% 0.86

2-Methylpentane 1.04% 1.04% 86.2 0.9 2.2086% Y 3.01% 2.59

3-Methylpentane 0.53% 0.53% 86.2 0.5 1.1231% Y 1.53% 1.32

n-Heptane 1.85% 1.85% 100.2 1.9 4.5682% Y 6.22% 6.23

Methylcyclohexane 0.18% 0.18% 98.2 0.2 0.4348% Y 0.59% 0.58

2,2,4-Trimethylpentane 0.07% 0.07% 114.2 0.1 0.1981% Y 0.27% 0.31

Benzene 0.31% 0.31% 78.1 0.2 0.6038% Y 0.82% 0.64

Toluene 0.38% 0.38% 92.1 0.3 0.8615% Y 1.17% 1.08

Ethylbenzene 0.00% 0.00% 106.2 0.0 0.0115% Y 0.02% 0.02

m-Xylene 0.16% 0.16% 106.2 0.2 0.4243% Y 0.58% 0.61

o-Xylene 0.02% 0.02% 106.2 0.0 0.0403% Y 0.05% 0.06

n-Octane 0.22% 0.22% 114.2 0.3 0.6219% Y 0.85% 0.97

n-Nonane 0.05% 0.05% 128.3 0.1 0.1598% Y 0.22% 0.28

n-Decane 0.04% 0.04% 142.3 0.1 0.1410% Y 0.19% 0.27

Total 100.00% 100.00% 40.6 100.00% 64.9
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-11

Table 8. Produced Water Working and Breathing Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 29.14% 29.14% 44.010 12.822 24.76% N

Nitrogen 0.00% 0.00% 28.010 0.000 0.00% N

Methane 12.59% 12.59% 16.040 2.019 3.90% N

Ethane 3.02% 3.02% 30.070 0.909 1.76% N

Propane 11.24% 11.24% 44.100 4.956 9.57% Y 13.76% 6.066

Isobutane 8.05% 8.05% 58.120 4.679 9.04% Y 12.99% 7.548

n-Butane 12.65% 12.65% 58.120 7.352 14.20% Y 20.41% 11.861

Isopentane 6.97% 6.97% 72.150 5.031 9.72% Y 13.96% 10.075

n-Pentane 5.97% 5.97% 72.150 4.308 8.32% Y 11.96% 8.628

Cyclopentane 0.00% 0.00% 70.130 0.000 0.00% Y 0.00% 0.000

n-Hexane 2.09% 2.09% 86.180 1.804 3.48% Y 5.01% 4.316

Cyclohexane 3.09% 3.09% 84.160 2.600 5.02% Y 7.22% 6.073

2,2-Dimethylbutane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

2,3-Dimethylbutane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

2-Methylpentane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

3-Methylpentane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

n-Heptane 3.55% 3.55% 100.202 3.558 6.87% Y 9.88% 9.897

Methylcyclohexane 0.00% 0.00% 98.190 0.000 0.00% Y 0.00% 0.000

2,2,4-Trimethylpentane 0.12% 0.12% 114.229 0.142 0.27% Y 0.39% 0.451

Benzene 0.26% 0.26% 78.110 0.200 0.39% Y 0.56% 0.434

Toluene 0.44% 0.44% 92.140 0.406 0.78% Y 1.13% 1.038

Ethylbenzene 0.02% 0.02% 106.170 0.017 0.03% Y 0.05% 0.051

m-Xylene 0.15% 0.15% 106.160 0.156 0.30% Y 0.43% 0.458

o-Xylene 0.00% 0.00% 106.160 0.000 0.00% Y 0.00% 0.000

n-Octane 0.36% 0.36% 114.229 0.415 0.80% Y 1.15% 1.316

n-Nonane 0.12% 0.12% 128.255 0.149 0.29% Y 0.41% 0.531

n-Decane 0.18% 0.18% 142.290 0.254 0.49% Y 0.70% 1.003

Total 100.00% 100.00% 51.777 100.00% 69.745
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-12

Table 9. Condensate Tank Post-Flash Gas Composition Analysis.

Table 10. Regenerated Overhead Vent Stream Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 0.00% 0.00% 44.010 0.000 0.00% N

Nitrogen 0.00% 0.00% 28.010 0.000 0.00% N

Methane 46.18% 46.18% 16.040 7.407 21.23% N

Ethane 14.42% 14.42% 30.070 4.335 12.43% N

Propane 15.42% 15.42% 44.100 6.801 19.50% Y 29.39% 12.960

Isobutane 5.69% 5.70% 58.120 3.310 9.49% Y 14.30% 8.313

n-Butane 7.51% 7.51% 58.120 4.364 12.51% Y 18.86% 10.961

Isopentane 3.54% 3.54% 72.150 2.557 7.33% Y 11.05% 7.972

n-Pentane 2.87% 2.87% 72.150 2.070 5.93% Y 8.94% 6.453

n-Hexane 0.91% 0.91% 86.180 0.786 2.25% Y 3.40% 2.928

Cyclohexane 0.15% 0.15% 84.160 0.125 0.36% Y 0.54% 0.454

2,2-Dimethylbutane 0.07% 0.07% 86.177 0.062 0.18% Y 0.27% 0.233

2,3-Dimethylbutane 0.24% 0.24% 86.177 0.207 0.59% Y 0.90% 0.771

2-Methylpentane 0.71% 0.71% 86.177 0.614 1.76% Y 2.65% 2.287

3-Methylpentane 0.34% 0.34% 86.177 0.294 0.84% Y 1.27% 1.093

n-Heptane 1.23% 1.23% 100.202 1.228 3.52% Y 5.31% 5.319

Methylcyclohexane 0.10% 0.10% 98.190 0.098 0.28% Y 0.42% 0.414

2,2,4-Trimethylpentane 0.04% 0.04% 114.229 0.049 0.14% Y 0.21% 0.242

Benzene 0.14% 0.14% 78.110 0.111 0.32% Y 0.48% 0.373

Toluene 0.16% 0.16% 92.140 0.145 0.42% Y 0.63% 0.579

Ethylbenzene 0.00% 0.00% 106.170 0.002 0.01% Y 0.01% 0.009

Xylenes 0.08% 0.08% 106.170 0.081 0.23% Y 0.35% 0.370

n-Octane 0.11% 0.11% 114.229 0.131 0.37% Y 0.56% 0.645

n-Nonane 0.04% 0.04% 128.255 0.046 0.13% Y 0.20% 0.257

n-Decane 0.04% 0.04% 142.290 0.061 0.17% Y 0.26% 0.374

Total 100.00% 100.00% 0.000 34.884 100.00% 100.00% 63.007

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Water 17.54% 17.54% 18.010 3.159 11.56% N

Carbon Dioxide 5.47% 5.47% 44.010 2.407 8.81% N

Nitrogen 0.11% 0.11% 28.010 0.032 0.12% N

Methane 55.61% 55.61% 16.040 8.920 32.64% N

Ethane 6.19% 6.19% 30.070 1.861 6.81% N

Propane 3.98% 3.98% 44.100 1.755 6.42% Y 16.03% 7.069

Isobutane 1.07% 1.07% 58.120 0.622 2.28% Y 5.68% 3.301

n-Butane 1.49% 1.49% 58.120 0.866 3.17% Y 7.91% 4.597

Isopentane 0.57% 0.57% 72.150 0.413 1.51% Y 3.77% 2.719

n-Pentane 0.58% 0.58% 72.150 0.421 1.54% Y 3.85% 2.776

n-Hexane 0.33% 0.33% 86.180 0.286 1.05% Y 2.61% 2.252

Cyclohexane 0.62% 0.62% 84.160 0.523 1.92% Y 4.78% 4.024

Other Hexanes 0.37% 0.37% 86.180 0.320 1.17% Y 2.92% 2.517

n-Heptane 0.61% 0.61% 100.202 0.615 2.25% Y 5.62% 5.630

Methylcyclohexane 0.79% 0.79% 98.190 0.775 2.83% Y 7.08% 6.947

2,2,4-Trimethylpentane 0.02% 0.02% 114.229 0.022 0.08% Y 0.20% 0.226

Benzene 1.35% 1.35% 78.110 1.055 3.86% Y 9.63% 7.522

Toluene 1.89% 1.89% 92.140 1.741 6.37% Y 15.90% 14.654

Ethylbenzene 0.06% 0.06% 106.170 0.065 0.24% Y 0.59% 0.628

Xylenes 0.60% 0.60% 106.170 0.641 2.35% Y 5.86% 6.218

n-Octane 0.73% 0.73% 114.229 0.829 3.03% Y 7.57% 8.652

Total 100.00% 100.00% 27.329 100.00% 100.00% 79.734
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-13

Table 11. Wet Gas Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 2.73% 2.73% 44.010 1.203 6.09% N

Nitrogen 0.17% 0.17% 28.010 0.048 0.24% N

Methane 84.98% 84.98% 16.040 13.631 69.04% N

Ethane 6.81% 6.81% 30.070 2.049 10.38% N

Propane 3.17% 3.17% 44.100 1.398 7.08% Y 49.67% 21.906

Isobutane 0.64% 0.64% 58.120 0.370 1.87% Y 13.14% 7.634

n-Butane 0.71% 0.71% 58.120 0.413 2.09% Y 14.67% 8.528

Isopentane 0.24% 0.24% 72.150 0.175 0.88% Y 6.21% 4.478

n-Pentane 0.20% 0.20% 72.150 0.144 0.73% Y 5.11% 3.686

n-Hexane 0.06% 0.06% 86.180 0.056 0.28% Y 1.98% 1.710

Cyclohexane 0.03% 0.03% 84.160 0.027 0.14% Y 0.95% 0.800

2,2-Dimethylbutane 0.00% 0.00% 86.177 0.004 0.02% Y 0.13% 0.113

2,3-Dimethylbutane 0.02% 0.02% 86.177 0.014 0.07% Y 0.50% 0.433

2-Methylpentane 0.05% 0.05% 86.177 0.042 0.21% Y 1.49% 1.288

3-Methylpentane 0.03% 0.03% 86.177 0.022 0.11% Y 0.77% 0.662

n-Heptane 0.06% 0.06% 100.202 0.059 0.30% Y 2.09% 2.094

Methylcyclohexane 0.03% 0.03% 98.190 0.032 0.16% Y 1.12% 1.103

2,2,4-Trimethylpentane 0.00% 0.00% 114.229 0.004 0.02% Y 0.15% 0.176

Benzene 0.01% 0.01% 78.110 0.012 0.06% Y 0.41% 0.323

Toluene 0.02% 0.02% 92.140 0.016 0.08% Y 0.57% 0.525

Ethylbenzene 0.00% 0.00% 106.170 0.001 0.00% Y 0.02% 0.020

m&p-Xylene 0.00% 0.00% 106.160 0.004 0.02% Y 0.15% 0.164

o-Xylene 0.00% 0.00% 106.160 0.001 0.00% Y 0.02% 0.024

n-Octane 0.01% 0.01% 114.229 0.016 0.08% Y 0.56% 0.635

n-Nonane 0.01% 0.01% 128.255 0.008 0.04% Y 0.27% 0.345

n-Decane 0.00% 0.00% 142.290 0.000 0.00% Y 0.00% 0.000

Total 100.00% 100.00% 19.745 100.00% 100.00% 56.648
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-14

Table 12. Toxic Speciation Profiles Used in Future Year Emission Inventory Development for Existing Wells.

benzene toluene ethylbenzene xylenes n-hexane formaldehyde

venting other than well venting, initial completion 

and dehydrator 0.403% 0.555% 0.017% 0.320% 4.744% 0.000%

flashing loss 0.822% 1.173% 0.016% 0.632% 3.927% 0.000%

Fugitive -working/breathing loss 0.830% 1.169% 0.016% 0.626% 3.965% 0.000%

diesel ICE 1.045% 1.518% 0.179% 1.205% 0.000% 8.510%

HD traffic 1.132% 0.613% 0.152% 0.801% 0.129% 7.924%

LD traffic 3.711% 10.147% 1.459% 5.744% 0.879% 2.456%

natural gas external combustion (boiler/heater) 4.000% 2.000% 0.000% 0.000% 0.000% 8.000%

dust 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%

compressor engine, lean burn 0.373% 0.346% 0.034% 0.156% 0.941% 44.746%

compressor engine, rich burn 5.338% 1.885% 0.084% 0.659% 0.000% 69.257%

natural gas drilling engine 0.373% 0.346% 0.034% 0.156% 0.941% 44.746%

flaring 0.000% 0.000% 0.000% 0.000% 0.000% 40.000%

diesel external combustion boiler 0.000% 0.000% 0.000% 0.000% 10.800% 48.700%

Reciprocating Engine 1.182% 0.430% 0.107% 0.430% 0.215% 8.700%

Turbine 0.000% 0.000% 0.000% 0.000% 0.000% 100.000%

produced water evaporation 13.858% 18.028% 1.529% 24.393% 0.147% 0.000%

Tank -working/breathing loss 0.478% 0.629% 0.009% 0.348% 3.398% 0.000%

Dehydrator Venting 9.631% 15.905% 0.591% 5.857% 2.613% 0.000%

venting -Well Venting and Initial completion 0.414% 0.570% 0.019% 0.177% 1.984% 0.000%

Source Type for lookup

VOC fractions

Source

Wamsutter Produced Gas Composition

Flash speciation from Wamsutter HYSYS

Wamsutter Fugitive Composition (Post Flash)

SPECIATE4, Profile 4674

From Catherine Yanca at EPA based on CRC E-55/E-59 Study

From David Brzezinski at EPA and MOVES

SPECIATE4, Profile 0003

AP-42, CH 3.2

AP-42, CH 3.2

AP-42, CH 3.2

SPECIATE4, Profile 1001

SPECIATE4, Profile 0002

SPECIATE4, Profile 1001

SPECIATE4, Profile 0007

EPA, Water 9 model Output. Based on data from evaporation 

facilities at Wamsutter Operations Center

Wamsutter Condensate Composition (Post Flash)

Wamsutter Regenerator Overhead Vent Stream Composition

Wamsutter Wet Gas Composition
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-15

Table 13. List of Toxic Speciation Profiles Used in Emission Inventory Development for Existing 

Wells by Source Category.
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-16

2008 Well Pad Construction Equipment Emissions 

ASSUMPTIONS

Activity data obtained from operator in blue text

Assumptions:

* Emission factors from EPA Federal Diesel Engine Standards 

http://www.epa.gov/otaq/standar

ds/nonroad/nonroadci.htm

* VOC/THC= 1.053 Conversion for HC->VOC for diesel engines (EPA, 2005; EPA420-R-05-0159, p. 5)

*

37% of fine particles assumed to be filterable and all filterable are assigned to EC (Source: AQTSD for Hell’s Gulch 

and Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

*

63% of fine particles assumed to be filterable and all filterable are assigned to SOA (Source: AQTSD for Hell’s Gulch 

and Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

EPA NONROAD model Fully Deteriorated Tier Emission Factors

N2O Emission factors (g/gallons) from The Climate Registry, General Reporting Protocol v1.1, Table 13.6

Equations:

Emissions (tons/year-well) = Emission factor (g/hp-hr) * Horsepower * Time Used (hours) * Load

453.6 (g/lb) * 2000 (lbs/ton)

PM2.5/PM10 = 97% EPA (2004) NONROAD

VOC/HC= 1.053 EPA NONROAD HC Conversions

NMHC/THC= 98.40% EPA NONROAD HC Conversions

SO2 Emission Factor Calculation Information 

2008 Fuel Sulfur content 0.0355 sulfur fuel weight percent from EPA's NMIM 

County Database

soxcnv Tiers I-III 0.02247 grams PM sulfur/grams fuel sulfur consumed

soxcnv Tier IV 0.3

grams PM sulfate/grams PM sulfur 7

soxbas 0.33

Density of Diesel Fuel 7.09 lb/gallons

Molecular weight of S 32 g/mol

Molecular weight of S02 64 g/mol

453.6 g/lb
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-17

Table 14. 2008 Well Pad Construction Equipment Emissions (lb/well pad) by Pollutants and by 

Equipment Type.

Loader

1

Diesel

Tier 1

200

175-300

60

0.4

0.433

293

NOx 6.860 72.60

VOC 1.021 10.80

CO 8.501 89.96

PM10 0.403 4.26

PM2.5 0.391 4.13

SO2 0.136 1.44

CO2 623 6597.37

CH4 0.016 0.16

PM_filt 0.145 1.53

PM_cond 0.246 2.60

(g/gal) N2O 0.260 0.17

Dozer

1

Diesel

Tier 1

500

300-600

60

0.4

0.371

628

NOx 6.860 181.49

VOC 1.021 27.00

CO 8.501 224.89

PM10 0.403 10.65

PM2.5 0.391 10.33

SO2 0.116 3.07

CO2 534 14120.07

CH4 0.016 0.41

PM_filt 0.145 3.82

PM_cond 0.246 6.51

(g/gal) N2O 0.260 0.36

Scraper

2

Diesel

Tier 1

700

600-750

60

0.4

0.371

1758

NOx 6.860 508.18

VOC 1.021 75.61

CO 8.501 629.70

PM10 0.403 29.83

PM2.5 0.391 28.93

SO2 0.116 8.60

CO2 534 39536.20

CH4 0.016 1.15

PM_filt 0.145 10.71

PM_cond 0.246 18.23

(g/gal) N2O 0.260 1.01

Engine Function

Number of Engines

Fuel Type

Engine Technology

Fuel Consumption 

Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Engine 2

Emission 

Factors 

(g/bhp-hr)

Emission 

Factors 

(g/bhp-hr)

Engine Technology

Rated horsepower

Load Factor

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Engine Function

Number of Engines

Fuel Type

BSFC (lb/hp-hr)

Rated horsepower

Horsepower Range

Time used (hrs)

Engine 1

Fuel Consumption 

Load Factor

BSFC (lb/hp-hr)

Equipment

Activity & Emission 

Factors

Emissions 

(lb/well pad)

Emission 

Factors 

(g/bhp-hr)

Engine 3

Fuel Consumption 
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-18

Grader

1

Diesel

Tier 1

350

300-600

60

0.4

0.371

440

NOx 6.860 127.05

VOC 1.021 18.90

CO 8.501 157.43

PM10 0.403 7.46

PM2.5 0.391 7.23

SO2 0.116 2.15

CO2 534 9884.05

CH4 0.016 0.29

PM_filt 0.145 2.68

PM_cond 0.246 4.56

(g/gal) N2O 0.260 0.25

Backhoe

1

Diesel

Tier 1

60

50-75

60

0.4

0.481

98

NOx 6.860 21.78

VOC 1.314 4.17

CO 6.425 20.40

PM10 1.076 3.42

PM2.5 1.044 3.31

SO2 0.151 0.48

CO2 692 2196.89

CH4 0.020 0.06

PM_filt 0.386 1.23

PM_cond 0.658 2.09

(g/gal) N2O 0.260 0.06

Roller

1

Diesel

Tier 1

200

175-300

60

0.4

0.371

251

NOx 6.860 72.60

VOC 1.021 10.80

CO 8.501 89.96

PM10 0.403 4.26

PM2.5 0.391 4.13

SO2 0.116 1.23

CO2 534 5648.03

CH4 0.016 0.16

PM_filt 0.145 1.53

PM_cond 0.246 2.60

(g/gal) N2O 0.260 0.14

Emission 

Factors 

(g/bhp-hr)

Emission 

Factors 

(g/bhp-hr)

Emission 

Factors 

(g/bhp-hr)

Activity & Emission 

Factors

Emissions 

(lb/well pad)

BSFC (lb/hp-hr)

Fuel Consumption 

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

Engine Function

Number of Engines

Equipment

BSFC (lb/hp-hr)

Engine 4

Fuel Consumption 

Engine 5 Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Fuel Consumption 

Engine 6 Engine Function

Number of Engines

Fuel Type
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-19

Water Truck

1

Diesel

Tier 1

210

175-300

60

0.4

0.371

264

NOx 6.860 76.23

VOC 1.021 11.34

CO 8.501 94.46

PM10 0.403 4.47

PM2.5 0.391 4.34

SO2 0.116 1.29

CO2 534 5930.43

CH4 0.016 0.17

PM_filt 0.145 1.61

PM_cond 0.246 2.73

(g/gal) N2O 0.260 0.15

Dump Truck

1

Diesel

Tier 1

330

300-600

60

0.4

0.371

414

NOx 6.860 119.79

VOC 1.021 17.82

CO 8.501 148.43

PM10 0.403 7.03

PM2.5 0.391 6.82

SO2 0.116 2.03

CO2 534 9319.25

CH4 0.016 0.27

PM_filt 0.145 2.52

PM_cond 0.246 4.30

(g/gal) N2O 0.260 0.24

Trencher

1

Diesel

Tier 1

250

175-300

60

0.4

0.371

314

NOx 6.860 90.75

VOC 1.021 13.50

CO 8.501 112.45

PM10 0.403 5.33

PM2.5 0.391 5.17

SO2 0.116 1.54

CO2 534 7060.04

CH4 0.016 0.21

PM_filt 0.145 1.91

PM_cond 0.246 3.25

(g/gal) N2O 0.260 0.18

Emission 

Factors 

(g/bhp-hr)

Emission 

Factors 

(g/bhp-hr)

Emission 

Factors 

(g/bhp-hr)

Equipment

Activity & Emission 

Factors

Emissions 

(lb/well pad)

Engine 8 Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Fuel Consumption 

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Engine 7 Engine Function

Number of Engines

Fuel Type

Engine 9 Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Fuel Consumption 

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Fuel Consumption 

BSFC (lb/hp-hr)

Load Factor
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-20

Table 15. Summary of 2008 Well Pad Construction Emissions (lb/well pad) by Pollutants for All Equipment.

Table 16. 2008 Well Pad Construction Equipment Emissions in tons per pad.

NOx 1,270

VOC 190

CO 1,568

PM10 77

PM2.5 74

SO2 22

CO2 100,292

CH4 3

PM_filt 28

PM_cond 47

N2O 3

Equipment Type Pollutant Emissions

(lb/year-well pad) 

Well Pad 

Construction 

Equipment

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Well Pad Const Equip (diesel ICE) 0.6352 0.0950 0.7838 0.0384 0.0372 0.0109 50.1462 0.0014 0.0138 0.0234 0.0013 new pads

Description Projection Well Pad Construction Equipment Emissions (tons per pad)
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-21

Table 17. Percent Change in Emission from Base Year 2008 for Well Pad Construction (aggregate factors to apply to total emissions across all 

equipment types).

Technology 

Assumption Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

Tier 1 2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-22

2008 Drilling and Completion Equipment Emissions

ASSUMPTIONS

Data provided by operators in blue text

Annual drill rig and well completion emissions (NOx, CO, VOC, SO2, and PM10) were developed 

for all drill rig and completion events that were recorded in the CDC project area during 2008. 

Emissions were developed based on Wyoming Oil and Gas Conservation Commission (WOGCC) 

data and from data provided by the operators to the WDEQ-AQD as part of the 2008 minor 

source inventory submittals. 

Well spud date and well depth data were obtained from the Wyoming Oil and Gas Commission 

(WOGCC) for all wells drilled in the project area beginning in November 2007 through 

December 2008. Well identification numbers were crossed checked between the WOGCC data 

and the WDEQ inventory files. Based on this comparison three data groups were established:

(1) Drilling and completion events that were included in the WDEQ data but not listed in the 

WOGCC database.

(2) Drilling and completion events common to both the WDEQ operator data and to WOGCC 

files.

(3) WOGCC well spud data information that was not included the WDEQ operator data.

The operator provided well completion data included in groups (1) and (2) were incorporated 

directly into the database.

For data group (3), where WOGCC spud information was available but no operator data were 

provided, average drilling rig emissions were developed from the operator data in group (2) and 

average completion emissions were developed from the operator data in groups (1) and (2). 

Specifically, average drill rig emissions and average well depth were determined for the wells in 

group (2). The drill rig emissions for wells in group (3) were determined by scaling the average 

emissions from the group (2) wells by the ratio of the average well depth of group (2) wells by 

the well depth of the group (3) well. [Note group (1) drilling data did not include WOGCC well 

depth so it was not used for the group (3) averages] Average completion emissions for the 

group (1) and (2) wells were applied for all group (3) wells. Where information was available

that indicated that a drilling event had not completed during 2008 then completion emissions 

were not applied to these wells. For these drilling events, the drilling emissions were scaled 

based on the percent completed during 2008. 
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-23

Table 18. Summary of 2008 Drilling and Completion Emissions (tons/year) by Pollutant.

Diesel Exhuast HC conversions (source: EPA NONROAD model documentation)

VOC/THC 1.053

NMHC/THC 0.984

CH4/THC 0.016

CH4/VOC 0.015

Diesel Exhuast PM2.5 conversions (source: EPA NONROAD model documentation)

PM2.5/PM10 97%

Fuel Consumption Drilling Completion

fuel sulfur 355 355 ppmw

fuel consumption 28,022,106 22,336,171 gallons

CO2/fuel consumption 10.21 10.21 kgCO2/gallon (source Climate Registry GHG Protocol)

diesel density 7.1 7.1 pounds/gallon

conversion 2.204 2.204 pounds/kilogram

CO2/fuel consumption 3.169 3.169 lbCO2/lbfuel

CO2 emissions 44,407 35,396 tons

N2O emission factor 0.260 0.260 grams/gallons

Molecular weight of S 32 32 g/mol

Molecular weight of S02 64 64 g/mol

Per NSPS Guidance, 37% of fine particles assumed to be filterable and all filterable are assigned to EC

Per NSPS Guidance, 63% of fine particles assumed to be filterable and all filterable are assigned toSOA

Venting GHG Conversions

VOC Fraction (weight) 15%

CO2 Fraction (weight) 6%

CH4 Fraction (weight) 69%

CH4/VOC 471%

CO2/VOC 42%

Emissions 

(tons/year) Drilling Completion (diesel ICE)

Completion 

(venting)

NOx 1166.3 168.8 0.0

VOC 105.9 0.0 129.8

CO 503.8 131.7 0.0

PM10 55.8 12.4 0.0

PM2.5 54.1 12.0 0.0

SO2 70.6 56.3 0.0

CO2 44,406.8 35,396.3 53.9

CH4 1.6 0.0 611.0

PM_filt 20.0 4.4 0.0

PM_cond 34.1 7.6 0.0

N2O 8.0 6.4 0.0

assumed all VOC emissions from venting
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-24

Table 19. Total 2008 Drilling and Completion Equipment Emissions in tons per year.

Table 20. Percent Change in Emission from Base Year 2008 for Drilling and Completion 

(aggregate factors to apply to total emissions across all equipment types).

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Drilling Equip (diesel ICE) 1,166.29 105.91 503.84 55.75 54.08 70.63 44,406.83 1.61 20.01 34.07 8.03

totals for year with 

spuds

Completion Equipment (diesel 

ICE) 168.79 0 131.70 12.37 11.99 56.30 35,396.29 0 4.44 7.56 6.40

totals for year with 

spuds

Initial Completion Venting 0 129.77 0 0 0 0 53.91 610.97 0 0 0

totals for year with 

spuds

Description Projection Drill Rig Emissions - total 2008 tons per year Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

unused values - no drilling activity post-2008 
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-25

2008 Well Pad and Access Road Construction Traffic Emissions

ASSUMPTIONS

Data provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2008 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

CONSTRUCTION TRAFFIC.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-26

Table 21. Summary of Traffic Activity Data Associated with Well Pad and Access Road 

Construction Phase.

Table 22. 2008 Exhaust Emissions (lb/pad) Associated with Well Pad and Access Road 

Construction Traffic by Vehicle Type.

Table 23. Summary of 2008 Fugitive Dust Emissions (tons/well pad) Associated with Well Pad 

and Access Road Construction Traffic.

Light Truck 20 20 14

Heavy Truck 20 20 21

Number of 

Round Trips 

Per Well

Equipment Type Mean Vehicle 

Speed (mph)

Round Trip OffRoad Trip Distance 

(miles)

NOx 2.67 1.649

SO2 0.02 0.015

CO 19.44 12.002

CO2 677.28 418

VOC 1.57 0.968

PM10 0.09 0.056

PM2.5 0.09 0.053

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.057

N2O 0.05 0.030

NOx 21.75 20.140

SO2 0.08 0.076

CO 15.96 14.782

CO2 2612.85 2419.310

VOC 1.93 1.789

PM10 1.30 1.206

PM2.5 1.26 1.169

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.084

N2O 0.04 0.035

Vehicle Type Pollutant 2008 Emission 

Factors (g/mile)

Base year 

Emissions 

(lb/well pad)

Heavy-Duty Truck 

Light-Duty Truck

Travel to well Light truck 7,000 20 14 14 20 280 0.20 0.03 0.02 0.00

Travel to well Heavy Truck 70,000 20 21 21 20 420 0.20 0.04 0.02 0.00

Total 0.07 0.01

PM2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well)

Activity Vehicle Type Av. Vehicle Weight (lb) Mean vehicle speed 

(mph)

# of Visits per 

Year 

Total # of Round 

Trips

Round Trip 

Distance (mi)

Total Miles 

Traveled

PM10
PROJECT EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-27

Table 24. 2008 Exhaust and Fugitive Dust Emissions Associated with Well Pad and Access Road Construction Traffic in tons per 

well pad.

Table 25. Percent Change in Emission from Base Year 2008 due to Fleet Turnover for Well Pad and Access Road Construction 

Traffic.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Construction Traffic, Road 

and Well pad (LD) 0.0008 0.0005 0.0060 2.79E-05 2.65E-05 7.30E-06 0.2090 2.86E-05 0 0 1.50E-05 new pads 0.0277 0.0028

Construction Traffic, Road 

and Well pad (HD) 0.0101 0.0009 0.0074 0.0006 0.0006 3.80E-05 1.2097 4.18E-05 0 0 1.73E-05 new pads 0.0416 0.0041

Description Total Road and Well Pad Construction Traffic Emissions (tons per well pad) Fugitive Road Projection

NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 -6% -39% -6% 0% -6% -4% -4% 0% 0% -8% -6% -7% -2% -6% 0% -4% -7% -7% 0% 0% 0% -5%

2010 -10% -46% -10% -1% -10% -9% -9% 0% 0% -12% -12% -16% -47% -9% 0% -6% -14% -14% 0% 0% 4% -10%

2011

-15% -50% -13% -2% -15% -16% -16% 0% 0% -15% -19% -25% -75% -14% 0% -13% -24% -24% 0% 0% 13% -16%

2012 -21% -55% -16% -3% -21% -22% -22% 0% 0% -19% -25% -33% -75% -19% 0% -21% -33% -33% 0% 0% 20% -21%

2013 -26% -56% -20% -4% -26% -27% -28% 0% 0% -22% -32% -41% -76% -24% 0% -28% -41% -41% 0% 0% 24% -27%

2014 -32% -57% -24% -5% -32% -33% -33% 0% 0% -25% -37% -48% -76% -28% 0% -34% -49% -49% 0% 0% 28% -32%

2015 -37% -57% -27% -7% -36% -38% -38% 0% 0% -28% -42% -54% -76% -32% 0% -40% -56% -56% 0% 0% 30% -36%

2016 -42% -58% -30% -9% -41% -42% -43% 0% 0% -31% -47% -60% -77% -37% 0% -46% -63% -63% 0% 0% 31% -40%

2017 -46% -59% -33% -10% -45% -46% -47% 0% 0% -34% -51% -65% -77% -40% 0% -51% -68% -68% 0% 0% 32% -44%

2018 -50% -60% -35% -12% -49% -50% -50% 0% 0% -36% -55% -69% -77% -43% 0% -56% -73% -73% 0% 0% 32% -47%

2019 -53% -60% -37% -13% -52% -53% -53% 0% 0% -38% -58% -73% -77% -45% 0% -60% -77% -77% 0% 0% 33% -50%

2020 -57% -61% -38% -14% -55% -55% -56% 0% 0% -39% -61% -76% -77% -47% 0% -64% -81% -81% 0% 0% 34% -53%

2021 -59% -62% -40% -16% -58% -57% -58% 0% 0% -41% -64% -78% -77% -49% 0% -67% -83% -83% 0% 0% 34% -55%

2022 -66% -63% -44% -19% -64% -63% -64% 0% 0% -43% -71% -84% -78% -53% 0% -74% -90% -90% 0% 0% 34% -61%

2023 -62% -62% -41% -17% -60% -59% -60% 0% 0% -42% -67% -81% -78% -51% 0% -70% -86% -86% 0% 0% 34% -58%

2024 -64% -63% -43% -18% -63% -61% -62% 0% 0% -43% -69% -82% -78% -52% 0% -72% -88% -88% 0% 0% 34% -60%

2025 -68% -64% -45% -19% -67% -64% -65% 0% 0% -44% -72% -85% -78% -54% 0% -76% -91% -91% 0% 0% 34% -63%

2026 -70% -64% -46% -20% -69% -66% -66% 0% 0% -43% -74% -86% -78% -56% 0% -79% -92% -92% 0% 0% 36% -65%

2027 -71% -64% -47% -21% -71% -67% -68% 0% 0% -43% -75% -87% -78% -56% 0% -80% -93% -93% 0% 0% 36% -66%

2028 -72% -64% -48% -21% -72% -68% -69% 0% 0% -44% -76% -88% -78% -57% 0% -81% -94% -94% 0% 0% 36% -67%

2029 -73% -65% -48% -22% -73% -69% -70% 0% 0% -45% -78% -88% -78% -58% 0% -83% -94% -94% 0% 0% 35% -68%

2030 -74% -65% -49% -22% -75% -70% -70% 0% 0% -45% -78% -89% -78% -58% 0% -84% -95% -95% 0% 0% 35% -69%

2031 -75% -65% -50% -23% -76% -70% -71% 0% 0% -47% -79% -89% -78% -59% 0% -85% -95% -95% 0% 0% 34% -70%

2032 -76% -65% -50% -23% -76% -71% -72% 0% 0% -47% -80% -89% -78% -60% 0% -85% -95% -95% 0% 0% 34% -70%

2033 -77% -66% -51% -24% -77% -72% -72% 0% 0% -48% -80% -89% -78% -61% 0% -86% -95% -95% 0% 0% 33% -71%

2034 -77% -66% -52% -24% -78% -72% -73% 0% 0% -48% -81% -90% -78% -61% 0% -86% -96% -96% 0% 0% 33% -71%

2035 -78% -66% -52% -24% -78% -73% -73% 0% 0% -48% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 33% -72%

2036 -78% -66% -53% -24% -79% -73% -74% 0% 0% -49% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 32% -72%

2037 -78% -66% -53% -25% -79% -73% -74% 0% 0% -49% -81% -90% -78% -63% -1% -87% -96% -96% 0% 0% 32% -72%

Year

Light-Duty Truck Heavy-Duty Truck 
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-28

2008 Drilling Construction Traffic Emissions

ASSUMPTIONS

Data Provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2008 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

DRILLING TRAFFIC

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-29

Table 26. Summary of Traffic Activity Data Associated with Drilling Phase.

Table 27. 2008 Exhaust Emissions (lb/spud) Associated with Drilling Traffic by Vehicle Type.

Table 28. Summary of 2008 Fugitive Dust Emissions (tons/spud) Associated with Drilling Traffic.

Table 29. 2008 Exhaust and Fugitive Dust Emissions Associated with Drilling Traffic in tons per 

spud.

Light Truck 20 20 98

Heavy Truck 20 20 224

Number of 

Round Trips 

Per Well

Equipment Type Mean Vehicle 

Speed (mph)

Round Trip Off-Road 

Trip Distance (miles)

NOx 2.67 11.546

SO2 0.02 0.102

CO 19.44 84.017

CO2 677.28 2927

VOC 1.57 6.777

PM10 0.09 0.390

PM2.5 0.09 0.370

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.401

N2O 0.05 0.209

NOx 21.75 214.823

SO2 0.08 0.810

CO 15.96 157.678

CO2 2612.85 25805.971

VOC 1.93 19.086

PM10 1.30 12.868

PM2.5 1.26 12.474

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.893

N2O 0.04 0.369

Vehicle Type Pollutant 2008 Emission 

Factors (g/mile)

Base year Emissions 

(lb/spud)

Light-Duty 

Truck

Heavy-Duty 

Truck 

Travel to well Light truck 7,000 20 98 98 20 1960 0.20 0.1940 0.02 0.0193

Travel to well Heavy Truck 70,000 20 224 224 20 4480 0.20 0.4435 0.02 0.0440

Total 0.40 0.64 0.04 0.06

Total # of 

Round 

Trips

Round 

Trip 

Distance 

(mi)

Total 

Miles 

Traveled

PM10

Activity Vehicle 

Type

Av. Vehicle 

Weight (lb)

Mean vehicle 

speed (mph)

# of Visits 

per Year 

PM2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spudl)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spud)

Projection

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Drilling Traffic (LD) 0.0058 0.0034 0.0420 0.0002 0.0002 5.11E-05 1.4633 0.0002 0 0 0.0001 total spuds 0.1940 0.0193

Drilling Traffic (HD) 0.1074 0.0095 0.0788 0.0064 0.0062 0.0004 12.9030 0.0004 0 0 0.0002 total spuds 0.4435 0.0440

Description Total Drill Traffic Emissions (tons per spud) Fugitive Road Dust 
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-30

Table 30. Percent Change in Emission from Base Year 2008 Due to Fleet Turnover for Drilling Traffic.

NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 -6% -39% -6% 0% -6% -4% -4% 0% 0% -8% -6% -7% -2% -6% 0% -4% -7% -7% 0% 0% 0% -5%

2010 -10% -46% -10% -1% -10% -9% -9% 0% 0% -12% -12% -16% -47% -9% 0% -6% -14% -14% 0% 0% 4% -10%

2011 -15% -50% -13% -2% -15% -16% -16% 0% 0% -15% -19% -25% -75% -14% 0% -13% -24% -24% 0% 0% 13% -16%

2012 -21% -55% -16% -3% -21% -22% -22% 0% 0% -19% -25% -33% -75% -19% 0% -21% -33% -33% 0% 0% 20% -21%

2013 -26% -56% -20% -4% -26% -27% -28% 0% 0% -22% -32% -41% -76% -24% 0% -28% -41% -41% 0% 0% 24% -27%

2014 -32% -57% -24% -5% -32% -33% -33% 0% 0% -25% -37% -48% -76% -28% 0% -34% -49% -49% 0% 0% 28% -32%

2015 -37% -57% -27% -7% -36% -38% -38% 0% 0% -28% -42% -54% -76% -32% 0% -40% -56% -56% 0% 0% 30% -36%

2016 -42% -58% -30% -9% -41% -42% -43% 0% 0% -31% -47% -60% -77% -37% 0% -46% -63% -63% 0% 0% 31% -40%

2017 -46% -59% -33% -10% -45% -46% -47% 0% 0% -34% -51% -65% -77% -40% 0% -51% -68% -68% 0% 0% 32% -44%

2018 -50% -60% -35% -12% -49% -50% -50% 0% 0% -36% -55% -69% -77% -43% 0% -56% -73% -73% 0% 0% 32% -47%

2019 -53% -60% -37% -13% -52% -53% -53% 0% 0% -38% -58% -73% -77% -45% 0% -60% -77% -77% 0% 0% 33% -50%

2020 -57% -61% -38% -14% -55% -55% -56% 0% 0% -39% -61% -76% -77% -47% 0% -64% -81% -81% 0% 0% 34% -53%

2021 -59% -62% -40% -16% -58% -57% -58% 0% 0% -41% -64% -78% -77% -49% 0% -67% -83% -83% 0% 0% 34% -55%

2022 -66% -63% -44% -19% -64% -63% -64% 0% 0% -43% -71% -84% -78% -53% 0% -74% -90% -90% 0% 0% 34% -61%

2023 -62% -62% -41% -17% -60% -59% -60% 0% 0% -42% -67% -81% -78% -51% 0% -70% -86% -86% 0% 0% 34% -58%

2024 -64% -63% -43% -18% -63% -61% -62% 0% 0% -43% -69% -82% -78% -52% 0% -72% -88% -88% 0% 0% 34% -60%

2025 -68% -64% -45% -19% -67% -64% -65% 0% 0% -44% -72% -85% -78% -54% 0% -76% -91% -91% 0% 0% 34% -63%

2026 -70% -64% -46% -20% -69% -66% -66% 0% 0% -43% -74% -86% -78% -56% 0% -79% -92% -92% 0% 0% 36% -65%

2027 -71% -64% -47% -21% -71% -67% -68% 0% 0% -43% -75% -87% -78% -56% 0% -80% -93% -93% 0% 0% 36% -66%

2028 -72% -64% -48% -21% -72% -68% -69% 0% 0% -44% -76% -88% -78% -57% 0% -81% -94% -94% 0% 0% 36% -67%

2029 -73% -65% -48% -22% -73% -69% -70% 0% 0% -45% -78% -88% -78% -58% 0% -83% -94% -94% 0% 0% 35% -68%

2030 -74% -65% -49% -22% -75% -70% -70% 0% 0% -45% -78% -89% -78% -58% 0% -84% -95% -95% 0% 0% 35% -69%

2031 -75% -65% -50% -23% -76% -70% -71% 0% 0% -47% -79% -89% -78% -59% 0% -85% -95% -95% 0% 0% 34% -70%

2032 -76% -65% -50% -23% -76% -71% -72% 0% 0% -47% -80% -89% -78% -60% 0% -85% -95% -95% 0% 0% 34% -70%

2033 -77% -66% -51% -24% -77% -72% -72% 0% 0% -48% -80% -89% -78% -61% 0% -86% -95% -95% 0% 0% 33% -71%

2034 -77% -66% -52% -24% -78% -72% -73% 0% 0% -48% -81% -90% -78% -61% 0% -86% -96% -96% 0% 0% 33% -71%

2035 -78% -66% -52% -24% -78% -73% -73% 0% 0% -48% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 33% -72%

2036 -78% -66% -53% -24% -79% -73% -74% 0% 0% -49% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 32% -72%

2037 -78% -66% -53% -25% -79% -73% -74% 0% 0% -49% -81% -90% -78% -63% -1% -87% -96% -96% 0% 0% 32% -72%

Heavy-Duty Truck 

Year

Light-Duty Truck
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-31

2008 Well Completion Traffic Emissions

ASSUMPTIONS

Data Provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2008 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

WELL COMPLETION TRAFFIC

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
EXISTING WELLS EMISSIONS INVENTORY

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Table 31. Summary of Traffic Activity Data Associated with Well Completion Phase.

Table 32. 2008 Exhaust Emissions (lb/spud) Associated with Completion Traffic by Vehicle 

Type.

Light Truck 20 20 66

Heavy Truck 20 20 138

Number of 

Round Trips 

Per Well

Equipment Type Mean Vehicle 

Speed (mph)

Round Trip OffRoad Trip 

Distance (miles)

NOx 2.67 7.776

SO2 0.02 0.069

CO 19.44 56.583

CO2 677.28 1971

VOC 1.57 4.564

PM10 0.09 0.263

PM2.5 0.09 0.249

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.270

N2O 0.05 0.141

NOx 21.75 132.347

SO2 0.08 0.499

CO 15.96 97.141

CO2 2612.85 15898.322

VOC 1.93 11.759

PM10 1.30 7.927

PM2.5 1.26 7.685

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.550

N2O 0.04 0.227

Vehicle Type Pollutant

2008 Emission 

Factors 

(g/mile)

Base year 

Emissions 

(lb/spud)

Light-Duty Truck

Heavy-Duty 

Truck 
EXISTING WELLS EMISSIONS INVENTORY

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Table 33. Summary of 2008 Fugitive Dust Emissions (tons/spud) Associated with Well Completion Traffic.

Table 34. 2008 Exhaust and Fugitive Dust Emissions Associated with Well Completion Traffic in tons per spud.

Table 35. Percent Change in Emission from Base Year 2008 Due to Fleet Turnover for Well Completion Traffic.

Travel to well Light truck 7,000 20 66 66 20 1320 0.20 0.13 0.02 0.01

Travel to well Heavy Truck 70,000 20 138 138 20 2760 0.20 0.27 0.02 0.03

Total 0.40 0.40 0.04 0.04

PM2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spud)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spud)

Operators

Total # of 

Round 

Trips

Round 

Trip 

Distance 

(mi)

Total 

Miles 

Traveled

PM10

Units Activity Vehicle Type Av. Vehicle 

Weight (lb)

Mean 

vehicle 

speed 

(mph)

# of Visits 

per Year 

Projection

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Completion Traffic (LD) 0.0039 0.0023 0.0283 0.0001 0.0001 3.44E-05 0.9855 0.0001 0 0 7.05E-05 total spuds 0.1307 0.0130

Completion Traffic (HD) 0.0662 0.0059 0.0486 0.0040 0.0038 0.0002 7.9492 0.0003 0 0 0.0001 total spuds 0.2732 0.0271

Description Total Completion Traffic Emissions (tons per spud) Fugitive Road Dust 

NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 -6% -39% -6% 0% -6% -4% -4% 0% 0% -8% -6% -7% -2% -6% 0% -4% -7% -7% 0% 0% 0% -5%

2010 -10% -46% -10% -1% -10% -9% -9% 0% 0% -12% -12% -16% -47% -9% 0% -6% -14% -14% 0% 0% 4% -10%

2011 -15% -50% -13% -2% -15% -16% -16% 0% 0% -15% -19% -25% -75% -14% 0% -13% -24% -24% 0% 0% 13% -16%

2012 -21% -55% -16% -3% -21% -22% -22% 0% 0% -19% -25% -33% -75% -19% 0% -21% -33% -33% 0% 0% 20% -21%

2013 -26% -56% -20% -4% -26% -27% -28% 0% 0% -22% -32% -41% -76% -24% 0% -28% -41% -41% 0% 0% 24% -27%

2014 -32% -57% -24% -5% -32% -33% -33% 0% 0% -25% -37% -48% -76% -28% 0% -34% -49% -49% 0% 0% 28% -32%

2015 -37% -57% -27% -7% -36% -38% -38% 0% 0% -28% -42% -54% -76% -32% 0% -40% -56% -56% 0% 0% 30% -36%

2016 -42% -58% -30% -9% -41% -42% -43% 0% 0% -31% -47% -60% -77% -37% 0% -46% -63% -63% 0% 0% 31% -40%

2017 -46% -59% -33% -10% -45% -46% -47% 0% 0% -34% -51% -65% -77% -40% 0% -51% -68% -68% 0% 0% 32% -44%

2018 -50% -60% -35% -12% -49% -50% -50% 0% 0% -36% -55% -69% -77% -43% 0% -56% -73% -73% 0% 0% 32% -47%

2019 -53% -60% -37% -13% -52% -53% -53% 0% 0% -38% -58% -73% -77% -45% 0% -60% -77% -77% 0% 0% 33% -50%

2020 -57% -61% -38% -14% -55% -55% -56% 0% 0% -39% -61% -76% -77% -47% 0% -64% -81% -81% 0% 0% 34% -53%

2021 -59% -62% -40% -16% -58% -57% -58% 0% 0% -41% -64% -78% -77% -49% 0% -67% -83% -83% 0% 0% 34% -55%

2022 -66% -63% -44% -19% -64% -63% -64% 0% 0% -43% -71% -84% -78% -53% 0% -74% -90% -90% 0% 0% 34% -61%

2023 -62% -62% -41% -17% -60% -59% -60% 0% 0% -42% -67% -81% -78% -51% 0% -70% -86% -86% 0% 0% 34% -58%

2024 -64% -63% -43% -18% -63% -61% -62% 0% 0% -43% -69% -82% -78% -52% 0% -72% -88% -88% 0% 0% 34% -60%

2025 -68% -64% -45% -19% -67% -64% -65% 0% 0% -44% -72% -85% -78% -54% 0% -76% -91% -91% 0% 0% 34% -63%

2026 -70% -64% -46% -20% -69% -66% -66% 0% 0% -43% -74% -86% -78% -56% 0% -79% -92% -92% 0% 0% 36% -65%

2027 -71% -64% -47% -21% -71% -67% -68% 0% 0% -43% -75% -87% -78% -56% 0% -80% -93% -93% 0% 0% 36% -66%

2028 -72% -64% -48% -21% -72% -68% -69% 0% 0% -44% -76% -88% -78% -57% 0% -81% -94% -94% 0% 0% 36% -67%

2029 -73% -65% -48% -22% -73% -69% -70% 0% 0% -45% -78% -88% -78% -58% 0% -83% -94% -94% 0% 0% 35% -68%

2030 -74% -65% -49% -22% -75% -70% -70% 0% 0% -45% -78% -89% -78% -58% 0% -84% -95% -95% 0% 0% 35% -69%

2031 -75% -65% -50% -23% -76% -70% -71% 0% 0% -47% -79% -89% -78% -59% 0% -85% -95% -95% 0% 0% 34% -70%

2032 -76% -65% -50% -23% -76% -71% -72% 0% 0% -47% -80% -89% -78% -60% 0% -85% -95% -95% 0% 0% 34% -70%

2033 -77% -66% -51% -24% -77% -72% -72% 0% 0% -48% -80% -89% -78% -61% 0% -86% -95% -95% 0% 0% 33% -71%

2034 -77% -66% -52% -24% -78% -72% -73% 0% 0% -48% -81% -90% -78% -61% 0% -86% -96% -96% 0% 0% 33% -71%

2035 -78% -66% -52% -24% -78% -73% -73% 0% 0% -48% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 33% -72%

2036 -78% -66% -53% -24% -79% -73% -74% 0% 0% -49% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 32% -72%

2037 -78% -66% -53% -25% -79% -73% -74% 0% 0% -49% -81% -90% -78% -63% -1% -87% -96% -96% 0% 0% 32% -72%

Year Light-Duty Truck Heavy-Duty Truck 
EXISTING WELLS EMISSIONS INVENTORY

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2008 Construction Fugitive Dust Emissions

ASSUMPTIONS

Watering control efficiency assumed to be 50%

Information from operators:

Data Provided by operator in blue text

Equations

Emissions equations from AP-42 Table 11.9-1 for Bulldozing Overburden emissions, Western 

Surface Coal Mining

For total suspended particles (TSP) ≤ 30 microns:

Emissions (TSP lbs/hr) =[ 5.7 s^1.2 / M ^1.3 ] * Control Efficiency

For PM ≤ 15 microns:

Emissions (PM15 lbs/hr) =[ 1.0 s^1.5 / M ^1.4 ] * Control Efficiency

Emissions (PM10 lbs/hr) = PM15 * 0.75

Emissions (PM2.5 lbs/hr) = TSP * 0.105

See variables definition in following table:

Table 36. Parameters Used in Emission Equations.

Table 37. Summary of 2008 Well Pad and Pipeline Construction Equipment Utilization Data.

Description Parameter Reference

Watering control efficiency 50%

M=soil moisture content 7.9 (AP-42 Table 11.9-3)

s=Soil silt content 6.9 (AP-42 Table 11.9-3)

PM10 multiplier 0.75 (AP-42 Table 11.9-1)

PM2.5 multiplier 0.105 (AP-42 Table 11.9-1)

Control of Open Fugitive Dust Sources, Section 

5.3.1 Watering of Unpaved Surfaces (1988). EPA

Time Used 

Per Pad

 (hours)

Well Pad-Access Road Construction Loader 1 60

Well Pad-Access Road Construction Dozer 1 60

Well Pad-Access Road Construction Scraper 2 60

Well Pad-Access Road Construction Grader 1 60

Well Pad-Access Road Construction Backhoe 1 60

Well Pad-Access Road Construction Roller 1 60

Well Pad-Access Road Construction Water Truck 1 60

Well Pad-Access Road Construction Dump Truck 1 60

Well Pad-Access Road Construction Trencher 1 60

* assumed hours of use consistent with activity estimates used in equipment exhaust emission estimates

Phase Equipment Tye # Units
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • February 2016 L-35

Table 38. Summary of 2008 Fugitive Dust Emissions (tons/well pad) from Well Pad and Access 

Road Construction Equipment.

Table 39. 2008 Construction Fugitive Dust Emissions in tons per well pad.

Table 40. Percent Change in Emission from Base Year 2008 for Construction Fugitive Dust.

Phase

Equipment 

Type TSP PM10 PM2.5 PM15

Well Pad-Access Road Construction Loader 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Dozer 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Scraper 0.1182 0.0226 0.0124 0.0301

Well Pad-Access Road Construction Grader 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Backhoe 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Roller 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Water Truck 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Dump Truck 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Trencher 0.0591 0.0113 0.0062 0.0151

Total 0.5911 0.1129 0.0621 0.1506

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Construction Dust, Fugitive 0 0 0 0.1129 0.0621 0 0 0 0 0 0 new pads

Description Projection Construction Fugitive Dust Emissions (tons per well pad)

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-36

2008 Construction Wind Erosion Emissions

ASSUMPTIONS

Emissions (

tons

yr ) = 

k* Erosion Potential (g/m2/year) * Disturbed Area (m2) * (#Disturbances/year)

453.6 (g/lb) *2000 (lbs/ton)

Table 41. 2008 Construction Dust Wind Erosion Emissions in tons per well pad.

Data obtained from operators in blue text

Disturbed Area Per Well:

Disturbed Area Per Well: 235224 ft2 21853.05 m

2

1 Acre 43,560 square feet

* AP-42 methodology described to the right was implemented in a computer program with hourly wind speed data

* 2007, 2008, and 2009 Wind Speed data from the Wamsutter Station were used as inputs

* Of all years evaluated, 2007 showed the greatest per pad wind erosion emissions:

Friction Velocity U* = 0.053 U10* (AP-42 Section 13.2.5.3 Equation 4)

Erosion Potential P (g/m2-time) = 58(U*-Ut*)2 + 25(U*-Ut*) for U*>Ut*; P=0 otherwise (AP-42 Section 13.2.5.3 Equation 3)

k is a particle size multiplier that depends on the aerodynamic size of the particle (from AP-42 Section 13.2.5.3). 

k = 0.5 for PM10

k = 0.075 for PM2.5

1.02 m/s = Threshold friction velocity for well pads (AP-42 Table 13.2.5-2 Overburden, Western Surface Coal Mine)

1.33 m/s = Threshold friction velocity for roads (AP-42 Table 13.2.5-2 Roadbed Material)

0.5 = Particle size multiplier for PM10

0.075 = Particle size multiplier for PM2.5

1 squ mile = 640 acres

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Construction Dust, Wind Erosion 0 0 0 3.06E-01 4.59E-02 0 0 0 0 0 0 new pads

Description Projection Construction Dust Wind Erosion Emissions (tons/well pad)
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-37

Table 42. Percent Change in Emission from Base Year 2008 for Construction Dust Wind 

Erosion.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-38

2008 Workover Equipment Emissions

ASSUMPTIONS

Activity data obtained from operators in blue text

Assumptions:

* Emission factors from EPA Federal Diesel Engine Standards 

http://www.epa.gov/otaq/standards/n

onroad/nonroadci.htm

* Crankcase Emission factors are 2% of HC Exhaust Emission Factor for Tier II and earlier per 

* EPA NONROAD Modeling Guidance p. 23 (EPA, 2004; EPA420-P-04-009). 

* VOC/THC= 1.053 Conversion for HC->VOC for diesel engines (EPA, 2005; EPA420-R-05-0159, p. 5)

*

37% of fine particles assumed to be filterable and all filterable are assigned to EC (Source: AQTSD for Hell’s Gulch and 

Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

*

63% of fine particles assumed to be filterable and all filterable are assigned to SOA (Source: AQTSD for Hell’s Gulch and 

Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

EPA NONROAD model Fully Deteriorated Tier 0 Emission Factors

N2O Emission factors (g/gallons) from The Climate Registry, General Reporting Protocol v1.1, Table 13.6

Equations:

Emissions (tons/year-well) = Emission factor (g/hp-hr) * Horsepower * Time Used (hours) * Load

453.6 (g/lb) * 2000 (lbs/ton)

PM2.5/PM10 = 97% EPA (2004) NONROAD

VOC/HC 1.053 EPA NONROAD HC Conversions

NMHC/THC 98.40% EPA NONROAD HC Conversions

SO2 Emission Factor Calculation Information 

2008 Fuel Sulfur content 0.0355 sulfur fuel weight percent From NMIM

soxcnv Tiers I-III 0.02247 grams PM sulfur/grams fuel sulfur consumed

soxcnv Tier IV 0.3

grams PM sulfate/grams PM sulfur 7

soxbas 0.33

Density of Diesel Fuel 7.09 lb/gallons

Molecular weight of S 32 g/mol

Molecular weight of S02 64 g/mol

453.6 g/lb
EXISTING WELLS EMISSIONS INVENTORY

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Table 43. 2008 Workover Rig Equipment Emissions (lb/well) by Pollutants and by Equipment 

Type.

Rig

1

Diesel

Tier 0

475

300-600

36

0.07

0.3

0.367

18

NOx 8.581 6.47

VOC 0.764 0.58

CO 3.200 2.41

PM10 0.512 0.39

PM2.5 0.497 0.37

SO2 0.115 0.09

CO2 529 398.64

CH4 0.012 0.01

PM_filt 0.184 0.14

PM_cond 0.313 0.24

N2O 0.260 0.01

Snubbing unit

1

Diesel

Tier 0

475

300-600

36

0.07

0.3

0.367

18

NOx 8.581 6.47

VOC 0.764 0.58

CO 3.200 2.41

PM10 0.512 0.39

PM2.5 0.497 0.37

SO2 0.115 0.09

CO2 529 398.64

CH4 0.012 0.01

PM_filt 0.184 0.14

PM_cond 0.313 0.24

N2O 0.260 0.01

Light plant

1

Diesel

Tier 0

45

25-50

0.07

36

0.7

0.408

4

NOx 7.066 1.18

VOC 2.022 0.34

CO 5.925 0.99

PM10 1.093 0.18

PM2.5 1.060 0.18

SO2 0.127 0.02

CO2 584 97.37

CH4 0.031 0.01

PM_filt 0.392 0.07

PM_cond 0.668 0.11

N2O 0.260 0.00

Emissions 

(lb/well)

Engine Function

Load Factor

Fuel Type

Engine Technology

Engine Technology

Rated horsepower

Horsepower Range

Rated horsepower

Engine 1

Fuel Consumption (Gallons)

Emission 

Factors 

(g/bhp-hr)

BSFC (lb/hp-hr)

Equipment

Activity & 

Emission 

Number of Engines

Fuel Type

BSFC (lb/hp-hr)

Horsepower Range

Time used (hrs)

Well workeover requirement (Yrs)

Load Factor

BSFC (lb/hp-hr)

Horsepower Range

Well workeover requirement (Yrs)

Time used (hrs)

Load Factor

Engine Function

Number of Engines

Fuel Type

Engine Technology

Engine 2

Fuel Consumption (Gallons)

Emission 

Factors 

(g/bhp-hr)

Time used (hrs)

Well workover frequency (events/yr)

Engine 3

Engine Function

Number of Engines

Fuel Consumption (Gallons)

Emission 

Factors 

(g/bhp-hr)

Rated horsepower
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-40

Table 44. Summary of 2008 Workover Rig Emissions (lb/well) by Pollutants for All Equipment.

Table 45. 2008 Workover Rig Equipment Emissions in tons per well.

Table 46. Percent Change in Emission from Base Year 2008 for Workover Rig Equipment

(aggregate factors to apply to total emissions across all equipment types).

NOx 14

VOC 1

CO 6

PM10 1

PM2.5 1

SO2 0

CO2 895

CH4 0

PM_filt 0

PM_cond 1

N2O 0

Equipment 

Type Pollutant

Emissions 

(lb/year-well) 

Workover Rig 

Equipment NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Workover Equipment (diesel ICE) 0.0071 0.0007 0.0029 0.0005 0.0005 9.73E-05 0.4473 1.13E-05 0.0002 0.0003 1.14E-05 active well counts

Description Projection Workover Rig Emissions (tons per well)

Technology 

Assumption Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

Tier 0 2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 0 2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-41

2008 Workover Traffic Emissions

ASSUMPTIONS

Data Provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2008 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

WORKOVER TRAFFIC.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
EXISTING WELLS EMISSIONS INVENTORY

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Table 47. Summary of Traffic Activity Data Associated with Well Workover Phase.

Table 48. 2008 Exhaust Emissions (lb/well) Associated with Workover Traffic by Vehicle Type.

Table 49. Summary of 2008 Fugitive Dust Emissions (tons/well) Associated with Workover 

Traffic.

Light Truck 20 20 6 0.07

Heavy Truck 20 20 8 0.07

Well workover 

frequency 

(events/yr)

Equipment 

Type

Mean Vehicle 

Speed (mph)

Round Trip OffRoad Trip 

Distance 

Number of 

Round Trips 

Per Well

NOx 2.67 0.047

SO2 0.02 0.000

CO 19.44 0.343

CO2 677.28 11.945

VOC 1.57 0.028

PM10 0.09 0.002

PM2.5 0.09 0.002

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.002

N2O 0.05 0.001

NOx 21.75 0.511

SO2 0.08 0.002

CO 15.96 0.375

CO2 2612.85 61.443

VOC 1.93 0.045

PM10 1.30 0.031

PM2.5 1.26 0.030

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.002

N2O 0.04 0.001

Heavy-Duty 

Truck 

Light-Duty Truck

Vehicle Type Pollutant

 2008 Emission 

Factors 

(g/mile)

Base year 

Emissions 

(lb/well)

Travel to well Light truck 7,000 20 6 0.4 20 8 0.20 0.00 0.02 0.00

Travel to well Heavy Truck 70,000 20 8 1 20 10.67 0.20 0.00 0.02 0.00

Total 0.40 0.00 0.04 0.00

PM2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well)

Em. Factor 

(lb/VMT) Emissions (tpy/well) Activity Vehicle Type Av. Vehicle 

Weight (lb)

Mean vehicle 

speed (mph) # of Visits per Year 

Total # of 

Round 

Trips

Round Trip 

Distance 

(mi)

Total 

Miles 

Traveled

PM10
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-43

Table 50. 2008 Exhaust and Fugitive Dust Emissions Associated with Workover Rigs Traffic in tons per well.

Table 51. Percent Change in Emission from Base Year 2008 Due to Fleet Turnover for Workover Rigs Traffic.

Projection

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

WorkoverTraffic (LD) 2.36E-05 1.38E-05 0.0002 7.96E-07 7.56E-07 2.09E-07 0.0060 8.18E-07 0 0 4.28E-07 active well counts 0.0008 0.0001

WorkoverTraffic (HD) 0.0003 2.27E-05 0.0002 1.53E-05 1.49E-05 9.65E-07 0.0307 1.06E-06 0 0 4.39E-07 active well counts 0.0011 0.0001

Description Total Workover Traffic Emissions (tons per well) Fugitive Road 

NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O N2O SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 -6% -39% -6% 0% -6% -4% -4% 0% 0% -8% -6% -5% -2% -6% 0% -4% -7% -7% 0% 0% 0% -5%

2010 -10% -46% -10% -1% -10% -9% -9% 0% 0% -12% -12% -10% -47% -9% 0% -6% -14% -14% 0% 0% 4% -10%

2011 -15% -50% -13% -2% -15% -16% -16% 0% 0% -15% -19% -16% -75% -14% 0% -13% -24% -24% 0% 0% 13% -16%

2012 -21% -55% -16% -3% -21% -22% -22% 0% 0% -19% -25% -21% -75% -19% 0% -21% -33% -33% 0% 0% 20% -21%

2013 -26% -56% -20% -4% -26% -27% -28% 0% 0% -22% -32% -27% -76% -24% 0% -28% -41% -41% 0% 0% 24% -27%

2014 -32% -57% -24% -5% -32% -33% -33% 0% 0% -25% -37% -32% -76% -28% 0% -34% -49% -49% 0% 0% 28% -32%

2015 -37% -57% -27% -7% -36% -38% -38% 0% 0% -28% -42% -36% -76% -32% 0% -40% -56% -56% 0% 0% 30% -36%

2016 -42% -58% -30% -9% -41% -42% -43% 0% 0% -31% -47% -40% -77% -37% 0% -46% -63% -63% 0% 0% 31% -40%

2017 -46% -59% -33% -10% -45% -46% -47% 0% 0% -34% -51% -44% -77% -40% 0% -51% -68% -68% 0% 0% 32% -44%

2018 -50% -60% -35% -12% -49% -50% -50% 0% 0% -36% -55% -47% -77% -43% 0% -56% -73% -73% 0% 0% 32% -47%

2019 -53% -60% -37% -13% -52% -53% -53% 0% 0% -38% -58% -50% -77% -45% 0% -60% -77% -77% 0% 0% 33% -50%

2020 -57% -61% -38% -14% -55% -55% -56% 0% 0% -39% -61% -53% -77% -47% 0% -64% -81% -81% 0% 0% 34% -53%

2021 -59% -62% -40% -16% -58% -57% -58% 0% 0% -41% -64% -55% -77% -49% 0% -67% -83% -83% 0% 0% 34% -55%

2022 -66% -63% -44% -19% -64% -63% -64% 0% 0% -43% -71% -61% -78% -53% 0% -74% -90% -90% 0% 0% 34% -61%

2023 -62% -62% -41% -17% -60% -59% -60% 0% 0% -42% -67% -58% -78% -51% 0% -70% -86% -86% 0% 0% 34% -58%

2024 -64% -63% -43% -18% -63% -61% -62% 0% 0% -43% -69% -60% -78% -52% 0% -72% -88% -88% 0% 0% 34% -60%

2025 -68% -64% -45% -19% -67% -64% -65% 0% 0% -44% -72% -63% -78% -54% 0% -76% -91% -91% 0% 0% 34% -63%

2026 -70% -64% -46% -20% -69% -66% -66% 0% 0% -43% -74% -65% -78% -56% 0% -79% -92% -92% 0% 0% 36% -65%

2027 -71% -64% -47% -21% -71% -67% -68% 0% 0% -43% -75% -66% -78% -56% 0% -80% -93% -93% 0% 0% 36% -66%

2028 -72% -64% -48% -21% -72% -68% -69% 0% 0% -44% -76% -67% -78% -57% 0% -81% -94% -94% 0% 0% 36% -67%

2029 -73% -65% -48% -22% -73% -69% -70% 0% 0% -45% -78% -68% -78% -58% 0% -83% -94% -94% 0% 0% 35% -68%

2030 -74% -65% -49% -22% -75% -70% -70% 0% 0% -45% -78% -69% -78% -58% 0% -84% -95% -95% 0% 0% 35% -69%

2031 -75% -65% -50% -23% -76% -70% -71% 0% 0% -47% -79% -70% -78% -59% 0% -85% -95% -95% 0% 0% 34% -70%

2032 -76% -65% -50% -23% -76% -71% -72% 0% 0% -47% -80% -70% -78% -60% 0% -85% -95% -95% 0% 0% 34% -70%

2033 -77% -66% -51% -24% -77% -72% -72% 0% 0% -48% -80% -71% -78% -61% 0% -86% -95% -95% 0% 0% 33% -71%

2034 -77% -66% -52% -24% -78% -72% -73% 0% 0% -48% -81% -71% -78% -61% 0% -86% -96% -96% 0% 0% 33% -71%

2035 -78% -66% -52% -24% -78% -73% -73% 0% 0% -48% -81% -72% -78% -62% 0% -87% -96% -96% 0% 0% 33% -72%

2036 -78% -66% -53% -24% -79% -73% -74% 0% 0% -49% -81% -72% -78% -62% 0% -87% -96% -96% 0% 0% 32% -72%

2037 -78% -66% -53% -25% -79% -73% -74% 0% 0% -49% -81% -72% -78% -63% -1% -87% -96% -96% 0% 0% 32% -72%

Light-Duty Truck Heavy-Duty Truck 

Year
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-44

2008 Heaters Emissions

ASSUMPTIONS

Table 52. Natural Gas Fired Heaters Emission Factors (lb/MMscf).

Table 53. Summary of Heaters Operational Data.

Table 54. Summary of 2008 Well-site Heater/Reboiler Emissions (lbs/well).

Table 55. 2008 Heater/Reboiler Emissions in tons per well.

Data Provided by operator in blue text

Assumptions

Assume no controls on the heater

Assume 10 percent of all wells have tank heaters

Equations

Emissions (tons/year) = Emission Factor (lbs/MMscf) * Heater Size (Btu/hr) * Time On (Hours/Year) 

Fuel Heat Value (Btu/scf) * 1x106 (scf/MMscf) * 2000 (lbs/ton)

NOx SO2 CO VOC PM10 PM2.5 PM_filt PM_cond CO2 CH4 N2O

100 0.6 84 5.5 7.6 7.6 1.9 5.7 120,000 2.3 2.2

Heaters (lb/MMscf) (from AP-42 Tables 1.4-1 and 1.4-2)

 (btu/hr) (Btu/scf) (hours)

Dehydrator Heater 500,000 1000 1 8760 0.5 4380

Separator Heater 500,000 1000 1 6552 0.5 3276

Tank Heater 500,000 1000 0.1 6750 0.5 3375

Equipment Type Heat Input Local Heating 

Value # Units/well

Time Used 

Per Unit Cycle 

Fraction

Actual 

Firing 

hours

Equipment Type NOx SO2 CO VOC PM10 PM2.5 PM_filt PM_cond CO2 CH4 N2O

Dehydrator Heater 219 0 184 12 17 17 4 12 262,800 5 5

Separator Heater 164 0 138 9 12 12 3 9 196,560 4 4

Tank Heater 17 0 14 0.93 1.28 1.28 0.32 0.96 20,250 0.39 0.37

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Heaters 0.1998 0.0110 0.1679 0.0152 0.0152 0 239.8050 0.0046 0.0038 0.0114 0.0044 active well counts

Description Projection Heater/Reboiler Emissions (tons per well)
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-45

Table 56. Percent Change in Emission from Base Year 2008 for Heaters/Reboilers.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
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2008 Fugitive Devices Emissions

ASSUMPTIONS

Activity data provided by operators in blue text

Hours of operation was assumed to be year round 24-7

Equation

where:

Efugitive is the fugitive VOC emissions per well [ton-VOC/yr]

EFi is the emission factor of TOC [kg/hr/source]

N is the total number of devices

Y is the ratio of VOC to TOC in the vented gas

tannual is total annual hours of operation

CH4 and CO2 emissions

Emissions.CH4 = Emission.VOC * WeightFraction.CH4 / WeightFraction.CO2

Emissions.CO2 = Emission.VOC * WeightFraction.CO2 / WeightFraction.VOC

Table 57. Total Organic Compound (TOC) Emission Factor (kg/hr/component).

Table 58. VOC, CO2 and CH4 Sales Gas and Condensate Gas Weight Fractions.

Efugitive  EFi  N  tannual Y

Light Oil Heavy Oil

>20o API <20o API

valves 4.50E-03 2.50E-03 8.40E-06 9.80E-05

pump seals 2.40E-03 1.30E-02 3.20E-05 2.40E-05

others 8.80E-03 7.50E-03 3.20E-05 1.40E-02

connectors 2.00E-04 2.10E-04 7.50E-06 1.10E-04

flanges 3.90E-04 1.10E-04 3.90E-07 2.90E-06

open-ended lines 2.00E-03 1.40E-03 1.40E-04 2.50E-04

Pump seals Heavy Oil EF uses other Heavy Oil EF

"Other" category includes compressor seals, pressure relief valves, diaphragms, drains, 

dump arms, hatches, instruments, meters, polished rods and vents

Do not calculate fugitives from pipelines containing only water

Emission Factors are from EPA, 1995 -AP-42 Table 2-4. "Oil and Gas Production 

Operations Average Emission Factors"

Well Equipment 

Component Gas Water/Oil Component Sales Gas Fugitive

VOC Fraction (weight) 14.60% 73.55%

CO2 Fraction (weight) 6.07% 3.02%

CH4 Fraction (weight) 68.75% 13.57%
EXISTING WELLS EMISSIONS INVENTORY

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Table 59. 2008 TOC and VOC Emissions (lbs/well) by Media and Equipment Type.

Table 60. 2008 Fugitive Device Emissions in tons per well.

Well Stream Gas Condensate

Well Stream Gas Condensate Well Stream Gas Condensate

valves 10 10 - 4.50E-03 869 869 0 135.48 135.48 0.00

pump seals 1 0 - 2.40E-03 46 0 0 7.23 0.00 0.00

others 0 0 - 8.80E-03 0 0 0 0.00 0.00 0.00

connectors 150 50 - 2.00E-04 579 193 0 90.32 30.11 0.00

flanges 15 15 - 3.90E-04 113 113 0 17.61 17.61 0.00

open-ended lines 0 0 - 2.00E-03 0 0 0 0.00 0.00 0.00

valves - - 20 2.50E-03 0 0 966 0.00 0.00 732.57

pump seals - - 0 1.30E-02 0 0 0 0.00 0.00 0.00

others - - 0 7.50E-03 0 0 0 0.00 0.00 0.00

connectors - - 50 2.10E-04 0 0 203 0.00 0.00 153.84

flanges - - 10 1.10E-04 0 0 21 0.00 0.00 16.12

open-ended lines - - 0 1.40E-03 0 0 0 0.00 0.00 0.00

valves - - - 8.40E-06 0 0 0 0.00 0.00 0.00

pump seals - - - 3.20E-05 0 0 0 0.00 0.00 0.00

others - - - 3.20E-05 0 0 0 0.00 0.00 0.00

connectors - - - 7.50E-06 0 0 0 0.00 0.00 0.00

flanges - - - 3.90E-07 0 0 0 0.00 0.00 0.00

open-ended lines - - - 1.40E-04 0 0 0 0.00 0.00 0.00

valves - - - 9.80E-05 0 0 0 0.00 0.00 0.00

pump seals - - - 2.40E-05 0 0 0 0.00 0.00 0.00

others - - - 1.40E-02 0 0 0 0.00 0.00 0.00

connectors - - - 1.10E-04 0 0 0 0.00 0.00 0.00

flanges - - - 2.90E-06 0 0 0 0.00 0.00 0.00

open-ended lines - - - 2.50E-04 0 0 0 0.00 0.00 0.00

VOC Emissions (lbs/yr)

Heavy Oil <20o API

Water/Oil

TOC Emission 

Factor (kg / hr / 

component)

TOC Emissions (lbs/yr)

Media

Type

Well Equipment Component

Gas

Light Oil >20o API

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Well Stream Fugitive 

Devices 0 0.1253 0 0 0 0 0.0521 0.5900 0 0 0 active well counts

Gas Stream Fugitive 

Devices 0 0.0916 0 0 0 0 0.0381 0.4313 0 0 0 active well counts

Condensate Fugitive 0 0.4513 0 0 0 0 0.0185 0.0833 0 0 0 active well counts

Description Projection Fugitive Device Emissions (tons per well)
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Table 61. Percent Change in Emission from Base Year 2008 for Fugitive Devices.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
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2008 Pneumatic Devices Emissions

ASSUMPTIONS

As per operator's input no bleed devices are used exclusively, hence zero emissions from this 

category

Table 62. 2008 Pneumatic Devices Emissions in tons per well.

Table 63. Percent Change in Emission from Base Year 2008 for Pneumatic Devices.

NOx VOC CO PM10 PM2.5 SO2 CH4 CO2 PM_filt PM_cond N2O

Pneumatic Devices 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 active well counts

Description Projection Pneumatic Devices Emissions (tons per well)

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
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2008 Tank Loadout (vapor losses) Emissions

ASSUMPTIONS

Table 64. VOC, CO2 and CH4 Condensate Post-Flash Gas Weight Fractions.

Table 65. Summary of Truck Load Activity Data.

Table 66. 2008 Well Site Condensate Tank Loadout Emissions in tons per barrel.

Data Provided by operator in blue text

Method from Wyoming Permitting Guidance for Oil and Gas Production Facilities

Wyoming DEQ, March, 2010, Chapter 6, Section 2, p.65 for Crude Oil, RVP 5

After AP-42, Section 5.2.1

Emissions VOC (tpy) =

Loading losses determined using AP-42 Section 5.2.2.1.1 Equation 1

LL =12.46 x S x P x M/T

LL=Loading Loss in (lbs/1000gallons)

S= Saturation Factor

P = true vapor pressure of liquid loaded (psia)

M = molecular weight of tank vapors (lb/(lb-mol))

T = temperature of bulk liquid loaded (R=F+460)

Loading Loss (lbs/1000 gal) * truck load rate (bbl/year) * 42 (gal/bbl) * VOC mass fraction

2000 (lbs/ton)

Compound Weight (%)

Methane (weight) 21.23%

VOC Fraction (weight) 66.34%

CO2 Fraction (weight) 0.00%

Type of Petroleum Liquid 

Loaded

Saturation 

Factor

True Vapor 

Pressure of 

Liquid Loaded 

(psia)

Molecular Weight 

of Vapors (lb/lbmole)

Temperature 

of Bulk Liquid 

(°R)

Mode of 

Operation

Loading Losses 

(lb/1000 gallons)

Capacity of 

Truck

Condensate RVP 8 0.6 7.2 50 520

Submerged loading: 

dedicated normal 

service 5.18 80 bbl

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Tank Loadout (vapor 

losses) 0 7.21E-05 0 0 0 0 0 2.31E-05 0 0 0

annual condensate 

production

Description Projection Base Year Well Site Condensate Tank Loadout Emissions (tons per barrel)
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Table 67. Percent Change in Emission from Base Year 2008 for Condensate Tank Loadout.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
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2008 Well Venting Emissions

ASSUMPTIONS

Table 68. Well Venting VOC, CH4 and CO2 Emission Factors (tons/well).

Table 69. 2008 Well Venting Emissions in tons per well.

Data provided by operator in blue text

Well venting includes all emissions from venting categories other than fugitive devices, pneumatic devices, 

chemical injection pumps, tank load out, condensate tanks, completion and dehydrator venting.

Weight (%) : Well 

Stream Gas (t/yr/well)

Venting VOC Emission Factor 0.75

Methane 69.04% 3.624

Carbon Dioxide 6.09% 0.320

VOC Fraction (weight) 14.25%

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Well Venting 0 0.7483 0 0 0 0 0.3198 3.6240 0 0 0 active well counts

Description Projection Base Year Well Venting Emissions (tons per well)
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Table 70. Percent Change in Emission from Base Year 2008 for Well Venting.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
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2008 Condensate Tank Flashing/Working/Breathing Emissions 

ASSUMPTIONS

where WtFraction = weight fraction of the pollutant 

Data provided by operator in blue text

Assume one tank per well

where:

E condensate,tanks is the per well emissions from condensate tanks [tons/yr-well]

EF condensate,tank is the derived VOC emissions factor for condensate tanks [lb-VOC/bbl]

P condensatetanks is the condensate production per gas wells throughput [bbl/well]

CF = Percentage of Volume Controlled

CO2 emissions

Emissions.CO2 = Emission.VOC * WtFraction.CO2 / WtFraction.VOC

 =

 

2000 ( )

68% percentage of condensate volume controlled

Flash Wt % Post-Flash Wt %

Carbon Dioxide 3.04% 0.00%

VOC Fraction 

(weight) 73.46% 66.34%
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Table 71: Flash speciation from Wamsutter HYSYS.

Chemical Mole %1

Molecular 

Weight

 (lb/lb-mol)2

Pounds per 

Bbl @ 365 

psig

Carbon Dioxide 2.80% 44.01 1.24

Nitrogen 0.02% 28.01 0.01

Methane 34.25% 16.04 5.52

Ethane 13.42% 30.07 4.05

Propane 17.98% 44.10 7.96

Isobutane 6.85% 58.12 4.00

n-Butane 9.34% 58.12 5.45

Isopentane 4.48% 72.15 3.25

n-Pentane 3.91% 72.15 2.83

Cyclopentane 0.00% 72.15 0.00

n-Hexane 1.36% 86.18 1.18

Cyclohexane 0.30% 84.16 0.25

2,2-Dimethylbutane 0.09% 86.18 0.08

2,3-Dimethylbutane 0.34% 86.18 0.30

2-Methylpentane 1.04% 86.18 0.90

3-Methylpentane 0.53% 86.18 0.46

n-Heptane 1.85% 100.20 1.86

Methylcylcohexane 0.18% 98.19 0.18

2,2,4 Trimethylpentane 0.07% 114.23 0.08

Benzene 0.31% 78.11 0.25

Toluene 0.38% 92.14 0.35

Ethylbenzene 0.00% 106.17 0.00

m-Xylene 0.16% 106.17 0.17

o-Xylene 0.02% 106.17 0.02

n-Octane 0.22% 114.23 0.25

n-Nonane 0.05% 128.26 0.07

n-Decane 0.04% 142.28 0.06

Total 100.00% 40.58 40.75

Total VOC 49.51% 29.93

1

 The flash gas composition is based on the 2008 HYSYS model for 

2

 The molecular weights and the higher heating values are from the 

"GSPA Engineering Data Book", Twelfth Edition, Section 23 Physical 

Properties, 2004.

Assumptions 365 PSIG Separator Pressure

75 Degrees F Temperature (Tank)

379.48 SCF/Mole

Total Flash @ 365 psig 381.05 SCF/Bbl Produced (From Wamsutter SCC Heat Input File)
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Table 72: Working and Breathing Loss Calculations.

Net Throughput(gal/yr): 47,632 bbls/yr: 1510

Turnovers: 2.93

From EPA's TANKS 4.09 Output based on the condensate composition from 2007 

Wamsutter HYSYS model. 

Components

Working 

Loss 

(lbs/yr)

Working Loss 

(lb/turnover)

Breathing 

Loss 

(lbs/yr)

Total 

Emissions 

(lbs/yr)

Condensate 368.64 125.82 3,232.66 3,601.30

Methane 78.28 26.72 686.48 764.76

Ethane 45.81 15.63 401.75 447.57

Propane 71.86 24.53 630.14 702

Isobutane 34.98 11.94 306.72 341.7

n-Butane 46.12 15.74 404.46 450.58

Isopentane 27.02 9.22 236.95 263.97

n-Pentane 21.87 7.46 191.8 213.68

n-Hexane 8.31 2.84 72.84 81.15

Cyclohexene 1.32 0.45 11.54 12.86

2,2-Dimethylbutane 0.66 0.23 5.79 6.45

2,3-Dimethylbutane 2.19 0.75 19.19 21.37

2-Methylpentane 6.49 2.22 56.93 63.42

3-Methylpentane 3.1 1.06 27.22 30.32

n-Heptane 12.98 4.43 113.84 126.82

Methylcyclohexane 1.03 0.35 9.06 10.09

2,2,4-Trimethylpentane 0.52 0.18 4.54 5.06

Benzene 1.17 0.40 10.23 11.4

Toluene 1.54 0.53 13.46 15

Ethylbenzene 0.02 0.01 0.19 0.21

Xylenes 0.85 0.29 7.48 8.34

n-Octane 1.38 0.47 12.1 13.49

n-Nonane 0.49 0.17 4.3 4.79

n-Decane 0.64 0.22 5.65 6.3

THC 368.63 125.81 3,232.66 3,601.33

VOC 244.54 83.46 2,144.43 2,389.00
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Table 73: TANKS 4.0.9d Emissions Report. Tank Identification and Physical Characteristics

Table 74: TANKS 4.0.9d Emissions Report. Liquid Contents of Storage Tank
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Table 75: TANKS 4.0.9d Emissions Report. Detail Calculations. 
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Table 76: TANKS 4.0.9d Emissions Report. Individual Tank Emissions Total (lbs).

Table 77. VOC and CH4 Flashing, Working and Breathing Emission Factors (lb/activity).

Table 78. 2008 Uncontrolled Condensate Tank Emissions in tons per activity.

Condensate tank losses 29.93 83.46 2144.43 5.52 26.72 686.48

Uncontrolled CH4 Emission Factors 

Flashing

 (lb per barrel)

Working

 (lb per turnover 

per well)

Breathing 

Losses 

(lb per well)

Flashing

 (lb per barrel)

Working

 (lb per turnover 

per well)

Breathing 

Losses 

(lb per well)

Source

Uncontrolled VOC Emission Factors NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Condensate Tank 

Flashing Losses 0.0000 0.0048 0.0000 0.0000 0.0000 0.0000 0.0002 0.0009 0.0000 0.0000 0.0000

annual 

condensate 

production

Condensate Tank 

Working Losses 0.0000 0.0134 0.0000 0.0000 0.0000 0.0000 0.0000 0.0043 0.0000 0.0000 0.0000

total turnovers 

per year

Condensate Tank 

Breathing Losses 0.0000 0.3431 0.0000 0.0000 0.0000 0.0000 0.0000 0.1098 0.0000 0.0000 0.0000

active well 

counts

Description Projection Condensate Tank Venting Emissions- Uncontrolled Volume (tons per barrel or tons per turnover per well or tons per well)
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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-60

Table 79. Percent Change in Emission from Base Year 2008 for Condensate Tank Losses.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
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2008 Condensate Tank Flaring Emissions

ASSUMPTIONS

Data provided by operator in blue text

 O2Emissions ( p r ivi y) = (Total CO2 Emission Potential of the Entire Gas – THC Component to CO2 Emission 

Potential – CO Component to CO2 Emission Potential) x Percentage of Production Controlled

THC Component CO2 Emissions Potentials (

tons

activity) =∑

(

lb emissions emitted

activity ) i×

N . f M l f C i mp u 

N . f M l f C i CO2

×Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of Compound C (lb/lb-mol) × 2000

CO component CO2 emissions potentials (

tons

activity) = 

CO emissions from flaring(

lb

activity)×

No.of Moles of C in compound

No.of Moles of C in CO2 × Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of CO ( lb

lb-mol

) × 2000

.

Where,

i= each compound identified in flaring gas speciation profile 

(lb emissions emitted/activity)i = Total TOG Emissions (lb/activity) from flaring X Weight 

Fraction of the Compound 

Table 80. Flaring Emission Factors

NOx, VOC, CH4, N2O and CO Emissions Calculation

where:

E flare is the flaring emissions per well [lb/yr]

EF i is the emissions factor for pollutant i [lb/MMBtu]

Q is the volume of gas flared supplied by operator [MMscf/yr]

HV is the heating value of the gas as provided by the operators [MMBtu/MMscf]

E flare  EF i  Q  HV NOx CO THC

0.068 0.37 0.14 25% 1.44 63%

Flaring Emission Factor (lb/MMBtu)* Fraction of THC 

as CH4

N2O 

(lb/MMSCF)b VOC/THCc 

b Emission Factor from API Compendium of greenhouse gas emissions methodologies for 

the oil and natural gas industry,2009 Table 4-11, GHG Emission Factors for Gas Flares in 

Developed Countries - Footnote C

cEPA SPECIATE Profile 0051

*Emission Factors are from AP-42

Condensate 2246.45 Btu/scf

Total Flash @ 381.05 SCF/Bbl Produced 

68% percentage of condensate volume controlled

1

2008 HYSYS model runs for the Wamsutter Operations Center at 365 psig.
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Table 81. 2008 CO2 Emissions (tons/bbl) Potential for All Gas Sample Species from Flashing 

Loss.

365.00 PSIG Separator Pressure

75.00 Degrees F Temperature (Tank)

379.48 SCF/lb-mole

Chemical Mole %1 

Molecular 

Weight

 (lb/lb-mol)2

Pounds per Bbl 

@ 365 psig

lb/

MMscf

lb CO2/ 

MMscf

HHV 

(Btu/scf)2

2008 CO2 

emission 

potential of the 

entire gas 

(tons/bbl)

Carbon Dioxide 2.80% 44.01 1.24 3,250 3,250 0 6.E-04

Nitrogen 0.02% 28.01 0.01 16 0 0.E+00

Methane 34.25% 16.04 5.52 14,478 39,725 1010 8.E-03

Ethane 13.42% 30.07 4.05 10,631 31,120 1770 6.E-03

Propane 17.98% 44.10 7.96 20,900 62,571 2516 1.E-02

Isobutane 6.85% 58.12 4.00 10,490 31,773 3252 6.E-03

n-Butane 9.34% 58.12 5.45 14,303 43,322 3262 8.E-03

Isopentane 4.48% 72.15 3.25 8,523 25,995 4001 5.E-03

n-Pentane 3.91% 72.15 2.83 7,432 22,665 4009 4.E-03

n-Hexane 1.36% 86.18 1.18 3,085 9,453 4756 2.E-03

Cyclohexane 0.30% 84.16 0.25 655 2,055 4482 4.E-04

2,2-Dimethylbutane 0.09% 86.18 0.08 201 615 4736 1.E-04

2,3-Dimethylbutane 0.34% 86.18 0.30 783 2,398 4745 5.E-04

2-Methylpentane 1.04% 86.18 0.90 2,362 7,237 4747 1.E-03

3-Methylpentane 0.53% 86.18 0.46 1,201 3,680 4750 7.E-04

n-Heptane 1.85% 100.20 1.86 4,885 15,019 5503 3.E-03

Methylcyclohexane 0.18% 98.19 0.18 465 1,667 5216 3.E-04

2,2,4-Trimethylpentane 0.07% 114.23 0.08 212 653 6249 1.E-04

Benzene 0.31% 78.11 0.25 646 2,183 3742 4.E-04

Toluene 0.38% 92.14 0.35 921 3,080 4475 6.E-04

Ethylbenzene 0.00% 106.17 0.00 12 41 5222 8.E-06

m-Xylene 0.16% 106.16 0.17 454 1,505 5208 3.E-04

o-Xylene 0.02% 106.16 0.02 43 143 5210 3.E-05

n-Octane 0.22% 114.23 0.25 665 2,050 6249 4.E-04

n-Nonane 0.05% 128.26 0.07 171 528 6996 1.E-04

n-Decane 0.04% 142.29 0.06 151 466 7743 9.E-05

VOC 100.00% 40.58 40.75 106,934 309,944 2246 0.059

Total VOC 49.51% 29.93 78,558

2

 The molecular weights and the higher heating values are from the "GSPA Engineering Data Book", Twelfth Edition, 

1

 The flash gas composition is based on the 2008 HYSYS model for Wamsutter at 365 psig.
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Table 82. 2008 CO2 Emissions (tons/turnover) Potential for All Gas Sample Species from 

Working Loss.

Throughput 1509.94 bbls/yr

Turnovers: 2.93

Vapor Density 0.06 lb/ft3

Components

Working 

Loss 

(lbs/yr)

Working Loss

(lb/ turnover well) Weight %

Molecular 

Weight

 (lb/lb-mol)1

Mole %

HHV 

(Btu/scf)1

lb/

MMscf

lb CO2/ 

MMscf

2008 CO2 

emission 

potential of the 

entire gas 

(Tons/turnover)

Methane 78.28 26.72 21.23% 16.04 46.18% 1010 19,519 53,555 0.0121

Ethane 45.81 15.63 12.43% 30.07 14.42% 1770 11,425 33,442 0.0044

Propane 71.86 24.53 19.50% 44.10 15.42% 2516 17,921 53,654 0.0111

Isobutane 34.98 11.94 9.49% 58.12 5.70% 3252 8,722 26,419 0.0027

n-Butane 46.12 15.74 12.51% 58.12 7.51% 3262 11,501 34,835 0.0046

Isopentane 27.02 9.22 7.33% 72.15 3.54% 4001 6,738 20,551 0.0016

n-Pentane 21.87 7.46 5.93% 72.15 2.87% 4009 5,454 16,634 0.0011

n-Hexane 8.31 2.84 2.25% 86.18 0.91% 4756 2,072 6,349 0.0002

Cyclohexane 1.32 0.45 0.36% 84.16 0.15% 4482 329 1,031 0.0000

2,2-Dimethylbutane 0.66 0.23 0.18% 86.18 0.07% 4736 165 504 0.0000

2,3-Dimethylbutane 2.19 0.75 0.59% 86.18 0.24% 4745 546 1,673 0.0000

2-Methylpentane 6.49 2.22 1.76% 86.18 0.71% 4747 1,619 4,960 0.0001

3-Methylpentane 3.10 1.06 0.84% 86.18 0.34% 4750 774 2,370 0.0000

n-Heptane 12.98 4.43 3.52% 100.20 1.23% 5503 3,237 9,952 0.0004

Methylcyclohexane 1.03 0.35 0.28% 98.19 0.10% 5216 257 922 0.0000

2,2,4-Trimethylpentane 0.52 0.18 0.14% 114.23 0.04% 6249 129 399 0.0000

Benzene 1.17 0.40 0.32% 78.11 0.14% 3742 291 985 0.0000

Toluene 1.54 0.53 0.42% 92.14 0.16% 4475 383 1,282 0.0000

Ethylbenzene 0.02 0.01 0.01% 106.17 0.00% 5222 5 17 0.0000

Xylenes 0.85 0.29 0.23% 106.17 0.08% 5208 212 704 0.0000

n-Octane 1.38 0.47 0.37% 114.23 0.11% 6249 344 1,061 0.0000

n-Nonane 0.49 0.17 0.13% 128.26 0.04% 6996 122 378 0.0000

n-Decane 0.64 0.22 0.17% 142.29 0.04% 7743 160 495 0.0000

THC 368.63 125.81 100.00% 34.88 100.00% 2016 91,926 272,174 0.04

VOC 244.54 83.46 66.34% 39.40% 60,983

From EPA's TANKS 4.09 Output based on the condensate composition from 2007 

Wamsutter HYSYS model. 

1

 The molecular weights and the higher heating values are from the "GSPA Engineering Data Book", Twelfth Edition, Section 23 Physical 
EXISTING WELLS EMISSIONS INVENTORY

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Table 83. 2008 CO2 Emissions (tons/well) Potential for All Gas Sample Species from Breathing 

Loss.

Throughput 1509.94 bbls/yr

Turnovers: 2.93

Vapor Density 0.06 lb/ft3

Components

Breathing 

Loss 

(lbs/well)

Weight %

Molecular 

Weight

 (lb/lb-mol)1

Mole %

HHV 

(Btu/scf)1

lb/

MMscf

lb CO2/ 

MMscf

2008 CO2 emission 

potential of the 

entire gas 

(tons/well)

Methane 686.48 21.23% 16.04 46.18% 1010 19,519 53,555 0.31

Ethane 401.75 12.43% 30.07 14.42% 1770 11,425 33,442 0.11

Propane 630.14 19.50% 44.10 15.42% 2516 17,921 53,654 0.29

Isobutane 306.72 9.49% 58.12 5.70% 3252 8,722 26,419 0.07

n-Butane 404.46 12.51% 58.12 7.51% 3262 11,501 34,835 0.12

Isopentane 236.95 7.33% 72.15 3.54% 4001 6,738 20,551 0.04

n-Pentane 191.8 5.93% 72.15 2.87% 4009 5,454 16,634 0.03

n-Hexane 72.84 2.25% 86.18 0.91% 4756 2,072 6,349 0.00

Cyclohexane 11.54 0.36% 84.16 0.15% 4482 329 1,031 0.00

2,2-Dimethylbutane 5.79 0.18% 86.18 0.07% 4736 165 504 0.00

2,3-Dimethylbutane 19.19 0.59% 86.18 0.24% 4745 546 1,673 0.00

2-Methylpentane 56.93 1.76% 86.18 0.71% 4747 1,619 4,960 0.00

3-Methylpentane 27.22 0.84% 86.18 0.34% 4750 774 2,370 0.00

n-Heptane 113.84 3.52% 100.20 1.23% 5503 3,237 9,952 0.01

Methylcyclohexane 9.06 0.28% 98.19 0.10% 5216 257 922 0.00

2,2,4-Trimethylpentane 4.54 0.14% 114.23 0.04% 6249 129 399 0.00

Benzene 10.23 0.32% 78.11 0.14% 3742 291 985 0.00

Toluene 13.46 0.42% 92.14 0.16% 4475 383 1,282 0.00

Ethylbenzene 0.19 0.01% 106.17 0.00% 5222 5 17 0.00

Xylenes 7.48 0.23% 106.17 0.08% 5208 212 704 0.00

n-Octane 12.1 0.37% 114.23 0.11% 6249 344 1,061 0.00

n-Nonane 4.3 0.13% 128.26 0.04% 6996 122 378 0.00

n-Decane 5.65 0.17% 142.29 0.04% 7743 160 495 0.00

THC 3232.66 100.00% 34.88 100.00% 2016 91,926 272,174 0.98

VOC 2144.43 66.34% 39.40% 60,983

1

 The molecular weights and the higher heating values are from the "GSPA Engineering Data Book", Twelfth Edition, Section 23 Physical 

Properties, 2004.

From EPA's TANKS 4.09 Output based on the condensate composition from 

2007 Wamsutter HYSYS model. 
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Table 84. Summary of THC and CO Component to CO2 Emissions Potentials (tons/activity) for 2008.

Table 85. 2008 Condensate Tank Flaring Emissions per activity metric of each Category.

Compound MW

(lb/lb-mol)

Flashing 

Emissions 

(lb/bbl)

Working 

Emissions

(lb/turnover)

Breathing 

Emissions

(lb/well)

TOG 31.47 0.15 0.75 19.30

CO 28.01 0.32 1.59 40.80

lb 

emitted/w

ell

Moles C in 

compound/

Moles C in 

CO2

CO2 

Emissions 

(tons/bbl)

lb 

emitted/t

urnover

Moles C in 

compound

/Moles C in 

CO2

CO2 Emissions 

(Tons/turnover)

lb 

emitted/well

Moles C in 

compound/M

oles C in 

CO2

CO2 

Emissions 

(tons/well)

Ethane Y N 30 30.07 0.04 2 0.0001 0.23 2 0.0003 5.79 2 0.0085

Formaldehyde N Y 20 30.03 0.03 1 0.0000 0.15 1 0.0001 3.86 1 0.0028

Methane Y N 20 16.04 0.03 1 0.0000 0.15 1 0.0002 3.86 1 0.0053

Propane Y Y 30 44.10 0.04 3 0.0001 0.23 3 0.0003 5.79 3 0.0087

100 0.15 0.0002 0.0002 0.75 0.0010 0.0012 19.30 0.0253 0.0321

0.0002 0.0012

Name HC? VOC?

WEIGHT_PER

(Flaring 

Speciation Profile 

(EPA SPECIATE 

0051))

Molecular 

Weight

 (lb/lb-mol)2

0.0321

Flashing 2008 CO2 emissions Working 2008 CO2 emissions Breathing 2008 CO2 emissions

THC component CO2 emissions CO component 

CO2 emissions 

potentials 

(tons/bbl) 

THC component CO2 emissions CO component 

CO2 emissions 

potentials 

(tons/well) 

THC component CO2 emissions CO component 

CO2 emissions 

potentials 

(tons/well) 

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Condensate Tank 

Flashing Flaring 1.98E-05 2.55E-05 0.0001 0 0 0 0.0399 1.02E-05 0 0 1.86E-07

annual condensate 

production

Condensate Tank 

Working Flaring 9.92E-05 0.0001 0.0005 0 0 0 0.0245 5.11E-05 0 0 1.04E-06

total turnovers per 

year

Condensate Tank 

Breathing Flaring 0.0025 0.0033 0.0139 0 0 0 0.6302 0.0013 0 0 2.67E-05 active well counts

Description Projection Condensate Tank Flaring Emissions (tons per activity metric)
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Table 86. Percent Change in Emission from Base Year 2008 for Condensate Tank Flaring.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-67

2008 Dehydrator Venting Emissions

ASSUMPTIONS

Table 87. Dehydrator Uncontrolled and Controlled VOC and CH4 Emissions (tons per well).

Data Provided by operator in blue text

Assume no change in pressure (365 psi)

Dehydrator VOC Emissions (t/yr)=2.0254*ln(flow (MMscf/yr))+0.9636

Dehydrator CH4 Emissions (t/yr)=0.0543*ln(flow (MMscf/yr))+7.3694

Assume one dehydrator per well

Total Waste Gas Stream (MMscf/yr/ well) =0.0013*flow(MMscf/yr)+0.5094

assumed no wells subject of control based on estimated uncontrolled VOC emissions below 15tpy VOC threshold

CO2 Emissions (tons/well/yr) = ((lb CO2/MMscf)* Total Waste Gas Stream (MMscf/well/yr))

2000

Year

Average 

production per 

year per well 

(MMscf/yr/well)

Uncontrolled VOC 

Emissions

(tons per well)

Controlled VOC 

Emissions

(tons per well)

Uncontrolled 

CH4 Emissions

(tons per well)

Controlled CH4 

Emissions*

(tons per well)

Uncontrolled C2H6 

Emissions (tons per 

well)

Total Waste 

Gas Stream 

(MMscf/yr/ well)

CO2 Emissions 

(tons per well)

2008 67.92 9.51 9.51 7.60 7.60 2 0.598 1.8358

2009 64.76 9.41 9.41 7.60 7.60 2 0.594 1.8232

2010 56.31 9.13 9.13 7.59 7.59 2 0.583 1.7895

2011 51.79 8.96 8.96 7.58 7.58 2 0.577 1.7714

2012 51.34 8.94 8.94 7.58 7.58 2 0.576 1.7696

2013 51.18 8.93 8.93 7.58 7.58 2 0.576 1.7690

2014 49.06 8.85 8.85 7.58 7.58 2 0.573 1.7605

2015 46.79 8.75 8.75 7.58 7.58 2 0.570 1.7514

2016 44.83 8.67 8.67 7.58 7.58 2 0.568 1.7436

2017 43.14 8.59 8.59 7.57 7.57 2 0.565 1.7369

2018 41.69 8.52 8.52 7.57 7.57 2 0.564 1.7311

2019 40.38 8.45 8.45 7.57 7.57 2 0.562 1.7258

2020 39.14 8.39 8.39 7.57 7.57 2 0.560 1.7209

2021 38.06 8.33 8.33 7.57 7.57 2 0.559 1.7166

2022 36.40 8.24 8.24 7.56 7.56 2 0.557 1.7100

2023 35.48 8.19 8.19 7.56 7.56 2 0.556 1.7063

2024 34.62 8.14 8.14 7.56 7.56 2 0.554 1.7028

2025 33.91 8.10 8.10 7.56 7.56 2 0.553 1.7000

2026 33.20 8.06 8.06 7.56 7.56 2 0.553 1.6972

2027 32.56 8.02 8.02 7.56 7.56 2 0.552 1.6946

2028 32.30 8.00 8.00 7.56 7.56 2 0.551 1.6936

2029 31.00 7.92 7.92 7.56 7.56 2 0.550 1.6884

2030 30.44 7.88 7.88 7.55 7.55 2 0.549 1.6861

2031 29.93 7.85 7.85 7.55 7.55 2 0.548 1.6841

2032 29.44 7.81 7.81 7.55 7.55 2 0.548 1.6822

2033 28.96 7.78 7.78 7.55 7.55 2 0.547 1.6802

2034 28.52 7.75 7.75 7.55 7.55 2 0.546 1.6785

2035 28.12 7.72 7.72 7.55 7.55 2 0.546 1.6769

2036 27.79 7.70 7.70 7.55 7.55 2 0.546 1.6756

2037 27.47 7.67 7.67 7.55 7.55 2 0.545 1.6743

* assumed CH4 control would be analagous to VOC control
EXISTING WELLS EMISSIONS INVENTORY

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Table 88. Summary of lb CO2 per MMSCF Estimation.

Chemical Mole %1 

Molecular Weight

 (lb/lb-mol)2

lb/

MMscf lb CO2/ MMscf HHV (Btu/scf)2

Water 17.54% 18.01 8060.8 0.0

Carbon Dioxide 5.47% 44.01 6142.9 6142.9 0

Nitrogen 0.11% 28.01 80.8 0

Methane 55.61% 16.04 22761.2 1010

Ethane 6.19% 30.07 4749.6 1770

Propane 3.98% 44.10 4478.8 2516

Isobutane 1.07% 58.12 1586.9 3252

n-Butane 1.49% 58.12 2209.8 3262

Isopentane 0.57% 72.15 1053.1 4001

n-Pentane 0.58% 72.15 1075.2 4009

n-Hexane 0.33% 86.18 730.1 4756

Cyclohexane 0.62% 84.16 1335.8 4482

Other Hexanes 0.37% 86.18 815.9 4745

n-Heptane 0.61% 100.20 1569.9 5503

Methylcyclohexane 0.79% 98.19 1976.9 5216

2,2,4-Trimethylpentane 0.02% 114.23 55.4 6249

Benzene 1.35% 78.11 2690.8 3742

Toluene 1.89% 92.14 4443.7 4475

Ethylbenzene 0.06% 106.17 165.3 5222

Xylenes 0.60% 106.17 1636.3 5208

n-Octane 0.73% 114.23 2116.2 6249

Total 100.00% 27.33 69735.3 6142.9 1254

Total VOC 15.07% 27940.0

1

 Mole percent is based on the GLYCalc run at 0.25 MMscf/day for Wamsutter.

2

 The molecular weights and the higher heating values are from GSPA Engineering Data Book, 12th Edition.

Assumptions

0.0821 L-atm/K-mol

298.15 oK

1 1 atm

1 ft3 28.31685 L

453.59237 mol/lb-mol

391.90 scf/lbmol
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-69

Table 89. Summary of Well Site Dehydrator Emissions in tons per well by Project Year. 

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Dehydrator Venting - Well Site 2008 0 9.5074 0 0 0 0 1.8358 7.5985 0 0 0 active well counts

Dehydrator Venting - Well Site 2009 0 9.4109 0 0 0 0 1.8232 7.5959 0 0 0 active well counts

Dehydrator Venting - Well Site 2010 0 9.1278 0 0 0 0 1.7895 7.5883 0 0 0 active well counts

Dehydrator Venting - Well Site 2011 0 8.9583 0 0 0 0 1.7714 7.5837 0 0 0 active well counts

Dehydrator Venting - Well Site 2012 0 8.9407 0 0 0 0 1.7696 7.5833 0 0 0 active well counts

Dehydrator Venting - Well Site 2013 0 8.9344 0 0 0 0 1.7690 7.5831 0 0 0 active well counts

Dehydrator Venting - Well Site 2014 0 8.8485 0 0 0 0 1.7605 7.5808 0 0 0 active well counts

Dehydrator Venting - Well Site 2015 0 8.7525 0 0 0 0 1.7514 7.5782 0 0 0 active well counts

Dehydrator Venting - Well Site 2016 0 8.6658 0 0 0 0 1.7436 7.5759 0 0 0 active well counts

Dehydrator Venting - Well Site 2017 0 8.5883 0 0 0 0 1.7369 7.5738 0 0 0 active well counts

Dehydrator Venting - Well Site 2018 0 8.5187 0 0 0 0 1.7311 7.5719 0 0 0 active well counts

Dehydrator Venting - Well Site 2019 0 8.4540 0 0 0 0 1.7258 7.5702 0 0 0 active well counts

Dehydrator Venting - Well Site 2020 0 8.3912 0 0 0 0 1.7209 7.5685 0 0 0 active well counts

Dehydrator Venting - Well Site 2021 0 8.3342 0 0 0 0 1.7166 7.5670 0 0 0 active well counts

Dehydrator Venting - Well Site 2022 0 8.2442 0 0 0 0 1.7100 7.5646 0 0 0 active well counts

Dehydrator Venting - Well Site 2023 0 8.1920 0 0 0 0 1.7063 7.5632 0 0 0 active well counts

Dehydrator Venting - Well Site 2024 0 8.1425 0 0 0 0 1.7028 7.5619 0 0 0 active well counts

Dehydrator Venting - Well Site 2025 0 8.1004 0 0 0 0 1.7000 7.5607 0 0 0 active well counts

Dehydrator Venting - Well Site 2026 0 8.0577 0 0 0 0 1.6972 7.5596 0 0 0 active well counts

Dehydrator Venting - Well Site 2027 0 8.0180 0 0 0 0 1.6946 7.5585 0 0 0 active well counts

Dehydrator Venting - Well Site 2028 0 8.0021 0 0 0 0 1.6936 7.5581 0 0 0 active well counts

Dehydrator Venting - Well Site 2029 0 7.9186 0 0 0 0 1.6884 7.5559 0 0 0 active well counts

Dehydrator Venting - Well Site 2030 0 7.8818 0 0 0 0 1.6861 7.5549 0 0 0 active well counts

Dehydrator Venting - Well Site 2031 0 7.8478 0 0 0 0 1.6841 7.5540 0 0 0 active well counts

Dehydrator Venting - Well Site 2032 0 7.8143 0 0 0 0 1.6822 7.5531 0 0 0 active well counts

Dehydrator Venting - Well Site 2033 0 7.7807 0 0 0 0 1.6802 7.5522 0 0 0 active well counts

Dehydrator Venting - Well Site 2034 0 7.7501 0 0 0 0 1.6785 7.5513 0 0 0 active well counts

Dehydrator Venting - Well Site 2035 0 7.7215 0 0 0 0 1.6769 7.5506 0 0 0 active well counts

Dehydrator Venting - Well Site 2036 0 7.6974 0 0 0 0 1.6756 7.5499 0 0 0 active well counts

Dehydrator Venting - Well Site 2037 0 7.6740 0 0 0 0 1.6743 7.5493 0 0 0 active well counts

Description Year Projection Dehydrator Emissions - Weighted Average (tons per well)
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-70

Table 90. Percent Change in Emission from Base Year 2008 for Dehydrators.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-71

2008 Production Traffic Emissions

ASSUMPTIONS

Data Provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

PRODUCTION TRAFFIC.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-72

Table 91. Summary of Traffic Activity Data Associated with Production Traffic.

Table 92. 2008 Exhaust Emissions (lb/well) Associated with Production Traffic by Vehicle 

Type.

Table 93. Summary of 2008 Fugitive Dust Emissions (tons/well) Associated with Production 

Traffic.

Light Truck 20 20 52

Heavy Truck 20 20 14

Heavy Trucks - Central Facility 0 0 0

Production traffic assumes that vehicles end up at the central facility

Equipment Type

Field

Mean Vehicle 

Speed (mph)

Round Trip OffRoad Trip Distance 

(miles)

Number of Round 

Trips Per Well 

(annual)

NOx 2.67 6.127

SO2 0.02 0.054

CO 19.44 44.580

CO2 677.28 1553

VOC 1.57 3.596

PM10 0.09 0.207

PM2.5 0.09 0.197

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.213

N2O 0.05 0.111

NOx 21.75 13.426

SO2 0.08 0.051

CO 15.96 9.855

CO2 2612.85 1612.873

VOC 1.93 1.193

PM10 1.30 0.804

PM2.5 1.26 0.780

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.056

N2O 0.04 0.023

NOx 21.75 0.000

SO2 0.08 0.000

CO 15.96 0.000

CO2 2612.85 0.000

VOC 1.93 0.000

PM10 1.30 0.000

PM2.5 1.26 0.000

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.000

N2O 0.04 0.000

Heavy-Duty Truck 

Light-Duty Truck

Vehicle Type Pollutant 2008 Emission 

Factors (g/mile)

Base year 

Emissions (lb/well)

Heavy-Duty Diesel Truck Travel 

to Central Facility

Travel to well Light truck 7,000 20 52 52 20 1040 0.20 0.10 0.02 0.01

Travel to well Heavy Truck 70,000 20 14 14 20 280 0.20 0.03 0.02 0.00

Travel to Central Facility Heavy Truck 70,000 0 0 0 0 0 0.00 0.00 0.02 0.00

Total 0.13 0.01

Total # of 

Round Trips

Round Trip 

Distance 

(mi)

Total Miles 

Traveled

P M10

Activity Vehicle Type Av. Vehicle Weight 

(lb)

Mean vehicle 

speed (mph)

# of Visits 

per Year 

P M2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well)
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-73

Table 94. 2008 Exhaust and Fugitive Dust Emissions Associated with Production Traffic.

Table 95. Percent Change in Emission from Base Year 2009 due to Fleet Turnover for Production Traffic.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Production Traffic (LD) 0.0031 0.0018 0.0223 0.0001 9.83E-05 2.71E-05 0.7764 0.0001 0 0 5.56E-05 active well counts 0.1030 0.0102

Production Traffic (HD) 0.0067 0.0006 0.0049 0.0004 0.0004 2.53E-05 0.8064 2.79E-05 0 0 1.15E-05 active well counts 0.0277 0.0028

Production Traffic, Central Facility 

(HD) 0 0 0 0 0 0 0 0 0 0 0 None 0.0000 0.0000

Description Projection Total Production Traffic Emissions (tons per well) Fugitive Road NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 -6% -39% -6% 0% -6% -4% -4% 0% 0% -8% -6% -7% -2% -6% 0% -4% -7% -7% 0% 0% 0% -5%

2010 -10% -46% -10% -1% -10% -9% -9% 0% 0% -12% -12% -16% -47% -9% 0% -6% -14% -14% 0% 0% 4% -10%

2011 -15% -50% -13% -2% -15% -16% -16% 0% 0% -15% -19% -25% -75% -14% 0% -13% -24% -24% 0% 0% 13% -16%

2012 -21% -55% -16% -3% -21% -22% -22% 0% 0% -19% -25% -33% -75% -19% 0% -21% -33% -33% 0% 0% 20% -21%

2013 -26% -56% -20% -4% -26% -27% -28% 0% 0% -22% -32% -41% -76% -24% 0% -28% -41% -41% 0% 0% 24% -27%

2014 -32% -57% -24% -5% -32% -33% -33% 0% 0% -25% -37% -48% -76% -28% 0% -34% -49% -49% 0% 0% 28% -32%

2015 -37% -57% -27% -7% -36% -38% -38% 0% 0% -28% -42% -54% -76% -32% 0% -40% -56% -56% 0% 0% 30% -36%

2016 -42% -58% -30% -9% -41% -42% -43% 0% 0% -31% -47% -60% -77% -37% 0% -46% -63% -63% 0% 0% 31% -40%

2017 -46% -59% -33% -10% -45% -46% -47% 0% 0% -34% -51% -65% -77% -40% 0% -51% -68% -68% 0% 0% 32% -44%

2018 -50% -60% -35% -12% -49% -50% -50% 0% 0% -36% -55% -69% -77% -43% 0% -56% -73% -73% 0% 0% 32% -47%

2019 -53% -60% -37% -13% -52% -53% -53% 0% 0% -38% -58% -73% -77% -45% 0% -60% -77% -77% 0% 0% 33% -50%

2020 -57% -61% -38% -14% -55% -55% -56% 0% 0% -39% -61% -76% -77% -47% 0% -64% -81% -81% 0% 0% 34% -53%

2021 -59% -62% -40% -16% -58% -57% -58% 0% 0% -41% -64% -78% -77% -49% 0% -67% -83% -83% 0% 0% 34% -55%

2022 -66% -63% -44% -19% -64% -63% -64% 0% 0% -43% -71% -84% -78% -53% 0% -74% -90% -90% 0% 0% 34% -61%

2023 -62% -62% -41% -17% -60% -59% -60% 0% 0% -42% -67% -81% -78% -51% 0% -70% -86% -86% 0% 0% 34% -58%

2024 -64% -63% -43% -18% -63% -61% -62% 0% 0% -43% -69% -82% -78% -52% 0% -72% -88% -88% 0% 0% 34% -60%

2025 -68% -64% -45% -19% -67% -64% -65% 0% 0% -44% -72% -85% -78% -54% 0% -76% -91% -91% 0% 0% 34% -63%

2026 -70% -64% -46% -20% -69% -66% -66% 0% 0% -43% -74% -86% -78% -56% 0% -79% -92% -92% 0% 0% 36% -65%

2027 -71% -64% -47% -21% -71% -67% -68% 0% 0% -43% -75% -87% -78% -56% 0% -80% -93% -93% 0% 0% 36% -66%

2028 -72% -64% -48% -21% -72% -68% -69% 0% 0% -44% -76% -88% -78% -57% 0% -81% -94% -94% 0% 0% 36% -67%

2029 -73% -65% -48% -22% -73% -69% -70% 0% 0% -45% -78% -88% -78% -58% 0% -83% -94% -94% 0% 0% 35% -68%

2030 -74% -65% -49% -22% -75% -70% -70% 0% 0% -45% -78% -89% -78% -58% 0% -84% -95% -95% 0% 0% 35% -69%

2031 -75% -65% -50% -23% -76% -70% -71% 0% 0% -47% -79% -89% -78% -59% 0% -85% -95% -95% 0% 0% 34% -70%

2032 -76% -65% -50% -23% -76% -71% -72% 0% 0% -47% -80% -89% -78% -60% 0% -85% -95% -95% 0% 0% 34% -70%

2033 -77% -66% -51% -24% -77% -72% -72% 0% 0% -48% -80% -89% -78% -61% 0% -86% -95% -95% 0% 0% 33% -71%

2034 -77% -66% -52% -24% -78% -72% -73% 0% 0% -48% -81% -90% -78% -61% 0% -86% -96% -96% 0% 0% 33% -71%

2035 -78% -66% -52% -24% -78% -73% -73% 0% 0% -48% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 33% -72%

2036 -78% -66% -53% -24% -79% -73% -74% 0% 0% -49% -81% -90% -78% -62% 0% -87% -96% -96% 0% 0% 32% -72%

2037 -78% -66% -53% -25% -79% -73% -74% 0% 0% -49% -81% -90% -78% -63% -1% -87% -96% -96% 0% 0% 32% -72%

Light-Duty Truck (%) Heavy-Duty Truck (%)

Year
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-74

2008 Chemical Injection Pump Emissions

ASSUMPTIONS

Data provided by operators in blue text

No statewide requirement for Pneumatic Pumps (Ref: OIL AND GAS PRODUCTION FACILITIES 

CHAPTER 6, SECTION 2 PERMITTING GUIDANCE, August 2007)

Table 96. Summary of Chemical Injection Pump Data.

VOC and CH4 Emissions (tons/well) = (lb/MMscf)c* Volume of Gas Vented per well

(lb/MMscf)c = Mole %(c)*(Weight (lb/lb-mol))(c)*sfc/mol

CO2 Emissions (tons/well) = (lb CO2/MMscf)* Volume of Gas Vented per well

where,

(lb/MMscf)c= lb emissions per MMscf for a particular compound

c = compound identified in Sales Gas Composition 

Mole% = Mole percentage of compound

Weight (lb/lb-mol)(c) = Molecular weight of a compound

Calculation Inputs

VOC Fraction (molar) 5.39%

VOC molecular weight 57.50

R 0.08206 L atm / K-mol

standard temp 298.15 K

standard press 1 atm

MCF to 1000 liter conversion 28.317 1000L/MCF

L/mol 24.47 L/mol

28.32 L/SCF

453.59237 mol/lb-mol

391.90 scf/lbmol

Methanol 1,381,989 1,368 47 1 - - 64.31 0.06

Glycol Heat Medium Pumps - - - 1 273 2.84 1,116.73 1.12

Total - - - - - - 1181.04 1.18

Gallons/well SCF/Gallon 

Number 

of Pump

Days 

Used in 

Quarter

SCF/Pump/Mi

 Type Gallons Used nute

Vented Volume 

(MCF/year)

Vented Volume 

(MMSCF/year)
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-75

Table 97. Uncontrolled 2008 Emissions (tons/well) Estimation by Compound.

Table 98. 2008 Chemical Injection Pump Emissions in tons per well.

Component Mole %1

Molecular 

Weight

 (lb/lb-mol)2 Weight %

lb/

MMscf

lb CO2/ 

MMscf

HHV 

(Btu/scf)2

Uncontrolled 

Emissions 

(TPY/well)

Carbon Dioxide 2.73% 44.01 6.07% 3066.1 3066.1 0 1.8106

Nitrogen 0.17% 28.01 0.24% 122.3 0 0.0722

Methane 84.90% 16.04 68.75% 34749.6 1010 20.5203

Ethane 6.81% 30.07 10.33% 5222.5 1770 3.0840

Propane 3.17% 44.10 7.05% 3564.0 2516 2.1046

Isobutane 0.64% 58.12 1.86% 942.4 3252 0.5565

n-Butane 0.71% 58.12 2.08% 1052.8 3262 0.6217

Isopentane 0.24% 72.15 0.88% 445.4 4001 0.2630

n-Pentane 0.20% 72.15 0.73% 366.5 4009 0.2164

n-Hexane 0.16% 86.18 0.69% 350.1 4756 0.2068

Cyclohexane 0.03% 84.16 0.13% 68.2 4482 0.0403

2,2-Dimethylbutane 0.00% 86.18 0.02% 9.4 4736 0.0055

2,3-Dimethylbutane 0.02% 86.18 0.07% 36.0 4745 0.0213

2-Methylpentane 0.05% 86.18 0.21% 107.2 4747 0.0633

3-Methylpentane 0.03% 86.18 0.11% 55.1 4750 0.0325

n-Heptane 0.06% 100.20 0.30% 149.9 5503 0.0885

Methylcyclohexane 0.03% 98.19 0.16% 80.6 5216 0.0476

2,2,4-Trimethylpentane 0.00% 114.23 0.02% 11.0 6249 0.0065

Benzene 0.01% 78.11 0.06% 29.8 3742 0.0176

Toluene 0.02% 92.14 0.08% 41.0 4475 0.0242

Ethylbenzene 0.00% 106.17 0.00% 1.2 5222 0.0007

m-Xylene 0.00% 106.16 0.03% 12.6 5208 0.0075

o-Xylene 0.00% 106.16 0.02% 11.0 5210 0.0065

n-Octane 0.00% 114.23 0.00% 1.8 6249 0.0010

n-Nonane 0.01% 128.26 0.09% 44.8 6996 0.0264

n-Decane 0.00% 142.29 0.00% 0.0 7743 0.0000

Total 100.00% 19.81 100.00% 50541.4 3066.1 1140.5767 29.8457

Total VOC 5.39% 14.60% 7380.8 4.3585

1 Mole percentage of the sales gas 

2

 The molecular weights and the higher heating values are from GSPA Engineering Data Book, 12th Edition.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Pneumatic Pumps 0 4.3585 0 0 0 0 1.8106 20.5203 0 0 0 active well counts

Description Projection

Chemical Injection Pump Emissions -Weighted Average(tons per well)
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-76

Table 99. Percent Change in Emission from Base Year 2008 for Chemical Injection Pump.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-77

2008 Compressor Emissions

ASSUMPTIONS

Data provided by operators in blue text

Table 100. Speciation Profiles used to Calculate CH4 and CO2 Emissions.

Table 101. Compressor Engine Emission Factors (turbine and rich burn SI).

Operator provided NOx, VOC and CO emissions for each compressor station. For remaining pollutants the unknown pollutant to NOx emission 

factor was multiplied by NOx emissions to get unknown pollutant emissions except for CH4 and CO2 either speciation profile or CO2/VOC and 

CH4/VOC weight ratio was multiplied to VOC emissions. 

Turbine CH4/VOC 2.33 SPECIATE PROFILE

4-Stroke Rich Burn CH4/VOC 8.24 SPECIATE PROFILE

Venting CH4/VOC 4.71 Sales/Produced Gas Composition

Venting CO2/VOC 0.42 Sales/Produced Gas Composition

4-Stroke Lean Burn CH4/VOC 8.24 SPECIATE PROFILE

EF (g/hp-hr) source EF (g/hp-hr) source

PM10 0.0240 EPA,AP-42 Turbine EFs 0.0704

EPA,AP-42, 4-Stroke Rich 

Burn Engine Efs

PM2.5 0.0240 EPA,AP-42 Turbine EFs 0.0704

EPA,AP-42, 4-Stroke Rich 

Burn Engine Efs

SO2 0.0000 0.0000

CO2 399.1680 EPA,AP-42 Turbine EFs 399.1680

EPA,AP-42, 4-Stroke Rich 

Burn Engine Efs

CH4 0.0210 SPECIATE Profile 0.7669 SPECIATE Profile

PM_cond 0.0171 EPA,AP-42 Turbine EFs 0.0360

EPA,AP-42, 4-Stroke Rich 

Burn Engine Efs

PM_filt 0.0069 EPA,AP-42 Turbine EFs 0.0345

EPA,AP-42, 4-Stroke Rich 

Burn Engine Efs

N2O 0.0109 EPA,AP-42 Turbine EFs 0.00076 API Compendium

Turbine

source: API Compendium Table 4-5. CH4 and N2O Combustion Emission Factors (Fuel Basis) for 

Common Industry Fuel Types - Natural Gas (tonnes/MMBtu)

Pollutant

Emission Factors

Reciprocating
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-78

Table 102. EPA AP-42 Compressor Engine Emission Factors (lean burn SI).

Pollutant

Emission Factor 

(lb/MMBTU)

Emission Factor 

(g/hp-hr)

PM_filt 7.71E-05 2.80E-04

PM_cond 9.91E-03 3.60E-02

PM10 9.99E-03 3.62E-02

PM2.5 9.99E-03 3.62E-02

CH4 1.25E+00 4.54E+00

CO2 1.10E+02 3.99E+02

N2O 0.00076

Assumed 8000 Btu/hp-hr heat input

Source: API Compendium Table 4-5. CH4 and N2O Combustion Emission 

Factors (Fuel Basis) for Common Industry Fuel Types - Natural Gas 

(tonnes/MMBtu)
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-79

Table 103. 2008 Actual Emissions (tons/year) by Facility and Process.

Station (Process) NOx VOC C O PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O Wamsutter Compressor Station (Colorado Interstate Gas) (Reciprocating Engine Rich Burn)

 - - - - - - - - - - - Wamsutter Compressor Station (Colorado Interstate Gas) (Reciprocating Engine 

Lean Burn)

 - - - - - - - - - - - Wamsutter Compressor Station (Colorado Interstate Gas) (Turbine) 155.9 22.8 109.0 7.0 7.0 2.0 291,586.4 53.2 2.0 5.0 8.0 Wamsutter Compressor Station (Colorado Interstate Gas) (Venting) - - - - - - - - - - - Wamsutter Compressor Station (Colorado Interstate Gas) (External NG Combustion)

 - - - - - - - - - - - Wamsutter Compressor Station (Colorado Interstate Gas) (Flashing) - - - - - - - - - - - Wamsutter Compressor Station (Colorado Interstate Gas) (working and breathing) - - - - - - - - - - - Wamsutter Compressor Station (Colorado Interstate Gas) (Flaring) - - - - - - - - - - -

Table Rock (Reciprocating Engine Rich Burn) 130.4 4.9 86.9 13.1 13.1 - 74,359.3 40.4 6.4 6.7 0.1

Table Rock (Reciprocating Engine Lean Burn) - - - - - - - - - - -

Table Rock (Turbine) - - - - - - - - - - -

Table Rock (Venting) - - - - - - - - - - -

Table Rock (External NG Combustion) - - - - - - - - - - -

Table Rock (Flashing) - - - - - - - - - - -

Table Rock (working and breathing) - - - - - - - - - - -

Table Rock (Flaring) - - - - - - - - - - -

Creston 221 (Reciprocating Engine Rich Burn) - - - - - - - - - - -

Creston 221 (Reciprocating Engine Lean Burn) 37.7 6.7 37.9 0.91 0.91 - 10,026.30 54.83 0.01 0.90 0.02

Creston 221 (Turbine) - - - - - - - - - - -

Creston 221 (Venting) 0.0 2.7 - - - - 1.12 12.72 - - -

Creston 221 (External NG Combustion) 2.1 0.0 1.8 0.16 0.16 0.01 2,542.57 0.05 0.04 0.12 0.05

Creston 221 (Flashing) - - - - - - - - - - -

Creston 221 (working and breathing) - - - - - - - - - - -

Creston 221 (Flaring) - - - - - - - - - - -

Fillmore Compressor Station (Reciprocating Engine Rich Burn) - - - - - - - - - - -

Fillmore Compressor Station (Reciprocating Engine Lean Burn) 6.6 14.8 12.6 0.16 0.16 - 1,764.00 121.62 0.00 0.16 0.00

Fillmore Compressor Station (Turbine) - - - - - - - - - - -

Fillmore Compressor Station (Venting) - 7.3 - - - - 3.04 34.46 - - -

Fillmore Compressor Station (External NG Combustion) 0.5 0.1 0.5 0.04 0.04 0.00 565.45 0.01 0.01 0.03 0.01

Fillmore Compressor Station (Flashing) - - - - - - - - - - -

Fillmore Compressor Station (working and breathing) - - - - - - - - - - -

Fillmore Compressor Station (Flaring) - - - - - - - - - - -

Frewen Lake Compressor Station (Reciprocating Engine Rich Burn) - - - - - - - - - - -

Frewen Lake Compressor Station (Reciprocating Engine Lean Burn) 53.8 10.0 85.5 1.30 1.30 - 14,307.43 82.56 0.01 1.29 0.03

Frewen Lake Compressor Station (Turbine) 91.9 30.2 19.1 10.32 10.32 - ######## 70.46 2.97 7.35 4.7

Frewen Lake Compressor Station (Venting) - 17.2 - - - - 7.14 80.89 - - -

Frewen Lake Compressor Station (External NG Combustion) - - - - - - - - - - -

Frewen Lake Compressor Station (Flashing) - - - - - - - - - - -

Frewen Lake Compressor Station (working and breathing) - - - - - - - - - - -

Frewen Lake Compressor Station (Flaring) - - - - - - - - - - -

Siberia Ridge Compressor Station (Reciprocating Engine Rich Burn) - - - - - - - - - - -

Siberia Ridge Compressor Station (Reciprocating Engine Lean Burn) 1.4 0.1 1.5 0.03 0.03 - 383.07 0.91 0.00 0.03 0.00

Siberia Ridge Compressor Station (Turbine) - - - - - - - - - - -

Siberia Ridge Compressor Station (Venting) - 1.1 - - - - 0.45 5.11 - - -

Siberia Ridge Compressor Station (External NG Combustion) 1.1 0.0 1.0 0.08 0.08 0.01 1,272.59 0.02 0.02 0.06 0.02

Siberia Ridge Compressor Station (Flashing) - - - - - - - - - - -

Siberia Ridge Compressor Station (working and breathing) - - - - - - - - - - -

Siberia Ridge Compressor Station (Flaring) - - - - - - - - - - -

Wamsutter Compressor Station (Rockies Express Pipeline) (Reciprocating Engine Rich Burn)

 - - - - - - - - - - - Wamsutter Compressor Station (Rockies Express Pipeline) (Reciprocating Engine 

Lean Burn)

 - - - - - - - - - - - Wamsutter Compressor Station (Rockies Express Pipeline) (Turbine) 84.3 49.1 71.5 9.5 9.5 - 157,669.9 114.6 2.7 6.7 4.3 Wamsutter Compressor Station (Rockies Express Pipeline) (Venting) - - - - - - - - - - - Wamsutter Compressor Station (Rockies Express Pipeline) (External NG Combustion)

 - - - - - - - - - - - Wamsutter Compressor Station (Rockies Express Pipeline) (Flashing) - - - - - - - - - - - Wamsutter Compressor Station (Rockies Express Pipeline) (working and 

breathing)

 - - - - - - - - - - - Wamsutter Compressor Station (Rockies Express Pipeline) (Flaring) - - - - - - - - - - -

Wamsutter A-6 Compressor Station (Marathon Oil) (Reciprocating Engine Rich 

Burn)

 - - - - - - - - - - - Wamsutter A-6 Compressor Station (Marathon Oil) (Reciprocating Engine Lean 

Burn)

 - - - - - - - - - - - Wamsutter A-6 Compressor Station (Marathon Oil) (Turbine) 40.0 42.2 13.6 4.5 4.5 - 74,813.7 98.5 1.3 3.2 2.0 Wamsutter A-6 Compressor Station (Marathon Oil) (Venting) - - - - - - - - - - - Wamsutter A-6 Compressor Station (Marathon Oil)) (External NG Combustion) - - - - - - - - - - - Wamsutter A-6 Compressor Station (Marathon Oil) (Flashing) - - - - - - - - - - - Wamsutter A-6 Compressor Station (Marathon Oil) (working and breathing) - - - - - - - - - - - Wamsutter A-6 Compressor Station (Marathon Oil) (Flaring) - - - - - - - - - - -

Table Rock Compressor Station (Chevron) (Reciprocating Engine Rich Burn) 14.8 11.6 8.1 1.5 1.5 - 8,439.6 95.6 0.7 0.8 0.0

Table Rock Compressor Station (Chevron) (Reciprocating Engine Lean Burn) - - - - - - - - - - -

Table Rock Compressor Station (Chevron) (Turbine) - - - - - - - - - - -

Table Rock Compressor Station (Chevron) (Venting) - - - - - - - - - - -

Table Rock Compressor Station (Chevron)k (External NG Combustion) - - - - - - - - - - -

Table Rock Compressor Station (Chevron) (Flashing) - - - - - - - - - - -

Table Rock Compressor Station (Chevron) (working and breathing) - - - - - - - - - - -

Table Rock Compressor Station (Chevron) (Flaring) - - - - - - - - - - -

Wamsutter A-6 Compressor Station (Marathon Oil) and Wamsutter Compressor Station (Rockies Express Pipeline) emissions assumed to be entirely from compressor engines. Assumed a turbine natural gas emission factor of 

0.21341975308642 g/hp-hr NOx to estimate CO2 and N2O emissions

Table Rock Compressor Station (Chevron) emissions assumed to be entirely from compressor engines. Assumed a spark ignition natural gas emission factor of 0.7 g/hp-hr NOx to estimate CO2 , N2O and PM emissions
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-80

Table 104. Compressor Engine Emissions in tons per activity.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Compressor Station (Reciprocating Engine Rich Burn) 145.20 16.50 95.00 14.61 14.61 0 82798.85 135.92 7.15 7.46 0.1576

totals for year with 

compressor station

Compressor Station (Reciprocating Engine Lean Burn) 99.51 31.55 137.47 2.40 2.40 0 26480.80 259.91 0.0186 2.39 0.0504

totals for year with 

compressor station

Compressor Station (Turbine) 372.14 144.30 213.20 31.27 31.27 2.00 696020.41 336.69 9.00 22.27 18.98

totals for year with 

compressor station

Compressor Station (Venting) 0.0042 28.29 0 0 0 0 11.75 133.18 0 0 0

totals for year with 

compressor station

Compressor Station (External NG Combustion) 3.65 0.1631 3.33 0.2774 0.2774 0.0219 4380.61 0.0840 0.0694 0.2081 0.0803

totals for year with 

compressor station

Compressor Station (Flashing) 0 0 0 0 0 0 0 0 0 0 0

totals for year with 

compressor station

Compressor Station (Working/Breathing) 0 0 0 0 0 0 0 0 0 0 0

totals for year with 

compressor station

Compressor Station (Flaring) 0 0 0 0 0 0 0 0 0 0 0

totals for year with 

compressor station

Description Projection Compressor Engine Emissions (tons total)
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-81

2008 Gas Plants Emissions

ASSUMPTIONS

Data provided by operators in blue text.

Table 105. Emission rates (lb/MMBTU or g/hp-hr) for estimating PM and GHG emissions.

Table 106: 2008 Actual Total Facility Emissions (tons/yr) for the Echo Springs Gas Plant

Pollutant

Echo Springs 

Gas Plant 

Emissions 

(tons/yr) 

NOx 568.1

CO 740.6

VOC 198.4

PM10 -

SO2 -

Reference Permits 0

Permit No. MD-10112

Permit date 40395

Table 107. Summary of Gas Plants Emissions in tons per year.

Operator provided the total facility NOx, VOC and CO actual emissions and permitted Nox,VOC and CO emissions by source for the 

Echo Spring Gas Plant. NOx, VOC and CO actual emissions by sources were then calculated by multiplying total facility actual 

emissions with the ratio of the gas plant permitted emissions by-source over total gas plant permitted emissions. For remaining 

pollutants, the unknown pollutant emission factor to NOx emission factor was multiplied by NOx emissions to get unknown pollutant 

emissions except for CH4 and CO2. Emissions for these pollutants were estimated either using speciation profiles or CO2/VOC and 

CH4/VOC weight ratio to VOC emissions.

Process NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

(Reciprocating Engine) 1.56 - - 0.04 0.04 0.00 399.17 4.54 0.00 0.04 0.00076

(Turbine) 0.35 - - 0.02 0.02 0.00 399.17 0.02 0.01 0.02 0.01089

(flaring) 0.068 - - 0 0 0 113 0.035 0 0 0.00131

(natural gas external combustion (boiler/heater)) 100 - - 7.6 7.6 0 120,000 2 1.9 5.7 2.2

(venting) - 14.60% - - - - 6.07% 68.75% - - -

gas fractions (wt)

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Gas Plant (Reciprocating Engine) 99.48 59.65 142.53 2.32 2.32 0 25510.69 289.89 0.0179 2.30 0.0486

totals for year 

with gas plant

Gas Plant (Turbine) 339.13 61.71 435.78 22.94 22.94 0 382382.05 20.12 6.60 16.34 10.43

totals for year 

with gas plant

Gas Plant (flaring) 40.70 38.57 110.89 0 0 0 67603.22 20.95 0 0 0.7812

totals for year 

with gas plant

Gas Plant (natural gas external 

combustion (boiler/heater)) 88.80 34.44 51.40 6.75 6.75 0 106558.39 2.04 1.69 5.06 1.95

totals for year 

with gas plant

Gas Plant (venting) 0 4.02 0 0 0 0 1.67 18.93 0 0 0

totals for year 

with gas plant

Description Gas Plant Emissions (tons total) Projection
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-82

2008 Evaporative Pond Emissions

Table 108. 2008 Emissions (tons/year) from Wamsutter North and South Evaporation Ponds.

Table 109. 2008 Average VOC emissions per well.

Table 110. VOC, CO2 and CH4 Weight Fractions (Produced Water Composition).

Table 111. 2008 Evaporation Pond Emissions in tons per well.

Parameter

Wamsutter 

North Pond

Wamsutter South 

Pond

4.67 5.85

Benzene 0.62 0.84

Ethylbenzene 0.07 0.09

Hexane (-n) 0.01 0.01

Methanol 2.09 2.31

Toluene 0.80 1.11

Xylene 0.92 1.25

Xylene (-o) 0.17 0.24

VOC Emissions (tpy)

Emissions (tpy) based on Water 9 model Output*

*based on data from evaporation facilities at Wamsutter Operations Center

Average VOC emissions per evaporation basin (tpy) 5.26

Average Evaporation Facilities per well a0.133%

Average VOC emissions per well (tpy) 0.01

a Based on two existing evaporation facilities for existing 1500 CDC wells

Methane 3.90% 0.0004

Carbon Dioxide 24.76% 0.0025

VOC Fraction (weight) 69.58%

Component % Wt Average per 

Well Emissions

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Evaporation Ponds 0 0.0070 0 0 0 0 0.0025 0.0004 0 0 0 active well counts

Description Evaporation Pond Emissions -Weighted Average(tons per well) Projection
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-83

Table 112. Percent Change in Emission from Base Year 2008 for Evaporation Ponds.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2008 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-84

Table 113. Existing Wells NOx Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 1. Existing Wells NOx Emissions (tons/year) Contribution by Source Category and by Project Year Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 293 5 1,166 52 169 32 0 0 0 570 0 0 29 0 62 20 0 568 621 0 0 3,587

2009 0 0 0 0 0 0 0 0 0 0 564 0 0 28 0 58 20 0 568 621 0 0 1,859

2010 0 0 0 0 0 0 0 0 0 0 558 0 0 28 0 51 20 0 568 621 0 0 1,845

2011 0 0 0 0 0 0 0 0 0 0 552 0 0 28 0 47 20 0 568 621 0 0 1,835

2012 0 0 0 0 0 0 0 0 0 0 547 0 0 27 0 46 19 0 568 621 0 0 1,828

2013 0 0 0 0 0 0 0 0 0 0 541 0 0 27 0 46 19 0 568 621 0 0 1,822

2014 0 0 0 0 0 0 0 0 0 0 536 0 0 27 0 44 19 0 568 621 0 0 1,814

2015 0 0 0 0 0 0 0 0 0 0 531 0 0 26 0 42 19 0 568 621 0 0 1,806

2016 0 0 0 0 0 0 0 0 0 0 525 0 0 26 0 40 19 0 568 621 0 0 1,798

2017 0 0 0 0 0 0 0 0 0 0 520 0 0 26 0 38 18 0 568 621 0 0 1,791

2018 0 0 0 0 0 0 0 0 0 0 515 0 0 26 0 37 18 0 568 621 0 0 1,784

2019 0 0 0 0 0 0 0 0 0 0 509 0 0 25 0 35 18 0 568 621 0 0 1,777

2020 0 0 0 0 0 0 0 0 0 0 504 0 0 25 0 34 18 0 568 621 0 0 1,770

2021 0 0 0 0 0 0 0 0 0 0 499 0 0 25 0 33 18 0 568 621 0 0 1,764

2022 0 0 0 0 0 0 0 0 0 0 495 0 0 24 0 32 17 0 568 621 0 0 1,757

2023 0 0 0 0 0 0 0 0 0 0 490 0 0 24 0 31 17 0 568 621 0 0 1,750

2024 0 0 0 0 0 0 0 0 0 0 485 0 0 24 0 30 17 0 568 621 0 0 1,744

2025 0 0 0 0 0 0 0 0 0 0 480 0 0 24 0 29 17 0 568 621 0 0 1,738

2026 0 0 0 0 0 0 0 0 0 0 475 0 0 23 0 28 17 0 568 621 0 0 1,732

2027 0 0 0 0 0 0 0 0 0 0 470 0 0 23 0 28 17 0 568 621 0 0 1,726

2028 0 0 0 0 0 0 0 0 0 0 461 0 0 23 0 27 16 0 568 621 0 0 1,715

2029 0 0 0 0 0 0 0 0 0 0 456 0 0 23 0 26 16 0 568 621 0 0 1,709

2030 0 0 0 0 0 0 0 0 0 0 452 0 0 22 0 25 16 0 568 621 0 0 1,704

2031 0 0 0 0 0 0 0 0 0 0 447 0 0 22 0 25 16 0 568 621 0 0 1,698

2032 0 0 0 0 0 0 0 0 0 0 443 0 0 22 0 24 16 0 568 621 0 0 1,693

2033 0 0 0 0 0 0 0 0 0 0 438 0 0 22 0 23 15 0 568 621 0 0 1,688

2034 0 0 0 0 0 0 0 0 0 0 434 0 0 21 0 23 15 0 568 621 0 0 1,682

2035 0 0 0 0 0 0 0 0 0 0 429 0 0 21 0 23 15 0 568 621 0 0 1,677

2036 0 0 0 0 0 0 0 0 0 0 425 0 0 21 0 22 15 0 568 621 0 0 1,672

2037 0 0 0 0 0 0 0 0 0 0 420 0 0 21 0 22 15 0 568 621 0 0 1,666

TOTAL 0 293 5 1,166 52 169 32 0 0 0 14,770 0 0 733 0 1,029 522 0 17,043 18,615 0 0 54,431

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

NOx [tpy]

0

720

1,440

2,160

2,880

3,600

4,320

5,040

5,760

6,480

7,200

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well NOx Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-85

Table 114. Existing Wells VOC Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 2. Existing Wells VOC Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 44 1 106 6 0 4 130 27,096 1,904 31 0 12,422 7 197 79 2 2,133 198 221 14,072 20 58,672

2009 0 0 0 0 0 0 0 0 26,548 1,885 31 0 12,295 7 185 75 2 2,111 198 221 13,311 20 56,889

2010 0 0 0 0 0 0 0 0 25,484 1,866 31 0 12,169 7 159 66 2 2,089 198 221 11,585 20 53,896

2011 0 0 0 0 0 0 0 0 24,751 1,846 30 0 12,042 7 145 61 2 2,067 198 221 10,624 19 52,014

2012 0 0 0 0 0 0 0 0 24,463 1,828 30 0 11,925 7 142 60 2 2,047 198 221 10,438 19 51,381

2013 0 0 0 0 0 0 0 0 24,206 1,810 30 0 11,808 7 141 59 2 2,027 198 221 10,307 19 50,835

2014 0 0 0 0 0 0 0 0 23,736 1,792 29 0 11,692 6 133 56 2 2,007 198 221 9,821 19 49,714

2015 0 0 0 0 0 0 0 0 23,244 1,774 29 0 11,575 6 126 54 2 1,987 198 221 9,316 19 48,551

2016 0 0 0 0 0 0 0 0 22,781 1,757 29 0 11,458 6 120 51 2 1,967 198 221 8,875 18 47,484

2017 0 0 0 0 0 0 0 0 22,347 1,739 29 0 11,341 6 114 49 2 1,947 198 221 8,490 18 46,501

2018 0 0 0 0 0 0 0 0 21,938 1,721 28 0 11,224 6 109 47 2 1,927 198 221 8,150 18 45,590

2019 0 0 0 0 0 0 0 0 21,545 1,703 28 0 11,108 6 104 46 2 1,907 198 221 7,840 18 44,725

2020 0 0 0 0 0 0 0 0 21,179 1,686 28 0 11,000 6 100 44 2 1,889 198 221 7,555 18 43,925

2021 0 0 0 0 0 0 0 0 20,830 1,670 27 0 10,893 6 96 43 2 1,870 198 221 7,298 18 43,173

2022 0 0 0 0 0 0 0 0 20,403 1,654 27 0 10,786 6 91 41 2 1,852 198 221 6,951 17 42,249

2023 0 0 0 0 0 0 0 0 20,072 1,637 27 0 10,679 6 88 39 2 1,833 198 221 6,729 17 41,549

2024 0 0 0 0 0 0 0 0 19,751 1,621 27 0 10,572 6 85 38 2 1,815 198 221 6,521 17 40,874

2025 0 0 0 0 0 0 0 0 19,449 1,604 26 0 10,465 6 83 37 2 1,797 198 221 6,340 17 40,245

2026 0 0 0 0 0 0 0 0 19,149 1,588 26 0 10,358 6 80 36 2 1,778 198 221 6,162 17 39,621

2027 0 0 0 0 0 0 0 0 18,858 1,572 26 0 10,251 6 78 35 2 1,760 198 221 5,996 16 39,018

2028 0 0 0 0 0 0 0 0 18,445 1,540 25 0 10,046 6 76 35 2 1,725 198 221 5,837 16 38,171

2029 0 0 0 0 0 0 0 0 18,076 1,525 25 0 9,949 5 72 33 2 1,708 198 221 5,580 16 37,410

2030 0 0 0 0 0 0 0 0 17,816 1,510 25 0 9,852 5 70 32 2 1,691 198 221 5,440 16 36,879

2031 0 0 0 0 0 0 0 0 17,564 1,495 25 0 9,754 5 68 32 2 1,675 198 221 5,310 16 36,364

2032 0 0 0 0 0 0 0 0 17,314 1,480 24 0 9,657 5 66 31 2 1,658 198 221 5,184 16 35,856

2033 0 0 0 0 0 0 0 0 17,066 1,466 24 0 9,560 5 64 30 2 1,641 198 221 5,060 15 35,353

2034 0 0 0 0 0 0 0 0 16,826 1,451 24 0 9,462 5 63 30 2 1,624 198 221 4,945 15 34,866

2035 0 0 0 0 0 0 0 0 16,591 1,436 24 0 9,365 5 61 29 2 1,608 198 221 4,836 15 34,390

2036 0 0 0 0 0 0 0 0 16,367 1,421 23 0 9,268 5 60 28 2 1,591 198 221 4,738 15 33,938

2037 0 0 0 0 0 0 0 0 16,146 1,406 23 0 9,170 5 59 28 2 1,574 198 221 4,643 15 33,490

TOTAL 0 44 1 106 6 0 4 130 620,038 49,387 812 0 322,148 178 3,035 1,324 55 55,305 5,952 6,624 227,956 518 1,293,623

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

VOC [tpy]

0

6,160

12,320

18,480

24,640

30,800

36,960

43,120

49,280

55,440

61,600

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well VOC Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-86

Table 115. Existing Wells SO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 3. Existing Wells SO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 5 0 71 0 56 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 135

2009 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2010 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2011 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2012 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2013 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2014 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2015 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2016 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2017 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2018 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2019 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2020 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2021 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2022 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2023 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2024 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2025 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2026 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2027 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2028 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2029 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2030 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2031 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2032 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2033 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2034 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2035 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2036 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

2037 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2

TOTAL 0 5 0 71 0 56 0 0 0 0 0 0 0 4 0 0 1 0 0 61 0 0 198

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

SO2 [tpy]

0.0

14.0

28.0

42.0

56.0

70.0

84.0

98.0

112.0

126.0

140.0

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well SO2 Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-87

Table 116. Existing Wells PM10 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 4. Existing Wells PM10 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 194 18 32 56 298 12 188 0 0 0 43 0 0 379 0 0 1 0 32 49 0 0 1,302

2009 0 0 0 0 0 0 0 0 0 0 43 0 0 375 0 0 1 0 32 49 0 0 500

2010 0 0 0 0 0 0 0 0 0 0 42 0 0 371 0 0 1 0 32 49 0 0 496

2011 0 0 0 0 0 0 0 0 0 0 42 0 0 368 0 0 1 0 32 49 0 0 491

2012 0 0 0 0 0 0 0 0 0 0 42 0 0 364 0 0 1 0 32 49 0 0 487

2013 0 0 0 0 0 0 0 0 0 0 41 0 0 360 0 0 1 0 32 49 0 0 483

2014 0 0 0 0 0 0 0 0 0 0 41 0 0 357 0 0 1 0 32 49 0 0 479

2015 0 0 0 0 0 0 0 0 0 0 40 0 0 353 0 0 1 0 32 49 0 0 475

2016 0 0 0 0 0 0 0 0 0 0 40 0 0 350 0 0 1 0 32 49 0 0 471

2017 0 0 0 0 0 0 0 0 0 0 40 0 0 346 0 0 1 0 32 49 0 0 467

2018 0 0 0 0 0 0 0 0 0 0 39 0 0 343 0 0 1 0 32 49 0 0 464

2019 0 0 0 0 0 0 0 0 0 0 39 0 0 339 0 0 1 0 32 49 0 0 460

2020 0 0 0 0 0 0 0 0 0 0 38 0 0 336 0 0 1 0 32 49 0 0 456

2021 0 0 0 0 0 0 0 0 0 0 38 0 0 332 0 0 1 0 32 49 0 0 452

2022 0 0 0 0 0 0 0 0 0 0 38 0 0 329 0 0 1 0 32 49 0 0 449

2023 0 0 0 0 0 0 0 0 0 0 37 0 0 326 0 0 1 0 32 49 0 0 445

2024 0 0 0 0 0 0 0 0 0 0 37 0 0 323 0 0 1 0 32 49 0 0 441

2025 0 0 0 0 0 0 0 0 0 0 36 0 0 319 0 0 1 0 32 49 0 0 438

2026 0 0 0 0 0 0 0 0 0 0 36 0 0 316 0 0 1 0 32 49 0 0 434

2027 0 0 0 0 0 0 0 0 0 0 36 0 0 313 0 0 1 0 32 49 0 0 430

2028 0 0 0 0 0 0 0 0 0 0 35 0 0 307 0 0 1 0 32 49 0 0 423

2029 0 0 0 0 0 0 0 0 0 0 35 0 0 304 0 0 1 0 32 49 0 0 420

2030 0 0 0 0 0 0 0 0 0 0 34 0 0 301 0 0 1 0 32 49 0 0 417

2031 0 0 0 0 0 0 0 0 0 0 34 0 0 298 0 0 1 0 32 49 0 0 413

2032 0 0 0 0 0 0 0 0 0 0 34 0 0 295 0 0 1 0 32 49 0 0 410

2033 0 0 0 0 0 0 0 0 0 0 33 0 0 292 0 0 1 0 32 49 0 0 407

2034 0 0 0 0 0 0 0 0 0 0 33 0 0 289 0 0 1 0 32 49 0 0 403

2035 0 0 0 0 0 0 0 0 0 0 33 0 0 286 0 0 1 0 32 49 0 0 400

2036 0 0 0 0 0 0 0 0 0 0 32 0 0 283 0 0 1 0 32 49 0 0 397

2037 0 0 0 0 0 0 0 0 0 0 32 0 0 280 0 0 1 0 32 49 0 0 393

TOTAL 194 18 32 56 298 12 188 0 0 0 1,123 0 0 9,833 0 0 35 0 960 1,457 0 0 14,206

Production Total (Costruction + 

Drilling + Completion 

+ Production)

PM10 [tpy]

Pollutant Year

Construction Drilling Completion

0

284

568

852

1,136

1,420

1,704

1,988

2,272

2,556

2,840

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well PM10 Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-88

Table 117. Existing Wells PM2.5 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 5. Existing Wells PM2.5 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 50 17 3 54 32 12 20 0 0 0 43 0 0 39 0 0 1 0 32 49 0 0 353

2009 0 0 0 0 0 0 0 0 0 0 43 0 0 39 0 0 1 0 32 49 0 0 163

2010 0 0 0 0 0 0 0 0 0 0 42 0 0 38 0 0 1 0 32 49 0 0 162

2011 0 0 0 0 0 0 0 0 0 0 42 0 0 38 0 0 1 0 32 49 0 0 162

2012 0 0 0 0 0 0 0 0 0 0 42 0 0 37 0 0 1 0 32 49 0 0 161

2013 0 0 0 0 0 0 0 0 0 0 41 0 0 37 0 0 1 0 32 49 0 0 160

2014 0 0 0 0 0 0 0 0 0 0 41 0 0 37 0 0 1 0 32 49 0 0 159

2015 0 0 0 0 0 0 0 0 0 0 40 0 0 36 0 0 1 0 32 49 0 0 158

2016 0 0 0 0 0 0 0 0 0 0 40 0 0 36 0 0 1 0 32 49 0 0 158

2017 0 0 0 0 0 0 0 0 0 0 40 0 0 36 0 0 1 0 32 49 0 0 157

2018 0 0 0 0 0 0 0 0 0 0 39 0 0 35 0 0 1 0 32 49 0 0 156

2019 0 0 0 0 0 0 0 0 0 0 39 0 0 35 0 0 1 0 32 49 0 0 155

2020 0 0 0 0 0 0 0 0 0 0 38 0 0 34 0 0 1 0 32 49 0 0 155

2021 0 0 0 0 0 0 0 0 0 0 38 0 0 34 0 0 1 0 32 49 0 0 154

2022 0 0 0 0 0 0 0 0 0 0 38 0 0 34 0 0 1 0 32 49 0 0 153

2023 0 0 0 0 0 0 0 0 0 0 37 0 0 33 0 0 1 0 32 49 0 0 152

2024 0 0 0 0 0 0 0 0 0 0 37 0 0 33 0 0 1 0 32 49 0 0 152

2025 0 0 0 0 0 0 0 0 0 0 36 0 0 33 0 0 1 0 32 49 0 0 151

2026 0 0 0 0 0 0 0 0 0 0 36 0 0 32 0 0 1 0 32 49 0 0 150

2027 0 0 0 0 0 0 0 0 0 0 36 0 0 32 0 0 1 0 32 49 0 0 149

2028 0 0 0 0 0 0 0 0 0 0 35 0 0 31 0 0 1 0 32 49 0 0 148

2029 0 0 0 0 0 0 0 0 0 0 35 0 0 31 0 0 1 0 32 49 0 0 147

2030 0 0 0 0 0 0 0 0 0 0 34 0 0 31 0 0 1 0 32 49 0 0 147

2031 0 0 0 0 0 0 0 0 0 0 34 0 0 31 0 0 1 0 32 49 0 0 146

2032 0 0 0 0 0 0 0 0 0 0 34 0 0 30 0 0 1 0 32 49 0 0 145

2033 0 0 0 0 0 0 0 0 0 0 33 0 0 30 0 0 1 0 32 49 0 0 145

2034 0 0 0 0 0 0 0 0 0 0 33 0 0 30 0 0 1 0 32 49 0 0 144

2035 0 0 0 0 0 0 0 0 0 0 33 0 0 29 0 0 1 0 32 49 0 0 144

2036 0 0 0 0 0 0 0 0 0 0 32 0 0 29 0 0 1 0 32 49 0 0 143

2037 0 0 0 0 0 0 0 0 0 0 32 0 0 29 0 0 1 0 32 49 0 0 142

TOTAL 50 17 3 54 32 12 20 0 0 0 1,123 0 0 1,009 0 0 34 0 960 1,457 0 0 4,772

Production Total (Costruction + 

Drilling + Completion 

+ Production)

PM2.5 [tpy]

Pollutant Year

Construction Drilling Completion

0

67

134

201

268

335

402

469

536

603

670

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well PM2.5 Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-89

Table 118. Existing Wells CO Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 6. Existing Wells CO Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 362 6 504 56 132 36 0 0 0 478 0 0 79 0 335 8 0 741 449 0 0 3,185

2009 0 0 0 0 0 0 0 0 0 0 474 0 0 78 0 317 8 0 741 449 0 0 2,066

2010 0 0 0 0 0 0 0 0 0 0 469 0 0 77 0 278 8 0 741 449 0 0 2,022

2011 0 0 0 0 0 0 0 0 0 0 464 0 0 76 0 257 8 0 741 449 0 0 1,994

2012 0 0 0 0 0 0 0 0 0 0 459 0 0 75 0 252 8 0 741 449 0 0 1,984

2013 0 0 0 0 0 0 0 0 0 0 455 0 0 74 0 249 8 0 741 449 0 0 1,976

2014 0 0 0 0 0 0 0 0 0 0 450 0 0 74 0 238 8 0 741 449 0 0 1,959

2015 0 0 0 0 0 0 0 0 0 0 446 0 0 73 0 226 8 0 741 449 0 0 1,943

2016 0 0 0 0 0 0 0 0 0 0 441 0 0 72 0 216 8 0 741 449 0 0 1,927

2017 0 0 0 0 0 0 0 0 0 0 437 0 0 71 0 208 8 0 741 449 0 0 1,913

2018 0 0 0 0 0 0 0 0 0 0 432 0 0 71 0 200 7 0 741 449 0 0 1,900

2019 0 0 0 0 0 0 0 0 0 0 428 0 0 70 0 193 7 0 741 449 0 0 1,887

2020 0 0 0 0 0 0 0 0 0 0 424 0 0 69 0 186 7 0 741 449 0 0 1,876

2021 0 0 0 0 0 0 0 0 0 0 420 0 0 69 0 180 7 0 741 449 0 0 1,865

2022 0 0 0 0 0 0 0 0 0 0 415 0 0 68 0 172 7 0 741 449 0 0 1,852

2023 0 0 0 0 0 0 0 0 0 0 411 0 0 67 0 167 7 0 741 449 0 0 1,842

2024 0 0 0 0 0 0 0 0 0 0 407 0 0 66 0 162 7 0 741 449 0 0 1,832

2025 0 0 0 0 0 0 0 0 0 0 403 0 0 66 0 158 7 0 741 449 0 0 1,823

2026 0 0 0 0 0 0 0 0 0 0 399 0 0 65 0 154 7 0 741 449 0 0 1,814

2027 0 0 0 0 0 0 0 0 0 0 395 0 0 64 0 150 7 0 741 449 0 0 1,806

2028 0 0 0 0 0 0 0 0 0 0 387 0 0 63 0 146 7 0 741 449 0 0 1,792

2029 0 0 0 0 0 0 0 0 0 0 383 0 0 63 0 140 7 0 741 449 0 0 1,782

2030 0 0 0 0 0 0 0 0 0 0 379 0 0 62 0 137 7 0 741 449 0 0 1,774

2031 0 0 0 0 0 0 0 0 0 0 376 0 0 61 0 134 7 0 741 449 0 0 1,767

2032 0 0 0 0 0 0 0 0 0 0 372 0 0 61 0 131 6 0 741 449 0 0 1,759

2033 0 0 0 0 0 0 0 0 0 0 368 0 0 60 0 128 6 0 741 449 0 0 1,752

2034 0 0 0 0 0 0 0 0 0 0 364 0 0 59 0 125 6 0 741 449 0 0 1,745

2035 0 0 0 0 0 0 0 0 0 0 361 0 0 59 0 122 6 0 741 449 0 0 1,738

2036 0 0 0 0 0 0 0 0 0 0 357 0 0 58 0 120 6 0 741 449 0 0 1,731

2037 0 0 0 0 0 0 0 0 0 0 353 0 0 58 0 118 6 0 741 449 0 0 1,724

TOTAL 0 362 6 504 56 132 36 0 0 0 12,407 0 0 2,028 0 5,598 215 0 22,218 13,470 0 0 57,031

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

CO [tpy]

0

1,100

2,200

3,300

4,400

5,500

6,600

7,700

8,800

9,900

11,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well CO Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-90

Table 119. Existing Wells Formaldehyde Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 7. Existing Wells Formaldehyde Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 4 0 9 0 0 0 0 0 0 3 0 0 0 0 32 0 0 85 148 0 0 282

2009 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 30 0 0 85 148 0 0 267

2010 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 26 0 0 85 148 0 0 263

2011 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 24 0 0 85 148 0 0 261

2012 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 24 0 0 85 148 0 0 260

2013 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 24 0 0 85 148 0 0 260

2014 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 23 0 0 85 148 0 0 259

2015 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 21 0 0 85 148 0 0 258

2016 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 20 0 0 85 148 0 0 257

2017 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 20 0 0 85 148 0 0 256

2018 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 19 0 0 85 148 0 0 255

2019 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 18 0 0 85 148 0 0 254

2020 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 18 0 0 85 148 0 0 254

2021 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 17 0 0 85 148 0 0 253

2022 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 16 0 0 85 148 0 0 252

2023 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 16 0 0 85 148 0 0 252

2024 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 15 0 0 85 148 0 0 251

2025 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 15 0 0 85 148 0 0 251

2026 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 15 0 0 85 148 0 0 251

2027 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 14 0 0 85 148 0 0 250

2028 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 14 0 0 85 148 0 0 250

2029 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 13 0 0 85 148 0 0 249

2030 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 13 0 0 85 148 0 0 249

2031 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 13 0 0 85 148 0 0 249

2032 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 12 0 0 85 148 0 0 248

2033 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 12 0 0 85 148 0 0 248

2034 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 12 0 0 85 148 0 0 248

2035 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 12 0 0 85 148 0 0 247

2036 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 11 0 0 85 148 0 0 247

2037 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 11 0 0 85 148 0 0 247

TOTAL 0 4 0 9 0 0 0 0 0 0 65 0 0 7 0 530 5 0 2,553 4,455 0 0 7,627

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

formaldehyde 

[tpy]

0

84

168

252

336

420

504

588

672

756

840

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well Formaldehyde Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-91

Table 120. Existing Wells n-hexane Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 8. Existing Wells n-hexane Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 3 708 80 0 0 589 0 7 0 0 42 0 1 547 0 1,978

2009 0 0 0 0 0 0 0 0 694 79 0 0 583 0 6 0 0 42 0 1 517 0 1,924

2010 0 0 0 0 0 0 0 0 666 79 0 0 577 0 5 0 0 41 0 1 450 0 1,820

2011 0 0 0 0 0 0 0 0 647 78 0 0 571 0 5 0 0 41 0 1 412 0 1,756

2012 0 0 0 0 0 0 0 0 639 77 0 0 566 0 5 0 0 41 0 1 405 0 1,734

2013 0 0 0 0 0 0 0 0 633 76 0 0 560 0 5 0 0 40 0 1 400 0 1,716

2014 0 0 0 0 0 0 0 0 620 76 0 0 555 0 5 0 0 40 0 1 381 0 1,677

2015 0 0 0 0 0 0 0 0 607 75 0 0 549 0 4 0 0 39 0 1 361 0 1,638

2016 0 0 0 0 0 0 0 0 595 74 0 0 544 0 4 0 0 39 0 1 344 0 1,601

2017 0 0 0 0 0 0 0 0 584 73 0 0 538 0 4 0 0 39 0 1 328 0 1,568

2018 0 0 0 0 0 0 0 0 573 73 0 0 532 0 4 0 0 38 0 1 315 0 1,537

2019 0 0 0 0 0 0 0 0 563 72 0 0 527 0 4 0 0 38 0 1 303 0 1,508

2020 0 0 0 0 0 0 0 0 553 71 0 0 522 0 3 0 0 37 0 1 292 0 1,481

2021 0 0 0 0 0 0 0 0 544 70 0 0 517 0 3 0 0 37 0 1 282 0 1,456

2022 0 0 0 0 0 0 0 0 533 70 0 0 512 0 3 0 0 37 0 1 268 0 1,425

2023 0 0 0 0 0 0 0 0 525 69 0 0 507 0 3 0 0 36 0 1 260 0 1,401

2024 0 0 0 0 0 0 0 0 516 68 0 0 502 0 3 0 0 36 0 1 252 0 1,378

2025 0 0 0 0 0 0 0 0 508 68 0 0 496 0 3 0 0 36 0 1 244 0 1,357

2026 0 0 0 0 0 0 0 0 500 67 0 0 491 0 3 0 0 35 0 1 237 0 1,336

2027 0 0 0 0 0 0 0 0 493 66 0 0 486 0 3 0 0 35 0 1 231 0 1,316

2028 0 0 0 0 0 0 0 0 482 65 0 0 477 0 3 0 0 34 0 1 225 0 1,287

2029 0 0 0 0 0 0 0 0 472 64 0 0 472 0 2 0 0 34 0 1 215 0 1,262

2030 0 0 0 0 0 0 0 0 466 64 0 0 467 0 2 0 0 34 0 1 209 0 1,244

2031 0 0 0 0 0 0 0 0 459 63 0 0 463 0 2 0 0 33 0 1 204 0 1,226

2032 0 0 0 0 0 0 0 0 452 62 0 0 458 0 2 0 0 33 0 1 199 0 1,209

2033 0 0 0 0 0 0 0 0 446 62 0 0 453 0 2 0 0 33 0 1 195 0 1,192

2034 0 0 0 0 0 0 0 0 440 61 0 0 449 0 2 0 0 32 0 1 190 0 1,176

2035 0 0 0 0 0 0 0 0 434 61 0 0 444 0 2 0 0 32 0 1 186 0 1,160

2036 0 0 0 0 0 0 0 0 428 60 0 0 440 0 2 0 0 32 0 1 182 0 1,145

2037 0 0 0 0 0 0 0 0 422 59 0 0 435 0 2 0 0 31 0 1 178 0 1,130

TOTAL 0 0 0 0 0 0 0 3 16,202 2,083 0 0 15,282 1 103 0 0 1,097 10 43 8,812 1 43,638

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

n-hexane [tpy]

0

208

416

624

832

1,040

1,248

1,456

1,664

1,872

2,080

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well n-hexane Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-92

Table 121. Existing Wells Benzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 9. Existing Wells Benzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 1 0 0 0 1 2,610 13 1 0 50 0 1 0 0 9 2 1 112 3 2,804

2009 0 0 0 0 0 0 0 0 2,557 13 1 0 50 0 1 0 0 9 2 1 106 3 2,742

2010 0 0 0 0 0 0 0 0 2,454 13 1 0 49 0 1 0 0 9 2 1 92 3 2,624

2011 0 0 0 0 0 0 0 0 2,384 13 1 0 49 0 1 0 0 9 2 1 84 3 2,545

2012 0 0 0 0 0 0 0 0 2,356 13 1 0 48 0 1 0 0 8 2 1 82 3 2,515

2013 0 0 0 0 0 0 0 0 2,331 13 1 0 48 0 1 0 0 8 2 1 81 3 2,489

2014 0 0 0 0 0 0 0 0 2,286 12 1 0 47 0 1 0 0 8 2 1 77 3 2,439

2015 0 0 0 0 0 0 0 0 2,239 12 1 0 47 0 1 0 0 8 2 1 73 3 2,386

2016 0 0 0 0 0 0 0 0 2,194 12 1 0 46 0 1 0 0 8 2 1 70 3 2,337

2017 0 0 0 0 0 0 0 0 2,152 12 1 0 46 0 1 0 0 8 2 1 67 3 2,292

2018 0 0 0 0 0 0 0 0 2,113 12 1 0 45 0 1 0 0 8 2 1 64 3 2,249

2019 0 0 0 0 0 0 0 0 2,075 12 1 0 45 0 0 0 0 8 2 1 61 2 2,208

2020 0 0 0 0 0 0 0 0 2,040 12 1 0 44 0 0 0 0 8 2 1 59 2 2,169

2021 0 0 0 0 0 0 0 0 2,006 12 1 0 44 0 0 0 0 8 2 1 57 2 2,133

2022 0 0 0 0 0 0 0 0 1,965 11 1 0 43 0 0 0 0 8 2 1 54 2 2,088

2023 0 0 0 0 0 0 0 0 1,933 11 1 0 43 0 0 0 0 8 2 1 52 2 2,054

2024 0 0 0 0 0 0 0 0 1,902 11 1 0 43 0 0 0 0 8 2 1 51 2 2,021

2025 0 0 0 0 0 0 0 0 1,873 11 1 0 42 0 0 0 0 7 2 1 49 2 1,990

2026 0 0 0 0 0 0 0 0 1,844 11 1 0 42 0 0 0 0 7 2 1 48 2 1,959

2027 0 0 0 0 0 0 0 0 1,816 11 1 0 41 0 0 0 0 7 2 1 46 2 1,929

2028 0 0 0 0 0 0 0 0 1,776 11 1 0 40 0 0 0 0 7 2 1 45 2 1,886

2029 0 0 0 0 0 0 0 0 1,741 11 1 0 40 0 0 0 0 7 2 1 43 2 1,848

2030 0 0 0 0 0 0 0 0 1,716 10 1 0 40 0 0 0 0 7 2 1 42 2 1,821

2031 0 0 0 0 0 0 0 0 1,691 10 1 0 39 0 0 0 0 7 2 1 41 2 1,795

2032 0 0 0 0 0 0 0 0 1,667 10 1 0 39 0 0 0 0 7 2 1 40 2 1,770

2033 0 0 0 0 0 0 0 0 1,644 10 1 0 39 0 0 0 0 7 2 1 39 2 1,744

2034 0 0 0 0 0 0 0 0 1,620 10 1 0 38 0 0 0 0 7 2 1 38 2 1,720

2035 0 0 0 0 0 0 0 0 1,598 10 1 0 38 0 0 0 0 7 2 1 37 2 1,696

2036 0 0 0 0 0 0 0 0 1,576 10 1 0 37 0 0 0 0 7 2 1 36 2 1,673

2037 0 0 0 0 0 0 0 0 1,555 10 1 0 37 0 0 0 0 7 2 1 36 2 1,650

TOTAL 0 0 0 1 0 0 0 1 59,713 341 32 0 1,299 5 14 0 1 229 63 21 1,783 72 63,576

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

benzene [tpy]

0

294

588

882

1,176

1,471

1,765

2,059

2,353

2,647

2,941

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well Benzene Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-93

Table 122. Existing Wells Ethylbenzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 10. Existing Wells Ethylbenzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 160 0 0 0 2 0 0 0 0 0 0 0 2 0 166

2009 0 0 0 0 0 0 0 0 157 0 0 0 2 0 0 0 0 0 0 0 2 0 162

2010 0 0 0 0 0 0 0 0 151 0 0 0 2 0 0 0 0 0 0 0 2 0 156

2011 0 0 0 0 0 0 0 0 146 0 0 0 2 0 0 0 0 0 0 0 2 0 151

2012 0 0 0 0 0 0 0 0 145 0 0 0 2 0 0 0 0 0 0 0 2 0 149

2013 0 0 0 0 0 0 0 0 143 0 0 0 2 0 0 0 0 0 0 0 2 0 148

2014 0 0 0 0 0 0 0 0 140 0 0 0 2 0 0 0 0 0 0 0 1 0 145

2015 0 0 0 0 0 0 0 0 137 0 0 0 2 0 0 0 0 0 0 0 1 0 142

2016 0 0 0 0 0 0 0 0 135 0 0 0 2 0 0 0 0 0 0 0 1 0 139

2017 0 0 0 0 0 0 0 0 132 0 0 0 2 0 0 0 0 0 0 0 1 0 136

2018 0 0 0 0 0 0 0 0 130 0 0 0 2 0 0 0 0 0 0 0 1 0 134

2019 0 0 0 0 0 0 0 0 127 0 0 0 2 0 0 0 0 0 0 0 1 0 132

2020 0 0 0 0 0 0 0 0 125 0 0 0 2 0 0 0 0 0 0 0 1 0 129

2021 0 0 0 0 0 0 0 0 123 0 0 0 2 0 0 0 0 0 0 0 1 0 127

2022 0 0 0 0 0 0 0 0 121 0 0 0 2 0 0 0 0 0 0 0 1 0 125

2023 0 0 0 0 0 0 0 0 119 0 0 0 2 0 0 0 0 0 0 0 1 0 123

2024 0 0 0 0 0 0 0 0 117 0 0 0 2 0 0 0 0 0 0 0 1 0 121

2025 0 0 0 0 0 0 0 0 115 0 0 0 2 0 0 0 0 0 0 0 1 0 119

2026 0 0 0 0 0 0 0 0 113 0 0 0 2 0 0 0 0 0 0 0 1 0 117

2027 0 0 0 0 0 0 0 0 112 0 0 0 2 0 0 0 0 0 0 0 1 0 115

2028 0 0 0 0 0 0 0 0 109 0 0 0 2 0 0 0 0 0 0 0 1 0 113

2029 0 0 0 0 0 0 0 0 107 0 0 0 2 0 0 0 0 0 0 0 1 0 110

2030 0 0 0 0 0 0 0 0 105 0 0 0 2 0 0 0 0 0 0 0 1 0 109

2031 0 0 0 0 0 0 0 0 104 0 0 0 2 0 0 0 0 0 0 0 1 0 107

2032 0 0 0 0 0 0 0 0 102 0 0 0 2 0 0 0 0 0 0 0 1 0 106

2033 0 0 0 0 0 0 0 0 101 0 0 0 2 0 0 0 0 0 0 0 1 0 104

2034 0 0 0 0 0 0 0 0 100 0 0 0 2 0 0 0 0 0 0 0 1 0 103

2035 0 0 0 0 0 0 0 0 98 0 0 0 2 0 0 0 0 0 0 0 1 0 101

2036 0 0 0 0 0 0 0 0 97 0 0 0 2 0 0 0 0 0 0 0 1 0 100

2037 0 0 0 0 0 0 0 0 96 0 0 0 2 0 0 0 0 0 0 0 1 0 99

TOTAL 0 0 0 0 0 0 0 0 3,667 8 0 0 54 2 0 0 0 10 2 2 34 8 3,788

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

ethylbenzene 

[tpy]

0

1 7

3 5

5 2

7 0

8 7

104

122

139

157

174

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well Ethylbenzene Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-94

Table 123. Existing Wells Toluene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 11. Existing Wells Toluene Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 1 0 2 0 0 0 1 4,310 18 1 0 69 1 1 0 0 12 1 0 159 4 4,579

2009 0 0 0 0 0 0 0 0 4,222 18 1 0 68 1 1 0 0 12 1 0 151 4 4,479

2010 0 0 0 0 0 0 0 0 4,053 18 1 0 68 1 1 0 0 12 1 0 130 4 4,288

2011 0 0 0 0 0 0 0 0 3,937 18 1 0 67 1 1 0 0 12 1 0 119 3 4,159

2012 0 0 0 0 0 0 0 0 3,891 18 1 0 66 1 1 0 0 12 1 0 117 3 4,110

2013 0 0 0 0 0 0 0 0 3,850 18 1 0 66 1 1 0 0 12 1 0 116 3 4,067

2014 0 0 0 0 0 0 0 0 3,775 17 1 0 65 1 1 0 0 11 1 0 110 3 3,985

2015 0 0 0 0 0 0 0 0 3,697 17 1 0 64 0 1 0 0 11 1 0 104 3 3,900

2016 0 0 0 0 0 0 0 0 3,623 17 1 0 64 0 1 0 0 11 1 0 99 3 3,821

2017 0 0 0 0 0 0 0 0 3,554 17 1 0 63 0 1 0 0 11 1 0 95 3 3,746

2018 0 0 0 0 0 0 0 0 3,489 17 1 0 62 0 1 0 0 11 1 0 91 3 3,676

2019 0 0 0 0 0 0 0 0 3,427 17 1 0 62 0 1 0 0 11 1 0 87 3 3,609

2020 0 0 0 0 0 0 0 0 3,368 16 1 0 61 0 1 0 0 11 1 0 84 3 3,546

2021 0 0 0 0 0 0 0 0 3,313 16 1 0 60 0 1 0 0 11 1 0 81 3 3,487

2022 0 0 0 0 0 0 0 0 3,245 16 1 0 60 0 1 0 0 11 1 0 77 3 3,414

2023 0 0 0 0 0 0 0 0 3,192 16 1 0 59 0 1 0 0 10 1 0 74 3 3,358

2024 0 0 0 0 0 0 0 0 3,141 16 1 0 59 0 1 0 0 10 1 0 72 3 3,304

2025 0 0 0 0 0 0 0 0 3,093 16 1 0 58 0 1 0 0 10 1 0 70 3 3,253

2026 0 0 0 0 0 0 0 0 3,046 15 1 0 58 0 1 0 0 10 1 0 68 3 3,202

2027 0 0 0 0 0 0 0 0 2,999 15 1 0 57 0 0 0 0 10 1 0 66 3 3,153

2028 0 0 0 0 0 0 0 0 2,934 15 1 0 56 0 0 0 0 10 1 0 64 3 3,084

2029 0 0 0 0 0 0 0 0 2,875 15 1 0 55 0 0 0 0 10 1 0 61 3 3,021

2030 0 0 0 0 0 0 0 0 2,833 15 0 0 55 0 0 0 0 10 1 0 59 3 2,977

2031 0 0 0 0 0 0 0 0 2,793 15 0 0 54 0 0 0 0 10 1 0 58 3 2,935

2032 0 0 0 0 0 0 0 0 2,754 14 0 0 54 0 0 0 0 9 1 0 56 3 2,893

2033 0 0 0 0 0 0 0 0 2,714 14 0 0 53 0 0 0 0 9 1 0 55 3 2,851

2034 0 0 0 0 0 0 0 0 2,676 14 0 0 53 0 0 0 0 9 1 0 54 3 2,811

2035 0 0 0 0 0 0 0 0 2,639 14 0 0 52 0 0 0 0 9 1 0 53 3 2,772

2036 0 0 0 0 0 0 0 0 2,603 14 0 0 51 0 0 0 0 9 1 0 51 3 2,734

2037 0 0 0 0 0 0 0 0 2,568 14 0 0 51 0 0 0 0 9 1 0 50 3 2,697

TOTAL 0 1 0 2 0 0 0 1 98,614 479 16 0 1,789 14 19 0 1 315 29 11 2,530 93 103,914

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

toluene [tpy]

0

480

960

1,440

1,920

2,400

2,880

3,360

3,840

4,320

4,800

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well Toluene Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-95

Table 124. Existing Wells Xylenes Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 12. Existing Wells Xylenes Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 1 0 1 0 0 0 0 1,587 10 0 0 40 0 1 0 0 4 0 0 86 5 1,735

2009 0 0 0 0 0 0 0 0 1,555 10 0 0 39 0 1 0 0 4 0 0 81 5 1,696

2010 0 0 0 0 0 0 0 0 1,493 10 0 0 39 0 1 0 0 4 0 0 70 5 1,622

2011 0 0 0 0 0 0 0 0 1,450 10 0 0 39 0 1 0 0 4 0 0 64 5 1,572

2012 0 0 0 0 0 0 0 0 1,433 10 0 0 38 0 0 0 0 4 0 0 63 5 1,553

2013 0 0 0 0 0 0 0 0 1,418 10 0 0 38 0 0 0 0 4 0 0 62 5 1,537

2014 0 0 0 0 0 0 0 0 1,390 9 0 0 37 0 0 0 0 4 0 0 59 5 1,506

2015 0 0 0 0 0 0 0 0 1,361 9 0 0 37 0 0 0 0 4 0 0 56 5 1,473

2016 0 0 0 0 0 0 0 0 1,334 9 0 0 37 0 0 0 0 3 0 0 53 4 1,443

2017 0 0 0 0 0 0 0 0 1,309 9 0 0 36 0 0 0 0 3 0 0 51 4 1,415

2018 0 0 0 0 0 0 0 0 1,285 9 0 0 36 0 0 0 0 3 0 0 49 4 1,388

2019 0 0 0 0 0 0 0 0 1,262 9 0 0 36 0 0 0 0 3 0 0 47 4 1,362

2020 0 0 0 0 0 0 0 0 1,240 9 0 0 35 0 0 0 0 3 0 0 45 4 1,339

2021 0 0 0 0 0 0 0 0 1,220 9 0 0 35 0 0 0 0 3 0 0 44 4 1,316

2022 0 0 0 0 0 0 0 0 1,195 9 0 0 35 0 0 0 0 3 0 0 41 4 1,288

2023 0 0 0 0 0 0 0 0 1,176 9 0 0 34 0 0 0 0 3 0 0 40 4 1,267

2024 0 0 0 0 0 0 0 0 1,157 9 0 0 34 0 0 0 0 3 0 0 39 4 1,246

2025 0 0 0 0 0 0 0 0 1,139 8 0 0 34 0 0 0 0 3 0 0 38 4 1,227

2026 0 0 0 0 0 0 0 0 1,121 8 0 0 33 0 0 0 0 3 0 0 37 4 1,208

2027 0 0 0 0 0 0 0 0 1,104 8 0 0 33 0 0 0 0 3 0 0 36 4 1,189

2028 0 0 0 0 0 0 0 0 1,080 8 0 0 32 0 0 0 0 3 0 0 35 4 1,163

2029 0 0 0 0 0 0 0 0 1,059 8 0 0 32 0 0 0 0 3 0 0 33 4 1,140

2030 0 0 0 0 0 0 0 0 1,043 8 0 0 32 0 0 0 0 3 0 0 32 4 1,123

2031 0 0 0 0 0 0 0 0 1,029 8 0 0 31 0 0 0 0 3 0 0 31 4 1,107

2032 0 0 0 0 0 0 0 0 1,014 8 0 0 31 0 0 0 0 3 0 0 31 4 1,091

2033 0 0 0 0 0 0 0 0 999 8 0 0 31 0 0 0 0 3 0 0 30 4 1,075

2034 0 0 0 0 0 0 0 0 985 8 0 0 30 0 0 0 0 3 0 0 29 4 1,060

2035 0 0 0 0 0 0 0 0 972 8 0 0 30 0 0 0 0 3 0 0 28 4 1,045

2036 0 0 0 0 0 0 0 0 959 7 0 0 30 0 0 0 0 3 0 0 28 4 1,031

2037 0 0 0 0 0 0 0 0 946 7 0 0 29 0 0 0 0 3 0 0 27 4 1,017

TOTAL 0 1 0 1 0 0 0 0 36,314 260 0 0 1,032 8 11 0 1 98 8 9 1,367 126 39,235

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

xylenes [tpy]

0

182

364

546

728

910

1,092

1,274

1,456

1,638

1,820

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well Xylenes Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-96

Table 125. Existing Wells CO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 13. Existing Wells CO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 23,168 655 44,407 6,637 35,396 4,128 54 5,232 310 683,444 0 5,160 4,616 0 110,507 1,275 911 582,056 809,692 540 7 2,318,196

2009 0 0 0 0 0 0 0 0 5,143 306 676,481 0 5,108 4,569 0 104,244 1,262 902 582,056 809,692 509 7 2,190,280

2010 0 0 0 0 0 0 0 0 4,996 303 669,518 0 5,055 4,522 0 89,949 1,249 893 582,056 809,692 438 7 2,168,679

2011 0 0 0 0 0 0 0 0 4,894 300 662,555 0 5,003 4,474 0 82,015 1,236 883 582,056 809,692 399 7 2,153,515

2012 0 0 0 0 0 0 0 0 4,842 297 656,128 0 4,954 4,431 0 80,532 1,224 875 582,056 809,692 391 7 2,145,429

2013 0 0 0 0 0 0 0 0 4,793 294 649,701 0 4,905 4,387 0 79,501 1,212 866 582,056 809,692 386 7 2,137,801

2014 0 0 0 0 0 0 0 0 4,722 291 643,273 0 4,857 4,343 0 75,518 1,200 858 582,056 809,692 367 7 2,127,185

2015 0 0 0 0 0 0 0 0 4,651 289 636,846 0 4,808 4,300 0 71,383 1,188 849 582,056 809,692 346 7 2,116,415

2016 0 0 0 0 0 0 0 0 4,584 286 630,418 0 4,760 4,256 0 67,774 1,176 841 582,056 809,692 328 7 2,106,178

2017 0 0 0 0 0 0 0 0 4,519 283 623,991 0 4,711 4,212 0 64,630 1,164 832 582,056 809,692 313 6 2,096,410

2018 0 0 0 0 0 0 0 0 4,458 280 617,564 0 4,663 4,169 0 61,860 1,152 823 582,056 809,692 299 6 2,087,023

2019 0 0 0 0 0 0 0 0 4,398 277 611,136 0 4,614 4,125 0 59,344 1,140 815 582,056 809,692 287 6 2,077,892

2020 0 0 0 0 0 0 0 0 4,343 274 605,245 0 4,570 4,085 0 57,027 1,129 807 582,056 809,692 275 6 2,069,510

2021 0 0 0 0 0 0 0 0 4,290 272 599,353 0 4,525 4,045 0 54,950 1,118 799 582,056 809,692 265 6 2,061,372

2022 0 0 0 0 0 0 0 0 4,232 269 593,461 0 4,481 4,005 0 52,117 1,107 791 582,056 809,692 251 6 2,052,469

2023 0 0 0 0 0 0 0 0 4,181 266 587,569 0 4,436 3,966 0 50,327 1,096 783 582,056 809,692 242 6 2,044,621

2024 0 0 0 0 0 0 0 0 4,130 264 581,677 0 4,392 3,926 0 48,657 1,085 776 582,056 809,692 234 6 2,036,895

2025 0 0 0 0 0 0 0 0 4,082 261 575,786 0 4,347 3,886 0 47,205 1,074 768 582,056 809,692 227 6 2,029,389

2026 0 0 0 0 0 0 0 0 4,033 258 569,894 0 4,303 3,846 0 45,780 1,063 760 582,056 809,692 220 6 2,021,911

2027 0 0 0 0 0 0 0 0 3,986 256 564,002 0 4,258 3,806 0 44,458 1,052 752 582,056 809,692 213 6 2,014,537

2028 0 0 0 0 0 0 0 0 3,904 250 552,754 0 4,173 3,730 0 43,242 1,031 737 582,056 809,692 207 6 2,001,784

2029 0 0 0 0 0 0 0 0 3,854 248 547,398 0 4,133 3,694 0 41,154 1,021 730 582,056 809,692 197 6 1,994,184

2030 0 0 0 0 0 0 0 0 3,811 246 542,042 0 4,093 3,657 0 40,045 1,011 723 582,056 809,692 192 6 1,987,573

2031 0 0 0 0 0 0 0 0 3,769 243 536,686 0 4,052 3,621 0 39,014 1,001 716 582,056 809,692 187 6 1,981,042

2032 0 0 0 0 0 0 0 0 3,727 241 531,330 0 4,012 3,585 0 38,014 991 708 582,056 809,692 182 6 1,974,544

2033 0 0 0 0 0 0 0 0 3,685 238 525,974 0 3,971 3,549 0 37,036 981 701 582,056 809,692 177 5 1,968,067

2034 0 0 0 0 0 0 0 0 3,644 236 520,617 0 3,931 3,513 0 36,130 971 694 582,056 809,692 173 5 1,961,663

2035 0 0 0 0 0 0 0 0 3,603 233 515,261 0 3,890 3,476 0 35,276 961 687 582,056 809,692 168 5 1,955,311

2036 0 0 0 0 0 0 0 0 3,563 231 509,905 0 3,850 3,440 0 34,513 951 680 582,056 809,692 165 5 1,949,052

2037 0 0 0 0 0 0 0 0 3,523 229 504,549 0 3,810 3,404 0 33,775 941 673 582,056 809,692 161 5 1,942,817

TOTAL 0 23,168 655 44,407 6,637 35,396 4,128 54 127,593 8,030 17,724,559 0 133,827 119,638 0 1,725,977 33,063 23,634 17,461,681 24,290,773 8,340 184 61,771,744

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2 [tpy]

Pollutant Year

Construction Drilling Completion

0

716,000

1,432,000

2,148,000

2,864,000

3,580,000

4,296,000

5,012,000

5,728,000

6,444,000

7,160,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well CO2 Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-97

Table 126. Existing Wells CO2e - from CH4 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 14. Existing Wells CO2e - from CH4 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 14 1 34 6 0 4 12,830 454,768 66,108 275 0 1,228,142 8 1,321 665 1 216,897 7,391 18,182 57,368 24 2,064,038

2009 0 0 0 0 0 0 0 0 449,981 65,435 272 0 1,215,630 8 1,245 630 1 214,687 7,391 18,182 54,394 23 2,027,879

2010 0 0 0 0 0 0 0 0 444,904 64,761 269 0 1,203,117 8 1,072 553 1 212,477 7,391 18,182 47,684 23 2,000,442

2011 0 0 0 0 0 0 0 0 440,014 64,088 267 0 1,190,605 8 975 510 1 210,267 7,391 18,182 43,932 23 1,976,261

2012 0 0 0 0 0 0 0 0 435,718 63,466 264 0 1,179,055 8 958 501 1 208,228 7,391 18,182 43,186 23 1,956,978

2013 0 0 0 0 0 0 0 0 431,440 62,844 262 0 1,167,505 8 945 495 1 206,188 7,391 18,182 42,650 22 1,937,932

2014 0 0 0 0 0 0 0 0 427,042 62,223 259 0 1,155,955 8 897 473 1 204,148 7,391 18,182 40,741 22 1,917,341

2015 0 0 0 0 0 0 0 0 422,632 61,601 256 0 1,144,405 8 847 450 1 202,108 7,391 18,182 38,762 22 1,896,663

2016 0 0 0 0 0 0 0 0 418,238 60,979 254 0 1,132,855 8 803 430 1 200,068 7,391 18,182 37,027 22 1,876,257

2017 0 0 0 0 0 0 0 0 413,861 60,358 251 0 1,121,305 7 765 412 1 198,029 7,391 18,182 35,508 21 1,856,090

2018 0 0 0 0 0 0 0 0 409,497 59,736 249 0 1,109,756 7 732 397 1 195,989 7,391 18,182 34,164 21 1,836,119

2019 0 0 0 0 0 0 0 0 405,142 59,114 246 0 1,098,206 7 701 383 1 193,949 7,391 18,182 32,937 21 1,816,279

2020 0 0 0 0 0 0 0 0 401,147 58,544 244 0 1,087,618 7 673 369 1 192,079 7,391 18,182 31,808 21 1,798,084

2021 0 0 0 0 0 0 0 0 397,162 57,974 241 0 1,077,031 7 648 358 1 190,209 7,391 18,182 30,790 21 1,780,014

2022 0 0 0 0 0 0 0 0 393,132 57,404 239 0 1,066,443 7 614 342 1 188,340 7,391 18,182 29,421 20 1,761,536

2023 0 0 0 0 0 0 0 0 389,157 56,835 236 0 1,055,856 7 593 332 1 186,470 7,391 18,182 28,537 20 1,743,615

2024 0 0 0 0 0 0 0 0 385,187 56,265 234 0 1,045,268 7 572 322 1 184,600 7,391 18,182 27,709 20 1,725,757

2025 0 0 0 0 0 0 0 0 381,229 55,695 232 0 1,034,681 7 555 314 1 182,730 7,391 18,182 26,982 20 1,708,016

2026 0 0 0 0 0 0 0 0 377,271 55,125 229 0 1,024,094 7 538 305 1 180,860 7,391 18,182 26,267 20 1,690,289

2027 0 0 0 0 0 0 0 0 373,318 54,555 227 0 1,013,506 7 522 298 1 178,991 7,391 18,182 25,601 19 1,672,616

2028 0 0 0 0 0 0 0 0 365,852 53,467 222 0 993,294 7 508 290 1 175,421 7,391 18,182 24,937 19 1,639,590

2029 0 0 0 0 0 0 0 0 362,200 52,949 220 0 983,669 7 482 278 1 173,721 7,391 18,182 23,919 19 1,623,037

2030 0 0 0 0 0 0 0 0 358,609 52,431 218 0 974,044 6 469 272 1 172,021 7,391 18,182 23,357 19 1,607,018

2031 0 0 0 0 0 0 0 0 355,023 51,913 216 0 964,419 6 457 266 1 170,322 7,391 18,182 22,830 18 1,591,042

2032 0 0 0 0 0 0 0 0 351,438 51,395 214 0 954,794 6 445 260 1 168,622 7,391 18,182 22,318 18 1,575,082

2033 0 0 0 0 0 0 0 0 347,854 50,877 212 0 945,169 6 433 254 1 166,922 7,391 18,182 21,817 18 1,559,133

2034 0 0 0 0 0 0 0 0 344,274 50,358 210 0 935,544 6 422 248 1 165,222 7,391 18,182 21,349 18 1,543,224

2035 0 0 0 0 0 0 0 0 340,697 49,840 207 0 925,919 6 412 243 1 163,522 7,391 18,182 20,905 18 1,527,343

2036 0 0 0 0 0 0 0 0 337,127 49,322 205 0 916,294 6 403 239 1 161,823 7,391 18,182 20,503 18 1,511,512

2037 0 0 0 0 0 0 0 0 333,558 48,804 203 0 906,669 6 394 234 0 160,123 7,391 18,182 20,113 17 1,495,694

TOTAL 0 14 1 34 6 0 4 12,830 11,747,471 1,714,466 7,134 0 31,850,850 211 20,401 11,121 18 5,625,033 221,715 545,445 957,515 610 52,714,880

Total (Costruction + 

Drilling + Completion 

Pollutant Year + Production)

Construction Drilling Completion Production

CO2e-from 

CH4 [tpy]

0

278,000

556,000

834,000

1,112,000

1,390,000

1,668,000

1,946,000

2,224,000

2,502,000

2,780,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well CO2e - from CH4 Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-98

Table 127. Existing Wells CO2e - from N2O Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 15. Existing Wells CO2e - from N2O Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 183 5 2,490 41 1,984 26 0 0 0 3,884 0 0 60 0 182 10 0 4,096 5,974 0 0 18,935

2009 0 0 0 0 0 0 0 0 0 0 3,845 0 0 59 0 172 10 0 4,096 5,974 0 0 14,156

2010 0 0 0 0 0 0 0 0 0 0 3,805 0 0 59 0 152 10 0 4,096 5,974 0 0 14,095

2011 0 0 0 0 0 0 0 0 0 0 3,766 0 0 58 0 140 10 0 4,096 5,974 0 0 14,043

2012 0 0 0 0 0 0 0 0 0 0 3,729 0 0 57 0 137 10 0 4,096 5,974 0 0 14,003

2013 0 0 0 0 0 0 0 0 0 0 3,692 0 0 57 0 136 10 0 4,096 5,974 0 0 13,964

2014 0 0 0 0 0 0 0 0 0 0 3,656 0 0 56 0 130 9 0 4,096 5,974 0 0 13,921

2015 0 0 0 0 0 0 0 0 0 0 3,619 0 0 56 0 124 9 0 4,096 5,974 0 0 13,878

2016 0 0 0 0 0 0 0 0 0 0 3,583 0 0 55 0 118 9 0 4,096 5,974 0 0 13,835

2017 0 0 0 0 0 0 0 0 0 0 3,546 0 0 55 0 113 9 0 4,096 5,974 0 0 13,793

2018 0 0 0 0 0 0 0 0 0 0 3,510 0 0 54 0 109 9 0 4,096 5,974 0 0 13,752

2019 0 0 0 0 0 0 0 0 0 0 3,473 0 0 53 0 105 9 0 4,096 5,974 0 0 13,711

2020 0 0 0 0 0 0 0 0 0 0 3,440 0 0 53 0 102 9 0 4,096 5,974 0 0 13,673

2021 0 0 0 0 0 0 0 0 0 0 3,406 0 0 52 0 99 9 0 4,096 5,974 0 0 13,636

2022 0 0 0 0 0 0 0 0 0 0 3,373 0 0 52 0 94 9 0 4,096 5,974 0 0 13,597

2023 0 0 0 0 0 0 0 0 0 0 3,339 0 0 51 0 92 9 0 4,096 5,974 0 0 13,560

2024 0 0 0 0 0 0 0 0 0 0 3,306 0 0 51 0 89 9 0 4,096 5,974 0 0 13,524

2025 0 0 0 0 0 0 0 0 0 0 3,272 0 0 50 0 87 8 0 4,096 5,974 0 0 13,487

2026 0 0 0 0 0 0 0 0 0 0 3,239 0 0 50 0 84 8 0 4,096 5,974 0 0 13,451

2027 0 0 0 0 0 0 0 0 0 0 3,205 0 0 49 0 82 8 0 4,096 5,974 0 0 13,415

2028 0 0 0 0 0 0 0 0 0 0 3,141 0 0 48 0 80 8 0 4,096 5,974 0 0 13,348

2029 0 0 0 0 0 0 0 0 0 0 3,111 0 0 48 0 77 8 0 4,096 5,974 0 0 13,313

2030 0 0 0 0 0 0 0 0 0 0 3,081 0 0 47 0 75 8 0 4,096 5,974 0 0 13,281

2031 0 0 0 0 0 0 0 0 0 0 3,050 0 0 47 0 74 8 0 4,096 5,974 0 0 13,248

2032 0 0 0 0 0 0 0 0 0 0 3,020 0 0 46 0 72 8 0 4,096 5,974 0 0 13,215

2033 0 0 0 0 0 0 0 0 0 0 2,989 0 0 46 0 70 8 0 4,096 5,974 0 0 13,183

2034 0 0 0 0 0 0 0 0 0 0 2,959 0 0 45 0 69 8 0 4,096 5,974 0 0 13,150

2035 0 0 0 0 0 0 0 0 0 0 2,928 0 0 45 0 67 8 0 4,096 5,974 0 0 13,118

2036 0 0 0 0 0 0 0 0 0 0 2,898 0 0 44 0 66 8 0 4,096 5,974 0 0 13,086

2037 0 0 0 0 0 0 0 0 0 0 2,868 0 0 44 0 65 7 0 4,096 5,974 0 0 13,053

TOTAL 0 183 5 2,490 41 1,984 26 0 0 0 100,735 0 0 1,547 0 3,063 261 0 122,871 179,218 0 0 412,425

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2e-from 

N2O [tpy]

Pollutant Year

Construction Drilling Completion

0

3,900

7,800

11,700

15,600

19,500

23,400

27,300

31,200

35,100

39,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well CO2e - from N2O Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
EXISTING WELLS EMISSIONS INVENTORY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-99

Table 128. Existing Wells CO2e - total Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 16. Existing Wells CO2e - total Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 23,365 661 46,930 6,685 37,381 4,158 12,884 460,000 66,418 687,604 0 1,233,303 4,684 1,321 111,354 1,286 217,808 593,542 833,848 57,908 31 4,401,169

2009 0 0 0 0 0 0 0 0 455,124 65,741 680,598 0 1,220,738 4,636 1,245 105,047 1,273 215,589 593,542 833,848 54,903 30 4,232,315

2010 0 0 0 0 0 0 0 0 449,900 65,065 673,593 0 1,208,173 4,588 1,072 90,654 1,259 213,370 593,542 833,848 48,122 30 4,183,215

2011 0 0 0 0 0 0 0 0 444,908 64,388 666,587 0 1,195,608 4,540 975 82,665 1,246 211,151 593,542 833,848 44,331 30 4,143,819

2012 0 0 0 0 0 0 0 0 440,560 63,763 660,121 0 1,184,009 4,496 958 81,170 1,234 209,102 593,542 833,848 43,577 29 4,116,411

2013 0 0 0 0 0 0 0 0 436,233 63,139 653,654 0 1,172,411 4,452 945 80,131 1,222 207,054 593,542 833,848 43,037 29 4,089,697

2014 0 0 0 0 0 0 0 0 431,765 62,514 647,188 0 1,160,812 4,407 897 76,121 1,210 205,006 593,542 833,848 41,108 29 4,058,447

2015 0 0 0 0 0 0 0 0 427,283 61,889 640,722 0 1,149,214 4,363 847 71,956 1,198 202,957 593,542 833,848 39,108 29 4,026,956

2016 0 0 0 0 0 0 0 0 422,822 61,265 634,255 0 1,137,615 4,319 803 68,322 1,186 200,909 593,542 833,848 37,355 28 3,996,270

2017 0 0 0 0 0 0 0 0 418,380 60,640 627,789 0 1,126,017 4,274 765 65,155 1,174 198,861 593,542 833,848 35,821 28 3,966,294

2018 0 0 0 0 0 0 0 0 413,955 60,016 621,322 0 1,114,418 4,230 732 62,366 1,162 196,812 593,542 833,848 34,463 28 3,936,894

2019 0 0 0 0 0 0 0 0 409,540 59,391 614,856 0 1,102,820 4,186 701 59,832 1,150 194,764 593,542 833,848 33,224 27 3,907,881

2020 0 0 0 0 0 0 0 0 405,490 58,818 608,928 0 1,092,188 4,145 673 57,499 1,139 192,886 593,542 833,848 32,083 27 3,881,267

2021 0 0 0 0 0 0 0 0 401,452 58,246 603,000 0 1,081,556 4,105 648 55,406 1,127 191,009 593,542 833,848 31,055 27 3,855,022

2022 0 0 0 0 0 0 0 0 397,364 57,673 597,073 0 1,070,924 4,064 614 52,553 1,116 189,131 593,542 833,848 29,672 27 3,827,601

2023 0 0 0 0 0 0 0 0 393,338 57,101 591,145 0 1,060,292 4,024 593 50,750 1,105 187,253 593,542 833,848 28,779 26 3,801,797

2024 0 0 0 0 0 0 0 0 389,318 56,528 585,217 0 1,049,660 3,983 572 49,068 1,094 185,376 593,542 833,848 27,943 26 3,776,176

2025 0 0 0 0 0 0 0 0 385,311 55,956 579,290 0 1,039,028 3,943 555 47,605 1,083 183,498 593,542 833,848 27,209 26 3,750,893

2026 0 0 0 0 0 0 0 0 381,304 55,383 573,362 0 1,028,396 3,902 538 46,169 1,072 181,620 593,542 833,848 26,487 26 3,725,651

2027 0 0 0 0 0 0 0 0 377,304 54,810 567,435 0 1,017,765 3,862 522 44,838 1,061 179,743 593,542 833,848 25,814 25 3,700,568

2028 0 0 0 0 0 0 0 0 369,756 53,717 556,118 0 997,467 3,785 508 43,613 1,040 176,158 593,542 833,848 25,145 25 3,654,721

2029 0 0 0 0 0 0 0 0 366,054 53,197 550,730 0 987,802 3,748 482 41,510 1,030 174,451 593,542 833,848 24,117 25 3,630,534

2030 0 0 0 0 0 0 0 0 362,420 52,676 545,341 0 978,137 3,711 469 40,392 1,020 172,744 593,542 833,848 23,548 24 3,607,872

2031 0 0 0 0 0 0 0 0 358,792 52,156 539,952 0 968,471 3,674 457 39,353 1,010 171,037 593,542 833,848 23,017 24 3,585,332

2032 0 0 0 0 0 0 0 0 355,165 51,635 534,563 0 958,806 3,638 445 38,346 999 169,330 593,542 833,848 22,500 24 3,562,841

2033 0 0 0 0 0 0 0 0 351,539 51,115 529,175 0 949,140 3,601 433 37,360 989 167,623 593,542 833,848 21,994 24 3,540,383

2034 0 0 0 0 0 0 0 0 347,918 50,594 523,786 0 939,475 3,564 422 36,447 979 165,916 593,542 833,848 21,521 23 3,518,037

2035 0 0 0 0 0 0 0 0 344,300 50,074 518,397 0 929,810 3,527 412 35,587 969 164,209 593,542 833,848 21,073 23 3,495,772

2036 0 0 0 0 0 0 0 0 340,690 49,553 513,008 0 920,144 3,491 403 34,818 959 162,502 593,542 833,848 20,668 23 3,473,650

2037 0 0 0 0 0 0 0 0 337,081 49,033 507,620 0 910,479 3,454 394 34,074 949 160,796 593,542 833,848 20,274 23 3,451,565

TOTAL 0 23,365 661 46,930 6,685 37,381 4,158 12,884 11,875,065 1,722,495 17,832,428 0 31,984,677 121,396 20,401 1,740,161 33,342 5,648,668 17,806,267 25,015,436 965,855 794 114,899,049

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2e-total 

[tpy]

Pollutant Year

Construction Drilling Completion

0

998,400

1,996,800

2,995,200

3,993,600

4,992,000

5,990,400

6,988,800

7,987,200

8,985,600

9,984,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

Existing Well CO2e - total Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-100

Project Emissions Inventory for Future Wells
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-101

Table 129: Summary of Future Wells Activity Data by Project Year.

Year Project Yr

Well Pads 

Constructed

No Action 

Spuds

Active Well 

Count

Annual 

Condensate 

Production 

(Mbbl/yr)

Annual Gas 

Production 

(MMSCF/yr)

Cumulative 

Well Pads 

Constructed

Cumulative 

Spuds

Cumulative 

Condensate 

Production 

(Mbbl)

Cumulative Gas 

Production (BSCF)

2008 1 0 0 0 0 0 0 0 0 0

2009 2 149 218 218 383 19,467 149 218 383 19

2010 3 200 292 510 1,180 59,873 350 510 1,563 79

2011 4 199 291 801 1,775 90,118 549 801 3,338 169

2012 5 195 285 1,086 2,201 111,714 744 1,086 5,539 281

2013 6 199 291 1,377 2,601 132,039 943 1,377 8,140 413

2014 7 197 288 1,664 2,897 147,076 1,140 1,664 11,038 560

2015 8 203 297 1,961 3,162 160,525 1,343 1,961 14,200 721

2016 9 159 232 2,193 3,346 169,835 1,502 2,193 17,546 891

2017 10 209 305 2,498 3,548 180,125 1,711 2,498 21,094 1,071

2018 11 229 335 2,833 4,105 208,392 1,940 2,833 25,200 1,279

2019 12 185 270 3,103 4,318 219,175 2,125 3,103 29,517 1,498

2020 13 185 270 3,373 4,474 227,096 2,310 3,373 33,991 1,725

2021 14 209 305 3,677 4,595 233,233 2,519 3,677 38,586 1,959

2022 15 198 289 3,966 4,925 249,985 2,717 3,966 43,510 2,209

2023 16 66 97 4,063 4,761 241,684 2,783 4,063 48,272 2,450

2024 17 0 0 4,063 4,193 212,837 2,783 4,063 52,465 2,663

2025 18 0 0 4,063 3,822 194,000 2,783 4,063 56,286 2,857

2026 19 0 0 4,063 3,558 180,603 2,783 4,063 59,844 3,038

2027 20 0 0 4,063 3,344 169,754 2,783 4,063 63,188 3,208

2028 21 0 0 4,063 3,162 160,490 2,783 4,063 66,350 3,368

2029 22 0 0 4,063 3,002 152,371 2,783 4,063 69,352 3,520

2030 23 0 0 4,063 2,859 145,103 2,783 4,063 72,210 3,665

2031 24 0 0 4,063 2,729 138,535 2,783 4,063 74,939 3,804

2032 25 0 0 4,063 2,610 132,497 2,783 4,063 77,550 3,937

2033 26 0 0 4,063 2,500 126,927 2,783 4,063 80,050 4,063

2034 27 0 0 4,063 2,398 121,740 2,783 4,063 82,448 4,185

2035 28 0 0 4,063 2,302 116,852 2,783 4,063 84,750 4,302

2036 29 0 0 4,063 2,211 112,229 2,783 4,063 86,961 4,414

2037 30 0 0 4,063 2,125 107,852 2,783 4,063 89,086 4,522

Total 2,783 4,063
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-102

Table 130: Projection Parameters used in Future Year Emission Inventory Development for 

New Wells by Source Category.

Source Category Projection

Added Compression (reciprocating) totals for CY 2012+

Added Compression (turbine) totals for CY 2012+

Added Gas Plant (Duct Burner) totals for CY 2012+

Added Gas Plant (Flares) totals for CY 2012+

Added Gas Plant (Fugitives) totals for CY 2012+

Added Gas Plant (Heaters) totals for CY 2012+

Added Gas Plant (Process) totals for CY 2012+

Added Gas Plant (Recip Engines) totals for CY 2012+

Added Gas Plant (Turbine Engines) totals for CY 2012+

Completion Equipment (diesel ICE) total spuds

Completion Traffic (HD) total spuds

Completion Traffic (HD) Dust total spuds

Completion Traffic (LD) total spuds

Completion Traffic (LD) Dust total spuds

Condensate Fugitive Devices active well counts

Condensate Tank Breathing Flaring breathing flares

Condensate Tank Breathing Losses active well counts

Condensate Tank Flashing Flaring flashing flares

Condensate Tank Flashing Losses annual condensate production

Condensate Tank Working Flaring working flares

Condensate Tank Working Losses total turnovers per year

Construction Dust, Fugitive new pads

Construction Dust, Wind Erosion new pads

Construction Traffic, Road and Well pad (HD) new pads

Construction Traffic, Road and Well pad (HD) Dust new pads

Construction Traffic, Road and Well pad (LD) new pads

Construction Traffic, Road and Well pad (LD) Dust new pads

Dehydrator Flaring dehydrator flares

Dehydrator Venting - Well Site active well counts

Drilling Equip (diesel ICE 125HP) total spuds

Drilling Equip (diesel ICE 1476HP) total spuds

Drilling Traffic (HD) total spuds

Drilling Traffic (HD) Dust total spuds

Drilling Traffic (LD) total spuds

Drilling Traffic (LD) Dust total spuds

Evaporation Ponds active well counts

Gas Stream Fugitive Devices active well counts

Heaters active well counts

Initial Completion Flaring total spuds

Initial Completion Venting total spuds

Pneumatic Devices active well counts

Pneumatic Pump Flaring pneumatic pump flares

Pneumatic Pumps active well counts

Production Traffic (HD) active well counts

Production Traffic (HD) Dust active well counts

Production Traffic (LD) active well counts

Production Traffic (LD) Dust active well counts

Production Traffic, Central Facility (HD) totals for CY 2012+

Production Traffic, Central Facility (HD) Dust totals for CY 2012+

Tank Loadout (vapor losses) annual condensate production

Well Pad Const Equip (diesel ICE) new pads

Well Stream Fugitive Devices active well counts

Well Venting active well counts

Workover Equipment (diesel ICE) active well counts

WorkoverTraffic (HD) active well counts

WorkoverTraffic (HD) Dust active well counts

WorkoverTraffic (LD) active well counts

WorkoverTraffic (LD) Dust active well counts
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-103

Table 131. Summary of Projection Factors used in Future Year Emission Inventory Development for New Wells.

Projection New pads 

per Year

Active Well 

Counts per Year

Total 

Spuds per 

Year

Annual Gas 

Production 

(MMscf/yr)

Annual 

Condensate 

Production 

(bbl/yr)

Totals for CY 

2012+

Total 

Turnovers 

per Year

Flashing 

Flares

Working 

Flares

Breathing 

Flares

Dehydrator 

Flares

Pneumatic 

Pump 

Flares

None

2008 0 0 0 0 0 0 0 0 0 0 0 0 1

2009 149 218 218 19467 383498 0 254 383498 254 218 218 218 1

2010 200 510 292 59873 1179503 0 781 1179503 781 510 540 510 1

2011 199 801 291 90118 1775323 0 1176 1775323 1176 801 839 801 1

2012 195 1086 285 111714 2200768 0 1457 2200768 1457 1086 1117 1086 1

2013 199 1377 291 132039 2601159 0 1723 2601159 1723 1377 1395 1377 1

2014 197 1664 288 147076 2897397 0 1919 2897397 1919 1664 1661 1664 1

2015 203 1961 297 160525 3162343 0 2094 3162343 2094 1961 1931 1961 1

2016 159 2193 232 169835 3345740 0 2216 3345740 2216 2193 2139 2193 1

2017 209 2498 305 180125 3548472 0 2498 3548472 2498 2498 2409 2498 1

2018 229 2833 335 208392 4105326 0 2833 4105326 2833 2833 2740 2833 1

2019 185 3103 270 219175 4317741 0 3103 4317741 3103 3103 2982 3103 1

2020 185 3373 270 227096 4473794 0 3373 4473794 3373 3373 3218 3373 1

2021 209 3677 305 233233 4594685 0 3677 4594685 3677 3677 3479 3677 1

2022 198 3966 289 249985 4924711 0 3966 4924711 3966 3966 3749 3966 1

2023 66 4063 97 241684 4761184 0 4063 4761184 4063 4063 3811 4063 1

2024 0 4063 0 212837 4192891 0 4063 4192891 4063 4063 3751 4063 1

2025 0 4063 0 194000 3821795 0 4063 3821795 4063 4063 3712 4063 1

2026 0 4063 0 180603 3557879 0 4063 3557879 4063 4063 3684 4063 1

2027 0 4063 0 169754 3344154 0 4063 3344154 4063 4063 3662 4063 1

2028 0 4063 0 160490 3161657 0 4063 3161657 4063 4063 3642 4063 1

2029 0 4063 0 152371 3001700 0 4063 3001700 4063 4063 3625 4063 1

2030 0 4063 0 145103 2858530 0 4063 2858530 4063 4063 3610 4063 1

2031 0 4063 0 138535 2729137 0 4063 2729137 4063 4063 3597 4063 1

2032 0 4063 0 132497 2610189 0 4063 2610189 4063 4063 3584 4063 1

2033 0 4063 0 126927 2500455 0 4063 2500455 4063 4063 3573 4063 1

2034 0 4063 0 121740 2398285 0 4063 2398285 4063 4063 3562 4063 1

2035 0 4063 0 116852 2301976 0 4063 2301976 4063 4063 3552 4063 1

2036 0 4063 0 112229 2210911 0 4063 2210911 4063 4063 3542 4063 1

2037 0 4063 0 107852 2124678 0 4063 2124678 4063 4063 3533 4063 1
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

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Gas Composition Analysis

Table 132. Summary of Gas Composition Analysis as Provided in Table 133 through Table 139.

Property

Sales/Produced 

Gas

Fugitive

(Post-Flash) Flashing Produced Water

Condensate (PostFlash)

Regenerator 

Overhead Vent 

Stream

Wet Gas

VOC Fraction (molar) 5.39% 49.52% 49.51% 55.26% 39.40% 15.07% 5.30%

VOC/TOC (weight) 15.59% 75.85% 75.78% 92.48% 66.34% 50.39% 15.22%

VOC MW 57.50 64.95 64.85 69.75 63.01 79.73 56.65

VOC Fraction (weight) 14.60% 73.55% 73.46% 69.58% 66.34% 40.07% 14.25%

CO2 Fraction (weight) 6.07% 3.02% 3.04% 24.76% 0.00% 8.81% 6.09%

CH4 Fraction (weight) 68.75% 13.57% 13.5% 3.9% 21.2% 32.6% 69.0%

H2S Fraction (weight) 0.00% 0.00% 0.0% 0.0% 0.0% 0.0% 0.0%

Heat Content (BTU/SCF) 1000 - - - - - -

benzene/VOC (weight) 0.40% 0.83% 0.82% 0.56% 0.48% 9.63% 0.41%

toluene/VOC (weight) 0.56% 1.17% 1.17% 1.13% 0.63% 15.90% 0.57%

ethylbenzene/VOC (weight) 0.02% 0.02% 0.02% 0.05% 0.01% 0.59% 0.02%

xylenes/VOC (weight) 0.32% 0.63% 0.63% 0.43% 0.35% 5.86% 0.18%

n-hexane/VOC (weight) 4.74% 3.96% 3.93% 5.01% 3.40% 2.61% 1.98%

formaldehyde/VOC (weight) 0% 0% 0% 0% 0% 0% 0%
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

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ASSUMPTIONS

Data obtained from operators in blue 

text

Table 133. Sales Gas Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 2.73% 2.73% 44.0 1.2 6.0666% N

Nitrogen 0.17% 0.17% 28.0 0.0 0.2420% N

Methane 84.99% 84.90% 16.0 13.6 68.7549% N

Ethane 6.81% 6.81% 30.1 2.0 10.3331% N

Propane 3.17% 3.17% 44.1 1.4 7.0516% Y 48.29% 21.29

Isobutane 0.64% 0.64% 58.1 0.4 1.8647% Y 12.77% 7.42

n-Butane 0.71% 0.71% 58.1 0.4 2.0830% Y 14.26% 8.29

Isopentane 0.24% 0.24% 72.2 0.2 0.8812% Y 6.03% 4.35

n-Pentane 0.20% 0.20% 72.2 0.1 0.7252% Y 4.97% 3.58

Cyclopentane 0.00% 0.00% 70.1 0.0 0.0000% Y 0.00% 0.00

n-Hexane 0.16% 0.16% 86.2 0.1 0.6928% Y 4.74% 4.09

Cyclohexane 0.03% 0.03% 84.2 0.0 0.1349% Y 0.92% 0.78

2,2-Dimethylbutane 0.00% 0.00% 86.2 0.0 0.0186% Y 0.13% 0.11

2,3-Dimethylbutane 0.02% 0.02% 86.2 0.0 0.0712% Y 0.49% 0.42

2-Methylpentane 0.05% 0.05% 86.2 0.0 0.2121% Y 1.45% 1.25

3-Methylpentane 0.03% 0.03% 86.2 0.0 0.1091% Y 0.75% 0.64

n-Heptane 0.06% 0.06% 100.2 0.1 0.2967% Y 2.03% 2.04

Methylcyclohexane 0.03% 0.03% 98.2 0.0 0.1594% Y 1.09% 1.07

2,2,4-Trimethylpentane 0.00% 0.00% 114.2 0.0 0.0218% Y 0.15% 0.17

Benzene 0.01% 0.01% 78.1 0.0 0.0589% Y 0.40% 0.31

Toluene 0.02% 0.02% 92.1 0.0 0.0811% Y 0.56% 0.51

Ethylbenzene 0.00% 0.00% 106.2 0.0 0.0024% Y 0.02% 0.02

m-Xylene 0.00% 0.00% 106.2 0.0 0.0250% Y 0.17% 0.18

o-Xylene 0.00% 0.00% 106.2 0.0 0.0218% Y 0.15% 0.16

n-Octane 0.00% 0.00% 114.2 0.0 0.0035% Y 0.02% 0.03

n-Nonane 0.01% 0.01% 128.3 0.0 0.0886% Y 0.61% 0.78

n-Decane 0.00% 0.00% 142.3 0.0 0.0000% Y 0.00% 0.00

Total 100.10% 100.00% 19.8 100.00% 57.5
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

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Table 134. Fugitive Post-Flash Gas Composition Analysis.

Table 135. Flash Gas Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 2.79% 2.79% 44.0 1.2 3.0190% N

Nitrogen 0.02% 0.02% 28.0 0.0 0.0151% N

Methane 34.37% 34.37% 16.0 5.5 13.5728% N

Ethane 13.30% 13.30% 30.1 4.0 9.8429% N

Propane 17.80% 17.80% 44.1 7.9 19.3288% Y 26.28% 11.59

Isobutane 6.84% 6.84% 58.1 4.0 9.7798% Y 13.30% 7.73

n-Butane 9.37% 9.37% 58.1 5.4 13.4078% Y 18.23% 10.60

Isopentane 4.55% 4.55% 72.2 3.3 8.0782% Y 10.98% 7.92

n-Pentane 3.97% 3.97% 72.2 2.9 7.0578% Y 9.60% 6.92

Cyclopentane 0.00% 0.00% 70.1 0.0 0.0000% Y 0.00% 0.00

n-Hexane 1.37% 1.37% 86.2 1.2 2.9160% Y 3.96% 3.42

Cyclohexane 0.30% 0.30% 84.2 0.3 0.6178% Y 0.84% 0.71

2,2-Dimethylbutane 0.09% 0.09% 86.2 0.1 0.1907% Y 0.26% 0.22

2,3-Dimethylbutane 0.35% 0.35% 86.2 0.3 0.7423% Y 1.01% 0.87

2-Methylpentane 1.06% 1.06% 86.2 0.9 2.2383% Y 3.04% 2.62

3-Methylpentane 0.54% 0.54% 86.2 0.5 1.1373% Y 1.55% 1.33

n-Heptane 1.85% 1.85% 100.2 1.9 4.5651% Y 6.21% 6.22

Methylcyclohexane 0.18% 0.18% 98.2 0.2 0.4350% Y 0.59% 0.58

2,2,4-Trimethylpentane 0.07% 0.07% 114.2 0.1 0.1980% Y 0.27% 0.31

Benzene 0.32% 0.32% 78.1 0.2 0.6104% Y 0.83% 0.65

Toluene 0.38% 0.38% 92.1 0.3 0.8601% Y 1.17% 1.08

Ethylbenzene 0.00% 0.00% 106.2 0.0 0.0114% Y 0.02% 0.02

m-Xylene 0.16% 0.16% 106.2 0.2 0.4206% Y 0.57% 0.61

o-Xylene 0.02% 0.02% 106.2 0.0 0.0399% Y 0.05% 0.06

n-Octane 0.22% 0.22% 114.2 0.3 0.6172% Y 0.84% 0.96

n-Nonane 0.05% 0.05% 128.3 0.1 0.1582% Y 0.22% 0.28

n-Decane 0.04% 0.04% 142.3 0.1 0.1395% Y 0.19% 0.27

Total 100.00% 100.00% 40.6 100.00% 65.0

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 2.80% 2.80% 44.0 1.2 3.0392% N

Nitrogen 0.02% 0.02% 28.0 0.0 0.0149% N

Methane 34.25% 34.25% 16.0 5.5 13.5394% N

Ethane 13.42% 13.42% 30.1 4.0 9.9421% N

Propane 17.98% 17.98% 44.1 7.9 19.5446% Y 26.60% 11.73

Isobutane 6.85% 6.85% 58.1 4.0 9.8099% Y 13.35% 7.76

n-Butane 9.34% 9.34% 58.1 5.4 13.3756% Y 18.21% 10.58

Isopentane 4.48% 4.48% 72.2 3.2 7.9707% Y 10.85% 7.83

n-Pentane 3.91% 3.91% 72.2 2.8 6.9497% Y 9.46% 6.83

Cyclopentane 0.00% 0.00% 70.1 0.0 0.0000% Y 0.00% 0.00

n-Hexane 1.36% 1.36% 86.2 1.2 2.8850% Y 3.93% 3.38

Cyclohexane 0.30% 0.30% 84.2 0.2 0.6125% Y 0.83% 0.70

2,2-Dimethylbutane 0.09% 0.09% 86.2 0.1 0.1877% Y 0.26% 0.22

2,3-Dimethylbutane 0.34% 0.34% 86.2 0.3 0.7319% Y 1.00% 0.86

2-Methylpentane 1.04% 1.04% 86.2 0.9 2.2086% Y 3.01% 2.59

3-Methylpentane 0.53% 0.53% 86.2 0.5 1.1231% Y 1.53% 1.32

n-Heptane 1.85% 1.85% 100.2 1.9 4.5682% Y 6.22% 6.23

Methylcyclohexane 0.18% 0.18% 98.2 0.2 0.4348% Y 0.59% 0.58

2,2,4-Trimethylpentane 0.07% 0.07% 114.2 0.1 0.1981% Y 0.27% 0.31

Benzene 0.31% 0.31% 78.1 0.2 0.6038% Y 0.82% 0.64

Toluene 0.38% 0.38% 92.1 0.3 0.8615% Y 1.17% 1.08

Ethylbenzene 0.00% 0.00% 106.2 0.0 0.0115% Y 0.02% 0.02

m-Xylene 0.16% 0.16% 106.2 0.2 0.4243% Y 0.58% 0.61

o-Xylene 0.02% 0.02% 106.2 0.0 0.0403% Y 0.05% 0.06

n-Octane 0.22% 0.22% 114.2 0.3 0.6219% Y 0.85% 0.97

n-Nonane 0.05% 0.05% 128.3 0.1 0.1598% Y 0.22% 0.28

n-Decane 0.04% 0.04% 142.3 0.1 0.1410% Y 0.19% 0.27

Total 100.00% 100.00% 40.6 100.00% 64.9
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

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Table 136. Produced Water Working and Breathing Gas Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 29.14% 29.14% 44.010 12.822 24.76% N

Nitrogen 0.00% 0.00% 28.010 0.000 0.00% N

Methane 12.59% 12.59% 16.040 2.019 3.90% N

Ethane 3.02% 3.02% 30.070 0.909 1.76% N

Propane 11.24% 11.24% 44.100 4.956 9.57% Y 13.76% 6.066

Isobutane 8.05% 8.05% 58.120 4.679 9.04% Y 12.99% 7.548

n-Butane 12.65% 12.65% 58.120 7.352 14.20% Y 20.41% 11.861

Isopentane 6.97% 6.97% 72.150 5.031 9.72% Y 13.96% 10.075

n-Pentane 5.97% 5.97% 72.150 4.308 8.32% Y 11.96% 8.628

Cyclopentane 0.00% 0.00% 70.130 0.000 0.00% Y 0.00% 0.000

n-Hexane 2.09% 2.09% 86.180 1.804 3.48% Y 5.01% 4.316

Cyclohexane 3.09% 3.09% 84.160 2.600 5.02% Y 7.22% 6.073

2,2-Dimethylbutane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

2,3-Dimethylbutane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

2-Methylpentane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

3-Methylpentane 0.00% 0.00% 86.177 0.000 0.00% Y 0.00% 0.000

n-Heptane 3.55% 3.55% 100.202 3.558 6.87% Y 9.88% 9.897

Methylcyclohexane 0.00% 0.00% 98.190 0.000 0.00% Y 0.00% 0.000

2,2,4-Trimethylpentane 0.12% 0.12% 114.229 0.142 0.27% Y 0.39% 0.451

Benzene 0.26% 0.26% 78.110 0.200 0.39% Y 0.56% 0.434

Toluene 0.44% 0.44% 92.140 0.406 0.78% Y 1.13% 1.038

Ethylbenzene 0.02% 0.02% 106.170 0.017 0.03% Y 0.05% 0.051

m-Xylene 0.15% 0.15% 106.160 0.156 0.30% Y 0.43% 0.458

o-Xylene 0.00% 0.00% 106.160 0.000 0.00% Y 0.00% 0.000

n-Octane 0.36% 0.36% 114.229 0.415 0.80% Y 1.15% 1.316

n-Nonane 0.12% 0.12% 128.255 0.149 0.29% Y 0.41% 0.531

n-Decane 0.18% 0.18% 142.290 0.254 0.49% Y 0.70% 1.003

Total 100.00% 100.00% 51.777 100.00% 69.745
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

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Table 137. Condensate Tank Post-Flash Gas Composition Analysis.

Table 138. Regenerated Overhead Vent Stream Composition Analysis.

Component Component Moles 

Percent Normalized Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 0.00% 0.00% 44.01 0.0000 0.00% N

Nitrogen 0.00% 0.00% 28.01 0.0000 0.00% N

Methane 46.18% 46.18% 16.04 7.4070 21.23% N

Ethane 14.42% 14.42% 30.07 4.3354 12.43% N

Propane 15.42% 15.42% 44.1 6.8008 19.50% Y 29.39% 12.960

Isobutane 5.69% 5.70% 58.12 3.3100 9.49% Y 14.30% 8.313

n-Butane 7.51% 7.51% 58.12 4.3644 12.51% Y 18.86% 10.961

Isopentane 3.54% 3.54% 72.15 2.5570 7.33% Y 11.05% 7.972

n-Pentane 2.87% 2.87% 72.15 2.0697 5.93% Y 8.94% 6.453

n-Hexane 0.91% 0.91% 86.18 0.7863 2.25% Y 3.40% 2.928

Cyclohexane 0.15% 0.15% 84.16 0.1247 0.36% Y 0.54% 0.454

2,2-Dimethylbutane 0.07% 0.07% 86.177 0.0625 0.18% Y 0.27% 0.233

2,3-Dimethylbutane 0.24% 0.24% 86.177 0.2072 0.59% Y 0.90% 0.771

2-Methylpentane 0.71% 0.71% 86.177 0.6143 1.76% Y 2.65% 2.287

3-Methylpentane 0.34% 0.34% 86.177 0.2936 0.84% Y 1.27% 1.093

n-Heptane 1.23% 1.23% 100.202 1.2284 3.52% Y 5.31% 5.319

Methylcyclohexane 0.10% 0.10% 98.19 0.0976 0.28% Y 0.42% 0.414

2,2,4-Trimethylpentane 0.04% 0.04% 114.229 0.0491 0.14% Y 0.21% 0.242

Benzene 0.14% 0.14% 78.11 0.1106 0.32% Y 0.48% 0.373

Toluene 0.16% 0.16% 92.14 0.1455 0.42% Y 0.63% 0.579

Ethylbenzene 0.00% 0.00% 106.17 0.0020 0.01% Y 0.01% 0.009

Xylenes 0.08% 0.08% 106.17 0.0806 0.23% Y 0.35% 0.370

n-Octane 0.11% 0.11% 114.2285 0.1306 0.37% Y 0.56% 0.645

n-Nonane 0.04% 0.04% 128.255 0.0464 0.13% Y 0.20% 0.257

n-Decane 0.04% 0.04% 142.29 0.0608 0.17% Y 0.26% 0.374

Total 100% 100% 34.8843 100% 100% 63.007

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Water 17.54% 17.54% 18.010 3.159 11.56% N

Carbon Dioxide 5.47% 5.47% 44.010 2.407 8.81% N

Nitrogen 0.11% 0.11% 28.010 0.032 0.12% N

Methane 55.61% 55.61% 16.040 8.920 32.64% N

Ethane 6.19% 6.19% 30.070 1.861 6.81% N

Propane 3.98% 3.98% 44.100 1.755 6.42% Y 16.03% 7.069

Isobutane 1.07% 1.07% 58.120 0.622 2.28% Y 5.68% 3.301

n-Butane 1.49% 1.49% 58.120 0.866 3.17% Y 7.91% 4.597

Isopentane 0.57% 0.57% 72.150 0.413 1.51% Y 3.77% 2.719

n-Pentane 0.58% 0.58% 72.150 0.421 1.54% Y 3.85% 2.776

n-Hexane 0.33% 0.33% 86.180 0.286 1.05% Y 2.61% 2.252

Cyclohexane 0.62% 0.62% 84.160 0.523 1.92% Y 4.78% 4.024

Other Hexanes 0.37% 0.37% 86.180 0.320 1.17% Y 2.92% 2.517

n-Heptane 0.61% 0.61% 100.202 0.615 2.25% Y 5.62% 5.630

Methylcyclohexane 0.79% 0.79% 98.190 0.775 2.83% Y 7.08% 6.947

2,2,4-Trimethylpentane 0.02% 0.02% 114.229 0.022 0.08% Y 0.20% 0.226

Benzene 1.35% 1.35% 78.110 1.055 3.86% Y 9.63% 7.522

Toluene 1.89% 1.89% 92.140 1.741 6.37% Y 15.90% 14.654

Ethylbenzene 0.06% 0.06% 106.170 0.065 0.24% Y 0.59% 0.628

Xylenes 0.60% 0.60% 106.170 0.641 2.35% Y 5.86% 6.218

n-Octane 0.73% 0.73% 114.229 0.829 3.03% Y 7.57% 8.652

Total 100.00% 100.00% 27.329 100.00% 100.00% 79.734
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

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Table 139. Wet Gas Composition Analysis.

Component Component 

Moles Percent

Normalized 

Mole MW Gas g/mol % Wt VOC species?

VOC 

renormalized 

wt%

VOC g/mol

Carbon Dioxide 2.73% 2.73% 44.010 1.203 6.09% N

Nitrogen 0.17% 0.17% 28.010 0.048 0.24% N

Methane 84.98% 84.98% 16.040 13.631 69.04% N

Ethane 6.81% 6.81% 30.070 2.049 10.38% N

Propane 3.17% 3.17% 44.100 1.398 7.08% Y 49.67% 21.906

Isobutane 0.64% 0.64% 58.120 0.370 1.87% Y 13.14% 7.634

n-Butane 0.71% 0.71% 58.120 0.413 2.09% Y 14.67% 8.528

Isopentane 0.24% 0.24% 72.150 0.175 0.88% Y 6.21% 4.478

n-Pentane 0.20% 0.20% 72.150 0.144 0.73% Y 5.11% 3.686

n-Hexane 0.06% 0.06% 86.180 0.056 0.28% Y 1.98% 1.710

Cyclohexane 0.03% 0.03% 84.160 0.027 0.14% Y 0.95% 0.800

2,2-Dimethylbutane 0.00% 0.00% 86.177 0.004 0.02% Y 0.13% 0.113

2,3-Dimethylbutane 0.02% 0.02% 86.177 0.014 0.07% Y 0.50% 0.433

2-Methylpentane 0.05% 0.05% 86.177 0.042 0.21% Y 1.49% 1.288

3-Methylpentane 0.03% 0.03% 86.177 0.022 0.11% Y 0.77% 0.662

n-Heptane 0.06% 0.06% 100.202 0.059 0.30% Y 2.09% 2.094

Methylcyclohexane 0.03% 0.03% 98.190 0.032 0.16% Y 1.12% 1.103

2,2,4-Trimethylpentane 0.00% 0.00% 114.229 0.004 0.02% Y 0.15% 0.176

Benzene 0.01% 0.01% 78.110 0.012 0.06% Y 0.41% 0.323

Toluene 0.02% 0.02% 92.140 0.016 0.08% Y 0.57% 0.525

Ethylbenzene 0.00% 0.00% 106.170 0.001 0.00% Y 0.02% 0.020

m&p-Xylene 0.00% 0.00% 106.160 0.004 0.02% Y 0.15% 0.164

o-Xylene 0.00% 0.00% 106.160 0.001 0.00% Y 0.02% 0.024

n-Octane 0.01% 0.01% 114.229 0.016 0.08% Y 0.56% 0.635

n-Nonane 0.01% 0.01% 128.255 0.008 0.04% Y 0.27% 0.345

n-Decane 0.00% 0.00% 142.290 0.000 0.00% Y 0.00% 0.000

Total 100.00% 100.00% 19.745 100.00% 100.00% 56.648
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-110

Table 140. Toxic Speciation Profiles used in Future Year Emission Inventory Development for Future Wells.

benzene toluene ethylbenzene xylenes n-hexane formaldehyde

venting other than well venting, initial completion 

and dehydrator 0.403% 0.555% 0.017% 0.320% 4.744% 0.000%

flashing loss 0.822% 1.173% 0.016% 0.632% 3.927% 0.000%

Fugitive -working/breathing loss 0.830% 1.169% 0.016% 0.626% 3.965% 0.000%

diesel ICE 1.045% 1.518% 0.179% 1.205% 0.000% 8.510%

HD traffic 1.132% 0.613% 0.152% 0.801% 0.129% 7.924%

LD traffic 3.711% 10.147% 1.459% 5.744% 0.879% 2.456%

natural gas external combustion (boiler/heater) 4.000% 2.000% 0.000% 0.000% 0.000% 8.000%

dust 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%

compressor engine, lean burn 0.373% 0.346% 0.034% 0.156% 0.941% 44.746%

compressor engine, rich burn 5.338% 1.885% 0.084% 0.659% 0.000% 69.257%

natural gas drilling engine 0.373% 0.346% 0.034% 0.156% 0.941% 44.746%

flaring 0.000% 0.000% 0.000% 0.000% 0.000% 40.000%

diesel external combustion boiler 0.000% 0.000% 0.000% 0.000% 10.800% 48.700%

Reciprocating Engine 1.182% 0.430% 0.107% 0.430% 0.215% 8.700%

Turbine 0.000% 0.000% 0.000% 0.000% 0.000% 100.000%

produced water evaporation 13.858% 18.028% 1.529% 24.393% 0.147% 0.000%

Tank -working/breathing loss 0.478% 0.629% 0.009% 0.348% 3.398% 0.000%

Dehydrator Venting 9.631% 15.905% 0.591% 5.857% 2.613% 0.000%

venting -Well Venting and Initial completion 0.414% 0.570% 0.019% 0.177% 1.984% 0.000%

Source Type for lookup

VOC fractions

Source

Wamsutter Produced Gas Composition

Flash speciation from Wamsutter HYSYS

Wamsutter Fugitive Composition (Post Flash)

SPECIATE4, Profile 4674

From Catherine Yanca at EPA based on CRC E-55/E-59 Study

From David Brzezinski at EPA and MOVES

SPECIATE4, Profile 0003

AP-42, CH 3.2

AP-42, CH 3.2

AP-42, CH 3.2

SPECIATE4, Profile 1001

SPECIATE4, Profile 0002

SPECIATE4, Profile 1001

SPECIATE4, Profile 0007

EPA, Water 9 model Output. Based on data from evaporation 

facilities at Wamsutter Operations Center

Wamsutter Condensate Composition (Post Flash)

Wamsutter Regenerator Overhead Vent Stream Composition

Wamsutter Wet Gas Composition
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-111

Table 141. List of Toxics Speciation Profiles used in Future Year Emission Inventory 

Development for Future Wells by Source Category.

Source Category Appropriate Speciation Profiles Used

Added Compression (reciprocating) Reciprocating Engine

Added Compression (turbine) Turbine

Added Gas Plant (Duct Burner) natural gas external combustion (boiler/heater)

Added Gas Plant (Flares) flaring

Added Gas Plant (Fugitives) venting other than well venting, initial completion and dehydrator

Added Gas Plant (Heaters) natural gas external combustion (boiler/heater)

Added Gas Plant (Process) natural gas external combustion (boiler/heater)

Added Gas Plant (Recip Engines) Reciprocating Engine

Added Gas Plant (Turbine Engines) Turbine

Completion Equipment (diesel ICE) diesel ICE

Completion Traffic (HD) HD traffic

Completion Traffic (HD) Dust dust

Completion Traffic (LD) LD traffic

Completion Traffic (LD) Dust dust

Condensate Fugitive Devices Fugitive -working/breathing loss 

Condensate Tank Breathing Flaring flaring

Condensate Tank Breathing Losses Tank -working/breathing loss 

Condensate Tank Flashing Flaring flaring

Condensate Tank Flashing Losses flashing loss

Condensate Tank Working Flaring flaring

Condensate Tank Working Losses Tank -working/breathing loss 

Construction Dust, Fugitive dust

Construction Dust, Wind Erosion dust

Construction Traffic, Road and Well pad (HD) HD traffic

Construction Traffic, Road and Well pad (HD) Dust dust

Construction Traffic, Road and Well pad (LD) LD traffic

Construction Traffic, Road and Well pad (LD) Dust dust

Dehydrator Flaring flaring

Dehydrator Venting - Well Site Dehydrator Venting

Drilling Equip (diesel ICE 125HP) diesel ICE

Drilling Equip (diesel ICE 1476HP) diesel ICE

Drilling Traffic (HD) HD traffic

Drilling Traffic (HD) Dust dust

Drilling Traffic (LD) LD traffic

Drilling Traffic (LD) Dust dust

Evaporation Ponds produced water evaporation

Gas Stream Fugitive Devices venting other than well venting, initial completion and dehydrator

Heaters natural gas external combustion (boiler/heater)

Initial Completion Flaring flaring

Initial Completion Venting venting -Well Venting and Initial completion

Pneumatic Devices venting other than well venting, initial completion and dehydrator

Pneumatic Pump Flaring flaring

Pneumatic Pumps venting other than well venting, initial completion and dehydrator

Production Traffic (HD) HD traffic

Production Traffic (HD) Dust dust

Production Traffic (LD) LD traffic

Production Traffic (LD) Dust dust

Production Traffic, Central Facility (HD) HD traffic

Production Traffic, Central Facility (HD) Dust dust

Tank Loadout (vapor losses) Tank -working/breathing loss 

Well Pad Const Equip (diesel ICE) diesel ICE

Well Stream Fugitive Devices venting other than well venting, initial completion and dehydrator

Well Venting venting -Well Venting and Initial completion

Workover Equipment (diesel ICE) diesel ICE

WorkoverTraffic (HD) HD traffic

WorkoverTraffic (HD) Dust dust

WorkoverTraffic (LD) LD traffic

WorkoverTraffic (LD) Dust dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-112

WYDEQ BACT Requirements Accounting

ASSUMPTIONS

Data obtained from operators in blue 

text

Table 142. Summary of Fraction and Number of Wells with WYDEQ BACT Control for 

Pneumatic Pumps.

Percent w/ no 

BACT

Absolute w/ no 

BACT

Absolute w/ 

BACT

Percent with BACT 

where BACT 

equipment is removed

Equipment with 

BACT equipment

Instances where 

BACT equipment 

taken offline Percent Absolute

New Project_2008 0 0

New Project_2009 218 218 0.0% 0 218 0.0% 218 0 100% 218

New Project_2010 292 510 0.0% 0 292 0.0% 510 0 100% 510

New Project_2011 291 801 0.0% 0 291 0.0% 801 0 100% 801

New Project_2012 285 1,086 0.0% 0 285 0.0% 1086 0 100% 1086

New Project_2013 291 1,377 0.0% 0 291 0.0% 1377 0 100% 1377

New Project_2014 288 1,664 0.0% 0 288 0.0% 1664 0 100% 1664

New Project_2015 297 1,961 0.0% 0 297 0.0% 1961 0 100% 1961

New Project_2016 232 2,193 0.0% 0 232 0.0% 2193 0 100% 2193

New Project_2017 305 2,498 0.0% 0 305 0.0% 2498 0 100% 2498

New Project_2018 335 2,833 0.0% 0 335 0.0% 2833 0 100% 2833

New Project_2019 270 3,103 0.0% 0 270 0.0% 3103 0 100% 3103

New Project_2020 270 3,373 0.0% 0 270 0.0% 3373 0 100% 3373

New Project_2021 305 3,677 0.0% 0 305 0.0% 3677 0 100% 3677

New Project_2022 289 3,966 0.0% 0 289 0.0% 3966 0 100% 3966

New Project_2023 97 4,063 0.0% 0 97 0.0% 4063 0 100% 4063

New Project_2024 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2025 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2026 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2027 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2028 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2029 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2030 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2031 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2032 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2033 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2034 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2035 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2036 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2037 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

assumed

New Equipment Existing Equipment

Total Equipment meeting BACT 

Inventory_Year

Equipment Installed 

Population

Cumulative 

Equipment 

Population

Pneumatic Pumps
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-113

Table 143. Summary of Fraction and Number of Wells with WYDEQ BACT Controls for 

Dehydrators.

 

Table 144. Summary of Fraction and Number of Wells with WYDEQ BACT Control for 

Condensate Tanks.

Percent w/ no 

BACT

Absolute w/ no 

BACT

Absolute w/ 

BACT

Percent with BACT 

where BACT 

equipment is 

removed

Equipment with 

BACT equipment

Instances where 

BACT equipment 

taken offline Percent Absolute

New Project_2008 0 0

New Project_2009 218 218 0.0% 0 218 0.0% 218 0 100% 218

New Project_2010 292 510 0.0% 0 292 0.0% 510 0 100% 510

New Project_2011 291 801 0.0% 0 291 0.0% 801 0 100% 801

New Project_2012 285 1,086 0.0% 0 285 0.0% 1086 0 100% 1086

New Project_2013 291 1,377 0.0% 0 291 0.0% 1377 0 100% 1377

New Project_2014 288 1,664 0.0% 0 288 0.0% 1664 0 100% 1664

New Project_2015 297 1,961 0.0% 0 297 0.0% 1961 0 100% 1961

New Project_2016 232 2,193 0.0% 0 232 0.0% 2193 0 100% 2193

New Project_2017 305 2,498 0.0% 0 305 0.0% 2498 0 100% 2498

New Project_2018 335 2,833 0.0% 0 335 0.0% 2833 0 100% 2833

New Project_2019 270 3,103 0.0% 0 270 0.0% 3103 0 100% 3103

New Project_2020 270 3,373 0.0% 0 270 0.0% 3373 0 100% 3373

New Project_2021 305 3,677 0.0% 0 305 0.0% 3677 0 100% 3677

New Project_2022 289 3,966 0.0% 0 289 0.0% 3966 0 100% 3966

New Project_2023 97 4,063 0.0% 0 97 0.0% 4063 0 100% 4063

New Project_2024 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2025 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2026 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2027 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2028 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2029 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2030 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2031 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2032 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2033 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2034 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2035 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2036 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2037 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

assumed

Existing Equipment

Total Equipment meeting 

BACT requirements

Inventory_Year

Equipment 

Installed 

Population

Cumulative 

Equipment 

Population

Dehydrators

New Equipment

Percent w/ no 

BACT

Absolute w/ no 

BACT

Absolute w/ 

BACT

Percent with BACT 

where BACT 

equipment is 

removed

Equipment with 

BACT equipment

Instances where 

BACT equipment 

taken offline Percent Absolute

New Project_2008 0 0

New Project_2009 218 218 0.0% 0 218 0.0% 218 0 100% 218

New Project_2010 292 510 0.0% 0 292 0.0% 510 0 100% 510

New Project_2011 291 801 0.0% 0 291 0.0% 801 0 100% 801

New Project_2012 285 1,086 0.0% 0 285 0.0% 1086 0 100% 1086

New Project_2013 291 1,377 0.0% 0 291 0.0% 1377 0 100% 1377

New Project_2014 288 1,664 0.0% 0 288 0.0% 1664 0 100% 1664

New Project_2015 297 1,961 0.0% 0 297 0.0% 1961 0 100% 1961

New Project_2016 232 2,193 0.0% 0 232 0.0% 2193 0 100% 2193

New Project_2017 305 2,498 0.0% 0 305 0.0% 2498 0 100% 2498

New Project_2018 335 2,833 0.0% 0 335 0.0% 2833 0 100% 2833

New Project_2019 270 3,103 0.0% 0 270 0.0% 3103 0 100% 3103

New Project_2020 270 3,373 0.0% 0 270 0.0% 3373 0 100% 3373

New Project_2021 305 3,677 0.0% 0 305 0.0% 3677 0 100% 3677

New Project_2022 289 3,966 0.0% 0 289 0.0% 3966 0 100% 3966

New Project_2023 97 4,063 0.0% 0 97 0.0% 4063 0 100% 4063

New Project_2024 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2025 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2026 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2027 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2028 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2029 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2030 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2031 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2032 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2033 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2034 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2035 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2036 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

New Project_2037 0 4,063 0.0% 0 0 0.0% 4063 0 100% 4063

assumed

Inventory_Year

Equipment 

Installed 

Population

Cumulative 

Equipment 

Population

New Equipment Existing Equipment

Total Equipment meeting 

BACT requirements

Condensate Tanks
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-114

2009 Well Pad Construction Equipment Emissions

ASSUMPTIONS

Activity data obtained from operator in blue text

Assumptions:

* Emission factors from EPA Federal Diesel Engine Standards 

http://www.epa.gov/otaq/standar

ds/nonroad/nonroadci.htm

* VOC/THC= 1.053 Conversion for HC->VOC for diesel engines (EPA, 2005; EPA420-R-05-0159, p. 5)

*

37% of fine particles assumed to be filterable and all filterable are assigned to EC (Source: AQTSD for Hell’s Gulch 

and Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

*

63% of fine particles assumed to be filterable and all filterable are assigned to SOA (Source: AQTSD for Hell’s Gulch 

and Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

EPA NONROAD model Fully Deteriorated Tier Emission Factors

N2O Emission factors (g/gallons) from The Climate Registry, General Reporting Protocol v1.1, Table 13.6

Equations:

Emissions (tons/year-well) = Emission factor (g/hp-hr) * Horsepower * Time Used (hours) * Load

453.6 (g/lb) * 2000 (lbs/ton)

PM2.5/PM10 = 97% EPA (2004) NONROAD

VOC/HC= 1.053 EPA NONROAD HC Conversions

NMHC/THC= 98.40% EPA NONROAD HC Conversions

SO2 Emission Factor Calculation Information 

2008 Fuel Sulfur content 0.0355 sulfur fuel weight percent from EPA's NMIM 

County Database

soxcnv Tiers I-III 0.02247 grams PM sulfur/grams fuel sulfur consumed

soxcnv Tier IV 0.3

grams PM sulfate/grams PM sulfur 7

soxbas 0.33

Density of Diesel Fuel 7.09 lb/gallons

Molecular weight of S 32 g/mol

Molecular weight of S02 64 g/mol

453.6 g/lb
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-115

Table 145. 2009 Well Pad Construction Equipment Emissions (lb/well pad) by Pollutants and 

by Equipment Type.

Equipment

Activity & 

Emission Factors

Emissions 

(lb/well pad)

Engine 1 Engine Function Loader

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 200

Horsepower Range 175-300

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.433

Fuel Consumption (Gallons) 293

Emission Factors 

(g/bhp-hr)

NOx 6.860 72.60

VOC 1.021 10.80

CO 8.501 89.96

PM10 0.403 4.26

PM2.5 0.391 4.13

SO2 0.136 1.44

CO2 623 6597.37

CH4 0.016 0.16

PM_filt 0.145 1.53

PM_cond 0.246 2.60

N2O 0.260 0.17

Engine 2 Engine Function Dozer

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 500

Horsepower Range 300-600

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.371

Fuel Consumption (Gallons) 628

Emission Factors 

(g/bhp-hr) NOx 6.860 181.49

VOC 1.021 27.00

CO 8.501 224.89

PM10 0.403 10.65

PM2.5 0.391 10.33

SO2 0.116 3.07

CO2 534 14120.07

CH4 0.016 0.41

PM_filt 0.145 3.82

PM_cond 0.246 6.51

N2O 0.260 0.36

Engine 3 Engine Function Scraper

Number of Engines 2

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 700

Horsepower Range 600-750

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.371

Fuel Consumption (Gallons) 1758

Emission Factors 

(g/bhp-hr)

(g/gal) for N2O

NOx 6.860 508.18

VOC 1.021 75.61

CO 8.501 629.70

PM10 0.403 29.83

PM2.5 0.391 28.93

SO2 0.116 8.60

CO2 534 39536.20

CH4 0.016 1.15

PM_filt 0.145 10.71

PM_cond 0.246 18.23

N2O 0.260 1.01

Engine 4 Engine Function Grader

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-116

Equipment

Activity & 

Emission Factors

Emissions 

(lb/well pad)

Rated horsepower 350

Horsepower Range 300-600

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.371

Fuel Consumption (Gallons) 440

Emission Factors 

(g/bhp-hr)

(g/gal) for N2O

NOx 6.860 127.05

VOC 1.021 18.90

CO 8.501 157.43

PM10 0.403 7.46

PM2.5 0.391 7.23

SO2 0.116 2.15

CO2 534 9884.05

CH4 0.016 0.29

PM_filt 0.145 2.68

PM_cond 0.246 4.56

N2O 0.260 0.25

Engine 5 Engine Function Backhoe

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 60

Horsepower Range 50-75

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.481

Fuel Consumption (Gallons) 98

Emission Factors 

(g/bhp-hr)

(g/gal) for N2O

NOx 6.860 21.78

VOC 1.314 4.17

CO 6.425 20.40

PM10 1.076 3.42

PM2.5 1.044 3.31

SO2 0.151 0.48

CO2 692 2196.89

CH4 0.020 0.06

PM_filt 0.386 1.23

PM_cond 0.658 2.09

N2O 0.260 0.06

Engine 6 Engine Function Roller

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 200

Horsepower Range 175-300

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.371

Fuel Consumption (Gallons) 251

Emission Factors 

(g/bhp-hr)

(g/gal) for N2O

NOx 6.860 72.60

VOC 1.021 10.80

CO 8.501 89.96

PM10 0.403 4.26

PM2.5 0.391 4.13

SO2 0.116 1.23

CO2 534 5648.03

CH4 0.016 0.16

PM_filt 0.145 1.53

PM_cond 0.246 2.60

N2O 0.260 0.14

Engine 7 Engine Function Water Truck

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 210

Horsepower Range 175-300

Time used (hrs) 60

Load Factor 0.4
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-117

Equipment

Activity & 

Emission Factors

Emissions 

(lb/well pad)

BSFC (lb/hp-hr) 0.371

Fuel Consumption (Gallons) 264

Emission Factors 

(g/bhp-hr)

(g/gal) for N2O

NOx 6.860 76.23

VOC 1.021 11.34

CO 8.501 94.46

PM10 0.403 4.47

PM2.5 0.391 4.34

SO2 0.116 1.29

CO2 534 5930.43

CH4 0.016 0.17

PM_filt 0.145 1.61

PM_cond 0.246 2.73

N2O 0.260 0.15

Engine 8 Engine Function Dump Truck

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 330

Horsepower Range 300-600

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.371

Fuel Consumption (Gallons) 414

Emission Factors 

(g/bhp-hr)

(g/gal) for N2O

NOx 6.860 119.79

VOC 1.021 17.82

CO 8.501 148.43

PM10 0.403 7.03

PM2.5 0.391 6.82

SO2 0.116 2.03

CO2 534 9319.25

CH4 0.016 0.27

PM_filt 0.145 2.52

PM_cond 0.246 4.30

N2O 0.260 0.24

Engine 9 Engine Function Trencher

Number of Engines 1

Fuel Type Diesel

Engine Technology Tier 1

Rated horsepower 250

Horsepower Range 175-300

Time used (hrs) 60

Load Factor 0.4

BSFC (lb/hp-hr) 0.371

Fuel Consumption (Gallons) 314

Emission Factors 

(g/bhp-hr)

(g/gal) for N2O

NOx 6.860 90.75

VOC 1.021 13.50

CO 8.501 112.45

PM10 0.403 5.33

PM2.5 0.391 5.17

SO2 0.116 1.54

CO2 534 7060.04

CH4 0.016 0.21

PM_filt 0.145 1.91

PM_cond 0.246 3.25

N2O 0.260 0.18
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-118

Table 146. Summary of 2009 Well Pad Construction Emissions (lb/well pad) by Pollutants for 

All Equipment.

Equipment Type Pollutant Emissions

(lb/year-well pad) 

Well Pad 

Construction 

Equipment

NOx 1,270

VOC 190

CO 1,568

PM10 77

PM2.5 74

SO2 22

CO2 100,292

CH4 3

PM_filt 28

PM_cond 47

N2O 3

Table 147. 2009 Well Pad Construction Equipment Emissions in tons per Pad.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Well Pad Const Equip 

(diesel ICE) 0.6352 0.0950 0.7838 0.0384 0.0372 0.0109 50.1462 0.0014 0.0138 0.0234 0.0013 new pads

Description Projection Well Pad Construction Equipment Emissions (tons per pad)
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-119

Table 148. Percent Change in Emission from Base Year 2009 for Well Pad Construction 

(aggregate factors to apply to total emissions across all equipment types).

Technology Assumption Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

Tier 1 2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 1 2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-120

2009 Well Pad and Access Road Construction Traffic Emissions

ASSUMPTIONS

Data provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2009 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

CONSTRUCTION TRAFFIC TO WELL.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-121

Table 149. Summary of Traffic Activity Data Associated with Well Pad and Access Road 

Construction Phase.

Table 150. 2009 Exhaust Emissions (lb/pad) Associated with Well Pad and Access Road 

Construction Traffic by Vehicle Type.

Table 151. Summary of 2009 Fugitive Dust Emissions (tons/pad) Associated with Well Pad and 

Access Road Construction Traffic.

Light Truck 20 20 14

Heavy Truck 20 20 21

Equipment Type Mean Vehicle 

Speed (mph)

Round Trip Off-Road 

Trip Distance (miles)

Number of Round Trips 

Per Pad

NOx 2.52 1.556

SO2 0.01 0.009

CO 18.19 11.227

CO2 675.15 417

VOC 1.48 0.913

PM10 0.09 0.054

PM2.5 0.08 0.051

PM_filt - 0.000

PM_cond - 0.000

CH4 0.08 0.052

N2O 0.05 0.028

NOx 20.23 18.728

SO2 0.08 0.074

CO 15.07 13.952

CO2 2612.44 2418.921

VOC 1.86 1.724

PM10 1.21 1.118

PM2.5 1.17 1.084

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.084

N2O 0.04 0.033

Light-Duty Truck

Heavy-Duty Truck 

Pollutant 2009 Emission Factors 

(g/mile)

Base year Emissions 

(lb/well pad) Vehicle Type

Travel to well Light truck 7,000 20 14 14 20 280 0.20 0.03 0.02 0.00

Travel to well Heavy Truck 70,000 20 21 21 20 420 0.20 0.04 0.02 0.00

Total 0.07 0.01

PM2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/pad)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/pad)

Total # of 

Round Trips

Round Trip 

Distance (mi)

Total Miles 

Traveled

PM10

Activity Vehicle Type Av. Vehicle 

Weight (lb)

Mean vehicle 

speed (mph)

# of Visits per 

Year 
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-122

Table 152. 2009 Exhaust and Fugitive Dust Emissions Associated with Well Pad and Access Road Construction Traffic in tons per pad.

Table 153. Percent Change in Emission from Base Year 2009 due to fleet turnover for Well Pad and Access Road Construction Traffic.

Projection

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Construction Traffic, Road and Well pad (LD) 0.0008 0.0005 0.0056 2.68E-05 2.55E-05 4.44E-06 0.2084 2.62E-05 0 0 1.41E-05 new pads 0.0277 0.0028

Construction Traffic, Road and Well pad (HD) 0.0094 0.0009 0.0070 0.0006 0.0005 3.72E-05 1.2095 4.18E-05 0 0 1.65E-05 new pads 0.0416 0.0041

Total Road and Well Pad Construction Traffic Emissions (tons per well pad) Description Fugitive Road NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 -5% -11% -3% 0% -4% -6% -6% 0% 0% -3% -7% -10% -45% -4% 0% -3% -7% -7% 0% 0% 4% -5%

2011 -10% -18% -7% -1% -10% -12% -13% 0% 0% -7% -14% -19% -74% -9% 0% -10% -18% -18% 0% 0% 13% -12%

2012 -16% -27% -11% -2% -16% -19% -19% 0% 0% -11% -21% -28% -75% -14% 0% -17% -28% -28% 0% 0% 20% -17%

2013 -22% -28% -15% -4% -22% -25% -25% 0% 0% -15% -28% -36% -75% -19% 0% -25% -37% -37% 0% 0% 24% -23%

2014 -28% -29% -18% -5% -27% -30% -31% 0% 0% -18% -34% -44% -76% -24% 0% -32% -45% -46% 0% 0% 28% -28%

2015 -33% -30% -22% -7% -33% -35% -36% 0% 0% -22% -39% -51% -76% -28% 0% -38% -53% -53% 0% 0% 30% -33%

2016 -38% -31% -26% -8% -38% -40% -40% 0% 0% -25% -44% -57% -76% -33% 0% -44% -60% -60% 0% 0% 31% -37%

2017 -43% -33% -28% -10% -42% -44% -44% 0% 0% -28% -48% -62% -76% -36% 0% -49% -66% -66% 0% 0% 32% -41%

2018 -47% -34% -31% -11% -46% -48% -48% 0% 0% -30% -52% -67% -76% -39% 0% -54% -71% -71% 0% 0% 33% -44%

2019 -51% -35% -33% -13% -49% -51% -51% 0% 0% -32% -56% -71% -77% -42% 0% -59% -75% -75% 0% 0% 33% -48%

2020 -54% -36% -34% -14% -52% -54% -54% 0% 0% -34% -59% -74% -77% -44% 0% -62% -79% -79% 0% 0% 34% -50%

2021 -57% -37% -36% -15% -55% -56% -56% 0% 0% -35% -62% -77% -77% -46% 0% -66% -82% -82% 0% 0% 34% -53%

2022 -64% -39% -40% -18% -62% -61% -62% 0% 0% -38% -69% -83% -77% -50% 0% -73% -89% -89% 0% 0% 35% -60%

2023 -60% -38% -37% -16% -58% -58% -59% 0% 0% -36% -64% -79% -77% -48% 0% -69% -85% -85% 0% 0% 34% -55%

2024 -62% -39% -39% -17% -60% -60% -60% 0% 0% -37% -67% -81% -77% -49% 0% -71% -87% -87% 0% 0% 34% -58%

2025 -66% -40% -41% -19% -65% -63% -64% 0% 0% -39% -71% -84% -77% -52% 0% -76% -90% -90% 0% 0% 34% -61%

2026 -68% -41% -42% -20% -67% -64% -65% 0% 0% -38% -72% -85% -77% -53% 0% -78% -91% -91% 0% 0% 36% -63%

2027 -69% -41% -43% -21% -69% -66% -66% 0% 0% -38% -74% -86% -77% -54% 0% -79% -92% -92% 0% 0% 36% -64%

2028 -71% -42% -44% -21% -70% -67% -68% 0% 0% -39% -75% -87% -77% -54% 0% -81% -93% -93% 0% 0% 36% -65%

2029 -72% -42% -45% -22% -72% -68% -69% 0% 0% -40% -76% -87% -77% -55% 0% -82% -94% -94% 0% 0% 36% -67%

2030 -73% -42% -46% -22% -73% -69% -69% 0% 0% -40% -77% -88% -77% -56% 0% -83% -94% -94% 0% 0% 35% -67%

2031 -74% -43% -46% -23% -74% -69% -70% 0% 0% -42% -78% -88% -77% -57% 0% -84% -95% -95% 0% 0% 34% -69%

2032 -74% -43% -47% -23% -75% -70% -71% 0% 0% -42% -79% -88% -77% -57% 0% -85% -95% -95% 0% 0% 34% -69%

2033 -75% -43% -48% -23% -76% -71% -71% 0% 0% -43% -79% -89% -78% -58% 0% -85% -95% -95% 0% 0% 33% -69%

2034 -76% -44% -48% -24% -76% -71% -72% 0% 0% -43% -79% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2035 -76% -44% -49% -24% -77% -72% -72% 0% 0% -44% -80% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2036 -77% -44% -49% -24% -77% -72% -73% 0% 0% -44% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -70%

2037 -77% -44% -50% -24% -78% -72% -73% 0% 0% -45% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -71%

Light-Duty Truck (%) Heavy-Duty Truck (%)

Year
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-123

2009 Completion Equipment Emissions

ASSUMPTIONS

Activity data obtained from operator in blue text

Assumptions:

Assumed that all equipment uses Tier 2 engines

* Emission factors from EPA Federal Diesel Engine Standards 

http://www.epa.gov/otaq/standar

ds/nonroad/nonroadci.htm

* VOC/THC= 1.053 Conversion for HC->VOC for diesel engines (EPA, 2005; EPA420-R-05-0159, p. 5)

*

37% of fine particles assumed to be filterable and all filterable are assigned to EC (Source: AQTSD for Hell’s Gulch 

and Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

*

63% of fine particles assumed to be filterable and all filterable are assigned to SOA (Source: AQTSD for Hell’s Gulch 

and Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

EPA NONROAD model Fully Deteriorated Tier Emission Factors

N2O Emission factors (g/gallons) from The Climate Registry, General Reporting Protocol v1.1, Table 13.6

Equations:

Emissions (tons/year-well) = Emission factor (g/hp-hr) * Horsepower * Time Used (hours) * Load

453.6 (g/lb) * 2000 (lbs/ton)

PM2.5/PM10 = 97% EPA (2004) NONROAD

VOC/HC= 1.053 EPA NONROAD HC Conversions

NMHC/THC= 98.40% EPA NONROAD HC Conversions

SO2 Emission Factor Calculation Information 

2008 Fuel Sulfur content 0.0355 sulfur fuel weight percent from EPA's NMIM County 

Database

soxcnv Tiers I-III 0.02247 grams PM sulfur/grams fuel sulfur consumed

soxcnv Tier IV 0.3

grams PM sulfate/grams PM sulfur 7

soxbas 0.33

Density of Diesel Fuel 7.09 lb/gallons

Molecular weight of S 32 g/mol

Molecular weight of S02 64 g/mol

453.6 g/lb
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-124

Table 154. 2009 Completion Equipment Emissions (lb/spud) by Pollutants and by Equipment 

Type.

Frac Pump

4

Diesel 

Tier 2

2250

>1200

20

0.3

0.367

2795

NOx 4.534 539.74

VOC 0.255 30.40

CO 2.610 310.71

PM10 0.149 17.75

PM2.5 0.145 17.22

SO2 0.115 13.73

CO2 530 63127.33

CH4 0.004 0.46

PM_filt 0.054 6.37

PM_cond 0.091 10.85

(g/gal) N2O 0.260 1.60

Hydraulic Triplex

2

Diesel 

Tier 2

700

600-750

20

0.3

0.367

435

NOx 4.534 83.96

VOC 0.255 4.73

CO 2.610 48.33

PM10 0.149 2.76

PM2.5 0.145 2.68

SO2 0.115 2.14

CO2 530 9819.81

CH4 0.004 0.07

PM_filt 0.054 0.99

PM_cond 0.091 1.69

(g/gal) N2O 0.260 0.25

Blender

1

Diesel 

Tier 2

350

300-600

20

0.3

0.367

109

NOx 4.534 20.99

VOC 0.255 1.18

CO 2.610 12.08

PM10 0.149 0.69

PM2.5 0.145 0.67

SO2 0.115 0.53

CO2 530 2454.95

CH4 0.004 0.02

PM_filt 0.054 0.25

PM_cond 0.091 0.42

(g/gal) N2O 0.260 0.06

Emission Factors 

(g/bhp-hr)

Emission Factors 

(g/bhp-hr)

BSFC (lb/hp-hr)

Engine 3

Equipment

Activity & Emission 

Factors

Emissions 

(lb/spud)

Fuel Consumption (Gallons)

Engine Function

Time used (hrs)

Load Factor

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Engine 2

Engine 1

Fuel Consumption (Gallons)

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Fuel Consumption (Gallons)

Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Engine Function

Number of Engines

Fuel Type

Engine Technology

Emission Factors 

(g/bhp-hr)
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-125

Pre gel

1

Diesel 

Tier 2

250

175-300

20

0.3

0.367

78

NOx 4.676 15.46

VOC 0.263 0.87

CO 2.610 8.63

PM10 0.149 0.49

PM2.5 0.145 0.48

SO2 0.115 0.38

CO2 530 1753.46

CH4 0.004 0.01

PM_filt 0.054 0.18

PM_cond 0.091 0.30

(g/gal) N2O 0.260 0.04

Frac Van

1

Diesel 

Tier 2

50

50-75

20

0.3

0.408

17

NOx 5.313 3.51

VOC 0.299 0.20

CO 3.728 2.47

PM10 0.298 0.20

PM2.5 0.289 0.19

SO2 0.128 0.08

CO2 589 389.86

CH4 0.005 0.00

PM_filt 0.107 0.07

PM_cond 0.182 0.12

(g/gal) N2O 0.260 0.01

Acid Pump

1

Diesel 

Tier 2

50

50-75

20

0.3

0.408

17

NOx 5.313 3.51

VOC 0.299 0.20

CO 3.728 2.47

PM10 0.298 0.20

PM2.5 0.289 0.19

SO2 0.128 0.08

CO2 589 389.86

CH4 0.005 0.00

PM_filt 0.107 0.07

PM_cond 0.182 0.12

(g/gal) N2O 0.260 0.01

Activity & Emission 

Factors

Emissions 

(lb/spud)

Emission Factors 

(g/bhp-hr)

Emission Factors 

(g/bhp-hr)

Emission Factors 

(g/bhp-hr)

Equipment

Engine 4 Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Fuel Consumption (Gallons)

Engine 5 Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Fuel Consumption (Gallons)

Engine 6

Fuel Consumption (Gallons)

Engine Technology

Engine Function

Number of Engines

Fuel Type

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-126

Table 155. Summary of 2009 Completion Emissions (lb/year-spud) by Pollutants for All 

Equipment.

Equipment 

Type Pollutant Emissions(lb/year-spud) 

Completion 

Equipment

NOx 671

VOC 38

CO 387

PM10 22

PM2.5 22

SO2 17

CO2 78,325

CH4 1

PM_filt 8

PM_cond 14

N2O 2

Table 156. 2009 Completion Construction Equipment Emissions in tons per spud.

Wireline 

1

Diesel 

Tier 2

50

50-75

20

0.3

0.408

17

NOx 5.313 3.51

VOC 0.299 0.20

CO 3.728 2.47

PM10 0.298 0.20

PM2.5 0.289 0.19

SO2 0.128 0.08

CO2 589 389.86

CH4 0.005 0.00

PM_filt 0.107 0.07

PM_cond 0.182 0.12

(g/gal) N2O 0.260 0.01

Equipment

Activity & Emission 

Factors

Emissions 

(lb/spud)

Engine 7 Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Emission Factors 

(g/bhp-hr)

Fuel Consumption (Gallons)

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Completion 

Equipment (diesel 

ICE) 0.3353 0.0189 0.1936 0.0111 0.0108 0.0085 39.1626 0.0003 0.0040 0.0068 0.0010 total spuds

Projection Completion Construction Equipment Emissions (tons per spud) Description
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-127

Table 157. Percent Change in Emission from Base Year 2009 for Completion Construction 

Equipment (aggregate factors to apply to total emissions across all equipment types).

Technology 

Assumption Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

Tier 2 2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-128

2009 Well Completion Traffic Emissions

ASSUMPTIONS

Data Provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2009 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

WELL COMPLETION TRAFFIC.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-129

Table 158. Summary of Traffic Activity Data Associated with Well Completion Phase.

Table 159. 2009 Exhaust Emissions (lb/spud) Associated with Well Completion Traffic by 

Vehicle Type.

Table 160. Summary of 2009 Fugitive Dust Emissions (tons/spud) Associated with Well 

Completion Traffic.

Light Truck 20 20 66

Heavy Truck 20 20 138

Mean Vehicle 

Speed (mph)

Round Trip Off-Road 

Trip Distance (miles)

Number of Round 

Trips Per Well Equipment Type

NOx 2.52 7.334

SO2 0.01 0.042

CO 18.19 52.926

CO2 675.15 1965

VOC 1.48 4.302

PM10 0.09 0.253

PM2.5 0.08 0.240

PM_filt - 0.000

PM_cond - 0.000

CH4 0.08 0.247

N2O 0.05 0.133

NOx 20.23 123.068

SO2 0.08 0.489

CO 15.07 91.682

CO2 2612.44 15895.770

VOC 1.86 11.326

PM10 1.21 7.348

PM2.5 1.17 7.123

PM_filt - 0.000

PM_cond - 0.000

CH4

0.09

0.549

N2O 0.04 0.216

Vehicle Type Pollutant 2009 Emission Factors

(g/mile)

Base year Emissions 

(lb/well pad)

Light-Duty Truck

Heavy-Duty Truck 

Travel to 

well Light truck 7,000 20 66 66 20 1320 0.20 0.13 0.02 0.01

Travel to 

well Heavy Truck 70,000 20 138 138 20 2760 0.20 0.27 0.02 0.03

Total 0.40 0.40 0.04 0.04

All Operators

Total # of 

Round Trips

Round Trip 

Distance (mi)

Total Miles 

Traveled Units Activity Vehicle Type Av. Vehicle Weight (lb)

Mean vehicle 

speed (mph)

# of Visits 

per Year 

PM2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spud)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spud)

PM10
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-130

Table 161. 2009 Exhaust and Fugitive Dust Emissions Associated with Well Completion Traffic in tons per spud.

Table 162. Percent Change in Emission from Base Year 2009 Due to Fleet Turnover for Well Completion Traffic.

Projection

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Completion Traffic (LD) 0.0037 0.0022 0.0265 0.0001 0.0001 2.10E-05 0.9824 0.0001 0 0 6.65E-05 total spuds 0.1307 0.0130

Completion Traffic (HD) 0.0615 0.0057 0.0458 0.0037 0.0036 0.0002 7.9479 0.0003 0 0 0.0001 total spuds 0.2732 0.0271

Description Total Completion Traffic Emissions (tons per pad) Fugitive Road NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 -5% -11% -3% 0% -4% -6% -6% 0% 0% -3% -7% -10% -45% -4% 0% -3% -7% -7% 0% 0% 4% -5%

2011 -10% -18% -7% -1% -10% -12% -13% 0% 0% -7% -14% -19% -74% -9% 0% -10% -18% -18% 0% 0% 13% -12%

2012 -16% -27% -11% -2% -16% -19% -19% 0% 0% -11% -21% -28% -75% -14% 0% -17% -28% -28% 0% 0% 20% -17%

2013 -22% -28% -15% -4% -22% -25% -25% 0% 0% -15% -28% -36% -75% -19% 0% -25% -37% -37% 0% 0% 24% -23%

2014 -28% -29% -18% -5% -27% -30% -31% 0% 0% -18% -34% -44% -76% -24% 0% -32% -45% -46% 0% 0% 28% -28%

2015 -33% -30% -22% -7% -33% -35% -36% 0% 0% -22% -39% -51% -76% -28% 0% -38% -53% -53% 0% 0% 30% -33%

2016 -38% -31% -26% -8% -38% -40% -40% 0% 0% -25% -44% -57% -76% -33% 0% -44% -60% -60% 0% 0% 31% -37%

2017 -43% -33% -28% -10% -42% -44% -44% 0% 0% -28% -48% -62% -76% -36% 0% -49% -66% -66% 0% 0% 32% -41%

2018 -47% -34% -31% -11% -46% -48% -48% 0% 0% -30% -52% -67% -76% -39% 0% -54% -71% -71% 0% 0% 33% -44%

2019 -51% -35% -33% -13% -49% -51% -51% 0% 0% -32% -56% -71% -77% -42% 0% -59% -75% -75% 0% 0% 33% -48%

2020 -54% -36% -34% -14% -52% -54% -54% 0% 0% -34% -59% -74% -77% -44% 0% -62% -79% -79% 0% 0% 34% -50%

2021 -57% -37% -36% -15% -55% -56% -56% 0% 0% -35% -62% -77% -77% -46% 0% -66% -82% -82% 0% 0% 34% -53%

2022 -64% -39% -40% -18% -62% -61% -62% 0% 0% -38% -69% -83% -77% -50% 0% -73% -89% -89% 0% 0% 35% -60%

2023 -60% -38% -37% -16% -58% -58% -59% 0% 0% -36% -64% -79% -77% -48% 0% -69% -85% -85% 0% 0% 34% -55%

2024 -62% -39% -39% -17% -60% -60% -60% 0% 0% -37% -67% -81% -77% -49% 0% -71% -87% -87% 0% 0% 34% -58%

2025 -66% -40% -41% -19% -65% -63% -64% 0% 0% -39% -71% -84% -77% -52% 0% -76% -90% -90% 0% 0% 34% -61%

2026 -68% -41% -42% -20% -67% -64% -65% 0% 0% -38% -72% -85% -77% -53% 0% -78% -91% -91% 0% 0% 36% -63%

2027 -69% -41% -43% -21% -69% -66% -66% 0% 0% -38% -74% -86% -77% -54% 0% -79% -92% -92% 0% 0% 36% -64%

2028 -71% -42% -44% -21% -70% -67% -68% 0% 0% -39% -75% -87% -77% -54% 0% -81% -93% -93% 0% 0% 36% -65%

2029 -72% -42% -45% -22% -72% -68% -69% 0% 0% -40% -76% -87% -77% -55% 0% -82% -94% -94% 0% 0% 36% -67%

2030 -73% -42% -46% -22% -73% -69% -69% 0% 0% -40% -77% -88% -77% -56% 0% -83% -94% -94% 0% 0% 35% -67%

2031 -74% -43% -46% -23% -74% -69% -70% 0% 0% -42% -78% -88% -77% -57% 0% -84% -95% -95% 0% 0% 34% -69%

2032 -74% -43% -47% -23% -75% -70% -71% 0% 0% -42% -79% -88% -77% -57% 0% -85% -95% -95% 0% 0% 34% -69%

2033 -75% -43% -48% -23% -76% -71% -71% 0% 0% -43% -79% -89% -78% -58% 0% -85% -95% -95% 0% 0% 33% -69%

2034 -76% -44% -48% -24% -76% -71% -72% 0% 0% -43% -79% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2035 -76% -44% -49% -24% -77% -72% -72% 0% 0% -44% -80% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2036 -77% -44% -49% -24% -77% -72% -73% 0% 0% -44% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -70%

2037 -77% -44% -50% -24% -78% -72% -73% 0% 0% -45% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -71%

Light-Duty Truck Heavy-Duty Truck 

Year
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-131

2009 Drilling Emissions

ASSUMPTIONS

Activity data obtained from the operators

*

Emission factors from EPA Federal Diesel 

Engine Tier 2 Standards http://www.epa.gov/otaq/standards/nonroad/nonroadci.htm

* Crankcase Emission factors are 2% of HC Exhaust Emission Factor for Tier II and earlier per 

* EPA NONROAD Modeling Guidance p. 23 (EPA, 2004; EPA420-P-04-009). 

* VOC/THC= 1.053 Conversion for HC->VOC for diesel engines (EPA, 2005; EPA420-R-05-0159, p. 5)

* 37% of fine particles assumed to be filterable and all filterable are assigned to EC (Source: AQTSD for Hell’s Gulch and Hi

* 63% of fine particles assumed to be filterable and all filterable are assigned to SOA (Source: AQTSD for Hell’s Gulch and 

* For ICE 125 hp, assumed 50% load factor due to usage in only winter months

Equations:

Emissions (tons/year-well) = Emission factor (g/hp-hr) * Horsepower * Time Used (hours) * Load

453.6 (g/lb) * 2000 (lbs/ton)

EPA Federal Tier 2 Standard Emission Rates

N2O Emission factors (g/gallons) from The Climate Registry, General Reporting Protocol v1.1, Table 13.6

PM2.5/PM10 = 97% EPA (2004) NONROAD

VOC/HC 1.053 EPA NONROAD HC Conversions

NMHC/THC 98.40% EPA NONROAD HC Conversions

SO2 Emission Factor Calculation Information 

2008 Fuel Sulfur content 0.0355 sulfur fuel weight percent

soxcnv Tiers I-III 0.02247 grams PM sulfur/grams fuel sulfur consumed

soxcnv Tier IV 0.3

grams PM sulfate/grams PM sulfur 7

soxbas 0.33

Density of Diesel Fuel 7.09 lb/gallons

Molecular weight of S 32 g/mol

Molecular weight of S02 64 g/mol

453.6 g/lb
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-132

Table 163. 2009 Drilling Equipment Emissions (lb/spud) by Pollutants and by Equipment Type.

Table 164. Summary of 2009 Drilling Equipment Emissions (lb/spud) by Pollutant and Engine 

Type.

Equipment 

Type Pollutant

Engine 1 Engine 2

Drilling 

Equipment

NOx 3,187 155

VOC 179 9

CO 1,834 123

PM10 105 7

PM2.5 102 7

SO2 74 3

CO2 339,463 15,971

CH4 3 0

PM_filt 38 3

PM_cond 64 5

N2O 9 0

Cat 3512C

3

Diesel

Tier 2

1476

>1200

240

0.3

0.334

15033

NOx 4.534 3186.65

VOC 0.255 179.48

CO 2.610 1834.42

PM10 0.149 104.82

PM2.5 0.145 101.68

SO2 0.105 73.85

CO2 483 339463.07

CH4 0.004 2.73

PM_filt 0.054 37.62

PM_cond 0.091 64.06

(g/gal) N2O 0.260 8.62

Boiler

1

Diesel

Tier 2

125

100-175

240

0.5

0.334

707

NOx 4.676 154.61

VOC 0.263 8.71

CO 3.728 123.30

PM10 0.224 7.40

PM2.5 0.217 7.18

SO2 0.105 3.47

CO2 483 15970.63

CH4 0.004 0.13

PM_filt 0.080 2.66

PM_cond 0.137 4.52

(g/gal) N2O 0.260 0.41

Time used (hrs)

Fuel Consumption (Gallons)

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Equipment

Activity & Emission 

Factors

Emissions (lb/well 

spud)

Engine Function

Fuel Consumption (Gallons)

Engine 1

Engine 2

Rated horsepower

Horsepower Range

Time used (hrs)

Load Factor

BSFC (lb/hp-hr)

Load Factor

BSFC (lb/hp-hr)

Emission Factors 

(g/bhp-hr)

Emission Factors 

(g/bhp-hr)

Engine Function

Number of Engines

Fuel Type

Engine Technology
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-133

Table 165. 2009 Drilling Equipment Emissions in tons per spud.

Table 166. Drilling Equipment Tier Assumptions throughout the Project Life.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Drilling Equip (diesel ICE 1476HP) 1.5933 0.0897 0.9172 0.0524 0.0508 0.036927 169.7315 0.0014 0.0188 0.0320 0.0043 total spuds

Drilling Equip (diesel ICE 125HP) 0.0773 0.0044 0.0616 0.0037 0.0036 0.001737 7.9853 0.0001 0.0013 0.0023 0.0002 total spuds

Description Projection Drilling Equipment Emissions (tons per spud) Year Tier 2

2009 100%

2010 100%

2011 100%

2012 100%

2013 100%

2014 100%

2015 100%

2016 100%

2017 100%

2018 100%

2019 100%

2020 100%

2021 100%

2022 100%

2023 100%

2024 100%

2025 100%

2026 100%

2027 100%

2028 100%

2029 100%

2030 100%

2031 100%

2032 100%

2033 100%

2034 100%

2035 100%

2036 100%

2037 100%
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-134

Table 167. Percent Change in Emission from Base Year 2009 (aggregate factors to apply to 

total emissions to all Diesel ICE 1476 HP Engines) for Drilling Equipment.

Table 168. Percent Change in Emission from Base Year 2009 (aggregate factors to apply to 

total emissions to all Diesel ICE 125HP Engines) for Drilling Equipment.

Technology 

Assumption Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

Tier 2 2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Technology 

Assumption Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

Tier 2 2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-135

2009 Drilling Construction Traffic Emissions

ASSUMPTIONS

Data Provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2009 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

DRILLING TRAFFIC.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-136

Table 169. Summary of Traffic Activity Data Associated with Drilling Phase.

Equipment Type Mean Vehicle 

Speed (mph)

Round Trip OffRoad Trip 

Distance (miles)

Number of 

Round Trips 

Per Spud

Light Truck 20 20 98

Heavy Truck 20 20 224

Table 170. 2009 Exhaust Emissions (lb/spud) Associated with Drilling Traffic by Vehicle Type.

Table 171. Summary of 2009 Fugitive Dust Emissions (tons/spud) Associated with Drilling 

Traffic.

Table 172. 2009 Exhaust and Fugitive Dust Emissions Associated with Drilling Traffic in tons 

per spud.

NOx 2.52 10.890

SO2 0.01 0.062

CO 18.19 78.587

CO2 675.15 2917

VOC 1.48 6.388

PM10 0.09 0.376

PM2.5 0.08 0.356

PM_filt -

 

0.000

PM_cond -

 

0.000

CH4 0.08 0.367

N2O 0.05 0.198

NOx 20.23 199.762

SO2 0.08 0.794

CO 15.07 148.818

CO2 2612.44 25801.829

VOC 1.86 18.384

PM10 1.21 11.928

PM2.5 1.17 11.563

PM_filt -

 

0.000

PM_cond -

 

0.000

CH4 0.09 0.891

N2O 0.04 0.351

Pollutant

2009 Emission 

Factors 

(g/mile)

Base Year 

Emissions 

(lb/spud)

Vehicle Type

Light-Duty 

Truck

Heavy-Duty 

Truck 

Travel to well Light truck 7,000 20 98 98 20 1960 0.20 0.19 0.02 0.02

Travel to well Heavy Truck 70,000 20 224 224 20 4480 0.20 0.44 0.02 0.04

Total 0.64 0.06

PM2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spud)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/spud)

Total # of 

Round Trips

Round Trip 

Distance (mi)

Total Miles 

Traveled

PM10

Activity Vehicle Type Av. Vehicle 

Weight (lb)

Mean vehicle 

speed (mph)

# of Visits per 

Year 

Projection

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Drilling Traffic (LD) 0.0054 0.0032 0.0393 0.0002 0.0002 3.11E-05 1.4587 0.0002 0 0 9.88E-05 total spuds 0.1940 0.0193

Drilling Traffic (HD) 0.0999 0.0092 0.0744 0.0060 0.0058 0.0004 12.9009 0.0004 0 0 0.0002 total spuds 0.4435 0.0440

Total Drill Traffic Emissions (tons per spud) Description Fugitive Road 
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-137

Table 173. Percent Change in Emission from Base Year 2009 Due to Fleet Turnover for Drilling Traffic.

NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 -5% -11% -3% 0% -4% -6% -6% 0% 0% -3% -7% -10% -45% -4% 0% -3% -7% -7% 0% 0% 4% -5%

2011 -10% -18% -7% -1% -10% -12% -13% 0% 0% -7% -14% -19% -74% -9% 0% -10% -18% -18% 0% 0% 13% -12%

2012 -16% -27% -11% -2% -16% -19% -19% 0% 0% -11% -21% -28% -75% -14% 0% -17% -28% -28% 0% 0% 20% -17%

2013 -22% -28% -15% -4% -22% -25% -25% 0% 0% -15% -28% -36% -75% -19% 0% -25% -37% -37% 0% 0% 24% -23%

2014 -28% -29% -18% -5% -27% -30% -31% 0% 0% -18% -34% -44% -76% -24% 0% -32% -45% -46% 0% 0% 28% -28%

2015 -33% -30% -22% -7% -33% -35% -36% 0% 0% -22% -39% -51% -76% -28% 0% -38% -53% -53% 0% 0% 30% -33%

2016 -38% -31% -26% -8% -38% -40% -40% 0% 0% -25% -44% -57% -76% -33% 0% -44% -60% -60% 0% 0% 31% -37%

2017 -43% -33% -28% -10% -42% -44% -44% 0% 0% -28% -48% -62% -76% -36% 0% -49% -66% -66% 0% 0% 32% -41%

2018 -47% -34% -31% -11% -46% -48% -48% 0% 0% -30% -52% -67% -76% -39% 0% -54% -71% -71% 0% 0% 33% -44%

2019 -51% -35% -33% -13% -49% -51% -51% 0% 0% -32% -56% -71% -77% -42% 0% -59% -75% -75% 0% 0% 33% -48%

2020 -54% -36% -34% -14% -52% -54% -54% 0% 0% -34% -59% -74% -77% -44% 0% -62% -79% -79% 0% 0% 34% -50%

2021 -57% -37% -36% -15% -55% -56% -56% 0% 0% -35% -62% -77% -77% -46% 0% -66% -82% -82% 0% 0% 34% -53%

2022 -64% -39% -40% -18% -62% -61% -62% 0% 0% -38% -69% -83% -77% -50% 0% -73% -89% -89% 0% 0% 35% -60%

2023 -60% -38% -37% -16% -58% -58% -59% 0% 0% -36% -64% -79% -77% -48% 0% -69% -85% -85% 0% 0% 34% -55%

2024 -62% -39% -39% -17% -60% -60% -60% 0% 0% -37% -67% -81% -77% -49% 0% -71% -87% -87% 0% 0% 34% -58%

2025 -66% -40% -41% -19% -65% -63% -64% 0% 0% -39% -71% -84% -77% -52% 0% -76% -90% -90% 0% 0% 34% -61%

2026 -68% -41% -42% -20% -67% -64% -65% 0% 0% -38% -72% -85% -77% -53% 0% -78% -91% -91% 0% 0% 36% -63%

2027 -69% -41% -43% -21% -69% -66% -66% 0% 0% -38% -74% -86% -77% -54% 0% -79% -92% -92% 0% 0% 36% -64%

2028 -71% -42% -44% -21% -70% -67% -68% 0% 0% -39% -75% -87% -77% -54% 0% -81% -93% -93% 0% 0% 36% -65%

2029 -72% -42% -45% -22% -72% -68% -69% 0% 0% -40% -76% -87% -77% -55% 0% -82% -94% -94% 0% 0% 36% -67%

2030 -73% -42% -46% -22% -73% -69% -69% 0% 0% -40% -77% -88% -77% -56% 0% -83% -94% -94% 0% 0% 35% -67%

2031 -74% -43% -46% -23% -74% -69% -70% 0% 0% -42% -78% -88% -77% -57% 0% -84% -95% -95% 0% 0% 34% -69%

2032 -74% -43% -47% -23% -75% -70% -71% 0% 0% -42% -79% -88% -77% -57% 0% -85% -95% -95% 0% 0% 34% -69%

2033 -75% -43% -48% -23% -76% -71% -71% 0% 0% -43% -79% -89% -78% -58% 0% -85% -95% -95% 0% 0% 33% -69%

2034 -76% -44% -48% -24% -76% -71% -72% 0% 0% -43% -79% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2035 -76% -44% -49% -24% -77% -72% -72% 0% 0% -44% -80% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2036 -77% -44% -49% -24% -77% -72% -73% 0% 0% -44% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -70%

2037 -77% -44% -50% -24% -78% -72% -73% 0% 0% -45% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -71%

Light-Duty Truck Heavy-Duty Truck 

Year
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-138

2009 Initial Completion Venting Emissions

ASSUMPTIONS

As per the operators, 100% of the Completions will be controlled by Flare. Hence, there will be 

no venting emissions from this category. 

Table 174. 2009 Initial Completion Venting Emissions in tons per pad.

Table 175. Percent Change in Emission from Base Year 2009 for Initial Completion Venting.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Initial Completion Venting 0 0 0 0 0 0 0 0 0 0 0 total spuds

Description Projection Well Completion Venting Emissions (tons/well)

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-139

2009 Initial Completion Flaring Emissions

ASSUMPTIONS

Activity data provided by operators in blue text

 O2Emissions ( p r ivi y) = (Total CO2 Emission Potential of the Entire Gas – THC Component to CO2 Emission 

Potential – CO Component to CO2 Emission Potential) x Percentage of Production Controlled

THC Component CO2 Emissions Potentials (

tons

activity) =∑

(

lb emissions emitted

activity ) i×

N . f M l f C i mp u 

N . f M l f C i CO2

×Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of Compound C (lb/lb-mol) × 2000

CO component CO2 emissions potentials (

tons

activity) = 

CO emissions from flaring(

lb

activity)×

No.of Moles of C in compound

No.of Moles of C in CO2 × Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of CO ( lb

lb-mol

) × 2000

.

Where,

i= each compound identified in flaring gas speciation profile 

(lb emissions emitted/activity)i = Total TOG Emissions (lb/activity) from flaring X Weight 

Fraction of the Compound i

Inputs

Average Gas Volume Per Day 1,500.00 MCF/day

Average Days Per Completion 3.00 days/well

Percentage of Gas to Green 

Completions (Sales) 96%

Percentage of Gas Flared 4%

Volume Flared Per Day 60.00 MCF/day

Volume Flared Per Well 180.00 MCF/well

HHV of Flared Gas 1,137.21 Btu/scf

Table 176. Flaring Emission Factors.

NOx, VOC, CH4, N2O and CO Emissions Calculation

where:

E flare is the flaring emissions per well [lb/yr]

EF i is the emissions factor for pollutant i [lb/MMBtu]

Q is the volume of gas flared supplied by operator [MMscf/yr]

HV is the heating value of the gas as provided by the operators [MMBtu/MMscf]

E flare  EF i  Q  HV NOx CO THC

0.068 0.37 0.14 25% 1.44 63%

Flaring Emission Factor (lb/MMBtu)* Fraction of THC 

as CH4

N2O 

(lb/MMSCF)b VOC/THCc 

b Emission Factor from API Compendium of greenhouse gas emissions methodologies for 

the oil and natural gas industry,2009 Table 4-11, GHG Emission Factors for Gas Flares in 

Developed Countries - Footnote C

cEPA SPECIATE Profile 0051

*Emission Factors are from AP-42
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-140

Table 177. Summary of 2009 CO2 Emissions (tons/spud) Potential for All Gas Sample Species 

from Initial Completion Flaring.

Table 178. Summary of 2009 THC and CO Component to CO2 Emissions Potentials 

(tons/activity).

Table 179. 2009 Well Completion Flaring Emissions in tons per spud.

Chemical Mole %

Molecular 

Weight 

(g/mol)1 Weight %

lb/

MCF lb CO2

/MCF HHV (Btu/scf)1

CO2 emission 

potential of the 

entire gas 

(tons/spud)

Carbon Dioxide 2.7329% 44.010 6.0914% 3.07 3.07 0.28

Nitrogen 0.1713% 28.010 0.2430% 0.12 0.00

Methane 84.9820% 16.040 69.0362% 34.78 95.43 1010 8.59

Ethane 6.8128% 30.070 10.3753% 5.23 15.30 1769.7 1.38

Propane 3.1701% 44.100 7.0805% 3.57 10.68 2516.2 0.96

Isobutane 0.6361% 58.120 1.8723% 0.94 2.86 3252 0.26

n-Butane 0.7106% 58.120 2.0916% 1.05 3.19 3262.4 0.29

Isopentane 0.2421% 72.150 0.8846% 0.45 1.36 4000.9 0.12

n-Pentane 0.1993% 72.150 0.7282% 0.37 1.12 4008.7 0.10

n-Hexane 0.0648% 86.180 0.2828% 0.14 0.44 4756 0.04

Cyclohexane 0.0318% 84.160 0.1355% 0.07 0.21 4481.6 0.02

2,2-Dimethylbutane 0.0043% 86.177 0.0188% 0.01 0.03 4735.9 0.00

2,3-Dimethylbutane 0.0164% 86.177 0.0716% 0.04 0.11 4744.9 0.01

2-Methylpentane 0.0488% 86.177 0.2130% 0.11 0.33 4747.4 0.03

3-Methylpentane 0.0251% 86.177 0.1095% 0.06 0.17 4750.3 0.02

n-Heptane 0.0587% 100.202 0.2979% 0.15 0.46 5502.5 0.04

Methylcyclohexane 0.0322% 98.190 0.1601% 0.08 0.25 5215.9 0.02

2,2,4-Trimethylpentane 0.0038% 114.229 0.0220% 0.01 0.03 6146.27 0.00

Benzene 0.0149% 78.110 0.0589% 0.03 0.10 3741.9 0.01

Toluene 0.0174% 92.140 0.0812% 0.04 0.14 4474.9 0.01

Ethylbenzene 0.0005% 106.170 0.0027% 0.00 0.00 5222 0.00

m&p-Xylene 0.0041% 106.160 0.0220% 0.01 0.04 5207.7 0.00

o-Xylene 0.0006% 106.160 0.0032% 0.00 0.01 5209.7 0.00

n-Octane 0.0137% 114.229 0.0793% 0.04 0.12 6248.9 0.01

n-Nonane 0.0059% 128.255 0.0383% 0.02 0.06 6996.4 0.01

n-Decane 0.0000% 142.290 0.0000% 0.00 0.00 7743 0.00

Total 100.0000% 19.74 100.0000% 50.38 135.51 1137.207149 12.20

Total NMHC 12.1139% 24.6294% 12.41

Total VOC 5.3011% 14.2541% 7.18

Total HAPs 0.1061% 0.4729% 0.24

1

 The molecular weights and the higher heating values are from GSPA Engineering Data Book, 12th Edition.

MW (lb/lb-mol) lb/well

TOG 31.47 35.82

CO 28.01 75.74

lb 

emitted/spud

Moles C in 

compound/Moles 

C in CO2

CO2 Emissions 

(tons/spud)

Ethane Y N 30 16.04 11 2 0.029

Formaldehyde N Y 20 30.03 7 1 0.005

Methane Y N 20 28.01 7 1 0.006

Propane Y Y 30 30.07 11 3 0.024

100 36 0.064 0.060

CO component CO2 

emissions potentials 

(tons/spud) 

0.060

Name HC? VOC?

WEIGHT_PER

(Flaring Speciation 

Profile (EPA 

SPECIATE 0051))

Molecular 

Weight

(lb/lb-mol)2

THC component CO2 emissions potentials 

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Initial Completion Flaring 0.0070 0.0090 0.0379 0 0 0 12.0729 0.0036 0 0 0.0001 total spuds

Description Projection Well Completion Flaring Emissions (tons/well)
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-141

Table 180. Percent Change in Emission from Base Year 2009 for Well Completion Flaring.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-142

2009 Construction Fugitive Dust Emissions

ASSUMPTIONS

Watering control efficiency assumed to be 50%

Due to lack of information on soil moisture or silt content, used values from AP-42 Table 11-

9.3 

Activity data provided by operators in blue

Equations

Emissions equations from AP-42 Table 11.9-1 for Bulldozing Overburden emissions, Western 

Surface Coal Mining

For Total Suspended Particles (TSP) ≤ 30 microns:

Emissions (TSP lbs/hr) =[ 5.7 s^1.2 / M ^1.3 ] * Control Efficiency

For PM ≤ 15 microns:

Emissions (PM15 lbs/hr) =[ 1.0 s^1.5 / M ^1.4 ] * Control Efficiency

Emissions (PM10 lbs/hr) = PM15 * 0.75

Emissions (PM2.5 lbs/hr) = TSP * 0.105

See variables definition in following table:

Table 181. Parameters Used in Emission Equations.

Table 182. Summary of 2009 Well Pad and Pipeline Construction Equipment Utilization Data.

Description Parameter Reference

Watering control efficiency 50%

M=soil moisture content 7.9 (AP-42 Table 11.9-3)

s=Soil silt content 6.9 (AP-42 Table 11.9-3)

PM10 multiplier 0.75 (AP-42 Table 11.9-1)

PM2.5 multiplier 0.105 (AP-42 Table 11.9-1)

Control of Open Fugitive Dust Sources, Section 

5.3.1 Watering of Unpaved Surfaces (1988). EPA

Phase Equipment # Units Time Used 

Type Per Pad

 (hours)

Well Pad-Access Road Construction Loader 1 60

Well Pad-Access Road Construction Dozer 1 60

Well Pad-Access Road Construction Scraper 2 60

Well Pad-Access Road Construction Grader 1 60

Well Pad-Access Road Construction Backhoe 1 60

Well Pad-Access Road Construction Roller 1 60

Well Pad-Access Road Construction Water Truck 1 60

Well Pad-Access Road Construction Dump Truck 1 60

Well Pad-Access Road Construction Trencher 1 60

* assumed hours of use consistent with activity estimates used in equipment exhaust emission estimates
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-143

Table 183. Summary of 2009 Fugitive Dust Emissions (tons/well pad) form Well Pad and 

Access Road Construction Equipment.

Table 184. 2009 Construction Fugitive Dust Emissions in tons per well pad.

Table 185. Percent Change in Emission from Base Year 2009 for Construction Fugitive Dust.

Fugitive Dust Emissions Per Well (tons/well)

Phase Equipment Type TSP PM10 PM2.5 PM15

Well Pad-Access Road Construction Loader 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Dozer 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Scraper 0.1182 0.0226 0.0124 0.0301

Well Pad-Access Road Construction Grader 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Backhoe 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Roller 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Water Truck 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Dump Truck 0.0591 0.0113 0.0062 0.0151

Well Pad-Access Road Construction Trencher 0.0591 0.0113 0.0062 0.0151

Total 0.5911 0.1129 0.0621 0.1506

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Construction Dust, Fugitive 0 0 0 0.1129 0.0621 0 0 0 0 0 0 new pads

Description Projection Construction Fugitive Dust Emissions (tons per well pad)

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
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2009 Construction Wind Erosion Emissions

ASSUMPTIONS

Emissions (

tons

yr ) = 

k* Erosion Potential (g/m2/year) * Disturbed Area (m2) * (#Disturbances/year)

453.6 (g/lb) *2000 (lbs/ton)

Table 186. 2009 Construction Dust Wind Erosion Emissions in tons per well pad.

Data obtained from operators in blue text

Disturbed Area Per Well:

Disturbed Area Per Well: 235224 ft2 21853.05 m

2

1 Acre 43,560 square feet

* AP-42 methodology described to the right was implemented in a computer program with hourly wind speed data

* 2007, 2008, and 2009 Wind Speed data from the Wamsutter Station were used as inputs

* Of all years evaluated, 2007 showed the greatest per pad wind erosion emissions:

Friction Velocity U* = 0.053 U10* (AP-42 Section 13.2.5.3 Equation 4)

Erosion Potential P (g/m2-time) = 58(U*-Ut*)2 + 25(U*-Ut*) for U*>Ut*; P=0 otherwise (AP-42 Section 13.2.5.3 Equation 3)

k is a particle size multiplier that depends on the aerodynamic size of the particle (from AP-42 Section 13.2.5.3). 

k = 0.5 for PM10

k = 0.075 for PM2.5

1.02 m/s = Threshold friction velocity for well pads (AP-42 Table 13.2.5-2 Overburden, Western Surface Coal Mine)

1.33 m/s = Threshold friction velocity for roads (AP-42 Table 13.2.5-2 Roadbed Material)

0.5 = Particle size multiplier for PM10

0.075 = Particle size multiplier for PM2.5

1 squ mile = 640 acres

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Construction Dust, Wind Erosion 0 0 0 0.3061 0.0459 0 0 0 0 0 0 new pads

Description Projection Construction Dust Wind Erosion Emissions (tons/well pad)
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Table 187. Percent Change in Emission from Base Year 2009 for Construction Dust Wind 

Erosion.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
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2009 Workover Equipment Emissions

ASSUMPTIONS

Activity data obtained from operators in blue text

Assumptions:

* Emission factors from EPA Federal Diesel Engine Standards 

http://www.epa.gov/otaq/standards/n

onroad/nonroadci.htm

* Crankcase Emission factors are 2% of HC Exhaust Emission Factor for Tier II and earlier per 

* EPA NONROAD Modeling Guidance p. 23 (EPA, 2004; EPA420-P-04-009). 

* VOC/THC= 1.053 Conversion for HC->VOC for diesel engines (EPA, 2005; EPA420-R-05-0159, p. 5)

*

37% of fine particles assumed to be filterable and all filterable are assigned to EC (Source: AQTSD for Hell’s Gulch and 

Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

*

63% of fine particles assumed to be filterable and all filterable are assigned to SOA (Source: AQTSD for Hell’s Gulch and 

Hightower Mountain Natural Gas Development Projects; March 2008, p.10)

EPA Federal Diesel Tier 2 Emission Factors

N2O Emission factors (g/gallons) from The Climate Registry, General Reporting Protocol v1.1, Table 13.6

Equations:

Emissions (tons/year-well) = Emission factor (g/hp-hr) * Horsepower * Time Used (hours) * Load

453.6 (g/lb) * 2000 (lbs/ton)

PM2.5/PM10 = 97% EPA (2004) NONROAD

VOC/HC 1.053 EPA NONROAD HC Conversions

NMHC/THC 98.40% EPA NONROAD HC Conversions

SO2 Emission Factor Calculation Information 

2008 Fuel Sulfur content 0.0355 sulfur fuel weight percent From NMIM

soxcnv Tiers I-III 0.02247 grams PM sulfur/grams fuel sulfur consumed

soxcnv Tier IV 0.3

grams PM sulfate/grams PM sulfur 7

soxbas 0.33

Density of Diesel Fuel 7.09 lb/gallons

Molecular weight of S 32 g/mol

Molecular weight of S02 64 g/mol

453.6 g/lb
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Table 188. 2009 Workover Rig Emissions (lb/well) by Pollutants and by Equipment Type.

Rig

1

Diesel

Tier 2

475

300-600

36

0.07

0.3

0.367

18

NOx 4.534 3.42

VOC 0.255 0.19

CO 2.610 1.97

PM10 0.149 0.11

PM2.5 0.145 0.11

SO2 0.115 0.09

CO2 530 399.81

CH4 0.004 0.00

PM_filt 0.054 0.04

PM_cond 0.091 0.07

N2O 0.260 0.01

Snubbing unit

1

Diesel

Tier 2

475

300-600

36

0.07

0.3

0.367

18

NOx 4.534 3.42

VOC 0.255 0.19

CO 2.610 1.97

PM10 0.149 0.11

PM2.5 0.145 0.11

SO2 0.115 0.09

CO2 530 399.81

CH4 0.004 0.00

PM_filt 0.054 0.04

PM_cond 0.091 0.07

N2O 0.260 0.01

Light plant

1

Diesel

Tier 2

45

25-50

0.07

36

0.7

0.408

4

NOx 5.313 0.89

VOC 0.299 0.05

CO 4.101 0.68

PM10 0.447 0.07

PM2.5 0.434 0.07

SO2 0.128 0.02

CO2 589 98.24

CH4 0.005 0.00

PM_filt 0.161 0.03

PM_cond 0.273 0.05

N2O 0.260 0.00

BSFC (lb/hp-hr)

Equipment

Activity & 

Emission 

Emissions 

(lb/well)

Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Well workover frequency (events/yr)

Load Factor

Load Factor

BSFC (lb/hp-hr)

Emission 

Factors 

(g/bhp-hr)

Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Time used (hrs)

Well workeover requirement (Yrs)

Load Factor

BSFC (lb/hp-hr)

Fuel Consumption (Gallons)

Fuel Consumption (Gallons)

Fuel Consumption (Gallons)

Emission 

Factors 

(g/bhp-hr)

Engine 1

Engine 2

Emission 

Factors 

(g/bhp-hr)

Engine 3 Engine Function

Number of Engines

Fuel Type

Engine Technology

Rated horsepower

Horsepower Range

Well workeover requirement (Yrs)

Time used (hrs)
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

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Table 189. Summary of 2009 Workover Rig Emissions (lb/well) by Pollutants for All 

Equipment.

Table 190. 2009 Workover Rig Equipment Emissions in tons per well.

Table 191. Percent Change in Emission from Base Year 2009 (aggregate factors to apply to 

total emissions across all equipment types) for Workover Rig Equipment.

NOx 8

VOC 0

CO 5

PM10 0

PM2.5 0

SO2 0

CO2 898

CH4 0

PM_filt 0

PM_cond 0

N2O 0

Workover Rig 

Equipment

Equipment 

Type Pollutant

Emissions (lb/yearwell) 

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Workover Equipment (diesel ICE) 0.0039 0.0002 0.0023 0.0001 0.0001 0.0001 0.4489 0.000003 0.0001 0.0001 0.00001 active well counts

Description Projection Workover Rig Emissions (tons per well)

Technology 

Assumption Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

Tier 2 2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2010 0% -53% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2011 0% -91% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2012 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2013 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2014 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2015 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2016 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2017 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2018 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2019 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2020 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2021 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2022 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2023 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2024 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2025 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2026 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2027 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2028 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2029 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2030 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2031 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2032 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2033 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2034 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2035 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2036 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Tier 2 2037 0% -97% 0% 0% 0% 0% 0% 0% 0% 0% 0%
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

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2009 Workover Traffic Emissions

ASSUMPTIONS

Data provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2009 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

WORKOVER TRAFFIC.

Table 192. Summary of Traffic Activity Data Associated with Well Workover Phase.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3

Light Truck 20 20 6 0.07

Heavy Truck 20 20 8 0.07

Well workover frequency 

(events/yr) Equipment Type Mean Vehicle Speed (mph)

Round Trip OffRoad Trip Distance 

(miles)

Number of Round 

Trips Per Well
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Table 193. 2009 Exhaust Emissions (lb/well) Associated with Workover Traffic by Vehicle 

Type.

Table 194. Summary of 2009 Fugitive Dust Emissions (tons/well) Associated with Workover 

Traffic.

NOx 2.52 0.044

SO2 0.01 0.000

CO 18.19 0.321

CO2 675.15 11.907

VOC 1.48 0.026

PM10 0.09 0.002

PM2.5 0.08 0.001

PM_filt - 0.000

PM_cond - 0.000

CH4 0.08 0.001

N2O 0.05 0.001

NOx 20.23 0.476

SO2 0.08 0.002

CO 15.07 0.354

CO2 2612.44 61.433

VOC 1.86 0.044

PM10 1.21 0.028

PM2.5 1.17 0.028

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.002

N2O 0.04 0.001

Vehicle Type Pollutant

2009 

Emission 

Factors 

(g/mile)

Base year 

Emissions 

(lb/well)

Light-Duty 

Truck

Heavy-Duty 

Truck 

Travel to well Light truck 7,000 20 6 0.4 20 8 0.20 0.00 0.02 0.00

Travel to well Heavy Truck 70,000 20 8 1 20 10.67 0.20 0.00 0.02 0.00

Total 0.40 0.00 0.04 0.00

Emissions 

(tpy/well)

Total # of 

Round Trips

PM10 PM2.5

Em. Factor 

(lb/VMT) 

Av. Vehicle 

Weight (lb)

Mean vehicle 

speed (mph)

# of Visits per 

Year 

Round Trip 

Distance (mi)

Total Miles 

Traveled Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well)

Activity Vehicle Type
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Table 195. 2009 Exhaust and Fugitive Dust Emissions Associated with Workover Rigs Traffic in tons per well.

Table 196. Percent Change in Emission from Base Year 2009 due to fleet turnover for Workover Rigs Traffic.

Projection

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

WorkoverTraffic (LD) 2.22E-05 1.30E-05 0.0002 7.67E-07 7.27E-07 1.27E-07 0.0060 7.50E-07 0 0 4.03E-07 active well counts 0.0008 0.0001

WorkoverTraffic (HD) 0.0002 2.19E-05 0.0002 1.42E-05 1.38E-05 9.45E-07 0.0307 1.06E-06 0 0 4.18E-07 active well counts 0.0011 0.0001

Description Total Workover Traffic Emissions (tons per well) Fugitive Road NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 -5% -11% -3% 0% -4% -6% -6% 0% 0% -3% -7% -10% -45% -4% 0% -3% -7% -7% 0% 0% 4% -5%

2011 -10% -18% -7% -1% -10% -12% -13% 0% 0% -7% -14% -19% -74% -9% 0% -10% -18% -18% 0% 0% 13% -12%

2012 -16% -27% -11% -2% -16% -19% -19% 0% 0% -11% -21% -28% -75% -14% 0% -17% -28% -28% 0% 0% 20% -17%

2013 -22% -28% -15% -4% -22% -25% -25% 0% 0% -15% -28% -36% -75% -19% 0% -25% -37% -37% 0% 0% 24% -23%

2014 -28% -29% -18% -5% -27% -30% -31% 0% 0% -18% -34% -44% -76% -24% 0% -32% -45% -46% 0% 0% 28% -28%

2015 -33% -30% -22% -7% -33% -35% -36% 0% 0% -22% -39% -51% -76% -28% 0% -38% -53% -53% 0% 0% 30% -33%

2016 -38% -31% -26% -8% -38% -40% -40% 0% 0% -25% -44% -57% -76% -33% 0% -44% -60% -60% 0% 0% 31% -37%

2017 -43% -33% -28% -10% -42% -44% -44% 0% 0% -28% -48% -62% -76% -36% 0% -49% -66% -66% 0% 0% 32% -41%

2018 -47% -34% -31% -11% -46% -48% -48% 0% 0% -30% -52% -67% -76% -39% 0% -54% -71% -71% 0% 0% 33% -44%

2019 -51% -35% -33% -13% -49% -51% -51% 0% 0% -32% -56% -71% -77% -42% 0% -59% -75% -75% 0% 0% 33% -48%

2020 -54% -36% -34% -14% -52% -54% -54% 0% 0% -34% -59% -74% -77% -44% 0% -62% -79% -79% 0% 0% 34% -50%

2021 -57% -37% -36% -15% -55% -56% -56% 0% 0% -35% -62% -77% -77% -46% 0% -66% -82% -82% 0% 0% 34% -53%

2022 -64% -39% -40% -18% -62% -61% -62% 0% 0% -38% -69% -83% -77% -50% 0% -73% -89% -89% 0% 0% 35% -60%

2023 -60% -38% -37% -16% -58% -58% -59% 0% 0% -36% -64% -79% -77% -48% 0% -69% -85% -85% 0% 0% 34% -55%

2024 -62% -39% -39% -17% -60% -60% -60% 0% 0% -37% -67% -81% -77% -49% 0% -71% -87% -87% 0% 0% 34% -58%

2025 -66% -40% -41% -19% -65% -63% -64% 0% 0% -39% -71% -84% -77% -52% 0% -76% -90% -90% 0% 0% 34% -61%

2026 -68% -41% -42% -20% -67% -64% -65% 0% 0% -38% -72% -85% -77% -53% 0% -78% -91% -91% 0% 0% 36% -63%

2027 -69% -41% -43% -21% -69% -66% -66% 0% 0% -38% -74% -86% -77% -54% 0% -79% -92% -92% 0% 0% 36% -64%

2028 -71% -42% -44% -21% -70% -67% -68% 0% 0% -39% -75% -87% -77% -54% 0% -81% -93% -93% 0% 0% 36% -65%

2029 -72% -42% -45% -22% -72% -68% -69% 0% 0% -40% -76% -87% -77% -55% 0% -82% -94% -94% 0% 0% 36% -67%

2030 -73% -42% -46% -22% -73% -69% -69% 0% 0% -40% -77% -88% -77% -56% 0% -83% -94% -94% 0% 0% 35% -67%

2031 -74% -43% -46% -23% -74% -69% -70% 0% 0% -42% -78% -88% -77% -57% 0% -84% -95% -95% 0% 0% 34% -69%

2032 -74% -43% -47% -23% -75% -70% -71% 0% 0% -42% -79% -88% -77% -57% 0% -85% -95% -95% 0% 0% 34% -69%

2033 -75% -43% -48% -23% -76% -71% -71% 0% 0% -43% -79% -89% -78% -58% 0% -85% -95% -95% 0% 0% 33% -69%

2034 -76% -44% -48% -24% -76% -71% -72% 0% 0% -43% -79% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2035 -76% -44% -49% -24% -77% -72% -72% 0% 0% -44% -80% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2036 -77% -44% -49% -24% -77% -72% -73% 0% 0% -44% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -70%

2037 -77% -44% -50% -24% -78% -72% -73% 0% 0% -45% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -71%

Light-Duty Truck Heavy-Duty Truck 

Year
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

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2009 Heater Emissions

ASSUMPTIONS

Data provided by operators in blue text

Assumptions

Assume no controls on the heater

Assume 10 percent of all new wells have tank heaters

Equations

Emissions (tons/year) = Emission Factor (lbs/MMscf) * Heater Size (Btu/hr) * Time On (Hours/Year) 

Fuel Heat Value (Btu/scf) * 1x106(scf/MMscf) * 2000 (lbs/ton)

Table 197. Natural Gas Fired Heaters Emission Factors (lb/MMscf).

Table 198. Summary of Heaters Operational Data.

Table 199. 2009 Well-site Heater/Reboiler Emissions (lbs/well).

Table 200. 2009 Heater/Reboiler Emissions in tons per well.

NOx SO2 CO VOC PM10 PM2.5 PM_filt PM_cond CO2 CH4 N2O

100 0.6 84 5.5 7.6 7.6 1.9 5.7 120,000 2.3 2.2

Heaters (lb/MMscf) (from AP-42 Tables 1.4-1 and 1.4-2)

 (btu/hr) (Btu/scf) (hours)

Dehydrator Heater 500,000 1000 1 8760 0.5 4380

Separator Heater 500,000 1000 1 6552 0.5 3276

Tank Heater 500,000 1000 0.1 6750 0.5 3375

Equipment Type Heat Input Local Heating 

Value # Units/well

Time Used 

Per Unit Cycle 

Fraction

Actual 

Firing 

hours

Equipment Type NOx SO2 CO VOC PM10 PM2.5 PM_filt PM_cond CO2 CH4 N2O

Dehydrator Heater 219.0000 0.0000 183.9600 12.0450 16.6440 16.6440 4.1610 12.4830 262800 5.0370 4.8180

Separator Heater 163.8000 0.0000 137.5920 9.0090 12.4488 12.4488 3.1122 9.3366 196560 3.7674 3.6036

Tank Heater 16.8750 0.0000 14.1750 0.9281 1.2825 1.2825 0.3206 0.9619 20250 0.3881 0.3713

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Heaters 0.1998 0.0110 0.1679 0.0152 0.0152 0 239.8050 0.0046 0.0038 0.0114 0.0044 active well counts

Description Projection Heater/Reboiler Emissions (tons per well)
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Table 201. Percent Change in Emission from Base Year 2009 for Heaters/Reboilers.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
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2009 Fugitive Devices Emissions

ASSUMPTIONS

Activity data provided by operators in blue text

Hours of operation was assumed to be year round 24-7

Equation

where:

Efugitive is the fugitive VOC emissions per well [ton-VOC/yr]

EFi is the emission factor of TOC [kg/hr/source]

N is the total number of devices

Y is the ratio of VOC to TOC in the vented gas

tannual is total annual hours of operation

CH4 and CO2 emissions

Emissions.CH4 = Emission.VOC * WeightFraction.CH4 / WeightFraction.CO2

Emissions.CO2 = Emission.VOC * WeightFraction.CO2 / WeightFraction.VOC

Table 202. Total Organic Compound (TOC) Emission Factor (kg/hr/component).

Table 203. VOC, CO2 and CH4 Sales Gas and Condensate Gas Weight Fractions.

Efugitive  EFi  N  tannual Y

Light Oil Heavy Oil

>20o API <20o API

valves 4.50E-03 2.50E-03 8.40E-06 9.80E-05

pump seals 2.40E-03 1.30E-02 3.20E-05 2.40E-05

others 8.80E-03 7.50E-03 3.20E-05 1.40E-02

connectors 2.00E-04 2.10E-04 7.50E-06 1.10E-04

flanges 3.90E-04 1.10E-04 3.90E-07 2.90E-06

open-ended lines 2.00E-03 1.40E-03 1.40E-04 2.50E-04

Do not calculate fugitives from pipelines containing only water

Emission Factors are from EPA, 1995 -AP-42 Table 2-4. "Oil and Gas Production Operations 

Average Emission Factors"

"Other" category includes compressor seals, pressure relief valves, diaphragms, drains, dump arms, hatches, instruments, m

Well Equipment 

Component Gas Water/Oil

Sales Gas Fugitive- Post Flash

VOC Fraction (weight) 14.60% 73.55%

CO2 Fraction (weight) 6.07% 3.02%

CH4 Fraction (weight) 68.75% 13.57%
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Table 204. 2009 TOC and VOC Emissions (lbs/well) by Media and Equipment Type.

Table 205. 2009 Fugitive Device Emissions in tons per well.

Table 206. Percent Change in Emission from Base Year 2009 for Fugitive Devices.

Well Stream Gas Condensate Well Stream Gas Condensate Well Stream Gas Condensate

valves 10 10 - 4.50E-03 869 869 0 135.48 135.48 0.00

pump seals 1 0 - 2.40E-03 46 0 0 7.23 0.00 0.00

others 0 0 - 8.80E-03 0 0 0 0.00 0.00 0.00

connectors 150 50 - 2.00E-04 579 193 0 90.32 30.11 0.00

flanges 15 15 - 3.90E-04 113 113 0 17.61 17.61 0.00

open-ended lines 0 0 - 2.00E-03 0 0 0 0.00 0.00 0.00

valves - - 20 2.50E-03 0 0 966 0.00 0.00 732.57

pump seals - - 0 1.30E-02 0 0 0 0.00 0.00 0.00

others - - 0 7.50E-03 0 0 0 0.00 0.00 0.00

connectors - - 50 2.10E-04 0 0 203 0.00 0.00 153.84

flanges - - 10 1.10E-04 0 0 21 0.00 0.00 16.12

open-ended lines - - 0 1.40E-03 0 0 0 0.00 0.00 0.00

valves - - - 8.40E-06 0 0 0 0.00 0.00 0.00

pump seals - - - 3.20E-05 0 0 0 0.00 0.00 0.00

others - - - 3.20E-05 0 0 0 0.00 0.00 0.00

connectors - - - 7.50E-06 0 0 0 0.00 0.00 0.00

flanges - - - 3.90E-07 0 0 0 0.00 0.00 0.00

open-ended lines - - - 1.40E-04 0 0 0 0.00 0.00 0.00

valves - - - 9.80E-05 0 0 0 0.00 0.00 0.00

pump seals - - - 2.40E-05 0 0 0 0.00 0.00 0.00

others - - - 1.40E-02 0 0 0 0.00 0.00 0.00

connectors - - - 1.10E-04 0 0 0 0.00 0.00 0.00

flanges - - - 2.90E-06 0 0 0 0.00 0.00 0.00

open-ended lines - - - 2.50E-04 0 0 0 0.00 0.00 0.00

Media

Type Well Equipment Component Counts

Gas

Light Oil >20o API

Heavy Oil <20o API

Water/Oil

TOC Emission Factor 

(kg / hr / component)

TOC Emissions (lbs/yr) VOC Emissions (lbs/yr)

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Well Stream Fugitive Devices 0 0.1253 0 0 0 0 0.0521 0.5900 0 0 0 active well counts

Gas Stream Fugitive Devices 0 0.0916 0 0 0 0 0.0381 0.4313 0 0 0 active well counts

Condensate Fugitive Devices 0 0.4513 0 0 0 0 0.0185 0.0833 0 0 0 active well counts

Description Projection Fugitive Device Emissions (tons per well) Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
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2009 Pneumatic Devices Emissions

ASSUMPTIONS

As per operator's input no bleed devices are used exclusively, hence zero emissions from this 

category

Table 207. Summary of 2009 Pneumatic Devices Emissions in tons per well.

Table 208. Percent Change in Emission from Base Year 2009 for Pneumatic Devices.

NOx VOC CO PM10 PM2.5 SO2 CH4 CO2 PM_filt PM_cond N2O

Pneumatic Devices 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 active well counts

Description Projection Pneumatic Devices Emissions (tons per well)

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
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2009 Tank Loadout (vapor losses) Emissions

ASSUMPTIONS

Table 209. VOC, CO2 and CH4 Condensate Post-Flash Gas Weight Fractions.

Table 210. Summary of Truck Load Activity Data.

Table 211. 2009 Well Site Condensate Tank Loadout Emissions in tons per barrel.

Data Provided by operator in blue text

Method from Wyoming Permitting Guidance for Oil and Gas Production Facilities

Wyoming DEQ, March, 2010, Chapter 6, Section 2, p.65 for Crude Oil, RVP 5

After AP-42, Section 5.2.1

Emissions VOC (tpy) =

Loading losses determined using AP-42 Section 5.2.2.1.1 Equation 1

LL =12.46 x S x P x M/T

LL=Loading Loss in (lbs/1000gallons)

S= Saturation Factor

P = true vapor pressure of liquid loaded (psia)

M = molecular weight of tank vapors (lb/(lb-mol))

T = temperature of bulk liquid loaded (R=F+460)

Loading Loss (lbs/1000 gal) * truck load rate (bbl/year) * 42 (gal/bbl) * VOC mass fraction

2000 (lbs/ton)

Compound

Methane (weight) 21.23%

CO2 (weight) 0.00%

VOC Fraction (weight) 66.34%

Type of Petroleum Liquid 

Loaded

Saturation 

Factor

True Vapor 

Pressure of 

Liquid Loaded 

(psia)

Molecular Weight 

of Vapors (lb/lbmole)

Temperature 

of Bulk Liquid 

(°R)

Mode of 

Operation

Loading Losses 

(lb/1000 gallons) Capacity of Truck

Condensate RVP 8 0.6 7.2 50 520

Submerged 

loading: 

dedicated 

normal service 5.18 80 bbl

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Tank Loadout (vapor losses) 0 7.21E-05 0 0 0 0 0 2.31E-05 0 0 0 annual condensate production

Description Projection Base Year Well Site Condensate Tank Loadout Emissions (tons per barrel)
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Table 212. Percent Change in Emission from Base Year 2009 for Condensate Tank Loadout.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
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2009 Well Venting Emissions

ASSUMPTIONS

Data provided by operator in blue 

Well venting includes all emissions from venting categories other than fugitive devices, pneumatic devices, 

chemical injection pumps, tank load out, condensate tanks, completion and dehydrator venting.

Table 213. Well Venting VOC, CH4 and CO2 Emission Factors (tons/well).

Table 214. 2009 Well Venting Emissions in tons per well.

Table 215. Percent Change in Emission from Base Year 2009 for Well Venting.

Weight Fraction 

(%)

 

Emission Factor 

(tons/yr/well)

Venting VOC Emission Factor 0.75

Methane (weight) 69.04% 3.624

Carbon Dioxide (weight) 6.09% 0.320

VOC Fraction (weight) 14.25%

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Well Venting 0 0.7483 0 0 0 0 0.3198 3.6240 0 0 0 active well counts

Description Projection Base Year Well Venting Emissions (tons per well)

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
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2009 Condensate Tank Flashing/Working/Breathing Venting Emissions 

ASSUMPTIONS

As per operator's input 100% production will be controlled with flare, hence zero venting 

emissions from this category.

Table 216. Summary of 2009 Condensate Tank Flashing, Working and Breathing Emissions in 

tons per activity.

Table 217. Percent Change in Emission from Base Year 2009 for Condensate Tank Losses.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Condensate Tank Flashing Losses 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 annual condensate production

Condensate Tank Working Losses 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 total turnovers per year

Condensate Tank Breathing Losses 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 active well counts

Description Projection Condensate Tank Venting Emissions

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2010 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2011 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2012 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2013 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2014 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2015 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2016 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2017 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2018 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2019 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2020 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2021 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2022 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2023 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2024 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2025 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2026 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2027 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2028 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2029 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2030 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2031 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2032 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2033 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2034 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2035 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2036 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%

2037 0% 0% 0% 0% 0.00% 0% 0% 0% 0% 0.00% 0%
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

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2009 Dehydrator Venting Emissions 

ASSUMPTIONS

As per operator's input 100% gas will be controlled with flare, hence zero venting emissions 

from this category

Table 218. 2009 Dehydrator Venting Emissions in tons per well by Project Year.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

g - Well Site 2009 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2010 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2011 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2012 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2013 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2014 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2015 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2016 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2017 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2018 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2019 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2020 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2021 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2022 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2023 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2024 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2025 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2026 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2027 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2028 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2029 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2030 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2031 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2032 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2033 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2034 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2035 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2036 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

g - Well Site 2037 0.0000 0.000 0.0000 0.0000 0.0000 0.0000 0.0000 0.000 0.0000 0.0000 0.0000 active well counts

Year Projection Dehydrator Venting Emissions - Weighted Average (tons per well)
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-162

2009 Chemical Injection Pump Venting Emissions 

ASSUMPTIONS

As per operator's input 100% gas will be controlled with flare, hence zero venting emissions 

from this category

Table 219. 2009 Chemical Injection Pump Venting Emissions in tons per well.

Table 220. Percent Change in Emission from Base Year 2009 for Chemical Injection Pump 

Venting.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Pneumatic Pumps 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 active well counts

Description Projection Chemical Injection Pump Emissions (tons per well)

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4

2009 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2010 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2011 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2012 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2013 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2014 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2015 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2016 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2017 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2018 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2019 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2020 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2021 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2022 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2023 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2024 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2025 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2026 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2027 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2028 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2029 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2030 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2031 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2032 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2033 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2034 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2035 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2036 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%

2037 0% 0% 0% 0.00% 0.00% 0% 0% 0% 0% 0.00%
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-163

2009 Production Flaring Emissions (Condensate Tank Flaring, 

Dehydrator Flaring and Chemical Injection Pump Flaring Emissions)

ASSUMPTIONS

100% percentage of flashing controlled

100% percentage of working controlled

100% percentage of breathing controlled

100%

percentage of dehydrator emissions 

controlled

100% percentage of pneumatic pump emissions 

controlled

 O2Emissions ( p r ivi y) = (Total CO2 Emission Potential of the Entire Gas – THC Component to CO2 Emission 

Potential – CO Component to CO2 Emission Potential) x Percentage of Production Controlled

THC Component CO2 Emissions Potentials (

tons

activity) =∑

(

lb emissions emitted

activity ) i×

N . f M l f C i mp u 

N . f M l f C i CO2

×Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of Compound C (lb/lb-mol) × 2000

CO component CO2 emissions potentials (

tons

activity) = 

CO emissions from flaring(

lb

activity)×

No.of Moles of C in compound

No.of Moles of C in CO2 × Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of CO ( lb

lb-mol

) × 2000

.

Where,

i= each compound identified in flaring gas speciation profile 

(lb emissions emitted/activity)i = Total TOG Emissions (lb/activity) from flaring X Weight 

Fraction of the Compound 

Table 221. Flaring Emission Factors.

NOx CO THC

0.068 0.37 0.14 25% 1.44 63%

Flaring Emission Factor (lb/MMBtu)* Fraction of THC 

as CH4

N2O 

(lb/MMSCF)b VOC/THCc 

b Emission Factor from API Compendium of greenhouse gas emissions methodologies for 

the oil and natural gas industry,2009 Table 4-11, GHG Emission Factors for Gas Flares in 

Developed Countries - Footnote C

cEPA SPECIATE Profile 0051

*Emission Factors are from AP-42

NOx, VOC, CH4, N2O and CO Emissions Calculation

where:

E flare is the flaring emissions per well [lb/yr]

EF i is the emissions factor for pollutant i [lb/MMBtu]

Q is the volume of gas flared supplied by operator [MMscf/yr]

HV is the heating value of the gas as provided by the operators [MMBtu/MMscf]

E flare  EF i  Q  HV
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-164

Table 222. 2009 Flaring Emissions in tons per activity metric of each Category.

Note: Detailed Flaring Emissions calculations for condensate tanks are summarized in Table 224 to Table 229, dehydrator is in Table 231 to 

Table 233 and pneumatic pumps are in Table 235 to Table 238.

Table 223. Change in Per Surrogate Flaring Activity (Multiplicative Scalar).

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Condensate Tank Flashing Flaring 2.91E-05 3.75E-05 0.0002 0 0 0 0.0586 1.50E-05 0 0 2.74E-07 flashing flares

Condensate Tank Working Flaring 0.0001 0.0002 0.0008 0 0 0 0.0361 7.51E-05 0 0 1.53E-06 working flares

Condensate Tank Breathing Flaring 0.0037 0.0048 0.0204 0 0 0 0.9267 0.0019 0 0 3.93E-05 breathing flares

Dehydrator Flaring 0.0267 0.0343 0.1451 0 0 0 53.1885 0.0137 0 0 0.0004 dehydrator flares

Pneumatic Pump Flaring 0.0458 0.0589 0.2492 0 0 0 79.6451 0.0236 0 0 0.0008 pneumatic pump flares

Description Projection Flaring Emissions (tons per activity metric)

Year flashing working breathing dehydrator* pneumatic pump

2009 100% 100% 100% 100% 100%

2010 100% 100% 100% 106% 100%

2011 100% 100% 100% 105% 100%

2012 100% 100% 100% 103% 100%

2013 100% 100% 100% 101% 100%

2014 100% 100% 100% 100% 100%

2015 100% 100% 100% 98% 100%

2016 100% 100% 100% 98% 100%

2017 100% 100% 100% 96% 100%

2018 100% 100% 100% 97% 100%

2019 100% 100% 100% 96% 100%

2020 100% 100% 100% 95% 100%

2021 100% 100% 100% 95% 100%

2022 100% 100% 100% 95% 100%

2023 100% 100% 100% 94% 100%

2024 100% 100% 100% 92% 100%

2025 100% 100% 100% 91% 100%

2026 100% 100% 100% 91% 100%

2027 100% 100% 100% 90% 100%

2028 100% 100% 100% 90% 100%

2029 100% 100% 100% 89% 100%

2030 100% 100% 100% 89% 100%

2031 100% 100% 100% 89% 100%

2032 100% 100% 100% 88% 100%

2033 100% 100% 100% 88% 100%

2034 100% 100% 100% 88% 100%

2035 100% 100% 100% 87% 100%

2036 100% 100% 100% 87% 100%

2037 100% 100% 100% 87% 100%

* incorporates changes over time in per well dehydrator emissions
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-165

2009 Condensate Tank Flashing/Working/Breathing Flaring Emissions

ASSUMPTIONS

Data provided by operator in blue text

 O2Emissions ( p r ivi y) = (Total CO2 Emission Potential of the Entire Gas – THC Component to CO2 Emission 

Potential – CO Component to CO2 Emission Potential) x Percentage of Production Controlled

THC Component CO2 Emissions Potentials (

tons

activity) =∑

(

lb emissions emitted

activity

) i×

N . f M l f C i mp u 

N . f M l f C i CO2

×Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of Compound C (lb/lb-mol) × 2000

CO component CO2 emissions potentials (

tons

activity) = 

CO emissions from flaring(

lb

activity)×

No.of Moles of C in compound

No.of Moles of C in CO2 × Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of CO ( lb

lb-mol

) × 2000

.

Where,

i= each compound identified in flaring gas speciation profile 

(lb emissions emitted/activity)i = Total TOG Emissions (lb/activity) from flaring X Weight 

Fraction of the Compound 

Table 224. Flaring Emission Factors.

NOx, VOC, CH4, N2O and CO Emissions Calculation

where:

E flare is the flaring emissions per well [lb/yr]

EF i is the emissions factor for pollutant i [lb/MMBtu]

Q is the volume of gas flared supplied by operator [MMscf/yr]

HV is the heating value of the gas as provided by the operators [MMBtu/MMscf]

E flare  EF i  Q  HV NOx CO THC

0.068 0.37 0.14 25% 1.44 63%

Flaring Emission Factor (lb/MMBtu)* Fraction of THC 

as CH4

N2O 

(lb/MMSCF)b VOC/THCc 

b Emission Factor from API Compendium of greenhouse gas emissions methodologies for 

the oil and natural gas industry,2009 Table 4-11, GHG Emission Factors for Gas Flares in 

Developed Countries - Footnote C

cEPA SPECIATE Profile 0051

*Emission Factors are from AP-42

Condensate 2246.45 Btu/scf

Total Flash @ 381.05 SCF/Bbl Produced 

100% percentage of condensate volume controlled

1

 2008 HYSYS model runs for the Wamsutter Operations Center at 365 psig.
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

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Table 225. 2009 CO2 Emissions (tons/bbl) Potential for All Gas Sample Species from Flashing 

Loss.

Assumptions 365.00 PSIG Separator Pressure

75.00 Degrees F Temperature (Tank)

379.48 SCF/lb-mole

Chemical Mole %1 

Molecular 

Weight

 (lb/lb-mol)2

Pounds per Bbl @ 

365 psig

lb/

MMscf lb CO2/ MMscf HHV (Btu/scf)2

2009 CO2 emission 

potential of the 

entire gas 

(tons/bbl)

Carbon Dioxide 2.80% 44.01 1.24 3249.9 3249.9 0 6.E-04

Nitrogen 0.02% 28.01 0.01 16.0 0 0.E+00

Methane 34.25% 16.04 5.52 14478.2 39724.7 1010 8.E-03

Ethane 13.42% 30.07 4.05 10631.5 31120.1 1770 6.E-03

Propane 17.98% 44.10 7.96 20899.7 62571.2 2516 1.E-02

Isobutane 6.85% 58.12 4.00 10490.1 31773.5 3252 6.E-03

n-Butane 9.34% 58.12 5.45 14303.0 43322.4 3262 8.E-03

Isopentane 4.48% 72.15 3.25 8523.4 25995.4 4001 5.E-03

n-Pentane 3.91% 72.15 2.83 7431.5 22665.4 4009 4.E-03

n-Hexane 1.36% 86.18 1.18 3085.0 9452.7 4756 2.E-03

Cyclohexane 0.30% 84.16 0.25 654.9 2054.9 4482 4.E-04

2,2-Dimethylbutane 0.09% 86.18 0.08 200.7 614.9 4736 1.E-04

2,3-Dimethylbutane 0.34% 86.18 0.30 782.7 2398.2 4745 5.E-04

2-Methylpentane 1.04% 86.18 0.90 2361.7 7236.8 4747 1.E-03

3-Methylpentane 0.53% 86.18 0.46 1200.9 3679.9 4750 7.E-04

n-Heptane 1.85% 100.20 1.86 4884.9 15018.6 5503 3.E-03

Methylcyclohexane 0.18% 98.19 0.18 465.0 1667.3 5216 3.E-04

2,2,4-Trimethylpentane 0.07% 114.23 0.08 211.8 652.9 6249 1.E-04

Benzene 0.31% 78.11 0.25 645.7 2182.9 3742 4.E-04

Toluene 0.38% 92.14 0.35 921.2 3080.1 4475 6.E-04

Ethylbenzene 0.00% 106.17 0.00 12.3 40.8 5222 8.E-06

m-Xylene 0.16% 106.16 0.17 453.7 1504.8 5208 3.E-04

o-Xylene 0.02% 106.16 0.02 43.1 142.8 5210 3.E-05

n-Octane 0.22% 114.23 0.25 665.0 2049.8 6249 4.E-04

n-Nonane 0.05% 128.26 0.07 170.9 527.7 6996 1.E-04

n-Decane 0.04% 142.29 0.06 150.8 466.4 7743 9.E-05

VOC 100.00% 40.58 40.75 106933.7 309944.3 2246.4540 0.1

Total VOC 49.51% 29.93 78558.2

2

 The molecular weights and the higher heating values are from the "GSPA Engineering Data Book", Twelfth Edition, Section 23 Physical Properties, 2004.

1

 The flash gas composition is based on the 2008 HYSYS model for Wamsutter at 365 psig.
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

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Table 226. 2009 CO2 Emissions (tons/turnover) Potential for All Gas Sample Species from 

Working Loss.

Throughput 1509.94 bbls/yr

Turnovers: 2.93

Vapor Density 0.06 lb/ft3

Components

Working Loss 

(lbs/yr)

Working Loss (lb/ 

turnover well) Weight %

Molecular Weight

 (lb/lb-mol)1 Mole % HHV (Btu/scf)1

lb/

MMscf

lb CO2/ 

MMscf

2009 CO2 

emission 

potential of the 

entire gas 

(Tons/turnover)

Methane 78.28 26.72 21.23% 16.04 46.18% 1010 19518.8 53555.1 0.0121

Ethane 45.81 15.63 12.43% 30.07 14.42% 1770 11424.6 33441.8 0.0044

Propane 71.86 24.53 19.50% 44.10 15.42% 2516 17921.3 53654.3 0.0111

Isobutane 34.98 11.94 9.49% 58.12 5.70% 3252 8722.4 26419.2 0.0027

n-Butane 46.12 15.74 12.51% 58.12 7.51% 3262 11501.0 34835.5 0.0046

Isopentane 27.02 9.22 7.33% 72.15 3.54% 4001 6738.2 20550.9 0.0016

n-Pentane 21.87 7.46 5.93% 72.15 2.87% 4009 5454.1 16634.4 0.0011

n-Hexane 8.31 2.84 2.25% 86.18 0.91% 4756 2072.0 6348.6 0.0002

Cyclohexane 1.32 0.45 0.36% 84.16 0.15% 4482 328.7 1031.2 0.0000

2,2-Dimethylbutane 0.66 0.23 0.18% 86.18 0.07% 4736 164.6 504.4 0.0000

2,3-Dimethylbutane 2.19 0.75 0.59% 86.18 0.24% 4745 545.9 1672.8 0.0000

2-Methylpentane 6.49 2.22 1.76% 86.18 0.71% 4747 1618.7 4960.0 0.0001

3-Methylpentane 3.10 1.06 0.84% 86.18 0.34% 4750 773.6 2370.4 0.0000

n-Heptane 12.98 4.43 3.52% 100.20 1.23% 5503 3237.1 9952.4 0.0004

Methylcyclohexane 1.03 0.35 0.28% 98.19 0.10% 5216 257.3 922.5 0.0000

2,2,4-Trimethylpentane 0.52 0.18 0.14% 114.23 0.04% 6249 129.4 398.8 0.0000

Benzene 1.17 0.40 0.32% 78.11 0.14% 3742 291.3 984.9 0.0000

Toluene 1.54 0.53 0.42% 92.14 0.16% 4475 383.4 1281.9 0.0000

Ethylbenzene 0.02 0.01 0.01% 106.17 0.00% 5222 5.2 17.2 0.0000

Xylenes 0.85 0.29 0.23% 106.17 0.08% 5208 212.3 704.2 0.0000

n-Octane 1.38 0.47 0.37% 114.23 0.11% 6249 344.1 1060.6 0.0000

n-Nonane 0.49 0.17 0.13% 128.26 0.04% 6996 122.2 377.5 0.0000

n-Decane 0.64 0.22 0.17% 142.29 0.04% 7743 160.1 495.3 0.0000

THC 368.63 125.81 100.00% 34.88 100.00% 2016.172946 91926.45836 272173.93 0.04

VOC 244.54 83.46 66.34% 39.40% 60983.02218

From EPA's TANKS 4.09 Output based on the condensate composition from 2007 Wamsutter 

HYSYS model. 

1

 The molecular weights and the higher heating values are from the "GSPA Engineering Data Book", Twelfth Edition, Section 23 Physical Properties, 2004.
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

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Table 227. 2009 CO2 Emissions (tons/well) Potential for All Gas Sample Species from 

Breathing Loss.

Throughput 1509.94 bbls/yr

Turnovers: 2.93

Vapor Density 0.06 lb/ft3

Components

Breathing Loss 

(lbs/well) Weight %

Molecular Weight

 (lb/lb-mol)1 Mole % HHV (Btu/scf)1

lb/

MMscf lb CO2/ MMscf

2009 CO2 

emission 

potential of the 

entire gas 

(tons/well)

Methane 686.48 21.23% 16.04 46.18% 1010 19518.83 53555.1 0.31

Ethane 401.75 12.43% 30.07 14.42% 1770 11424.60 33441.8 0.11

Propane 630.14 19.50% 44.10 15.42% 2516 17921.33 53654.3 0.29

Isobutane 306.72 9.49% 58.12 5.70% 3252 8722.37 26419.2 0.07

n-Butane 404.46 12.51% 58.12 7.51% 3262 11501.01 34835.5 0.12

Isopentane 236.95 7.33% 72.15 3.54% 4001 6738.23 20550.9 0.04

n-Pentane 191.8 5.93% 72.15 2.87% 4009 5454.10 16634.4 0.03

n-Hexane 72.84 2.25% 86.18 0.91% 4756 2071.95 6348.6 0.00

Cyclohexane 11.54 0.36% 84.16 0.15% 4482 328.67 1031.2 0.00

2,2-Dimethylbutane 5.79 0.18% 86.18 0.07% 4736 164.62 504.4 0.00

2,3-Dimethylbutane 19.19 0.59% 86.18 0.24% 4745 545.93 1672.8 0.00

2-Methylpentane 56.93 1.76% 86.18 0.71% 4747 1618.72 4960.0 0.00

3-Methylpentane 27.22 0.84% 86.18 0.34% 4750 773.58 2370.4 0.00

n-Heptane 113.84 3.52% 100.20 1.23% 5503 3237.08 9952.4 0.01

Methylcyclohexane 9.06 0.28% 98.19 0.10% 5216 257.26 922.5 0.00

2,2,4-Trimethylpentane 4.54 0.14% 114.23 0.04% 6249 129.39 398.8 0.00

Benzene 10.23 0.32% 78.11 0.14% 3742 291.33 984.9 0.00

Toluene 13.46 0.42% 92.14 0.16% 4475 383.41 1281.9 0.00

Ethylbenzene 0.19 0.01% 106.17 0.00% 5222 5.20 17.2 0.00

Xylenes 7.48 0.23% 106.17 0.08% 5208 212.35 704.2 0.00

n-Octane 12.1 0.37% 114.23 0.11% 6249 344.11 1060.6 0.00

n-Nonane 4.3 0.13% 128.26 0.04% 6996 122.24 377.5 0.00

n-Decane 5.65 0.17% 142.29 0.04% 7743 160.14 495.3 0.00

THC 3232.66 100.00% 34.88 100.00% 2016.172946 91926.45836 272173.9343 0.98

VOC 2144.43 66.34% 39.40% 60983.02218

From EPA's TANKS 4.09 Output based on the condensate composition from 2007 Wamsutter HYSYS model. 
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-169

Table 228. Summary of 2009 THC and CO Component to CO2 Emissions Potentials (tons/activity).

Table 229. 2009 Condensate Tank Flaring Emissions per activity metric of each Category.

MW 

(lb/lbmol)Flashing 

(lb/bbl)

Working

(lb/turnover)

Breathing

(lb/well)

TOG 31.47 0.15 0.75 19.30

CO 28.01 0.32 1.59 40.80

lb 

emitted/wel

l

Moles C in 

compound/

Moles C in 

CO2

CO2 Emissions 

(tons/bbl)

lb 

emitted/tu

rnover

Moles C in 

compound/

Moles C in 

CO2

CO2 Emissions 

(tons/turnover)

lb 

emitted/w

ell

Moles C in 

compound/Mol

es C in CO2

CO2 

Emissions 

(tons/well)

Ethane Y N 30 30.07 0.04 2 0.0001 0.23 2 0.0003 5.79 2 0.0085

Formaldehyde N Y 20 30.03 0.03 1 0.0000 0.15 1 0.0001 3.86 1 0.0028

Methane Y N 20 16.04 0.03 1 0.0000 0.15 1 0.0002 3.86 1 0.0053

Propane Y Y 30 44.10 0.04 3 0.0001 0.23 3 0.0003 5.79 3 0.0087

100 0.15 0.0002 0.0002 0.75 0.0010 0.0012 19.30 0.0253 0.0321

THC component CO2 emissions CO 

component 

CO2 

emissions 

potentials 

(tons/bbl) 

0.0002

Name HC? VOC?

WEIGHT_PER

(Flaring 

Speciation Profile 

(EPA SPECIATE 

0051))

Molecular 

Weight

(lb/lb-mol) 2

Flashing 2009 CO2 Emissions Working 2009 CO2 Emissions

THC component CO2 emissions potentials 

CO component 

CO2 emissions 

potentials 

(tons/turnover) 

0.0012

Breathing 2009 CO2 Emissions

THC component CO2 emissions 

CO component 

CO2 emissions 

potentials 

(tons/well) 

0.0321

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Condensate Tank Flashing Flaring 2.91E-05 3.75E-05 0.0002 0 0 0 0.0586 1.50E-05 0 0 2.74E-07 flashing flares

Condensate Tank Working Flaring 0.0001 0.0002 0.0008 0 0 0 0.0361 7.51E-05 0 0 1.53E-06 working flares

Condensate Tank Breathing Flaring 0.0037 0.0048 0.0204 0 0 0 0.9267 0.0019 0 0 3.93E-05 breathing flares

Description Projection Flaring Emissions (tons per activity metric)
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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-170

2009 Dehydrator Flaring Emissions

ASSUMPTIONS

 O2Emissions ( p r ivi y) = (Total CO2 Emission Potential of the Entire Gas – THC Component to CO2 Emission 

Potential – CO Component to CO2 Emission Potential) x Percentage of Production Controlled

THC Component CO2 Emissions Potentials (

tons

activity) =∑

(

lb emissions emitted

activity ) i×

N . f M l f C i mp u 

N . f M l f C i CO2

×Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of Compound C (lb/lb-mol) × 2000

CO component CO2 emissions potentials (

tons

activity) = 

CO emissions from flaring(

lb

activity)×

No.of Moles of C in compound

No.of Moles of C in CO2 × Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of CO ( lb

lb-mol

) × 2000

.

Where,

i= each compound identified in flaring gas speciation profile 

(lb emissions emitted/activity)i = Total TOG Emissions (lb/activity) from flaring X Weight 

Fraction of the Compound 

.

Table 230. Flaring Emission Factors.

Data Provided by operator in blue text

Assume no change in pressure (365 psi)

Assume one dehydrator per well

Total Waste Gas Stream (MMscf/yr/ well) =0.0013*Flow (MMSCF/yr/well)+0.5094

NOx, VOC, CH4, N2O and CO Emissions Calculation

where:

E flare is the flaring emissions per well [lb/yr]

EF i is the emissions factor for pollutant i [lb/MMBtu]

Q is the volume of gas flared supplied by operator [MMscf/yr]

HV is the heating value of the gas as provided by the operators [MMBtu/MMscf]

E flare  EF i  Q  HV NOx CO THC

0.068 0.37 0.14 25% 1.44 63%

Flaring Emission Factor (lb/MMBtu)* Fraction of THC 

as CH4

N2O 

(lb/MMSCF)b VOC/THCc 

b Emission Factor from API Compendium of greenhouse gas emissions methodologies for 

the oil and natural gas industry,2009 Table 4-11, GHG Emission Factors for Gas Flares in 

Developed Countries - Footnote C

cEPA SPECIATE Profile 0051

*Emission Factors are from AP-42
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-171

Table 231. 2009 CO2 Emissions (tons/well) Potential for All Gas Sample Species from 

Dehydrator Flaring.

Table 232. Summary of 2009 THC and CO Component to CO2 Emissions Potentials 

(tons/activity).

Table 233. 2009 Dehydrator Flaring Emissions in tons per activity.

Chemical Mole %1 

Molecular 

Weight

 (lb/lb-mol)2

lb/

MMscf

lb CO2/ 

MMscf

HHV 

(Btu/scf)2

2009 CO2 emission 

potential of the entire gas 

(tons/well)

Water 17.54% 18.01 8060.8 0.0 0.00

Carbon Dioxide 5.47% 44.01 6142.9 6142.9 0 1.92

Nitrogen 0.11% 28.01 80.8 0 0.00

Methane 55.61% 16.04 22761.2 62451.3 1010 19.53

Ethane 6.19% 30.07 4749.6 13903.0 1770 4.35

Propane 3.98% 44.10 4478.8 13408.9 2516 4.19

Isobutane 1.07% 58.12 1586.9 4806.5 3252 1.50

n-Butane 1.49% 58.12 2209.8 6693.2 3262 2.09

Isopentane 0.57% 72.15 1053.1 3211.8 4001 1.00

n-Pentane 0.58% 72.15 1075.2 3279.2 4009 1.03

n-Hexane 0.33% 86.18 730.1 2237.1 4756 0.70

Cyclohexane 0.62% 84.16 1335.8 4191.1 4482 1.31

Other Hexanes 0.37% 86.18 815.9 2499.8 4745 0.78

n-Heptane 0.61% 100.20 1569.9 4826.8 5503 1.51

Methylcyclohexane 0.79% 98.19 1976.9 7088.5 5216 2.22

2,2,4-Trimethylpentane 0.02% 114.23 55.4 170.7 6249 0.05

Benzene 1.35% 78.11 2690.8 9096.5 3742 2.85

Toluene 1.89% 92.14 4443.7 14857.6 4475 4.65

Ethylbenzene 0.06% 106.17 165.3 548.0 5222 0.17

Xylenes 0.60% 106.17 1636.3 5426.4 5208 1.70

n-Octane 0.73% 114.23 2116.2 6522.5 6249 2.04

Total 100.00% 27.33 69735.3 171362.1 1253.5833 53.6

Total VOC 15.07% 27940.0

1

 Mole percent is based on the GLYCalc run at 0.25 MMscf/day for Wamsutter.

2

 The molecular weights and the higher heating values are from GSPA Engineering Data Book, 12th Edition.

Assumptions

0.0821 L-atm/K-mol

298.15 oK

1 1 atm

1 ft3 28.31685 L

453.59237 mol/lb-mol

391.90 scf/lbmol

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Dehydrator Flaring 0.0267 0.0343 0.1451 0 0 0 53.1885 0.0137 0 0 0.0004 dehydrator flares

Description Projection Flaring Emissions (tons per activity metric)
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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-172

2009 Chemical Injection Pump Flaring Emissions

ASSUMPTIONS

Data provided by operators in blue text

 O2Emissions ( p r ivi y) = (Total CO2 Emission Potential of the Entire Gas – THC Component to CO2 Emission 

Potential – CO Component to CO2 Emission Potential) x Percentage of Production Controlled

THC Component CO2 Emissions Potentials (

tons

activity) =∑

(

lb emissions emitted

activity ) i×

N . f M l f C i mp u 

N . f M l f C i CO2

×Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of Compound C (lb/lb-mol) × 2000

CO component CO2 emissions potentials (

tons

activity) = 

CO emissions from flaring (

lb

activity) ×

No.of Moles of C in compound

No.of Moles of C in CO2 × Molecular Weight of CO2 (lb/lb-mol)

Molecular weight of CO ( lb

lb-mol ) × 2000

Where,

i= each compound identified in flaring gas speciation profile 

(lb emissions emitted/activity)i = Total TOG Emissions (lb/activity) from flaring X Weight 

Fraction of the Compound 

NOx, VOC, CH4, N2O and CO Emissions Calculation

where:

E flare is the flaring emissions per well [lb/yr]

EF i is the emissions factor for pollutant i [lb/MMBtu]

Q is the volume of gas flared supplied by operator [MMscf/yr]

HV is the heating value of the gas as provided by the operators [MMBtu/MMscf]

E flare  EF i  Q  HV

VOC Fraction (molar) 5.39%

VOC molecular weight 57.50

R 0.08206 L atm / K-mol

standard temp 298.15 K

standard press 1 atm

MCF to 1000 liter conversion 28.317 1000L/MCF

L/mol 24.47 L/mol

28.32 L/SCF

453.59237 mol/lb-mol

391.90 scf/lbmol
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-173

Table 234. Flaring Emission Factors.

Table 235. Summary of Chemical Injection Pump Data.

Table 236. 2009 CO2 Emissions (tons/well) Potential for All Gas Sample Species from Pump 

Flaring.

NOx CO THC

0.068 0.37 0.14 25% 1.44 63%

Flaring Emission Factor (lb/MMBtu)* Fraction of THC 

as CH4

N2O 

(lb/MMSCF)b VOC/THCc 

b Emission Factor from API Compendium of greenhouse gas emissions methodologies for 

the oil and natural gas industry,2009 Table 4-11, GHG Emission Factors for Gas Flares in 

Developed Countries - Footnote C

cEPA SPECIATE Profile 0051

*Emission Factors are from AP-42

Methanol 1,381,989 1,368 47 1 - - 64.31 0.06

Glycol Heat Medium Pumps - - - 1 273 2.84 1,116.73 1.12

Total - - - - - - 1181.04 1.18

Vented Volume 

 Type Gallons Used Gallons/well SCF/Gallon Number of Pump (MMSCF/year)

Days Used in 

Quarter SCF/Pump/Minute

Vented Volume 

(MCF/year)

Component Mole %1

Molecular 

Weight

 (lb/lb-mol)2 Weight %

lb/

MMscf lb CO2/ MMscf HHV (Btu/scf)2

CO2 emission 

potential of the 

entire gas 

(tons/well)

Carbon Dioxide 2.73% 44.01 6.07% 3066.1 3066.1 0 1.8106

Nitrogen 0.17% 28.01 0.24% 122.3 0 0.0000

Methane 84.90% 16.04 68.75% 34749.6 95344.9 1010 56.3030

Ethane 6.81% 30.07 10.33% 5222.5 15287.1 1770 9.0273

Propane 3.17% 44.10 7.05% 3564.0 10670.1 2516 6.3009

Isobutane 0.64% 58.12 1.86% 942.4 2854.6 3252 1.6857

n-Butane 0.71% 58.12 2.08% 1052.8 3188.8 3262 1.8830

Isopentane 0.24% 72.15 0.88% 445.4 1358.3 4001 0.8021

n-Pentane 0.20% 72.15 0.73% 366.5 1117.8 4009 0.6601

n-Hexane 0.16% 86.18 0.69% 350.1 1072.8 4756 0.6335

Cyclohexane 0.03% 84.16 0.13% 68.2 213.9 4482 0.1263

2,2-Dimethylbutane 0.00% 86.18 0.02% 9.4 28.8 4736 0.0170

2,3-Dimethylbutane 0.02% 86.18 0.07% 36.0 110.3 4745 0.0652

2-Methylpentane 0.05% 86.18 0.21% 107.2 328.5 4747 0.1940

3-Methylpentane 0.03% 86.18 0.11% 55.1 168.9 4750 0.0997

n-Heptane 0.06% 100.20 0.30% 149.9 461.0 5503 0.2722

Methylcyclohexane 0.03% 98.19 0.16% 80.6 288.9 5216 0.1706

2,2,4-Trimethylpentane 0.00% 114.23 0.02% 11.0 34.0 6249 0.0201

Benzene 0.01% 78.11 0.06% 29.8 100.6 3742 0.0594

Toluene 0.02% 92.14 0.08% 41.0 137.0 4475 0.0809

Ethylbenzene 0.00% 106.17 0.00% 1.2 4.1 5222 0.0024

m-Xylene 0.00% 106.16 0.03% 12.6 41.9 5208 0.0247

o-Xylene 0.00% 106.16 0.02% 11.0 36.5 5210 0.0216

n-Octane 0.00% 114.23 0.00% 1.8 5.4 6249 0.0032

n-Nonane 0.01% 128.26 0.09% 44.8 138.2 6996 0.0816

n-Decane 0.00% 142.29 0.00% 0.0 0.0 7743 0.0000

Total 100.00% 19.81 100.00% 50541.4 136,059 1140.5805 80.3

Total VOC 5.39% 14.60% 7380.8

1 Mole percentage of the sales gas 

2

 The molecular weights and the higher heating values are from GSPA Engineering Data Book, 12th Edition.
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-174

Table 237. Summary of 2009 THC and CO Component to CO2 Emissions Potentials 

(tons/activity).

Table 238. 2009 Chemical Injection Pump Flaring Emissions in tons per well.

lb 

emitted/we

l l

Moles C in 

compound/Moles C in 

CO2

CO2 Emissions 

(tons/well)

Ethane Y N 30 30.07 71 2 0.1

Formaldehyde N Y 20 30.03 47 1 0.0

Methane Y N 20 16.04 47 1 0.1

Propane Y Y 30 44.10 71 3 0.1

100 236 0.31 0.39

THC component CO2 emissions potentials CO component CO2 

emissions potentials 

(tons/well) 

0.4

Name HC? VOC? WEIGHT_

PER

Molecular 

Weight

 (lb/lb-mol)2

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Pneumatic Pump Flaring 0.0458 0.0589 0.2492 0 0 0 79.6451 0.0236 0 0 0.0008 pneumatic pump flares

Description Projection Flaring Emissions (tons per activity metric)
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-175

2009 Production Traffic Emissions

ASSUMPTIONS

Data Provided by operators in blue text

Emission Factor Estimates Based on EPA MOVES model runs

BLM, 2003 after (EPA, AP-42, Volume I, Section 13.2.2 Unpaved Roads (11/06))

Heavy truck weighs 70,000 lbs 

Light truck weighs 7,000 lbs 

EPA, Control of Open Fugitive Dust Sources, Section 5.3.1 Watering of Unpaved Surfaces (1988)

Assumed 50% fugitive dust control resulting from watering.

Data for Number of Days of Measurable (>0.01") Precipitation

Data assumed representative of project area from Western Regional Climate Center 

for WAMSUTTER, WY (data source nearest project area). Mean for data from 1948-2004 is 

Measurable precip (>0.01") occurred on 48 days/year

http://www.wrcc.dri.edu/htmlfiles/wy/wy.01.html

Equations

MOVES Emissions (tons/year-well) = Emission factor (g/mile) * # Trips * Trip Distance (miles) 

453.6 (g/lb) * 2000 (lbs/ton)

ASSUMPTIONS TO ESTIMATE 2009 FUGITIVE PARTICULATE EMISSIONS ASSOCIATED WITH 

PRODUCTION TRAFFIC.

Source for Data for Constants: EPA (1995), AP-42, Section 13.2.2 Unpaved Roads (11/06). Table 13.2.2-2.

Constant P M10 P M2.5

k 1.8 0.18

E [lb/VMT] = k(s/12)a(W/3)d*(365-P) *(Control Efficiency) a 1.00 1.00

(M/0.2)c 365 d 0.50 0.50

c 0.2 0.2

C 0.00047 0.00036

Value

E = size-specific emission factor (lb/VMT)

s = surface material silt content (%) 5.1

W = mean vehicle weight (tons) 35

W = mean vehicle weight (tons) 3.5

M = surface material moisture content (%) 2.4

P = Precipitation Days (>0.01" rainfall) 48 Precipitation days at Wamsutter, WY from NCDC climatology

Variable Description Reference

Control efficiency for watering (%) = 50 EPA, Control of Open Fugitive Dust Sources , 

Section 5.3.1 Watering of Unpaved Surfaces (1988)

EPA, AP-42 , Volume I, Section 13.2.2 Unpaved Roads (11/06)

Heavy truck weighs 70000 lbs

Light truck weighs 7000 lbs

AP-42 Table 11.9-3 as in Jonah EIS Table B.1.3
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-176

Table 239. Summary of Traffic Activity Data Associated with Production Traffic.

Equipment Type

Field

Mean Vehicle 

Speed (mph)

Round Trip 

Off-Road Trip 

Distance 

(miles)

Number of Round 

Trips Per Well or 

Central Facilities 

(annual)

Light Truck 20 20 52

Heavy Truck 20 20 14

Heavy Trucks - Central Facility 0 0 0

Production traffic assumes that vehicles end up at the central facility

Table 240. 2009 Exhaust Emissions (lb/well) Associated with Production Traffic by Vehicle 

Type.

NOx 2.52 5.779

SO2 0.01 0.033

CO 18.19 41.699

CO2 675.15 1548

VOC 1.48 3.390

PM10 0.09 0.199

PM2.5 0.08 0.189

PM_filt - 0.000

PM_cond - 0.000

CH4 0.08 0.195

N2O 0.05 0.105

NOx 20.23 12.485

SO2 0.08 0.050

CO 15.07 9.301

CO2 2612.44 1612.614

VOC 1.86 1.149

PM10 1.21 0.745

PM2.5 1.17 0.723

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.056

N2O 0.04 0.022

NOx 20.23 0.000

SO2 0.08 0.000

CO 15.07 0.000

CO2 2612.44 0.000

VOC 1.86 0.000

PM10 1.21 0.000

PM2.5 1.17 0.000

PM_filt - 0.000

PM_cond - 0.000

CH4 0.09 0.000

N2O 0.04 0.000

* units are lb totals for travel to central facility

Heavy-Duty Diesel 

Truck Travel to 

Central Facility

Heavy-Duty Truck 

Light-Duty Truck

Vehicle Type Pollutant 2009 Emission 

Factors (g/mile)

Base year Emissions 

(lb/well)
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-177

Table 241. Summary of 2009 Fugitive Dust Emissions (tons/well) Associated with Production Traffic.

Table 242. 2009 Exhaust and Fugitive Dust Emissions Associated with Production Traffic in tons per well.

Travel to well Light truck 7,000 20 52 52 20 1040 0.20 0.10 0.02 0.01

Travel to well Heavy Truck 70,000 20 14 14 20 280 0.20 0.03 0.02 0.00

Travel to Central 

Facility Heavy Truck 70,000 0 0 0 0 0 0.00 0.00 0.02 0.00

Total 0.40 0.13 0.06 0.01

Total # of 

Round Trips

Round Trip 

Distance (mi)

Total Miles 

Traveled

PM10

Activity Vehicle Type Av. Vehicle Weight (lb)

Mean vehicle speed 

(mph)

# of Visits per 

Year 

PM2.5

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well)

Em. Factor 

(lb/VMT) 

Emissions 

(tpy/well) NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O PM10 PM2.5

Production Traffic (LD) 0.0029 0.0017 0.0208 9.97E-05 9.45E-05 1.65E-05 0.7740 9.74E-05 0 0 5.24E-05 active well counts 0.1030 0.0102

Production Traffic (HD) 0.0062 0.0006 0.0047 0.0004 0.0004 2.48E-05 0.8063 2.79E-05 0 0 1.10E-05 active well counts 0.0277 0.0028

Production Traffic, Central Facility (HD) 0 0 0 0 0 0 0 0 0 0 0 totals for CY 2012+ 0 0

Description Projection Total Production Traffic Emissions (tons per well) Fugitive Road 
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-178

Table 243. Percent Change in Emission from Base Year 2009 due to fleet turnover for Production Traffic.

NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4 N2O

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 -5% -11% -3% 0% -4% -6% -6% 0% 0% -3% -7% -10% -45% -4% 0% -3% -7% -7% 0% 0% 4% -5%

2011 -10% -18% -7% -1% -10% -12% -13% 0% 0% -7% -14% -19% -74% -9% 0% -10% -18% -18% 0% 0% 13% -12%

2012 -16% -27% -11% -2% -16% -19% -19% 0% 0% -11% -21% -28% -75% -14% 0% -17% -28% -28% 0% 0% 20% -17%

2013 -22% -28% -15% -4% -22% -25% -25% 0% 0% -15% -28% -36% -75% -19% 0% -25% -37% -37% 0% 0% 24% -23%

2014 -28% -29% -18% -5% -27% -30% -31% 0% 0% -18% -34% -44% -76% -24% 0% -32% -45% -46% 0% 0% 28% -28%

2015 -33% -30% -22% -7% -33% -35% -36% 0% 0% -22% -39% -51% -76% -28% 0% -38% -53% -53% 0% 0% 30% -33%

2016 -38% -31% -26% -8% -38% -40% -40% 0% 0% -25% -44% -57% -76% -33% 0% -44% -60% -60% 0% 0% 31% -37%

2017 -43% -33% -28% -10% -42% -44% -44% 0% 0% -28% -48% -62% -76% -36% 0% -49% -66% -66% 0% 0% 32% -41%

2018 -47% -34% -31% -11% -46% -48% -48% 0% 0% -30% -52% -67% -76% -39% 0% -54% -71% -71% 0% 0% 33% -44%

2019 -51% -35% -33% -13% -49% -51% -51% 0% 0% -32% -56% -71% -77% -42% 0% -59% -75% -75% 0% 0% 33% -48%

2020 -54% -36% -34% -14% -52% -54% -54% 0% 0% -34% -59% -74% -77% -44% 0% -62% -79% -79% 0% 0% 34% -50%

2021 -57% -37% -36% -15% -55% -56% -56% 0% 0% -35% -62% -77% -77% -46% 0% -66% -82% -82% 0% 0% 34% -53%

2022 -64% -39% -40% -18% -62% -61% -62% 0% 0% -38% -69% -83% -77% -50% 0% -73% -89% -89% 0% 0% 35% -60%

2023 -60% -38% -37% -16% -58% -58% -59% 0% 0% -36% -64% -79% -77% -48% 0% -69% -85% -85% 0% 0% 34% -55%

2024 -62% -39% -39% -17% -60% -60% -60% 0% 0% -37% -67% -81% -77% -49% 0% -71% -87% -87% 0% 0% 34% -58%

2025 -66% -40% -41% -19% -65% -63% -64% 0% 0% -39% -71% -84% -77% -52% 0% -76% -90% -90% 0% 0% 34% -61%

2026 -68% -41% -42% -20% -67% -64% -65% 0% 0% -38% -72% -85% -77% -53% 0% -78% -91% -91% 0% 0% 36% -63%

2027 -69% -41% -43% -21% -69% -66% -66% 0% 0% -38% -74% -86% -77% -54% 0% -79% -92% -92% 0% 0% 36% -64%

2028 -71% -42% -44% -21% -70% -67% -68% 0% 0% -39% -75% -87% -77% -54% 0% -81% -93% -93% 0% 0% 36% -65%

2029 -72% -42% -45% -22% -72% -68% -69% 0% 0% -40% -76% -87% -77% -55% 0% -82% -94% -94% 0% 0% 36% -67%

2030 -73% -42% -46% -22% -73% -69% -69% 0% 0% -40% -77% -88% -77% -56% 0% -83% -94% -94% 0% 0% 35% -67%

2031 -74% -43% -46% -23% -74% -69% -70% 0% 0% -42% -78% -88% -77% -57% 0% -84% -95% -95% 0% 0% 34% -69%

2032 -74% -43% -47% -23% -75% -70% -71% 0% 0% -42% -79% -88% -77% -57% 0% -85% -95% -95% 0% 0% 34% -69%

2033 -75% -43% -48% -23% -76% -71% -71% 0% 0% -43% -79% -89% -78% -58% 0% -85% -95% -95% 0% 0% 33% -69%

2034 -76% -44% -48% -24% -76% -71% -72% 0% 0% -43% -79% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2035 -76% -44% -49% -24% -77% -72% -72% 0% 0% -44% -80% -89% -78% -59% 0% -86% -95% -95% 0% 0% 33% -70%

2036 -77% -44% -49% -24% -77% -72% -73% 0% 0% -44% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -70%

2037 -77% -44% -50% -24% -78% -72% -73% 0% 0% -45% -80% -89% -78% -60% 0% -87% -96% -96% 0% 0% 32% -71%

Light-Duty Truck Heavy-Duty Truck 

Year
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-179

2009 Compressor Emissions

ASSUMPTIONS

Data provided by operators in blue text

Additional compressor stations will come online from 2012.

Table 244. Compressor Engines Activity Data.

Existing Capacity (Wamsutter and Table 

Rock)

32,810 hp

1,000 mmscfd

Normalized Capacity 32.81 hp/mmscfd

Gas Production capacity to be added 760 mmscfd

Additional horsepower needed 24,936 hp

Reciprocating 

Engines Turbine

Fraction of horsepower at existing stations 2.7% 97.3%

Additional horsepower needed by type 684 24,252

Estimated Load Factor 100% 100%

Equations:

Emissions (tons/year) = Emission factor (g/hp-hr) * Horsepower * Time Used (hours) * Load

453.5 (g/lb) * 2000 (lbs/ton)
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-180

Table 245. Compressor Engine Emission Factors (turbine and rich burn SI) and Compressor

Emissions in lbs per year.

Table 246. Compression Station Emissions (tons/yr).

Turbine

EF (g/hp-hr) source EF (g/hp-hr) source

NOx 0.21

Average turbine emission 

factor from the existing 

Echo Springs Facility 0.7 Assumed BACT level 99,955 9,247

CO 0.21 min of existing turbines 2.0 Assumed BACT level 98,354 26,419

VOC 0.01 min of existing turbines 0.1

min of existing 

reciprocating engines 4,215 1,230

PM10 0.0240 EPA,AP-42 Turbine EFs 0.0704

EPA,AP-42, 4-Stroke 

Rich Burn Engine Efs 11,217 930

PM2.5 0.0240 EPA,AP-42 Turbine EFs 0.0704

EPA,AP-42, 4-Stroke 

Rich Burn Engine Efs 11,217 930

SO2 0.0000 0.0000 0 0

CO2 399.1680 EPA,AP-42 Turbine EFs 399.1680

EPA,AP-42, 4-Stroke 

Rich Burn Engine Efs 186,950,734 5,272,819

CH4 0.0210 SPECIATE Profile 0.7669 SPECIATE Profile 9,835 10,130

PM_cond 0.0171 EPA,AP-42 Turbine EFs 0.0360

EPA,AP-42, 4-Stroke 

Rich Burn Engine Efs 7,988 475

PM_filt 0.0069 EPA,AP-42 Turbine EFs 0.0345

EPA,AP-42, 4-Stroke 

Rich Burn Engine Efs 3,229 455

N2O 0.0109 EPA,AP-42 Turbine EFs 0.0008 API Compendium 5,099 10

Pollutant

Emission Factors Emissions (lb/yr)

Reciprocating

Turbine Reciprocating

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Added Compression (turbine) 49.9777 2.1076 49.1769 5.6085 5.6085 0.0000 93,475 4.9177 1.6146 3.9939 2.5493 totals for CY 2012+

Added Compression (reciprocating) 4.6233 0.6149 13.2095 0.4652 0.4652 0.0000 2,636 5.0652 0.2277 0.2375 0.0050 totals for CY 2012+

Description Projection Compression Station Emissions (tons)
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-181

New Gas Plants Emissions

ASSUMPTIONS

Data provided by operators in blue text

Additional Gas Production Capacity will be added from 2012.

Existing Capacity (Echo Spring Gas Plant) 740 mmscfd

Gas Production capacity to be added 760 mmscfd

Additional horsepower needed 24,936 hp

Table 247. New Gas Plant Emissions by Source in tons per year.

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Added Gas Plant (Recip Engines) 43.2959 5.7583 123.7024 4.3565 4.3565 0 24689.0265 47.4337 2.1322 2.2243 0.0470 totals for CY 2012+

Added Gas Plant (Turbine Engines) 195.2504 8.3969 195.9274 22.3451 22.3451 0 372418.7367 19.5927 6.4327 15.9124 10.1569 totals for CY 2012+

Added Gas Plant (Duct Burner) 17.4087 0.8511 9.6715 1.4701 1.4701 0.1161 23211.6324 0.4449 0.3675 1.1026 0.4255 totals for CY 2012+

Added Gas Plant (Heaters) 77.0640 6.6152 53.5697 6.5076 6.5076 0.5138 102751.9589 1.9694 1.6269 4.8807 1.8838 totals for CY 2012+

Added Gas Plant (Flares) 39.5405 36.4595 111.2270 0 0 0 65678.3294 3.7403 0 0 0.8349 totals for CY 2012+

Added Gas Plant (Process) 10.4757 10.3730 9.5514 0.7962 0.7962 0.0629 12570.8108 0.2409 0.1990 0.5971 0.2305 totals for CY 2012+

Added Gas Plant (Fugitives) 0 3.7000 0 0 0 0 1.5371 17.4200 0 0 0 totals for CY 2012+

Description Projection

Well Pad Construction Equipment Emissions (tons)
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-182

Table 248. Summary of New Gas Plant Emissions by source in tons per year.

Unit NOx CO VOC PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O Units

Total Engine Capacity 100,406 100,406 100,406 100,406 100,406 100,406 100,406 100,406 100,406 100406.00 100406.00 hp

Normalized Capacity 136 136 136 136 136 136 136 136 136 136 136 hp/mmscfd

Added Capacity 760 760 760 760 760 760 760 760 760 760.00 760.00 mmscfd

Additional Capacity Needed 103,120 103,120 103,120 103,120 103,120 103,120 103,120 103,120 103,120 103119.68 103119.68 hp

Fraction Recip Engines 0.062 0.062 0.062 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06

Recip Engine Capacity 6,413 6,413 6,413 6,413 6,413 6,413 6,413 6,413 6,413 6412.76 6412.76 hp

Load Factor 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% 100%

Assumed BACT Emission Factor 0.7 2.0 1.0 0.0704 0.0704 0.0000 399 1 0.0345 0.0360 0.0008 g/hp-hr

VOC/HC 9.3% SPECIATE Profile 1001

Recip Engine Emissions 43 124 5.8 4 4 0 24,689 47 2 2 0 t/yr

Turbine Fraction 0.94 0.94 0.94 0.94 0.94 0.94 0.94 0.94 0.94 0.94 0.94

Turbine Capacity 96,707 96,707 96,707 96,707 96,707 96,707 96,707 96,707 96,707 96,707 96,707 hp

Load Factor 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% 100%

Assumed BACT Level 0.209 0.210 0.030 0.0240 0.0240 0.0000 399.1680 0.0210 0.0069 0.0171 0.0109 g/hp-hr

Assumed BACT Level 15

VOC/HC 30% SPECIATE Profile 0007

Turbine Emissions 195 196 8 22 22 0 372,419 20 6 16 10 t/yr

Duct Burner 

Existing Capacity 43 43 43 43.00 43.00 43.00 43.00 43.00 43.00 43.00 43.00 mmbtu/hr

Normalized Capacity 0.058 0.058 0.058 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 mmbtu/mmscfd

Added Capacity 760 760 760 760 760 760 760 760 760 760 760 mmscf/d

Additional Capacity Needed 44 44 44 44.16 44.16 44.16 44.16 44.16 44.16 44.16 44.16 mmbtu/hr

BACT Level Assumed 0.09 0.05 0.01 0.01 0.01 0.00 120.00 0.00 0.00 0.01 0.0022 lbs/mmbtu

VOC/HC 44% SPECIATE Profile 0003

Duct Burner Emissions 17.4 9.7 0.85 1.5 1.5 0.1 23211.6 0.4 0.4 1.1 0.4 t/yr

Total Engine Emissions 256 329 1 5 28 28 0 420319 67 9 19 11 t/yr

Existing Heater Capacity 190 190 190 190 190 190 190 190 190 190 190 mmbtu/hr

Normalized Capacity 0.257 0.257 0.257 0.26 0.26 0.26 0.26 0.26 0.26 0.26 0.26 mmbtu/mmscfd

Added Capacity 760 760 760 760 760 760 760 760 760 760 760 mmscf/d

Additional Capacity Needed 195 195 195 195 195 195 195 195 195 195 195 mmbtu/hr

BACT level assumed 0.09 0.06 0.02 0.01 0.01 0.00 120.00 0.00 0.00 0.01 0.0022 lbs/mmbtu

VOC/HC 44% SPECIATE Profile 0003

Heater Emissions 77.1 53.6 6.62 6.5 6.5 0.5 102752.0 2.0 1.6 4.9 1.9 t/yr

Emissions from Flaring at 740 mmscfd 38.5 108.3 35.5 0.00 0.00 0.00 63,950 4 0.00 0.00 0.81 t/yr

Emissions from Flaring at 760 mmscfd 39.5 111.2 36.5 0.00 0.00 0.00 65,678 4 0.00 0.00 0.83 t/yr

Process Emissions at 740 mmscfd 10.2 9.3 10.1 0.78 0.78 0.06 12240.00 0.23 0.19 0.58 0.22 t/yr

Process Emissions at 760 mmscfd 10.5 9.6 10.4 0.80 0.80 0.06 12570.81 0.24 0.20 0.60 0.23 t/yr

Fugitive Emissions at 740 mmscfd 0 0 3.7 0.00 0.00 0.00 1.54 17.42 0.00 0.00 0.00 t/yr

Fugitive Emissions at 760 mmscfd 0 0 3.7 0.00 0.00 0.00 1.54 17.42 0.00 0.00 0.00 t/yr

Facility Total 383 504 72 35 35 1 601322 91 11 25 14 t/yr

Engines

Duct Burner

Heaters

Flares

Process

Fugitive
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-183

2009 Evaporative Pond Emissions

Data provided by operators in blue text.

Table 249. 2009 Emissions (tons/year) from Wamsutter North and South Evaporation Ponds.

Table 250. 2009 Average VOC emissions (tons/year).

Table 251. VOC, CO2 and CH4 Weight Fractions.

Component % Wt

Average per Well 

Emissions

(TPY)

Methane 3.90% 0.0001

Carbon Dioxide 24.76% 0.0006

VOC Fraction (weight) 69.58%

Table 252. 2009 Evaporation Pond Emissions in tons per well.

Parameter

Wamsutter 

North Pond

Wamsutter South 

Pond

4.67 5.85

Benzene 0.62 0.84

Ethylbenzene 0.07 0.09

Hexane (-n) 0.01 0.01

Methanol 2.09 2.31

Toluene 0.80 1.11

Xylene 0.92 1.25

Xylene (-o) 0.17 0.24

VOC Emissions (tpy)

Emissions (tpy) based on Water 9 model Output*

*based on data from evaporation facilities at Wamsutter Operations Center

Average VOC emissions per 

evaporation basin (tpy) 5.26

Average Evaporation Facilities per 

well 0.033%

Average VOC emissions per well 

(tpy) 0.002

Based on two existing evaporation facilities for 1500 CDC wells. 

Only 25% of project wells are assumed to be associated with an 

evaporation pond

NOx VOC CO PM10 PM2.5 SO2 CO2 CH4 PM_filt PM_cond N2O

Evaporation Ponds 0 0.0018 0 0 0 0 0.0006 0.0001 0 0 0 active well counts

Description Evaporation Pond Emissions -Weighted Average(tons per well) Projection
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-184

Table 253. Percent Change in Emission from Base Year 2009 for Evaporation Ponds.

Year NOx SO2 CO CO2 VOC PM10 PM2.5 PM_filt PM_cond CH4

2009 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2010 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2011 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2012 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2013 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2014 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2015 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2016 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2017 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2018 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2019 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2020 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2021 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2022 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2023 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2024 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2025 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2026 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2027 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2028 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2029 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2030 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2031 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2032 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2033 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2034 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2035 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2036 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

2037 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-185

Table 254. New Project Wells NOx Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 17. New Project Wells NOx Emissions (tons/year) Contribution by Source Category and by Project Year. Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 95 2 364 23 73 14 2 0 0 44 0 0 2 0 28 1 0 0 0 0 0 646

2010 0 127 2 488 28 98 17 2 0 0 102 0 0 4 0 74 2 0 0 0 0 0 945

2011 0 126 2 485 25 97 15 2 0 0 160 0 0 6 0 114 3 0 0 0 0 0 1,037

2012 0 124 1 476 22 96 13 2 0 0 217 0 0 8 0 148 4 0 174 25 0 0 1,310

2013 0 126 1 485 20 97 12 2 0 0 275 0 0 9 0 181 5 0 174 25 0 0 1,414

2014 0 125 1 481 17 97 11 2 0 0 333 0 0 10 0 211 6 0 174 25 0 0 1,492

2015 0 129 1 496 16 100 10 2 0 0 392 0 0 10 0 241 8 0 174 25 0 0 1,603

2016 0 101 1 388 11 78 7 2 0 0 438 0 0 10 0 263 8 0 174 25 0 0 1,505

2017 0 133 1 509 13 102 8 2 0 0 499 0 0 10 0 292 10 0 174 25 0 0 1,776

2018 0 146 1 560 12 112 7 2 0 0 566 0 0 10 0 333 11 0 174 25 0 0 1,960

2019 0 117 1 451 9 90 5 2 0 0 620 0 0 10 0 359 12 0 174 25 0 0 1,875

2020 0 117 1 451 8 91 5 2 0 0 674 0 0 10 0 384 13 0 174 25 0 0 1,953

2021 0 133 1 509 8 102 5 2 0 0 735 0 0 10 0 409 14 0 174 25 0 0 2,126

2022 0 126 0 483 6 97 3 2 0 0 793 0 0 9 0 440 15 0 174 25 0 0 2,172

2023 0 42 0 162 2 33 1 1 0 0 812 0 0 10 0 442 16 0 174 25 0 0 1,720

2024 0 0 0 0 0 0 0 0 0 0 812 0 0 10 0 424 16 0 174 25 0 0 1,460

2025 0 0 0 0 0 0 0 0 0 0 812 0 0 8 0 412 16 0 174 25 0 0 1,447

2026 0 0 0 0 0 0 0 0 0 0 812 0 0 8 0 404 16 0 174 25 0 0 1,438

2027 0 0 0 0 0 0 0 0 0 0 812 0 0 7 0 397 16 0 174 25 0 0 1,431

2028 0 0 0 0 0 0 0 0 0 0 812 0 0 7 0 391 16 0 174 25 0 0 1,424

2029 0 0 0 0 0 0 0 0 0 0 812 0 0 7 0 386 16 0 174 25 0 0 1,419

2030 0 0 0 0 0 0 0 0 0 0 812 0 0 6 0 381 16 0 174 25 0 0 1,414

2031 0 0 0 0 0 0 0 0 0 0 812 0 0 6 0 377 16 0 174 25 0 0 1,410

2032 0 0 0 0 0 0 0 0 0 0 812 0 0 6 0 373 16 0 174 25 0 0 1,406

2033 0 0 0 0 0 0 0 0 0 0 812 0 0 6 0 370 16 0 174 25 0 0 1,402

2034 0 0 0 0 0 0 0 0 0 0 812 0 0 6 0 367 16 0 174 25 0 0 1,399

2035 0 0 0 0 0 0 0 0 0 0 812 0 0 6 0 364 16 0 174 25 0 0 1,396

2036 0 0 0 0 0 0 0 0 0 0 812 0 0 6 0 361 16 0 174 25 0 0 1,393

2037 0 0 0 0 0 0 0 0 0 0 812 0 0 6 0 358 16 0 174 25 0 0 1,390

TOTAL 0 1,768 14 6,788 217 1,363 135 28 0 0 18,027 0 0 223 0 9,285 348 0 4,521 645 0 0 43,362

Production Total (Costruction + 

Drilling + Completion 

+ Production)

NOx [tpy]

Pollutant Year

Construction Drilling Completion

0

410

820

1,230

1,640

2,050

2,460

2,870

3,280

3,690

4,100

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well NOx Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-186

Table 255. New Project Wells VOC Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 18. New Project Wells VOC Emissions (tons/year) Contribution by Source Category and by Project Year. Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 14 0 21 3 4 2 2 0 146 2 0 0 1 28 36 0 163 0 0 0 0 421

2010 0 19 0 28 4 6 2 3 0 341 6 0 0 1 85 95 0 382 0 0 0 1 972

2011 0 19 0 27 3 5 2 3 0 535 9 0 0 2 128 147 0 599 0 0 0 1 1,481

2012 0 19 0 27 3 5 2 3 0 726 12 0 0 2 159 190 0 813 33 1 0 2 1,996

2013 0 19 0 27 3 5 2 3 0 920 15 0 0 2 188 233 0 1,030 33 1 0 2 2,484

2014 0 19 0 27 2 5 2 3 0 1,112 18 0 0 3 209 272 0 1,245 33 1 0 3 2,955

2015 0 19 0 28 2 6 1 3 0 1,310 22 0 0 3 228 310 0 1,468 33 1 0 3 3,438

2016 0 15 0 22 2 4 1 2 0 1,466 24 0 0 3 241 339 0 1,641 33 1 0 4 3,799

2017 0 20 0 29 2 6 1 3 0 1,669 27 0 0 3 256 375 1 1,869 33 1 0 4 4,299

2018 0 22 0 32 2 6 1 3 0 1,893 31 0 0 3 296 429 1 2,120 33 1 0 5 4,878

2019 0 18 0 25 1 5 1 2 0 2,073 34 0 0 3 311 462 1 2,322 33 1 0 5 5,299

2020 0 18 0 25 1 5 1 2 0 2,253 37 0 0 4 323 494 1 2,524 33 1 0 6 5,727

2021 0 20 0 29 1 6 1 3 0 2,457 40 0 0 4 331 527 1 2,751 33 1 0 6 6,211

2022 0 19 0 27 1 5 1 3 0 2,650 44 0 0 3 355 567 1 2,968 33 1 0 7 6,684

2023 0 6 0 9 0 2 0 1 0 2,715 45 0 0 4 343 569 1 3,040 33 1 0 7 6,776

2024 0 0 0 0 0 0 0 0 0 2,715 45 0 0 3 302 546 1 3,040 33 1 0 7 6,693

2025 0 0 0 0 0 0 0 0 0 2,715 45 0 0 3 276 530 1 3,040 33 1 0 7 6,651

2026 0 0 0 0 0 0 0 0 0 2,715 45 0 0 3 257 519 1 3,040 33 1 0 7 6,621

2027 0 0 0 0 0 0 0 0 0 2,715 45 0 0 3 241 511 1 3,040 33 1 0 7 6,596

2028 0 0 0 0 0 0 0 0 0 2,715 45 0 0 3 228 503 1 3,040 33 1 0 7 6,575

2029 0 0 0 0 0 0 0 0 0 2,715 45 0 0 2 216 497 1 3,040 33 1 0 7 6,557

2030 0 0 0 0 0 0 0 0 0 2,715 45 0 0 2 206 491 1 3,040 33 1 0 7 6,541

2031 0 0 0 0 0 0 0 0 0 2,715 45 0 0 2 197 485 1 3,040 33 1 0 7 6,526

2032 0 0 0 0 0 0 0 0 0 2,715 45 0 0 2 188 481 1 3,040 33 1 0 7 6,513

2033 0 0 0 0 0 0 0 0 0 2,715 45 0 0 2 180 476 1 3,040 33 1 0 7 6,500

2034 0 0 0 0 0 0 0 0 0 2,715 45 0 0 2 173 472 1 3,040 33 1 0 7 6,488

2035 0 0 0 0 0 0 0 0 0 2,715 45 0 0 2 166 468 1 3,040 33 1 0 7 6,478

2036 0 0 0 0 0 0 0 0 0 2,715 45 0 0 2 159 464 1 3,040 33 1 0 7 6,467

2037 0 0 0 0 0 0 0 0 0 2,715 45 0 0 2 153 461 1 3,040 33 1 0 7 6,457

TOTAL 0 264 2 382 31 77 20 36 0 60,274 991 0 0 74 6,423 11,948 20 67,497 852 32 0 158 149,082

Production Total (Costruction + 

Drilling + Completion 

+ Production)

VOC [tpy]

Pollutant Year

Construction Drilling Completion

0

6,160

12,320

18,480

24,640

30,800

36,960

43,120

49,280

55,440

61,600

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well VOC Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-187

Table 256. New Project Wells SO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 19. New Project Wells SO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 2 0 8 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 12

2010 0 1 0 5 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8

2011 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2012 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2013 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2014 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2015 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2016 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2017 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2018 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2019 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2020 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2021 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2022 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2023 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2024 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2025 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2026 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2027 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2028 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2029 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2030 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2031 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2032 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2033 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2034 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2035 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2036 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2037 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

TOTAL 0 4 0 19 1 4 0 0 0 0 0 0 0 1 0 0 0 0 8 0 0 0 37

Production Total (Costruction + 

Drilling + Completion 

+ Production)

SO2 [tpy]

Pollutant Year

Construction Drilling Completion

0.0

14.0

28.0

42.0

56.0

70.0

84.0

98.0

112.0

126.0

140.0

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well SO2 Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-188

Table 257. New Project Wells PM10 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 20. New Project Wells PM10 Emissions (tons/year) Contribution by Source Category and by Project Year. Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 63 6 10 12 140 2 89 0 0 0 3 0 0 29 0 0 0 0 0 0 0 0 355

2010 84 8 14 16 188 3 119 0 0 0 8 0 0 68 0 0 0 0 0 0 0 0 508

2011 83 8 14 16 187 3 118 0 0 0 12 0 0 106 0 0 0 0 0 0 0 0 548

2012 82 7 14 16 183 3 116 0 0 0 16 0 0 144 0 0 0 0 16 3 0 0 601

2013 83 8 14 16 186 3 118 0 0 0 21 0 0 183 0 0 0 0 16 3 0 0 652

2014 83 8 14 16 184 3 117 0 0 0 25 0 0 221 0 0 0 0 16 3 0 0 690

2015 85 8 14 17 190 3 120 0 0 0 30 0 0 260 0 0 0 0 16 3 0 0 747

2016 67 6 11 13 148 3 94 0 0 0 33 0 0 291 0 0 0 0 16 3 0 0 686

2017 87 8 15 17 195 3 123 0 0 0 38 0 0 332 0 0 0 0 16 3 0 0 837

2018 96 9 16 19 214 4 136 0 0 0 43 0 0 376 0 0 0 0 16 3 0 0 932

2019 77 7 13 15 172 3 109 0 0 0 47 0 0 412 0 0 0 0 16 3 0 0 875

2020 77 7 13 15 172 3 109 0 0 0 51 0 0 447 0 0 1 0 16 3 0 0 915

2021 87 8 14 17 195 3 123 0 0 0 56 0 0 488 0 0 1 0 16 3 0 0 1,011

2022 83 8 14 16 184 3 117 0 0 0 60 0 0 526 0 0 1 0 16 3 0 0 1,031

2023 28 3 5 5 62 1 39 0 0 0 62 0 0 539 0 0 1 0 16 3 0 0 763

2024 0 0 0 0 0 0 0 0 0 0 62 0 0 539 0 0 1 0 16 3 0 0 620

2025 0 0 0 0 0 0 0 0 0 0 62 0 0 539 0 0 1 0 16 3 0 0 620

2026 0 0 0 0 0 0 0 0 0 0 62 0 0 539 0 0 1 0 16 3 0 0 620

2027 0 0 0 0 0 0 0 0 0 0 62 0 0 539 0 0 1 0 16 3 0 0 620

2028 0 0 0 0 0 0 0 0 0 0 62 0 0 539 0 0 1 0 16 3 0 0 620

2029 0 0 0 0 0 0 0 0 0 0 62 0 0 539 0 0 1 0 16 3 0 0 620

2030 0 0 0 0 0 0 0 0 0 0 62 0 0 539 0 0 1 0 16 3 0 0 620

2031 0 0 0 0 0 0 0 0 0 0 62 0 0 539 0 0 1 0 16 3 0 0 620

2032 0 0 0 0 0 0 0 0 0 0 62 0 0 539 0 0 1 0 16 3 0 0 620

2033 0 0 0 0 0 0 0 0 0 0 62 0 0 539 0 0 1 0 16 3 0 0 620

2034 0 0 0 0 0 0 0 0 0 0 62 0 0 539 0 0 1 0 16 3 0 0 620

2035 0 0 0 0 0 0 0 0 0 0 62 0 0 539 0 0 1 0 16 3 0 0 620

2036 0 0 0 0 0 0 0 0 0 0 62 0 0 539 0 0 1 0 16 3 0 0 620

2037 0 0 0 0 0 0 0 0 0 0 62 0 0 539 0 0 1 0 16 3 0 0 620

TOTAL 1,166 107 194 228 2,602 45 1,649 0 0 0 1,370 0 0 11,964 0 0 14 0 419 72 0 0 19,828

Production Total (Costruction + 

Drilling + Completion 

+ Production)

PM10 [tpy]

Pollutant Year

Construction Drilling Completion

0.0

155.0

310.0

465.0

620.0

775.0

930.0

1,085.0

1,240.0

1,395.0

1,550.0

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well PM10 Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-189

Table 258. New Project Wells PM2.5 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 21. New Project Wells PM2.5 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 16 6 1 12 15 2 10 0 0 0 3 0 0 3 0 0 0 0 0 0 0 0 68

2010 22 7 1 16 20 3 13 0 0 0 8 0 0 7 0 0 0 0 0 0 0 0 97

2011 21 7 1 16 20 3 13 0 0 0 12 0 0 11 0 0 0 0 0 0 0 0 105

2012 21 7 1 16 19 3 12 0 0 0 16 0 0 15 0 0 0 0 16 3 0 0 130

2013 21 7 1 16 20 3 12 0 0 0 21 0 0 19 0 0 0 0 16 3 0 0 140

2014 21 7 1 16 19 3 12 0 0 0 25 0 0 22 0 0 0 0 16 3 0 0 147

2015 22 8 1 16 20 3 12 0 0 0 30 0 0 26 0 0 0 0 16 3 0 0 158

2016 17 6 1 13 15 3 10 0 0 0 33 0 0 29 0 0 0 0 16 3 0 0 146

2017 23 8 1 17 20 3 13 0 0 0 38 0 0 33 0 0 0 0 16 3 0 0 175

2018 25 9 2 18 22 4 14 0 0 0 43 0 0 38 0 0 0 0 16 3 0 0 192

2019 20 7 1 15 17 3 11 0 0 0 47 0 0 41 0 0 0 0 16 3 0 0 182

2020 20 7 1 15 17 3 11 0 0 0 51 0 0 45 0 0 0 0 16 3 0 0 190

2021 23 8 1 17 20 3 12 0 0 0 56 0 0 49 0 0 1 0 16 3 0 0 208

2022 21 7 1 16 19 3 12 0 0 0 60 0 0 53 0 0 1 0 16 3 0 0 211

2023 7 2 0 5 6 1 4 0 0 0 62 0 0 54 0 0 1 0 16 3 0 0 162

2024 0 0 0 0 0 0 0 0 0 0 62 0 0 54 0 0 1 0 16 3 0 0 135

2025 0 0 0 0 0 0 0 0 0 0 62 0 0 54 0 0 1 0 16 3 0 0 135

2026 0 0 0 0 0 0 0 0 0 0 62 0 0 54 0 0 1 0 16 3 0 0 135

2027 0 0 0 0 0 0 0 0 0 0 62 0 0 54 0 0 1 0 16 3 0 0 135

2028 0 0 0 0 0 0 0 0 0 0 62 0 0 54 0 0 1 0 16 3 0 0 135

2029 0 0 0 0 0 0 0 0 0 0 62 0 0 54 0 0 1 0 16 3 0 0 135

2030 0 0 0 0 0 0 0 0 0 0 62 0 0 54 0 0 1 0 16 3 0 0 135

2031 0 0 0 0 0 0 0 0 0 0 62 0 0 54 0 0 1 0 16 3 0 0 135

2032 0 0 0 0 0 0 0 0 0 0 62 0 0 54 0 0 1 0 16 3 0 0 135

2033 0 0 0 0 0 0 0 0 0 0 62 0 0 54 0 0 1 0 16 3 0 0 135

2034 0 0 0 0 0 0 0 0 0 0 62 0 0 54 0 0 1 0 16 3 0 0 135

2035 0 0 0 0 0 0 0 0 0 0 62 0 0 54 0 0 1 0 16 3 0 0 135

2036 0 0 0 0 0 0 0 0 0 0 62 0 0 54 0 0 1 0 16 3 0 0 135

2037 0 0 0 0 0 0 0 0 0 0 62 0 0 54 0 0 1 0 16 3 0 0 135

TOTAL 300 104 20 221 269 44 170 0 0 0 1,370 0 0 1,196 0 0 13 0 419 72 0 0 4,198

Production Total (Costruction + 

Drilling + Completion 

+ Production)

PM2.5 [tpy]

Pollutant Year

Construction Drilling Completion

0

39

78

117

156

195

234

273

312

351

390

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well PM2.5 Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-190

Table 259. New Project Wells CO Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 22. New Project Wells CO Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 117 2 213 25 42 16 8 0 0 37 0 0 6 0 151 1 0 0 0 0 0 617

2010 0 157 2 286 32 57 20 11 0 0 86 0 0 13 0 403 1 0 0 0 0 0 1,069

2011 0 156 2 284 30 56 19 11 0 0 134 0 0 19 0 620 2 0 0 0 0 0 1,335

2012 0 153 2 279 28 55 18 11 0 0 182 0 0 25 0 804 3 0 229 28 0 0 1,818

2013 0 156 2 284 27 56 17 11 0 0 231 0 0 30 0 987 3 0 229 28 0 0 2,062

2014 0 155 2 282 26 56 16 11 0 0 279 0 0 35 0 1,150 4 0 229 28 0 0 2,272

2015 0 159 2 291 25 57 16 11 0 0 329 0 0 39 0 1,311 5 0 229 28 0 0 2,503

2016 0 125 1 227 18 45 12 9 0 0 368 0 0 41 0 1,433 5 0 229 28 0 0 2,542

2017 0 164 2 298 23 59 15 12 0 0 419 0 0 45 0 1,587 6 0 229 28 0 0 2,886

2018 0 180 2 328 24 65 15 13 0 0 476 0 0 50 0 1,814 7 0 229 28 0 0 3,229

2019 0 145 1 264 19 52 12 10 0 0 521 0 0 53 0 1,955 7 0 229 28 0 0 3,296

2020 0 145 1 264 18 52 12 10 0 0 566 0 0 56 0 2,087 8 0 229 28 0 0 3,477

2021 0 164 2 298 20 59 13 12 0 0 617 0 0 59 0 2,227 8 0 229 28 0 0 3,735

2022 0 155 1 283 18 56 11 11 0 0 666 0 0 60 0 2,396 9 0 229 28 0 0 3,923

2023 0 52 0 95 6 19 4 4 0 0 682 0 0 64 0 2,406 9 0 229 28 0 0 3,598

2024 0 0 0 0 0 0 0 0 0 0 682 0 0 62 0 2,307 9 0 229 28 0 0 3,318

2025 0 0 0 0 0 0 0 0 0 0 682 0 0 60 0 2,242 9 0 229 28 0 0 3,251

2026 0 0 0 0 0 0 0 0 0 0 682 0 0 58 0 2,197 9 0 229 28 0 0 3,203

2027 0 0 0 0 0 0 0 0 0 0 682 0 0 57 0 2,159 9 0 229 28 0 0 3,165

2028 0 0 0 0 0 0 0 0 0 0 682 0 0 57 0 2,128 9 0 229 28 0 0 3,133

2029 0 0 0 0 0 0 0 0 0 0 682 0 0 56 0 2,100 9 0 229 28 0 0 3,104

2030 0 0 0 0 0 0 0 0 0 0 682 0 0 55 0 2,075 9 0 229 28 0 0 3,079

2031 0 0 0 0 0 0 0 0 0 0 682 0 0 54 0 2,053 9 0 229 28 0 0 3,055

2032 0 0 0 0 0 0 0 0 0 0 682 0 0 54 0 2,032 9 0 229 28 0 0 3,034

2033 0 0 0 0 0 0 0 0 0 0 682 0 0 53 0 2,013 9 0 229 28 0 0 3,014

2034 0 0 0 0 0 0 0 0 0 0 682 0 0 52 0 1,995 9 0 229 28 0 0 2,996

2035 0 0 0 0 0 0 0 0 0 0 682 0 0 52 0 1,978 9 0 229 28 0 0 2,978

2036 0 0 0 0 0 0 0 0 0 0 682 0 0 51 0 1,963 9 0 229 28 0 0 2,962

2037 0 0 0 0 0 0 0 0 0 0 682 0 0 50 0 1,948 9 0 229 28 0 0 2,946

TOTAL 0 2,181 26 3,977 340 787 216 154 0 0 15,142 0 0 1,365 0 50,521 208 0 5,945 736 0 0 81,600

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO [tpy]

Pollutant Year

Construction Drilling Completion

0

606

1,212

1,818

2,424

3,030

3,636

4,242

4,848

5,454

6,060

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well CO Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-191

Table 260. New Project Wells Formaldehyde Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 23. New Project Wells Formaldehyde Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 1 0 2 0 0 0 1 0 0 0 0 0 0 0 14 0 0 0 0 0 0 19

2010 0 2 0 2 0 0 0 1 0 0 0 0 0 0 0 38 0 0 0 0 0 0 45

2011 0 2 0 2 0 0 0 1 0 0 1 0 0 0 0 59 0 0 0 0 0 0 65

2012 0 2 0 2 0 0 0 1 0 0 1 0 0 0 0 76 0 0 11 1 0 0 95

2013 0 2 0 2 0 0 0 1 0 0 1 0 0 0 0 93 0 0 11 1 0 0 113

2014 0 2 0 2 0 0 0 1 0 0 1 0 0 0 0 109 0 0 11 1 0 0 128

2015 0 2 0 2 0 0 0 1 0 0 2 0 0 0 0 124 0 0 11 1 0 0 144

2016 0 1 0 2 0 0 0 1 0 0 2 0 0 0 0 136 0 0 11 1 0 0 154

2017 0 2 0 2 0 0 0 1 0 0 2 0 0 0 0 150 0 0 11 1 0 0 171

2018 0 2 0 3 0 1 0 1 0 0 2 0 0 0 0 172 0 0 11 1 0 0 193

2019 0 1 0 2 0 0 0 1 0 0 3 0 0 0 0 185 0 0 11 1 0 0 205

2020 0 1 0 2 0 0 0 1 0 0 3 0 0 0 0 197 0 0 11 1 0 0 218

2021 0 2 0 2 0 0 0 1 0 0 3 0 0 0 0 211 0 0 11 1 0 0 232

2022 0 2 0 2 0 0 0 1 0 0 3 0 0 0 0 227 0 0 11 1 0 0 248

2023 0 1 0 1 0 0 0 0 0 0 4 0 0 0 0 228 0 0 11 1 0 0 245

2024 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 218 0 0 11 1 0 0 234

2025 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 212 0 0 11 1 0 0 228

2026 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 208 0 0 11 1 0 0 224

2027 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 204 0 0 11 1 0 0 220

2028 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 201 0 0 11 1 0 0 217

2029 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 199 0 0 11 1 0 0 215

2030 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 196 0 0 11 1 0 0 212

2031 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 194 0 0 11 1 0 0 210

2032 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 192 0 0 11 1 0 0 208

2033 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 190 0 0 11 1 0 0 206

2034 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 189 0 0 11 1 0 0 205

2035 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 187 0 0 11 1 0 0 203

2036 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 186 0 0 11 1 0 0 202

2037 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 184 0 0 11 1 0 0 200

TOTAL 0 22 0 33 2 7 1 15 0 0 79 0 0 3 0 4,779 2 0 294 26 0 0 5,262

Production Total (Costruction + 

Drilling + Completion 

+ Production)

formaldehyde 

[tpy]

Pollutant Year

Construction Drilling Completion

0

53

106

159

212

265

318

371

424

477

530

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well Formaldehyde Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-192

Table 261. New Project Wells n-hexane Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 24. New Project Wells n-hexane Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 0 0 0 0 0 0 0 0 6 0 0 0 0 1 0 0 3 0 0 0 0 10

2010 0 0 0 0 0 0 0 0 0 14 0 0 0 0 3 0 0 8 0 0 0 0 25

2011 0 0 0 0 0 0 0 0 0 23 0 0 0 0 4 0 0 12 0 0 0 0 39

2012 0 0 0 0 0 0 0 0 0 31 0 0 0 0 5 0 0 16 0 0 0 0 52

2013 0 0 0 0 0 0 0 0 0 39 0 0 0 0 6 0 0 20 0 0 0 0 66

2014 0 0 0 0 0 0 0 0 0 47 0 0 0 0 7 0 0 25 0 0 0 0 79

2015 0 0 0 0 0 0 0 0 0 55 0 0 0 0 8 0 0 29 0 0 0 0 92

2016 0 0 0 0 0 0 0 0 0 62 0 0 0 0 8 0 0 33 0 0 0 0 103

2017 0 0 0 0 0 0 0 0 0 70 0 0 0 0 9 0 0 37 0 0 0 0 116

2018 0 0 0 0 0 0 0 0 0 80 0 0 0 0 10 0 0 42 0 0 0 0 132

2019 0 0 0 0 0 0 0 0 0 87 0 0 0 0 11 0 0 46 0 0 0 0 144

2020 0 0 0 0 0 0 0 0 0 95 0 0 0 0 11 0 0 50 0 0 0 0 156

2021 0 0 0 0 0 0 0 0 0 104 0 0 0 0 11 0 0 55 0 0 0 0 170

2022 0 0 0 0 0 0 0 0 0 112 0 0 0 0 12 0 0 59 0 0 0 0 183

2023 0 0 0 0 0 0 0 0 0 115 0 0 0 0 12 0 0 60 0 0 0 0 187

2024 0 0 0 0 0 0 0 0 0 115 0 0 0 0 10 0 0 60 0 0 0 0 185

2025 0 0 0 0 0 0 0 0 0 115 0 0 0 0 9 0 0 60 0 0 0 0 184

2026 0 0 0 0 0 0 0 0 0 115 0 0 0 0 9 0 0 60 0 0 0 0 184

2027 0 0 0 0 0 0 0 0 0 115 0 0 0 0 8 0 0 60 0 0 0 0 183

2028 0 0 0 0 0 0 0 0 0 115 0 0 0 0 8 0 0 60 0 0 0 0 183

2029 0 0 0 0 0 0 0 0 0 115 0 0 0 0 7 0 0 60 0 0 0 0 182

2030 0 0 0 0 0 0 0 0 0 115 0 0 0 0 7 0 0 60 0 0 0 0 182

2031 0 0 0 0 0 0 0 0 0 115 0 0 0 0 7 0 0 60 0 0 0 0 182

2032 0 0 0 0 0 0 0 0 0 115 0 0 0 0 6 0 0 60 0 0 0 0 181

2033 0 0 0 0 0 0 0 0 0 115 0 0 0 0 6 0 0 60 0 0 0 0 181

2034 0 0 0 0 0 0 0 0 0 115 0 0 0 0 6 0 0 60 0 0 0 0 181

2035 0 0 0 0 0 0 0 0 0 115 0 0 0 0 6 0 0 60 0 0 0 0 181

2036 0 0 0 0 0 0 0 0 0 115 0 0 0 0 5 0 0 60 0 0 0 0 180

2037 0 0 0 0 0 0 0 0 0 115 0 0 0 0 5 0 0 60 0 0 0 0 180

TOTAL 0 0 0 0 0 0 0 0 0 2,542 0 0 0 1 218 0 0 1,339 2 0 0 0 4,103

Production Total (Costruction + 

Drilling + Completion 

+ Production)

n-hexane [tpy]

Pollutant Year

Construction Drilling Completion

0

208

416

624

832

1,040

1,248

1,456

1,664

1,872

2,080

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well n-hexane Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-193

Table 262. New Project Wells Benzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 25. New Project Wells Benzene Emissions (tons/year) Contribution by Source Category and by Project Year. Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 0 0 0 0 0 0 0 0 6 0 0 0 0 1 0 0 3 0 0 0 0 10

2010 0 0 0 0 0 0 0 0 0 14 0 0 0 0 3 0 0 8 0 0 0 0 25

2011 0 0 0 0 0 0 0 0 0 23 0 0 0 0 4 0 0 12 0 0 0 0 39

2012 0 0 0 0 0 0 0 0 0 31 0 0 0 0 5 0 0 16 0 0 0 0 52

2013 0 0 0 0 0 0 0 0 0 39 0 0 0 0 6 0 0 20 0 0 0 0 66

2014 0 0 0 0 0 0 0 0 0 47 0 0 0 0 7 0 0 25 0 0 0 0 79

2015 0 0 0 0 0 0 0 0 0 55 0 0 0 0 8 0 0 29 0 0 0 0 92

2016 0 0 0 0 0 0 0 0 0 62 0 0 0 0 8 0 0 33 0 0 0 0 103

2017 0 0 0 0 0 0 0 0 0 70 0 0 0 0 9 0 0 37 0 0 0 0 116

2018 0 0 0 0 0 0 0 0 0 80 0 0 0 0 10 0 0 42 0 0 0 0 132

2019 0 0 0 0 0 0 0 0 0 87 0 0 0 0 11 0 0 46 0 0 0 0 144

2020 0 0 0 0 0 0 0 0 0 95 0 0 0 0 11 0 0 50 0 0 0 0 156

2021 0 0 0 0 0 0 0 0 0 104 0 0 0 0 11 0 0 55 0 0 0 0 170

2022 0 0 0 0 0 0 0 0 0 112 0 0 0 0 12 0 0 59 0 0 0 0 183

2023 0 0 0 0 0 0 0 0 0 115 0 0 0 0 12 0 0 60 0 0 0 0 187

2024 0 0 0 0 0 0 0 0 0 115 0 0 0 0 10 0 0 60 0 0 0 0 185

2025 0 0 0 0 0 0 0 0 0 115 0 0 0 0 9 0 0 60 0 0 0 0 184

2026 0 0 0 0 0 0 0 0 0 115 0 0 0 0 9 0 0 60 0 0 0 0 184

2027 0 0 0 0 0 0 0 0 0 115 0 0 0 0 8 0 0 60 0 0 0 0 183

2028 0 0 0 0 0 0 0 0 0 115 0 0 0 0 8 0 0 60 0 0 0 0 183

2029 0 0 0 0 0 0 0 0 0 115 0 0 0 0 7 0 0 60 0 0 0 0 182

2030 0 0 0 0 0 0 0 0 0 115 0 0 0 0 7 0 0 60 0 0 0 0 182

2031 0 0 0 0 0 0 0 0 0 115 0 0 0 0 7 0 0 60 0 0 0 0 182

2032 0 0 0 0 0 0 0 0 0 115 0 0 0 0 6 0 0 60 0 0 0 0 181

2033 0 0 0 0 0 0 0 0 0 115 0 0 0 0 6 0 0 60 0 0 0 0 181

2034 0 0 0 0 0 0 0 0 0 115 0 0 0 0 6 0 0 60 0 0 0 0 181

2035 0 0 0 0 0 0 0 0 0 115 0 0 0 0 6 0 0 60 0 0 0 0 181

2036 0 0 0 0 0 0 0 0 0 115 0 0 0 0 5 0 0 60 0 0 0 0 180

2037 0 0 0 0 0 0 0 0 0 115 0 0 0 0 5 0 0 60 0 0 0 0 180

TOTAL 0 0 0 0 0 0 0 0 0 2,542 0 0 0 1 218 0 0 1,339 2 0 0 0 4,103

Production Total (Costruction + 

Drilling + Completion 

+ Production)

n-hexane [tpy]

Pollutant Year

Construction Drilling Completion

0

294

589

883

1,178

1,472

1,766

2,061

2,355

2,650

2,944

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well Benzene Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-194

Table 263. New Project Wells Ethylbenzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 26. New Project Wells Ethylbenzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2010 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2011 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2012 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2013 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2014 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2015 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2016 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2017 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2018 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2019 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2020 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

2021 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2022 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2023 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2024 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2025 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2026 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2027 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2028 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2029 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2030 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2031 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2032 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2033 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2034 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2035 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2036 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

2037 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1

TOTAL 0 0 0 1 0 0 0 0 0 10 0 0 0 1 1 0 0 13 0 0 0 2 28

Production Total (Costruction + 

Drilling + Completion 

+ Production)

ethylbenzene 

[tpy]

Pollutant Year

Construction Drilling Completion

0.0

17.4

34.8

52.2

69.6

87.0

104.4

121.8

139.2

156.6

174.0

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well Ethylbenzene Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-195

Table 264. New Project Wells Toluene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 27. New Project Wells Toluene Emissions (tons/year) Contribution by Source Category and by Project Year. Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 3

2010 0 0 0 0 0 0 0 0 0 3 0 0 0 0 1 0 0 2 0 0 0 0 7

2011 0 0 0 0 0 0 0 0 0 5 0 0 0 0 1 0 0 3 0 0 0 0 11

2012 0 0 0 0 0 0 0 0 0 7 0 0 0 0 1 0 0 5 0 0 0 0 15

2013 0 0 0 0 0 0 0 0 0 9 0 0 0 0 1 0 0 6 0 0 0 0 18

2014 0 0 0 0 0 0 0 0 0 11 0 0 0 0 1 0 0 7 0 0 0 1 21

2015 0 0 0 0 0 0 0 0 0 13 0 0 0 0 1 0 0 8 0 0 0 1 25

2016 0 0 0 0 0 0 0 0 0 14 0 0 0 0 2 0 0 9 0 0 0 1 27

2017 0 0 0 0 0 0 0 0 0 16 1 0 0 0 2 0 0 11 0 0 0 1 31

2018 0 0 0 0 0 0 0 0 0 18 1 0 0 0 2 0 0 12 0 0 0 1 35

2019 0 0 0 0 0 0 0 0 0 20 1 0 0 0 2 0 0 13 0 0 0 1 38

2020 0 0 0 0 0 0 0 0 0 22 1 0 0 0 2 0 0 14 0 0 0 1 41

2021 0 0 0 0 0 0 0 0 0 24 1 0 0 0 2 0 0 16 0 0 0 1 45

2022 0 0 0 0 0 0 0 0 0 26 1 0 0 0 2 0 0 17 0 0 0 1 48

2023 0 0 0 0 0 0 0 0 0 26 1 0 0 0 2 0 0 17 0 0 0 1 49

2024 0 0 0 0 0 0 0 0 0 26 1 0 0 0 2 0 0 17 0 0 0 1 48

2025 0 0 0 0 0 0 0 0 0 26 1 0 0 0 2 0 0 17 0 0 0 1 48

2026 0 0 0 0 0 0 0 0 0 26 1 0 0 0 2 0 0 17 0 0 0 1 48

2027 0 0 0 0 0 0 0 0 0 26 1 0 0 0 2 0 0 17 0 0 0 1 48

2028 0 0 0 0 0 0 0 0 0 26 1 0 0 0 1 0 0 17 0 0 0 1 48

2029 0 0 0 0 0 0 0 0 0 26 1 0 0 0 1 0 0 17 0 0 0 1 48

2030 0 0 0 0 0 0 0 0 0 26 1 0 0 0 1 0 0 17 0 0 0 1 48

2031 0 0 0 0 0 0 0 0 0 26 1 0 0 0 1 0 0 17 0 0 0 1 47

2032 0 0 0 0 0 0 0 0 0 26 1 0 0 0 1 0 0 17 0 0 0 1 47

2033 0 0 0 0 0 0 0 0 0 26 1 0 0 0 1 0 0 17 0 0 0 1 47

2034 0 0 0 0 0 0 0 0 0 26 1 0 0 0 1 0 0 17 0 0 0 1 47

2035 0 0 0 0 0 0 0 0 0 26 1 0 0 0 1 0 0 17 0 0 0 1 47

2036 0 0 0 0 0 0 0 0 0 26 1 0 0 0 1 0 0 17 0 0 0 1 47

2037 0 0 0 0 0 0 0 0 0 26 1 0 0 0 1 0 0 17 0 0 0 1 47

TOTAL 0 4 0 6 1 1 1 0 0 585 20 0 0 6 40 0 0 384 5 0 0 29 1,082

Production Total (Costruction + 

Drilling + Completion 

+ Production)

toluene [tpy]

Pollutant Year

Construction Drilling Completion

0

481

962

1,443

1,924

2,405

2,886

3,367

3,848

4,329

4,810

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well Toluene Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-196

Table 265. New Project Wells Xylenes Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 28. New Project Wells Xylenes Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 2

2010 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 1 0 0 0 0 4

2011 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 1 0 0 0 0 5

2012 0 0 0 0 0 0 0 0 0 4 0 0 0 0 1 0 0 1 0 0 0 0 7

2013 0 0 0 0 0 0 0 0 0 5 0 0 0 0 1 0 0 2 0 0 0 1 9

2014 0 0 0 0 0 0 0 0 0 6 0 0 0 0 1 0 0 2 0 0 0 1 10

2015 0 0 0 0 0 0 0 0 0 7 0 0 0 0 1 0 0 3 0 0 0 1 12

2016 0 0 0 0 0 0 0 0 0 8 0 0 0 0 1 0 0 3 0 0 0 1 13

2017 0 0 0 0 0 0 0 0 0 9 0 0 0 0 1 0 0 3 0 0 0 1 15

2018 0 0 0 0 0 0 0 0 0 10 0 0 0 0 1 0 0 4 0 0 0 1 17

2019 0 0 0 0 0 0 0 0 0 11 0 0 0 0 1 0 0 4 0 0 0 1 18

2020 0 0 0 0 0 0 0 0 0 12 0 0 0 0 1 0 0 4 0 0 0 1 20

2021 0 0 0 0 0 0 0 0 0 13 0 0 0 0 1 0 0 5 0 0 0 2 21

2022 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 23

2023 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 23

2024 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 23

2025 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 23

2026 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 22

2027 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 22

2028 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 22

2029 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 22

2030 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 22

2031 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 22

2032 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 22

2033 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 22

2034 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 22

2035 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 22

2036 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 22

2037 0 0 0 0 0 0 0 0 0 14 0 0 0 0 1 0 0 5 0 0 0 2 22

TOTAL 0 3 0 5 1 1 0 0 0 318 0 0 0 3 22 0 0 120 0 0 0 39 512

Production Total (Costruction + 

Drilling + Completion 

+ Production)

xylenes [tpy]

Pollutant Year

Construction Drilling Completion

0

182

364

546

728

910

1,092

1,274

1,456

1,638

1,820

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well Xylenes Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-197

Table 266. New Project Wells CO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 29. New Project Wells CO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 7,485 212 38,728 3,129 8,534 1,946 2,631 0 24 52,258 0 0 352 0 51,634 98 70 0 0 0 0 167,101

2010 0 10,042 284 51,960 4,196 11,450 2,609 3,530 0 55 122,372 0 0 823 0 138,992 229 163 0 0 0 0 346,707

2011 0 9,980 282 51,637 4,166 11,379 2,590 3,508 0 87 192,049 0 0 1,286 0 213,265 360 256 0 0 0 0 490,846

2012 0 9,793 276 50,669 4,082 11,166 2,538 3,442 0 118 260,421 0 0 1,735 0 275,918 488 347 273,000 43,635 0 1 937,628

2013 0 9,980 280 51,637 4,153 11,379 2,582 3,508 0 150 330,098 0 0 2,184 0 337,636 618 440 273,000 43,635 0 1 1,071,283

2014 0 9,886 277 51,153 4,108 11,272 2,554 3,475 0 181 399,123 0 0 2,622 0 392,326 747 532 273,000 43,635 0 1 1,194,894

2015 0 10,198 285 52,767 4,230 11,628 2,629 3,585 0 213 470,325 0 0 3,066 0 446,131 880 627 273,000 43,635 0 1 1,323,200

2016 0 7,968 222 41,229 3,299 9,085 2,050 2,801 0 238 525,958 0 0 3,401 0 486,653 985 701 273,000 43,635 0 1 1,401,228

2017 0 10,463 291 54,139 4,324 11,930 2,687 3,678 0 271 599,011 0 0 3,842 0 537,422 1,121 799 273,000 43,635 0 2 1,546,615

2018 0 11,508 319 59,544 4,747 13,121 2,949 4,045 0 308 679,358 0 0 4,323 0 614,703 1,272 906 273,000 43,635 0 2 1,713,741

2019 0 9,263 257 47,926 3,815 10,561 2,370 3,256 0 337 744,028 0 0 4,702 0 661,763 1,393 992 273,000 43,635 0 2 1,807,298

2020 0 9,271 256 47,966 3,812 10,570 2,368 3,259 0 366 808,752 0 0 5,075 0 705,231 1,514 1,078 273,000 43,635 0 2 1,916,156

2021 0 10,463 289 54,139 4,297 11,930 2,669 3,678 0 399 881,804 0 0 5,499 0 750,745 1,651 1,176 273,000 43,635 0 2 2,045,376

2022 0 9,925 272 51,355 4,061 11,317 2,522 3,489 0 431 951,101 0 0 5,836 0 807,749 1,781 1,268 273,000 43,635 0 2 2,167,744

2023 0 3,329 92 17,226 1,365 3,796 848 1,170 0 441 974,345 0 0 6,040 0 809,259 1,824 1,299 273,000 43,635 0 3 2,137,672

2024 0 0 0 0 0 0 0 0 0 441 974,345 0 0 6,009 0 772,764 1,824 1,299 273,000 43,635 0 3 2,073,320

2025 0 0 0 0 0 0 0 0 0 441 974,345 0 0 5,952 0 748,933 1,824 1,299 273,000 43,635 0 3 2,049,432

2026 0 0 0 0 0 0 0 0 0 441 974,345 0 0 5,927 0 731,985 1,824 1,299 273,000 43,635 0 3 2,032,459

2027 0 0 0 0 0 0 0 0 0 441 974,345 0 0 5,906 0 718,260 1,824 1,299 273,000 43,635 0 3 2,018,713

2028 0 0 0 0 0 0 0 0 0 441 974,345 0 0 5,887 0 706,540 1,824 1,299 273,000 43,635 0 3 2,006,974

2029 0 0 0 0 0 0 0 0 0 441 974,345 0 0 5,870 0 696,268 1,824 1,299 273,000 43,635 0 3 1,996,685

2030 0 0 0 0 0 0 0 0 0 441 974,345 0 0 5,855 0 687,074 1,824 1,299 273,000 43,635 0 3 1,987,476

2031 0 0 0 0 0 0 0 0 0 441 974,345 0 0 5,841 0 678,764 1,824 1,299 273,000 43,635 0 3 1,979,153

2032 0 0 0 0 0 0 0 0 0 441 974,345 0 0 5,828 0 671,126 1,824 1,299 273,000 43,635 0 3 1,971,501

2033 0 0 0 0 0 0 0 0 0 441 974,345 0 0 5,816 0 664,079 1,824 1,299 273,000 43,635 0 3 1,964,442

2034 0 0 0 0 0 0 0 0 0 441 974,345 0 0 5,806 0 657,518 1,824 1,299 273,000 43,635 0 3 1,957,870

2035 0 0 0 0 0 0 0 0 0 441 974,345 0 0 5,797 0 651,333 1,824 1,299 273,000 43,635 0 3 1,951,677

2036 0 0 0 0 0 0 0 0 0 441 974,345 0 0 5,789 0 645,485 1,824 1,299 273,000 43,635 0 3 1,945,821

2037 0 0 0 0 0 0 0 0 0 441 974,345 0 0 5,781 0 639,947 1,824 1,299 273,000 43,635 0 3 1,940,275

TOTAL 0 139,557 3,894 722,077 57,785 159,120 35,912 49,053 0 9,800 21,631,836 0 0 132,850 0 16,899,500 40,496 28,844 7,098,005 1,134,503 0 56 48,143,288

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2 [tpy]

Pollutant Year

Construction Drilling Completion

0

443,000

886,000

1,329,000

1,772,000

2,215,000

2,658,000

3,101,000

3,544,000

3,987,000

4,430,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well CO2 Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-198

Table 267. New Project Wells CO2e - from CH4 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 30. New Project Wells CO2e - from CH4 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 5 0 7 3 1 2 16 0 5,055 21 0 0 1 186 301 0 16,585 0 0 0 0 22,182

2010 0 6 0 9 4 2 2 22 0 11,837 49 0 0 1 572 801 0 38,836 0 0 0 1 52,142

2011 0 6 0 9 4 2 3 22 0 18,577 77 0 0 2 860 1,231 0 60,948 0 0 0 2 81,743

2012 0 6 0 9 4 2 3 21 0 25,190 105 0 0 3 1,067 1,598 0 82,647 866 95 0 2 111,617

2013 0 6 0 9 4 2 3 22 0 31,930 133 0 0 3 1,261 1,960 0 104,759 866 95 0 3 141,056

2014 0 6 0 9 4 2 3 22 0 38,606 161 0 0 4 1,404 2,285 0 126,665 866 95 0 3 170,135

2015 0 6 0 9 5 2 3 22 0 45,494 189 0 0 5 1,533 2,605 0 149,261 866 95 0 4 200,099

2016 0 5 0 7 4 1 2 17 0 50,875 212 0 0 5 1,621 2,847 0 166,917 866 95 0 5 223,480

2017 0 6 0 9 5 2 3 23 0 57,941 241 0 0 6 1,720 3,152 0 190,101 866 95 0 5 254,176

2018 0 7 0 10 5 2 3 25 0 65,713 273 0 0 6 1,990 3,603 0 215,600 866 95 0 6 288,205

2019 0 6 0 8 4 2 3 20 0 71,968 299 0 0 7 2,093 3,884 0 236,123 866 95 0 6 315,385

2020 0 6 0 8 4 2 3 20 0 78,229 326 0 0 7 2,168 4,146 0 256,664 866 95 0 7 342,552

2021 0 6 0 9 5 2 3 23 0 85,295 355 0 0 8 2,227 4,423 0 279,848 866 95 0 8 373,173

2022 0 6 0 9 4 2 3 22 0 91,998 383 0 0 8 2,387 4,760 0 301,840 866 95 0 8 402,391

2023 0 2 0 3 1 1 1 7 0 94,247 392 0 0 9 2,307 4,779 0 309,216 866 95 0 8 411,935

2024 0 0 0 0 0 0 0 0 0 94,247 392 0 0 9 2,032 4,582 0 309,216 866 95 0 8 411,448

2025 0 0 0 0 0 0 0 0 0 94,247 392 0 0 8 1,852 4,454 0 309,216 866 95 0 8 411,140

2026 0 0 0 0 0 0 0 0 0 94,247 392 0 0 9 1,724 4,363 0 309,216 866 95 0 8 410,921

2027 0 0 0 0 0 0 0 0 0 94,247 392 0 0 9 1,621 4,290 0 309,216 866 95 0 8 410,744

2028 0 0 0 0 0 0 0 0 0 94,247 392 0 0 9 1,532 4,227 0 309,216 866 95 0 8 410,593

2029 0 0 0 0 0 0 0 0 0 94,247 392 0 0 8 1,455 4,172 0 309,216 866 95 0 8 410,460

2030 0 0 0 0 0 0 0 0 0 94,247 392 0 0 8 1,385 4,122 0 309,216 866 95 0 8 410,341

2031 0 0 0 0 0 0 0 0 0 94,247 392 0 0 8 1,323 4,078 0 309,216 866 95 0 8 410,234

2032 0 0 0 0 0 0 0 0 0 94,247 392 0 0 8 1,265 4,036 0 309,216 866 95 0 8 410,135

2033 0 0 0 0 0 0 0 0 0 94,247 392 0 0 8 1,212 3,999 0 309,216 866 95 0 8 410,044

2034 0 0 0 0 0 0 0 0 0 94,247 392 0 0 8 1,162 3,963 0 309,216 866 95 0 8 409,959

2035 0 0 0 0 0 0 0 0 0 94,247 392 0 0 8 1,116 3,930 0 309,216 866 95 0 8 409,879

2036 0 0 0 0 0 0 0 0 0 94,247 392 0 0 8 1,071 3,899 0 309,216 866 95 0 8 409,803

2037 0 0 0 0 0 0 0 0 0 94,247 392 0 0 8 1,030 3,869 0 309,216 866 95 0 8 409,732

TOTAL 0 84 4 122 60 24 38 306 0 2,092,410 8,707 0 0 191 43,175 100,360 6 6,865,040 22,518 2,475 0 186 9,135,705

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2e-from 

CH4 [tpy]

Pollutant Year

Construction Drilling Completion

0

227,000

454,000

681,000

908,000

1,135,000

1,362,000

1,589,000

1,816,000

2,043,000

2,270,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well CO2e - from CH4 Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-199

Table 268. New Project Wells CO2e - from N2O Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 31. New Project Wells CO2e - from N2O Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 59 1 305 19 67 12 9 0 0 297 0 0 4 0 123 1 0 0 0 0 0 897

2010 0 79 2 409 23 90 15 12 0 0 695 0 0 10 0 316 2 0 0 0 0 0 1,653

2011 0 79 2 406 22 90 14 12 0 0 1,091 0 0 14 0 488 3 0 0 0 0 0 2,220

2012 0 77 1 399 20 88 13 11 0 0 1,480 0 0 17 0 641 4 0 1,911 359 0 0 5,022

2013 0 79 1 406 19 90 12 12 0 0 1,876 0 0 20 0 794 5 0 1,911 359 0 0 5,584

2014 0 78 1 403 17 89 11 12 0 0 2,268 0 0 22 0 936 6 0 1,911 359 0 0 6,113

2015 0 81 1 415 16 91 10 12 0 0 2,673 0 0 24 0 1,077 7 0 1,911 359 0 0 6,679

2016 0 63 1 324 12 71 8 9 0 0 2,989 0 0 25 0 1,186 8 0 1,911 359 0 0 6,967

2017 0 83 1 426 15 94 9 12 0 0 3,404 0 0 26 0 1,324 9 0 1,911 359 0 0 7,674

2018 0 91 1 469 15 103 10 13 0 0 3,861 0 0 28 0 1,510 10 0 1,911 359 0 0 8,381

2019 0 73 1 377 11 83 7 11 0 0 4,229 0 0 28 0 1,636 11 0 1,911 359 0 0 8,738

2020 0 73 1 377 11 83 7 11 0 0 4,596 0 0 29 0 1,756 12 0 1,911 359 0 0 9,227

2021 0 83 1 426 11 94 7 12 0 0 5,012 0 0 29 0 1,887 13 0 1,911 359 0 0 9,845

2022 0 78 1 404 9 89 6 12 0 0 5,405 0 0 26 0 2,032 14 0 1,911 359 0 0 10,347

2023 0 26 0 136 3 30 2 4 0 0 5,538 0 0 30 0 2,054 14 0 1,911 359 0 0 10,107

2024 0 0 0 0 0 0 0 0 0 0 5,538 0 0 28 0 1,997 14 0 1,911 359 0 0 9,848

2025 0 0 0 0 0 0 0 0 0 0 5,538 0 0 25 0 1,960 14 0 1,911 359 0 0 9,808

2026 0 0 0 0 0 0 0 0 0 0 5,538 0 0 24 0 1,934 14 0 1,911 359 0 0 9,780

2027 0 0 0 0 0 0 0 0 0 0 5,538 0 0 23 0 1,913 14 0 1,911 359 0 0 9,758

2028 0 0 0 0 0 0 0 0 0 0 5,538 0 0 22 0 1,894 14 0 1,911 359 0 0 9,738

2029 0 0 0 0 0 0 0 0 0 0 5,538 0 0 21 0 1,879 14 0 1,911 359 0 0 9,722

2030 0 0 0 0 0 0 0 0 0 0 5,538 0 0 20 0 1,864 14 0 1,911 359 0 0 9,707

2031 0 0 0 0 0 0 0 0 0 0 5,538 0 0 19 0 1,851 14 0 1,911 359 0 0 9,693

2032 0 0 0 0 0 0 0 0 0 0 5,538 0 0 19 0 1,840 14 0 1,911 359 0 0 9,681

2033 0 0 0 0 0 0 0 0 0 0 5,538 0 0 18 0 1,829 14 0 1,911 359 0 0 9,669

2034 0 0 0 0 0 0 0 0 0 0 5,538 0 0 18 0 1,818 14 0 1,911 359 0 0 9,659

2035 0 0 0 0 0 0 0 0 0 0 5,538 0 0 18 0 1,809 14 0 1,911 359 0 0 9,649

2036 0 0 0 0 0 0 0 0 0 0 5,538 0 0 18 0 1,800 14 0 1,911 359 0 0 9,640

2037 0 0 0 0 0 0 0 0 0 0 5,538 0 0 17 0 1,791 14 0 1,911 359 0 0 9,631

TOTAL 0 1,103 17 5,682 223 1,252 142 163 0 0 122,941 0 0 621 0 43,940 319 0 49,687 9,347 0 0 235,435

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2e-from 

N2O [tpy]

Pollutant Year

Construction Drilling Completion

0

2,600

5,200

7,800

10,400

13,000

15,600

18,200

20,800

23,400

26,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well CO2e - from N2O Emissions 

By Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
PROJECT EMISSIONS INVENTORY FOR FUTURE WELLS

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-200

Table 269. New Project Wells CO2e - total Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 32. New Project Wells CO2e - total Emissions (tons/year) Contribution by Source Category and by Project Year. Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers Well Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 7,549 213 39,039 3,151 8,603 1,960 2,656 0 5,079 52,576 0 0 357 186 52,057 99 16,654 0 0 0 1 190,179

2010 0 10,128 286 52,378 4,223 11,542 2,627 3,564 0 11,892 123,116 0 0 834 572 140,109 231 38,999 0 0 0 1 400,502

2011 0 10,065 284 52,052 4,191 11,470 2,607 3,541 0 18,664 193,218 0 0 1,302 860 214,985 362 61,204 0 0 0 2 574,809

2012 0 9,876 278 51,076 4,106 11,255 2,553 3,475 0 25,308 262,005 0 0 1,755 1,067 278,158 491 82,994 275,777 44,089 0 3 1,054,268

2013 0 10,065 282 52,052 4,176 11,470 2,597 3,541 0 32,079 332,107 0 0 2,207 1,261 340,391 623 105,200 275,777 44,089 0 4 1,217,923

2014 0 9,971 279 51,564 4,130 11,363 2,567 3,508 0 38,787 401,552 0 0 2,649 1,404 395,546 753 127,197 275,777 44,089 0 4 1,371,142

2015 0 10,285 287 53,191 4,251 11,721 2,642 3,619 0 45,707 473,187 0 0 3,095 1,533 449,813 888 149,889 275,777 44,089 0 5 1,529,978

2016 0 8,036 223 41,561 3,314 9,158 2,060 2,828 0 51,113 529,159 0 0 3,431 1,621 490,686 993 167,618 275,777 44,089 0 6 1,631,675

2017 0 10,552 293 54,574 4,343 12,026 2,699 3,713 0 58,213 602,656 0 0 3,874 1,720 541,899 1,130 190,900 275,777 44,089 0 7 1,808,465

2018 0 11,606 321 60,023 4,767 13,227 2,962 4,084 0 66,021 683,492 0 0 4,357 1,990 619,816 1,282 216,506 275,777 44,089 0 8 2,010,328

2019 0 9,342 258 48,311 3,830 10,646 2,380 3,287 0 72,306 748,556 0 0 4,737 2,093 667,283 1,404 237,115 275,777 44,089 0 8 2,131,421

2020 0 9,349 257 48,352 3,827 10,655 2,377 3,290 0 78,596 813,674 0 0 5,111 2,168 711,134 1,526 257,742 275,777 44,089 0 9 2,267,934

2021 0 10,552 290 54,574 4,313 12,026 2,679 3,713 0 85,695 887,171 0 0 5,536 2,227 757,055 1,664 281,024 275,777 44,089 0 10 2,428,395

2022 0 10,010 273 51,768 4,075 11,408 2,530 3,522 0 92,429 956,889 0 0 5,870 2,387 814,541 1,795 303,108 275,777 44,089 0 11 2,580,482

2023 0 3,358 92 17,364 1,370 3,826 851 1,181 0 94,688 980,275 0 0 6,078 2,307 816,091 1,839 310,516 275,777 44,089 0 11 2,559,715

2024 0 0 0 0 0 0 0 0 0 94,688 980,275 0 0 6,045 2,032 779,344 1,839 310,516 275,777 44,089 0 11 2,494,616

2025 0 0 0 0 0 0 0 0 0 94,688 980,275 0 0 5,986 1,852 755,347 1,839 310,516 275,777 44,089 0 11 2,470,380

2026 0 0 0 0 0 0 0 0 0 94,688 980,275 0 0 5,959 1,724 738,282 1,839 310,516 275,777 44,089 0 11 2,453,160

2027 0 0 0 0 0 0 0 0 0 94,688 980,275 0 0 5,938 1,621 724,462 1,839 310,516 275,777 44,089 0 11 2,439,215

2028 0 0 0 0 0 0 0 0 0 94,688 980,275 0 0 5,917 1,532 712,661 1,839 310,516 275,777 44,089 0 11 2,427,305

2029 0 0 0 0 0 0 0 0 0 94,688 980,275 0 0 5,899 1,455 702,318 1,839 310,516 275,777 44,089 0 11 2,416,867

2030 0 0 0 0 0 0 0 0 0 94,688 980,275 0 0 5,883 1,385 693,060 1,839 310,516 275,777 44,089 0 11 2,407,523

2031 0 0 0 0 0 0 0 0 0 94,688 980,275 0 0 5,868 1,323 684,693 1,839 310,516 275,777 44,089 0 11 2,399,079

2032 0 0 0 0 0 0 0 0 0 94,688 980,275 0 0 5,855 1,265 677,002 1,839 310,516 275,777 44,089 0 11 2,391,317

2033 0 0 0 0 0 0 0 0 0 94,688 980,275 0 0 5,843 1,212 669,906 1,839 310,516 275,777 44,089 0 11 2,384,156

2034 0 0 0 0 0 0 0 0 0 94,688 980,275 0 0 5,832 1,162 663,299 1,839 310,516 275,777 44,089 0 11 2,377,488

2035 0 0 0 0 0 0 0 0 0 94,688 980,275 0 0 5,823 1,116 657,072 1,839 310,516 275,777 44,089 0 11 2,371,205

2036 0 0 0 0 0 0 0 0 0 94,688 980,275 0 0 5,814 1,071 651,183 1,839 310,516 275,777 44,089 0 11 2,365,264

2037 0 0 0 0 0 0 0 0 0 94,688 980,275 0 0 5,806 1,030 645,607 1,839 310,516 275,777 44,089 0 11 2,359,638

TOTAL 0 140,744 3,915 727,881 58,068 160,397 36,091 49,521 0 2,102,209 21,763,483 0 0 133,662 43,175 17,043,799 40,821 6,893,884 7,170,211 1,146,325 0 242 57,514,428

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2e-total 

[tpy]

Pollutant Year

Construction Drilling Completion

0

672,900

1,345,800

2,018,700

2,691,600

3,364,500

4,037,400

4,710,300

5,383,200

6,056,100

6,729,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

New Project Well CO2e - total Emissions By 

Source Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-201

Total Project Emissions Summary
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-202

Table 270. Total New and Existing Wells NOx Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 33. Total New and Existing Wells NOx Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 293 5 1,166 52 169 32 0 0 0 570 0 0 29 0 62 20 0 568 621 0 0 3,587

2009 0 95 2 364 23 73 14 2 0 0 607 0 0 30 0 86 21 0 568 621 0 0 2,505

2010 0 127 2 488 28 98 17 2 0 0 660 0 0 32 0 125 22 0 568 621 0 0 2,791

2011 0 126 2 485 25 97 15 2 0 0 712 0 0 34 0 161 23 0 568 621 0 0 2,872

2012 0 124 1 476 22 96 13 2 0 0 764 0 0 35 0 194 24 0 742 645 0 0 3,138

2013 0 126 1 485 20 97 12 2 0 0 816 0 0 36 0 227 24 0 742 645 0 0 3,236

2014 0 125 1 481 17 97 11 2 0 0 869 0 0 36 0 255 25 0 742 645 0 0 3,306

2015 0 129 1 496 16 100 10 2 0 0 923 0 0 37 0 283 26 0 742 645 0 0 3,409

2016 0 101 1 388 11 78 7 2 0 0 964 0 0 36 0 303 27 0 742 645 0 0 3,303

2017 0 133 1 509 13 102 8 2 0 0 1,019 0 0 36 0 330 28 0 742 645 0 0 3,567

2018 0 146 1 560 12 112 7 2 0 0 1,081 0 0 36 0 370 29 0 742 645 0 0 3,744

2019 0 117 1 451 9 90 5 2 0 0 1,129 0 0 36 0 395 30 0 742 645 0 0 3,652

2020 0 117 1 451 8 91 5 2 0 0 1,178 0 0 35 0 418 31 0 742 645 0 0 3,723

2021 0 133 1 509 8 102 5 2 0 0 1,234 0 0 35 0 442 32 0 742 645 0 0 3,890

2022 0 126 0 483 6 97 3 2 0 0 1,287 0 0 33 0 472 33 0 742 645 0 0 3,929

2023 0 42 0 162 2 33 1 1 0 0 1,302 0 0 34 0 473 33 0 742 645 0 0 3,470

2024 0 0 0 0 0 0 0 0 0 0 1,297 0 0 33 0 454 33 0 742 645 0 0 3,204

2025 0 0 0 0 0 0 0 0 0 0 1,292 0 0 32 0 441 33 0 742 645 0 0 3,185

2026 0 0 0 0 0 0 0 0 0 0 1,287 0 0 31 0 432 32 0 742 645 0 0 3,170

2027 0 0 0 0 0 0 0 0 0 0 1,282 0 0 31 0 424 32 0 742 645 0 0 3,156

2028 0 0 0 0 0 0 0 0 0 0 1,273 0 0 30 0 418 32 0 742 645 0 0 3,139

2029 0 0 0 0 0 0 0 0 0 0 1,268 0 0 29 0 412 32 0 742 645 0 0 3,128

2030 0 0 0 0 0 0 0 0 0 0 1,264 0 0 29 0 407 32 0 742 645 0 0 3,118

2031 0 0 0 0 0 0 0 0 0 0 1,259 0 0 28 0 402 31 0 742 645 0 0 3,108

2032 0 0 0 0 0 0 0 0 0 0 1,255 0 0 28 0 397 31 0 742 645 0 0 3,099

2033 0 0 0 0 0 0 0 0 0 0 1,250 0 0 28 0 393 31 0 742 645 0 0 3,090

2034 0 0 0 0 0 0 0 0 0 0 1,246 0 0 27 0 390 31 0 742 645 0 0 3,081

2035 0 0 0 0 0 0 0 0 0 0 1,241 0 0 27 0 386 31 0 742 645 0 0 3,073

2036 0 0 0 0 0 0 0 0 0 0 1,237 0 0 27 0 383 31 0 742 645 0 0 3,064

2037 0 0 0 0 0 0 0 0 0 0 1,232 0 0 26 0 380 31 0 742 645 0 0 3,056

TOTAL 0 2,061 19 7,954 270 1,531 167 28 0 0 32,797 0 0 957 0 10,314 870 0 21,564 19,260 0 0 97,793

Production Total (Costruction + 

Drilling + Completion 

+ Production)

NOx [tpy]

Pollutant Year

Construction Drilling Completion

0

410

820

1,230

1,640

2,050

2,460

2,870

3,280

3,690

4,100

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well NOx Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-203

Table 271. Total New and Existing Wells VOC Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 34. Total New and Existing Wells VOC Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 44 1 106 6 0 4 130 27,096 1,904 31 0 12,422 7 197 79 2 2,133 198 221 14,072 20 58,672

2009 0 14 0 21 3 4 2 2 26,548 2,031 33 0 12,295 7 213 111 2 2,274 198 221 13,311 20 57,310

2010 0 19 0 28 4 6 2 3 25,484 2,206 36 0 12,169 8 244 161 2 2,471 198 221 11,585 20 54,868

2011 0 19 0 27 3 5 2 3 24,751 2,381 39 0 12,042 8 273 207 2 2,667 198 221 10,624 21 53,495

2012 0 19 0 27 3 5 2 3 24,463 2,554 42 0 11,925 9 301 250 2 2,860 231 222 10,438 21 53,376

2013 0 19 0 27 3 5 2 3 24,206 2,730 45 0 11,808 9 328 292 2 3,057 231 222 10,307 21 53,319

2014 0 19 0 27 2 5 2 3 23,736 2,904 48 0 11,692 9 342 328 2 3,253 231 222 9,821 22 52,668

2015 0 19 0 28 2 6 1 3 23,244 3,085 51 0 11,575 9 354 364 2 3,455 231 222 9,316 22 51,990

2016 0 15 0 22 2 4 1 2 22,781 3,222 53 0 11,458 9 361 390 2 3,608 231 222 8,875 22 51,282

2017 0 20 0 29 2 6 1 3 22,347 3,408 56 0 11,341 10 370 424 2 3,816 231 222 8,490 23 50,801

2018 0 22 0 32 2 6 1 3 21,938 3,614 59 0 11,224 10 405 476 3 4,047 231 222 8,150 23 50,467

2019 0 18 0 25 1 5 1 2 21,545 3,776 62 0 11,108 10 416 508 3 4,228 231 222 7,840 23 50,024

2020 0 18 0 25 1 5 1 2 21,179 3,940 65 0 11,000 10 423 538 3 4,412 231 222 7,555 24 49,652

2021 0 20 0 29 1 6 1 3 20,830 4,127 68 0 10,893 10 428 569 3 4,622 231 222 7,298 24 49,384

2022 0 19 0 27 1 5 1 3 20,403 4,304 71 0 10,786 9 446 607 3 4,819 231 222 6,951 24 48,933

2023 0 6 0 9 0 2 0 1 20,072 4,352 72 0 10,679 10 431 608 3 4,874 231 222 6,729 24 48,326

2024 0 0 0 0 0 0 0 0 19,751 4,336 71 0 10,572 9 387 584 3 4,855 231 222 6,521 24 47,567

2025 0 0 0 0 0 0 0 0 19,449 4,319 71 0 10,465 9 358 568 3 4,837 231 222 6,340 24 46,896

2026 0 0 0 0 0 0 0 0 19,149 4,303 71 0 10,358 9 337 556 3 4,818 231 222 6,162 24 46,241

2027 0 0 0 0 0 0 0 0 18,858 4,286 71 0 10,251 8 319 546 3 4,800 231 222 5,996 24 45,614

2028 0 0 0 0 0 0 0 0 18,445 4,255 70 0 10,046 8 303 538 3 4,765 231 222 5,837 23 44,747

2029 0 0 0 0 0 0 0 0 18,076 4,240 70 0 9,949 8 288 530 3 4,748 231 222 5,580 23 43,968

2030 0 0 0 0 0 0 0 0 17,816 4,225 70 0 9,852 8 276 523 3 4,732 231 222 5,440 23 43,419

2031 0 0 0 0 0 0 0 0 17,564 4,210 69 0 9,754 8 265 517 3 4,715 231 222 5,310 23 42,890

2032 0 0 0 0 0 0 0 0 17,314 4,195 69 0 9,657 7 254 511 3 4,698 231 222 5,184 23 42,369

2033 0 0 0 0 0 0 0 0 17,066 4,180 69 0 9,560 7 245 506 3 4,681 231 222 5,060 23 41,853

2034 0 0 0 0 0 0 0 0 16,826 4,166 69 0 9,462 7 236 501 2 4,665 231 222 4,945 22 41,354

2035 0 0 0 0 0 0 0 0 16,591 4,151 68 0 9,365 7 227 497 2 4,648 231 222 4,836 22 40,868

2036 0 0 0 0 0 0 0 0 16,367 4,136 68 0 9,268 7 219 493 2 4,631 231 222 4,738 22 40,405

2037 0 0 0 0 0 0 0 0 16,146 4,121 68 0 9,170 7 212 488 2 4,615 231 222 4,643 22 39,948

TOTAL 0 308 3 488 37 77 23 166 620,038 109,661 1,804 0 322,148 252 9,459 13,272 75 122,803 6,804 6,656 227,956 677 1,442,705

Production Total (Costruction + 

Drilling + Completion 

+ Production)

VOC [tpy]

Pollutant Year

Construction Drilling Completion

0

6,160

12,320

18,480

24,640

30,800

36,960

43,120

49,280

55,440

61,600

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well VOC Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-204

Table 272. Total New and Existing Wells SO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 35. Total New and Existing Wells SO2 Emissions (tons/year) Contribution by Source Category and by Project Year. Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 5 0 71 0 56 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 135

2009 0 3 0 19 0 4 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 29

2010 0 2 0 12 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 19

2011 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 5

2012 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2013 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2014 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2015 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2016 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2017 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2018 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2019 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2020 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2021 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2022 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 4

2023 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2024 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2025 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2026 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2027 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2028 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2029 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2030 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2031 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2032 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2033 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2034 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2035 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2036 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

2037 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 3

TOTAL 0 12 0 112 1 65 1 0 0 0 0 0 0 7 0 0 2 0 18 61 0 0 279

Production Total (Costruction + 

Drilling + Completion 

+ Production)

SO2 [tpy]

Pollutant Year

Construction Drilling Completion

0.0

14.0

28.0

42.0

56.0

70.0

84.0

98.0

112.0

126.0

140.0

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well SO2 Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-205

Table 273. Total New and Existing Wells PM10 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 36. Total New and Existing Wells PM10 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 194 18 32 56 298 12 188 0 0 0 43 0 0 379 0 0 1 0 32 49 0 0 1,302

2009 63 6 10 12 140 2 89 0 0 0 46 0 0 404 0 0 1 0 32 49 0 0 855

2010 84 8 14 16 188 3 119 0 0 0 50 0 0 439 0 0 1 0 32 49 0 0 1,004

2011 83 8 14 16 187 3 118 0 0 0 54 0 0 474 0 0 1 0 32 49 0 0 1,040

2012 82 7 14 16 183 3 116 0 0 0 58 0 0 508 0 0 1 0 48 51 0 0 1,088

2013 83 8 14 16 186 3 118 0 0 0 62 0 0 543 0 0 1 0 48 51 0 0 1,135

2014 83 8 14 16 184 3 117 0 0 0 66 0 0 578 0 0 2 0 48 51 0 0 1,169

2015 85 8 14 17 190 3 120 0 0 0 70 0 0 614 0 0 2 0 48 51 0 0 1,223

2016 67 6 11 13 148 3 94 0 0 0 73 0 0 641 0 0 2 0 48 51 0 0 1,157

2017 87 8 15 17 195 3 123 0 0 0 77 0 0 678 0 0 2 0 48 51 0 0 1,305

2018 96 9 16 19 214 4 136 0 0 0 82 0 0 719 0 0 2 0 48 51 0 0 1,395

2019 77 7 13 15 172 3 109 0 0 0 86 0 0 751 0 0 2 0 48 51 0 0 1,335

2020 77 7 13 15 172 3 109 0 0 0 90 0 0 783 0 0 2 0 48 51 0 0 1,371

2021 87 8 14 17 195 3 123 0 0 0 94 0 0 820 0 0 2 0 48 51 0 0 1,463

2022 83 8 14 16 184 3 117 0 0 0 98 0 0 855 0 0 2 0 48 51 0 0 1,479

2023 28 3 5 5 62 1 39 0 0 0 99 0 0 865 0 0 2 0 48 51 0 0 1,208

2024 0 0 0 0 0 0 0 0 0 0 99 0 0 862 0 0 2 0 48 51 0 0 1,061

2025 0 0 0 0 0 0 0 0 0 0 98 0 0 858 0 0 2 0 48 51 0 0 1,058

2026 0 0 0 0 0 0 0 0 0 0 98 0 0 855 0 0 2 0 48 51 0 0 1,054

2027 0 0 0 0 0 0 0 0 0 0 97 0 0 852 0 0 2 0 48 51 0 0 1,050

2028 0 0 0 0 0 0 0 0 0 0 97 0 0 845 0 0 2 0 48 51 0 0 1,043

2029 0 0 0 0 0 0 0 0 0 0 96 0 0 842 0 0 2 0 48 51 0 0 1,040

2030 0 0 0 0 0 0 0 0 0 0 96 0 0 839 0 0 2 0 48 51 0 0 1,037

2031 0 0 0 0 0 0 0 0 0 0 96 0 0 836 0 0 2 0 48 51 0 0 1,033

2032 0 0 0 0 0 0 0 0 0 0 95 0 0 833 0 0 2 0 48 51 0 0 1,030

2033 0 0 0 0 0 0 0 0 0 0 95 0 0 830 0 0 2 0 48 51 0 0 1,027

2034 0 0 0 0 0 0 0 0 0 0 95 0 0 827 0 0 2 0 48 51 0 0 1,023

2035 0 0 0 0 0 0 0 0 0 0 94 0 0 824 0 0 2 0 48 51 0 0 1,020

2036 0 0 0 0 0 0 0 0 0 0 94 0 0 822 0 0 2 0 48 51 0 0 1,017

2037 0 0 0 0 0 0 0 0 0 0 94 0 0 819 0 0 2 0 48 51 0 0 1,013

TOTAL 1,360 124 226 284 2,900 58 1,837 0 0 0 2,493 0 0 21,797 0 0 49 0 1,379 1,528 0 0 34,034

Production Total (Costruction + 

Drilling + Completion 

+ Production)

PM10 [tpy]

Pollutant Year

Construction Drilling Completion

0

155

310

465

620

775

930

1,085

1,240

1,395

1,550

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well PM10 Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-206

Table 274. Total New and Existing Wells PM2.5 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 37. Total New and Existing Wells PM2.5 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 50 17 3 54 32 12 20 0 0 0 43 0 0 39 0 0 1 0 32 49 0 0 353

2009 16 6 1 12 15 2 10 0 0 0 46 0 0 42 0 0 1 0 32 49 0 0 231

2010 22 7 1 16 20 3 13 0 0 0 50 0 0 45 0 0 1 0 32 49 0 0 260

2011 21 7 1 16 20 3 13 0 0 0 54 0 0 49 0 0 1 0 32 49 0 0 266

2012 21 7 1 16 19 3 12 0 0 0 58 0 0 52 0 0 1 0 48 51 0 0 291

2013 21 7 1 16 20 3 12 0 0 0 62 0 0 56 0 0 1 0 48 51 0 0 300

2014 21 7 1 16 19 3 12 0 0 0 66 0 0 59 0 0 1 0 48 51 0 0 306

2015 22 8 1 16 20 3 12 0 0 0 70 0 0 63 0 0 2 0 48 51 0 0 316

2016 17 6 1 13 15 3 10 0 0 0 73 0 0 65 0 0 2 0 48 51 0 0 304

2017 23 8 1 17 20 3 13 0 0 0 77 0 0 69 0 0 2 0 48 51 0 0 331

2018 25 9 2 18 22 4 14 0 0 0 82 0 0 73 0 0 2 0 48 51 0 0 348

2019 20 7 1 15 17 3 11 0 0 0 86 0 0 76 0 0 2 0 48 51 0 0 337

2020 20 7 1 15 17 3 11 0 0 0 90 0 0 79 0 0 2 0 48 51 0 0 344

2021 23 8 1 17 20 3 12 0 0 0 94 0 0 83 0 0 2 0 48 51 0 0 362

2022 21 7 1 16 19 3 12 0 0 0 98 0 0 86 0 0 2 0 48 51 0 0 364

2023 7 2 0 5 6 1 4 0 0 0 99 0 0 87 0 0 2 0 48 51 0 0 314

2024 0 0 0 0 0 0 0 0 0 0 99 0 0 87 0 0 2 0 48 51 0 0 287

2025 0 0 0 0 0 0 0 0 0 0 98 0 0 87 0 0 2 0 48 51 0 0 286

2026 0 0 0 0 0 0 0 0 0 0 98 0 0 86 0 0 2 0 48 51 0 0 285

2027 0 0 0 0 0 0 0 0 0 0 97 0 0 86 0 0 2 0 48 51 0 0 284

2028 0 0 0 0 0 0 0 0 0 0 97 0 0 85 0 0 2 0 48 51 0 0 283

2029 0 0 0 0 0 0 0 0 0 0 96 0 0 85 0 0 2 0 48 51 0 0 282

2030 0 0 0 0 0 0 0 0 0 0 96 0 0 85 0 0 2 0 48 51 0 0 282

2031 0 0 0 0 0 0 0 0 0 0 96 0 0 84 0 0 2 0 48 51 0 0 281

2032 0 0 0 0 0 0 0 0 0 0 95 0 0 84 0 0 2 0 48 51 0 0 280

2033 0 0 0 0 0 0 0 0 0 0 95 0 0 84 0 0 2 0 48 51 0 0 280

2034 0 0 0 0 0 0 0 0 0 0 95 0 0 83 0 0 2 0 48 51 0 0 279

2035 0 0 0 0 0 0 0 0 0 0 94 0 0 83 0 0 2 0 48 51 0 0 278

2036 0 0 0 0 0 0 0 0 0 0 94 0 0 83 0 0 2 0 48 51 0 0 278

2037 0 0 0 0 0 0 0 0 0 0 94 0 0 82 0 0 2 0 48 51 0 0 277

TOTAL 350 121 23 275 301 56 191 0 0 0 2,493 0 0 2,205 0 0 47 0 1,379 1,528 0 0 8,970

Production Total (Costruction + 

Drilling + Completion 

+ Production)

PM2.5 [tpy]

Pollutant Year

Construction Drilling Completion

0

39

78

117

156

195

234

273

312

351

390

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well PM2.5 Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-207

Table 275. Total New and Existing Wells CO Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 38. Total New and Existing Wells CO Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 362 6 504 56 132 36 0 0 0 478 0 0 79 0 335 8 0 741 449 0 0 3,185

2009 0 117 2 213 25 42 16 8 0 0 510 0 0 83 0 469 9 0 741 449 0 0 2,684

2010 0 157 2 286 32 57 20 11 0 0 554 0 0 90 0 682 9 0 741 449 0 0 3,090

2011 0 156 2 284 30 56 19 11 0 0 598 0 0 95 0 876 10 0 741 449 0 0 3,329

2012 0 153 2 279 28 55 18 11 0 0 642 0 0 100 0 1,057 10 0 969 477 0 0 3,802

2013 0 156 2 284 27 56 17 11 0 0 686 0 0 105 0 1,236 11 0 969 477 0 0 4,038

2014 0 155 2 282 26 56 16 11 0 0 730 0 0 108 0 1,388 12 0 969 477 0 0 4,231

2015 0 159 2 291 25 57 16 11 0 0 775 0 0 112 0 1,538 12 0 969 477 0 0 4,445

2016 0 125 1 227 18 45 12 9 0 0 809 0 0 114 0 1,650 13 0 969 477 0 0 4,469

2017 0 164 2 298 23 59 15 12 0 0 856 0 0 117 0 1,794 13 0 969 477 0 0 4,799

2018 0 180 2 328 24 65 15 13 0 0 908 0 0 120 0 2,013 14 0 969 477 0 0 5,129

2019 0 145 1 264 19 52 12 10 0 0 949 0 0 123 0 2,148 15 0 969 477 0 0 5,184

2020 0 145 1 264 18 52 12 10 0 0 990 0 0 125 0 2,273 15 0 969 477 0 0 5,353

2021 0 164 2 298 20 59 13 12 0 0 1,037 0 0 128 0 2,407 16 0 969 477 0 0 5,600

2022 0 155 1 283 18 56 11 11 0 0 1,081 0 0 128 0 2,568 16 0 969 477 0 0 5,775

2023 0 52 0 95 6 19 4 4 0 0 1,093 0 0 131 0 2,572 17 0 969 477 0 0 5,440

2024 0 0 0 0 0 0 0 0 0 0 1,089 0 0 129 0 2,469 16 0 969 477 0 0 5,150

2025 0 0 0 0 0 0 0 0 0 0 1,085 0 0 126 0 2,400 16 0 969 477 0 0 5,074

2026 0 0 0 0 0 0 0 0 0 0 1,081 0 0 123 0 2,350 16 0 969 477 0 0 5,018

2027 0 0 0 0 0 0 0 0 0 0 1,077 0 0 122 0 2,309 16 0 969 477 0 0 4,971

2028 0 0 0 0 0 0 0 0 0 0 1,069 0 0 120 0 2,274 16 0 969 477 0 0 4,925

2029 0 0 0 0 0 0 0 0 0 0 1,065 0 0 118 0 2,240 16 0 969 477 0 0 4,886

2030 0 0 0 0 0 0 0 0 0 0 1,061 0 0 117 0 2,212 16 0 969 477 0 0 4,853

2031 0 0 0 0 0 0 0 0 0 0 1,058 0 0 116 0 2,186 16 0 969 477 0 0 4,822

2032 0 0 0 0 0 0 0 0 0 0 1,054 0 0 114 0 2,163 16 0 969 477 0 0 4,793

2033 0 0 0 0 0 0 0 0 0 0 1,050 0 0 113 0 2,141 16 0 969 477 0 0 4,766

2034 0 0 0 0 0 0 0 0 0 0 1,046 0 0 112 0 2,120 16 0 969 477 0 0 4,741

2035 0 0 0 0 0 0 0 0 0 0 1,043 0 0 110 0 2,101 16 0 969 477 0 0 4,716

2036 0 0 0 0 0 0 0 0 0 0 1,039 0 0 109 0 2,083 16 0 969 477 0 0 4,693

2037 0 0 0 0 0 0 0 0 0 0 1,035 0 0 108 0 2,066 15 0 969 477 0 0 4,671

TOTAL 0 2,544 32 4,481 395 918 252 154 0 0 27,549 0 0 3,393 0 56,120 423 0 28,163 14,206 0 0 138,631

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO [tpy]

Pollutant Year

Construction Drilling Completion

0

606

1,212

1,818

2,424

3,030

3,636

4,242

4,848

5,454

6,060

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well CO Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-208

Table 276. Total New and Existing Wells Formaldehyde Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 39. Total New and Existing Wells Formaldehyde Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 4 0 9 0 0 0 0 0 0 3 0 0 0 0 32 0 0 85 148 0 0 282

2009 0 1 0 2 0 0 0 1 0 0 3 0 0 0 0 44 0 0 85 148 0 0 285

2010 0 2 0 2 0 0 0 1 0 0 3 0 0 0 0 64 0 0 85 148 0 0 307

2011 0 2 0 2 0 0 0 1 0 0 3 0 0 0 0 83 0 0 85 148 0 0 326

2012 0 2 0 2 0 0 0 1 0 0 3 0 0 0 0 100 0 0 96 149 0 0 355

2013 0 2 0 2 0 0 0 1 0 0 4 0 0 0 0 117 0 0 96 149 0 0 373

2014 0 2 0 2 0 0 0 1 0 0 4 0 0 0 0 131 0 0 96 149 0 0 387

2015 0 2 0 2 0 0 0 1 0 0 4 0 0 0 0 145 0 0 96 149 0 0 402

2016 0 1 0 2 0 0 0 1 0 0 4 0 0 0 0 156 0 0 96 149 0 0 411

2017 0 2 0 2 0 0 0 1 0 0 4 0 0 0 0 170 0 0 96 149 0 0 427

2018 0 2 0 3 0 1 0 1 0 0 5 0 0 0 0 190 0 0 96 149 0 0 448

2019 0 1 0 2 0 0 0 1 0 0 5 0 0 0 0 203 0 0 96 149 0 0 460

2020 0 1 0 2 0 0 0 1 0 0 5 0 0 0 0 215 0 0 96 149 0 0 472

2021 0 2 0 2 0 0 0 1 0 0 5 0 0 0 0 228 0 0 96 149 0 0 485

2022 0 2 0 2 0 0 0 1 0 0 6 0 0 0 0 243 0 0 96 149 0 0 501

2023 0 1 0 1 0 0 0 0 0 0 6 0 0 0 0 243 0 0 96 149 0 0 497

2024 0 0 0 0 0 0 0 0 0 0 6 0 0 0 0 234 0 0 96 149 0 0 486

2025 0 0 0 0 0 0 0 0 0 0 6 0 0 0 0 227 0 0 96 149 0 0 479

2026 0 0 0 0 0 0 0 0 0 0 6 0 0 0 0 222 0 0 96 149 0 0 474

2027 0 0 0 0 0 0 0 0 0 0 6 0 0 0 0 218 0 0 96 149 0 0 470

2028 0 0 0 0 0 0 0 0 0 0 6 0 0 0 0 215 0 0 96 149 0 0 467

2029 0 0 0 0 0 0 0 0 0 0 6 0 0 0 0 212 0 0 96 149 0 0 464

2030 0 0 0 0 0 0 0 0 0 0 6 0 0 0 0 209 0 0 96 149 0 0 461

2031 0 0 0 0 0 0 0 0 0 0 6 0 0 0 0 207 0 0 96 149 0 0 459

2032 0 0 0 0 0 0 0 0 0 0 6 0 0 0 0 205 0 0 96 149 0 0 456

2033 0 0 0 0 0 0 0 0 0 0 6 0 0 0 0 203 0 0 96 149 0 0 454

2034 0 0 0 0 0 0 0 0 0 0 5 0 0 0 0 201 0 0 96 149 0 0 452

2035 0 0 0 0 0 0 0 0 0 0 5 0 0 0 0 199 0 0 96 149 0 0 451

2036 0 0 0 0 0 0 0 0 0 0 5 0 0 0 0 197 0 0 96 149 0 0 449

2037 0 0 0 0 0 0 0 0 0 0 5 0 0 0 0 195 0 0 96 149 0 0 447

TOTAL 0 26 0 42 2 7 1 15 0 0 144 0 0 9 0 5,309 6 0 2,847 4,480 0 0 12,889

Production Total (Costruction + 

Drilling + Completion 

+ Production)

formaldehyde 

[tpy]

Pollutant Year

Construction Drilling Completion

0

53

106

159

212

265

318

371

424

477

530

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well Formaldehyde Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-209

Table 277. Total New and Existing Wells n-hexane Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 40. Total New and Existing Wells n-hexane Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 3 708 80 0 0 589 0 7 0 0 42 0 1 547 0 1,978

2009 0 0 0 0 0 0 0 0 694 86 0 0 583 0 7 0 0 45 0 1 517 0 1,934

2010 0 0 0 0 0 0 0 0 666 93 0 0 577 0 8 0 0 49 0 1 450 0 1,845

2011 0 0 0 0 0 0 0 0 647 100 0 0 571 0 9 0 0 53 0 1 412 0 1,795

2012 0 0 0 0 0 0 0 0 639 108 0 0 566 0 10 0 0 57 0 1 405 0 1,786

2013 0 0 0 0 0 0 0 0 633 115 0 0 560 0 11 0 0 61 0 1 400 0 1,781

2014 0 0 0 0 0 0 0 0 620 123 0 0 555 0 12 0 0 65 0 1 381 0 1,756

2015 0 0 0 0 0 0 0 0 607 130 0 0 549 0 12 0 0 69 0 1 361 0 1,730

2016 0 0 0 0 0 0 0 0 595 136 0 0 544 0 12 0 0 72 0 1 344 0 1,704

2017 0 0 0 0 0 0 0 0 584 144 0 0 538 0 13 0 0 76 0 1 328 0 1,684

2018 0 0 0 0 0 0 0 0 573 152 0 0 532 0 14 0 0 80 0 1 315 0 1,669

2019 0 0 0 0 0 0 0 0 563 159 0 0 527 0 14 0 0 84 0 1 303 0 1,652

2020 0 0 0 0 0 0 0 0 553 166 0 0 522 0 14 0 0 88 0 1 292 0 1,637

2021 0 0 0 0 0 0 0 0 544 174 0 0 517 0 15 0 0 92 0 1 282 0 1,625

2022 0 0 0 0 0 0 0 0 533 182 0 0 512 0 15 0 0 96 0 1 268 0 1,607

2023 0 0 0 0 0 0 0 0 525 184 0 0 507 0 15 0 0 97 0 1 260 0 1,588

2024 0 0 0 0 0 0 0 0 516 183 0 0 502 0 13 0 0 96 0 1 252 0 1,563

2025 0 0 0 0 0 0 0 0 508 182 0 0 496 0 12 0 0 96 0 1 244 0 1,541

2026 0 0 0 0 0 0 0 0 500 181 0 0 491 0 11 0 0 96 0 1 237 0 1,520

2027 0 0 0 0 0 0 0 0 493 181 0 0 486 0 11 0 0 95 0 1 231 0 1,499

2028 0 0 0 0 0 0 0 0 482 179 0 0 477 0 10 0 0 95 0 1 225 0 1,470

2029 0 0 0 0 0 0 0 0 472 179 0 0 472 0 10 0 0 94 0 1 215 0 1,444

2030 0 0 0 0 0 0 0 0 466 178 0 0 467 0 9 0 0 94 0 1 209 0 1,426

2031 0 0 0 0 0 0 0 0 459 178 0 0 463 0 9 0 0 94 0 1 204 0 1,408

2032 0 0 0 0 0 0 0 0 452 177 0 0 458 0 9 0 0 93 0 1 199 0 1,391

2033 0 0 0 0 0 0 0 0 446 176 0 0 453 0 8 0 0 93 0 1 195 0 1,373

2034 0 0 0 0 0 0 0 0 440 176 0 0 449 0 8 0 0 93 0 1 190 0 1,357

2035 0 0 0 0 0 0 0 0 434 175 0 0 444 0 8 0 0 92 0 1 186 0 1,341

2036 0 0 0 0 0 0 0 0 428 174 0 0 440 0 7 0 0 92 0 1 182 0 1,325

2037 0 0 0 0 0 0 0 0 422 174 0 0 435 0 7 0 0 92 0 1 178 0 1,310

TOTAL 0 0 0 0 0 0 0 3 16,202 4,625 0 0 15,282 2 321 0 0 2,437 12 43 8,812 1 47,741

Production Total (Costruction + 

Drilling + Completion 

+ Production)

n-hexane [tpy]

Pollutant Year

Construction Drilling Completion

0

208

416

624

832

1,040

1,248

1,456

1,664

1,872

2,080

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well n-hexane Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-210

Table 278. Total New and Existing Wells Benzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 41. Total New and Existing Wells Benzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 1 0 0 0 1 2,610 13 1 0 50 0 1 0 0 9 2 1 112 3 2,804

2009 0 0 0 0 0 0 0 0 2,557 14 1 0 50 0 1 0 0 9 2 1 106 3 2,744

2010 0 0 0 0 0 0 0 0 2,454 15 1 0 49 0 1 0 0 10 2 1 92 3 2,630

2011 0 0 0 0 0 0 0 0 2,384 16 2 0 49 0 1 0 0 11 2 1 84 3 2,553

2012 0 0 0 0 0 0 0 0 2,356 18 2 0 48 0 1 0 0 12 2 1 82 3 2,526

2013 0 0 0 0 0 0 0 0 2,331 19 2 0 48 0 2 0 0 13 2 1 81 3 2,502

2014 0 0 0 0 0 0 0 0 2,286 20 2 0 47 0 2 0 0 13 2 1 77 3 2,455

2015 0 0 0 0 0 0 0 0 2,239 21 2 0 47 0 2 0 0 14 2 1 73 3 2,405

2016 0 0 0 0 0 0 0 0 2,194 22 2 0 46 0 2 0 0 15 2 1 70 3 2,358

2017 0 0 0 0 0 0 0 0 2,152 24 2 0 46 0 2 0 0 16 2 1 67 3 2,315

2018 0 0 0 0 0 0 0 0 2,113 25 2 0 45 0 2 0 0 17 2 1 64 3 2,275

2019 0 0 0 0 0 0 0 0 2,075 26 2 0 45 0 2 0 0 17 2 1 61 3 2,236

2020 0 0 0 0 0 0 0 0 2,040 27 3 0 44 0 2 0 0 18 2 1 59 3 2,200

2021 0 0 0 0 0 0 0 0 2,006 29 3 0 44 0 2 0 0 19 2 1 57 3 2,167

2022 0 0 0 0 0 0 0 0 1,965 30 3 0 43 0 2 0 0 20 2 1 54 3 2,125

2023 0 0 0 0 0 0 0 0 1,933 30 3 0 43 0 2 0 0 20 2 1 52 3 2,091

2024 0 0 0 0 0 0 0 0 1,902 30 3 0 43 0 2 0 0 20 2 1 51 3 2,057

2025 0 0 0 0 0 0 0 0 1,873 30 3 0 42 0 2 0 0 20 2 1 49 3 2,026

2026 0 0 0 0 0 0 0 0 1,844 30 3 0 42 0 2 0 0 20 2 1 48 3 1,994

2027 0 0 0 0 0 0 0 0 1,816 30 3 0 41 0 2 0 0 20 2 1 46 3 1,964

2028 0 0 0 0 0 0 0 0 1,776 29 3 0 40 0 1 0 0 20 2 1 45 3 1,922

2029 0 0 0 0 0 0 0 0 1,741 29 3 0 40 0 1 0 0 20 2 1 43 3 1,884

2030 0 0 0 0 0 0 0 0 1,716 29 3 0 40 0 1 0 0 20 2 1 42 3 1,857

2031 0 0 0 0 0 0 0 0 1,691 29 3 0 39 0 1 0 0 19 2 1 41 3 1,831

2032 0 0 0 0 0 0 0 0 1,667 29 3 0 39 0 1 0 0 19 2 1 40 3 1,805

2033 0 0 0 0 0 0 0 0 1,644 29 3 0 39 0 1 0 0 19 2 1 39 3 1,780

2034 0 0 0 0 0 0 0 0 1,620 29 3 0 38 0 1 0 0 19 2 1 38 3 1,755

2035 0 0 0 0 0 0 0 0 1,598 29 3 0 38 0 1 0 0 19 2 1 37 3 1,731

2036 0 0 0 0 0 0 0 0 1,576 29 3 0 37 0 1 0 0 19 2 1 36 3 1,708

2037 0 0 0 0 0 0 0 0 1,555 28 3 0 37 0 1 0 0 19 2 1 36 3 1,685

TOTAL 0 3 0 5 1 1 0 1 59,713 758 72 0 1,299 8 45 0 1 508 72 21 1,783 94 64,384

Production Total (Costruction + 

Drilling + Completion 

+ Production)

benzene [tpy]

Pollutant Year

Construction Drilling Completion

0

294

589

883

1,178

1,472

1,766

2,061

2,355

2,650

2,944

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well Benzene Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-211

Table 279. Total New and Existing Wells Ethylbenzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 42. Total New and Existing Wells Ethylbenzene Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 0 0 0 0 0 0 0 160 0 0 0 2 0 0 0 0 0 0 0 2 0 166

2009 0 0 0 0 0 0 0 0 157 0 0 0 2 0 0 0 0 0 0 0 2 0 162

2010 0 0 0 0 0 0 0 0 151 0 0 0 2 0 0 0 0 0 0 0 2 0 156

2011 0 0 0 0 0 0 0 0 146 0 0 0 2 0 0 0 0 1 0 0 2 0 152

2012 0 0 0 0 0 0 0 0 145 0 0 0 2 0 0 0 0 1 0 0 2 0 150

2013 0 0 0 0 0 0 0 0 143 0 0 0 2 0 0 0 0 1 0 0 2 0 148

2014 0 0 0 0 0 0 0 0 140 0 0 0 2 0 0 0 0 1 0 0 1 0 146

2015 0 0 0 0 0 0 0 0 137 0 0 0 2 0 0 0 0 1 0 0 1 0 143

2016 0 0 0 0 0 0 0 0 135 1 0 0 2 0 0 0 0 1 0 0 1 0 140

2017 0 0 0 0 0 0 0 0 132 1 0 0 2 0 0 0 0 1 0 0 1 0 137

2018 0 0 0 0 0 0 0 0 130 1 0 0 2 0 0 0 0 1 0 0 1 0 135

2019 0 0 0 0 0 0 0 0 127 1 0 0 2 0 0 0 0 1 0 0 1 0 133

2020 0 0 0 0 0 0 0 0 125 1 0 0 2 0 0 0 0 1 0 0 1 0 130

2021 0 0 0 0 0 0 0 0 123 1 0 0 2 0 0 0 0 1 0 0 1 0 128

2022 0 0 0 0 0 0 0 0 121 1 0 0 2 0 0 0 0 1 0 0 1 0 126

2023 0 0 0 0 0 0 0 0 119 1 0 0 2 0 0 0 0 1 0 0 1 0 124

2024 0 0 0 0 0 0 0 0 117 1 0 0 2 0 0 0 0 1 0 0 1 0 122

2025 0 0 0 0 0 0 0 0 115 1 0 0 2 0 0 0 0 1 0 0 1 0 120

2026 0 0 0 0 0 0 0 0 113 1 0 0 2 0 0 0 0 1 0 0 1 0 118

2027 0 0 0 0 0 0 0 0 112 1 0 0 2 0 0 0 0 1 0 0 1 0 116

2028 0 0 0 0 0 0 0 0 109 1 0 0 2 0 0 0 0 1 0 0 1 0 114

2029 0 0 0 0 0 0 0 0 107 1 0 0 2 0 0 0 0 1 0 0 1 0 112

2030 0 0 0 0 0 0 0 0 105 1 0 0 2 0 0 0 0 1 0 0 1 0 110

2031 0 0 0 0 0 0 0 0 104 1 0 0 2 0 0 0 0 1 0 0 1 0 108

2032 0 0 0 0 0 0 0 0 102 1 0 0 2 0 0 0 0 1 0 0 1 0 107

2033 0 0 0 0 0 0 0 0 101 1 0 0 2 0 0 0 0 1 0 0 1 0 105

2034 0 0 0 0 0 0 0 0 100 1 0 0 2 0 0 0 0 1 0 0 1 0 104

2035 0 0 0 0 0 0 0 0 98 1 0 0 2 0 0 0 0 1 0 0 1 0 103

2036 0 0 0 0 0 0 0 0 97 1 0 0 2 0 0 0 0 1 0 0 1 0 101

2037 0 0 0 0 0 0 0 0 96 1 0 0 2 0 0 0 0 1 0 0 1 0 100

TOTAL 0 1 0 1 0 0 0 0 3,667 17 0 0 54 3 1 0 0 23 2 2 34 10 3,816

Production Total (Costruction + 

Drilling + Completion 

+ Production)

ethylbenzene 

[tpy]

Pollutant Year

Construction Drilling Completion

0.0

17.4

34.8

52.2

69.6

87.0

104.4

121.8

139.2

156.6

174.0

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well Ethylbenzene Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-212

Table 280. Total New and Existing Wells Toluene Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 43. Total New and Existing Wells Toluene Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 1 0 2 0 0 0 1 4,310 18 1 0 69 1 1 0 0 12 1 0 159 4 4,579

2009 0 0 0 0 0 0 0 0 4,222 20 1 0 68 1 1 0 0 13 1 0 151 4 4,482

2010 0 0 0 0 0 0 0 0 4,053 21 1 0 68 1 2 0 0 14 1 0 130 4 4,296

2011 0 0 0 0 0 0 0 0 3,937 23 1 0 67 1 2 0 0 15 1 0 119 4 4,170

2012 0 0 0 0 0 0 0 0 3,891 25 1 0 66 1 2 0 0 16 1 0 117 4 4,125

2013 0 0 0 0 0 0 0 0 3,850 26 1 0 66 1 2 0 0 17 1 0 116 4 4,085

2014 0 0 0 0 0 0 0 0 3,775 28 1 0 65 1 2 0 0 19 1 0 110 4 4,007

2015 0 0 0 0 0 0 0 0 3,697 30 1 0 64 1 2 0 0 20 1 0 104 4 3,925

2016 0 0 0 0 0 0 0 0 3,623 31 1 0 64 1 2 0 0 21 1 0 99 4 3,848

2017 0 0 0 0 0 0 0 0 3,554 33 1 0 63 1 2 0 0 22 1 0 95 4 3,777

2018 0 0 0 0 0 0 0 0 3,489 35 1 0 62 1 3 0 0 23 1 0 91 4 3,711

2019 0 0 0 0 0 0 0 0 3,427 37 1 0 62 1 3 0 0 24 1 0 87 4 3,647

2020 0 0 0 0 0 0 0 0 3,368 38 1 0 61 1 3 0 0 25 1 0 84 4 3,588

2021 0 0 0 0 0 0 0 0 3,313 40 1 0 60 1 3 0 0 26 1 0 81 4 3,532

2022 0 0 0 0 0 0 0 0 3,245 42 1 0 60 1 3 0 0 27 1 0 77 4 3,462

2023 0 0 0 0 0 0 0 0 3,192 42 1 0 59 1 3 0 0 28 1 0 74 4 3,407

2024 0 0 0 0 0 0 0 0 3,141 42 1 0 59 1 2 0 0 28 1 0 72 4 3,352

2025 0 0 0 0 0 0 0 0 3,093 42 1 0 58 1 2 0 0 28 1 0 70 4 3,301

2026 0 0 0 0 0 0 0 0 3,046 42 1 0 58 1 2 0 0 27 1 0 68 4 3,250

2027 0 0 0 0 0 0 0 0 2,999 42 1 0 57 1 2 0 0 27 1 0 66 4 3,201

2028 0 0 0 0 0 0 0 0 2,934 41 1 0 56 1 2 0 0 27 1 0 64 4 3,131

2029 0 0 0 0 0 0 0 0 2,875 41 1 0 55 1 2 0 0 27 1 0 61 4 3,069

2030 0 0 0 0 0 0 0 0 2,833 41 1 0 55 1 2 0 0 27 1 0 59 4 3,025

2031 0 0 0 0 0 0 0 0 2,793 41 1 0 54 1 2 0 0 27 1 0 58 4 2,983

2032 0 0 0 0 0 0 0 0 2,754 41 1 0 54 1 2 0 0 27 1 0 56 4 2,940

2033 0 0 0 0 0 0 0 0 2,714 41 1 0 53 1 2 0 0 27 1 0 55 4 2,899

2034 0 0 0 0 0 0 0 0 2,676 40 1 0 53 1 1 0 0 27 1 0 54 4 2,858

2035 0 0 0 0 0 0 0 0 2,639 40 1 0 52 1 1 0 0 26 1 0 53 4 2,819

2036 0 0 0 0 0 0 0 0 2,603 40 1 0 51 1 1 0 0 26 1 0 51 4 2,781

2037 0 0 0 0 0 0 0 0 2,568 40 1 0 51 1 1 0 0 26 1 0 50 4 2,744

TOTAL 0 5 0 7 1 1 1 1 98,614 1,064 36 0 1,789 20 59 0 1 700 34 11 2,530 122 104,995

Production Total (Costruction + 

Drilling + Completion 

+ Production)

toluene [tpy]

Pollutant Year

Construction Drilling Completion

0

481

962

1,443

1,924

2,405

2,886

3,367

3,848

4,329

4,810

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well Toluene Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-213

Table 281. Total New and Existing Wells Xylenes Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 44. Total New and Existing Wells Xylenes Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 1 0 1 0 0 0 0 1,587 10 0 0 40 0 1 0 0 4 0 0 86 5 1,735

2009 0 0 0 0 0 0 0 0 1,555 11 0 0 39 0 1 0 0 4 0 0 81 5 1,697

2010 0 0 0 0 0 0 0 0 1,493 12 0 0 39 0 1 0 0 4 0 0 70 5 1,625

2011 0 0 0 0 0 0 0 0 1,450 13 0 0 39 0 1 0 0 5 0 0 64 5 1,578

2012 0 0 0 0 0 0 0 0 1,433 13 0 0 38 0 1 0 0 5 0 0 63 5 1,561

2013 0 0 0 0 0 0 0 0 1,418 14 0 0 38 0 1 0 0 5 0 0 62 5 1,546

2014 0 0 0 0 0 0 0 0 1,390 15 0 0 37 0 1 0 0 6 0 0 59 5 1,516

2015 0 0 0 0 0 0 0 0 1,361 16 0 0 37 0 1 0 0 6 0 0 56 5 1,485

2016 0 0 0 0 0 0 0 0 1,334 17 0 0 37 0 1 0 0 6 0 0 53 5 1,456

2017 0 0 0 0 0 0 0 0 1,309 18 0 0 36 0 1 0 0 7 0 0 51 6 1,430

2018 0 0 0 0 0 0 0 0 1,285 19 0 0 36 0 1 0 0 7 0 0 49 6 1,405

2019 0 0 0 0 0 0 0 0 1,262 20 0 0 36 0 1 0 0 7 0 0 47 6 1,381

2020 0 0 0 0 0 0 0 0 1,240 21 0 0 35 0 1 0 0 8 0 0 45 6 1,358

2021 0 0 0 0 0 0 0 0 1,220 22 0 0 35 0 1 0 0 8 0 0 44 6 1,337

2022 0 0 0 0 0 0 0 0 1,195 23 0 0 35 0 2 0 0 9 0 0 41 6 1,311

2023 0 0 0 0 0 0 0 0 1,176 23 0 0 34 0 2 0 0 9 0 0 40 6 1,290

2024 0 0 0 0 0 0 0 0 1,157 23 0 0 34 0 1 0 0 9 0 0 39 6 1,269

2025 0 0 0 0 0 0 0 0 1,139 23 0 0 34 0 1 0 0 9 0 0 38 6 1,250

2026 0 0 0 0 0 0 0 0 1,121 23 0 0 33 0 1 0 0 9 0 0 37 6 1,230

2027 0 0 0 0 0 0 0 0 1,104 23 0 0 33 0 1 0 0 9 0 0 36 6 1,212

2028 0 0 0 0 0 0 0 0 1,080 22 0 0 32 0 1 0 0 8 0 0 35 6 1,186

2029 0 0 0 0 0 0 0 0 1,059 22 0 0 32 0 1 0 0 8 0 0 33 6 1,162

2030 0 0 0 0 0 0 0 0 1,043 22 0 0 32 0 1 0 0 8 0 0 32 6 1,145

2031 0 0 0 0 0 0 0 0 1,029 22 0 0 31 0 1 0 0 8 0 0 31 6 1,129

2032 0 0 0 0 0 0 0 0 1,014 22 0 0 31 0 1 0 0 8 0 0 31 6 1,113

2033 0 0 0 0 0 0 0 0 999 22 0 0 31 0 1 0 0 8 0 0 30 5 1,098

2034 0 0 0 0 0 0 0 0 985 22 0 0 30 0 1 0 0 8 0 0 29 5 1,082

2035 0 0 0 0 0 0 0 0 972 22 0 0 30 0 1 0 0 8 0 0 28 5 1,067

2036 0 0 0 0 0 0 0 0 959 22 0 0 30 0 1 0 0 8 0 0 28 5 1,053

2037 0 0 0 0 0 0 0 0 946 22 0 0 29 0 1 0 0 8 0 0 27 5 1,039

TOTAL 0 4 0 6 1 1 1 0 36,314 578 0 0 1,032 11 33 0 1 218 9 9 1,367 165 39,748

Production Total (Costruction + 

Drilling + Completion 

+ Production)

xylenes [tpy]

Pollutant Year

Construction Drilling Completion

0

182

364

546

728

910

1,092

1,274

1,456

1,638

1,820

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well Xylenes Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-214

Table 282. Total New and Existing Wells CO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 45. Total New and Existing Wells CO2 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 23,168 655 44,407 6,637 35,396 4,128 54 5,232 310 683,444 0 5,160 4,616 0 110,507 1,275 911 582,056 809,692 540 7 2,318,196

2009 0 7,485 212 38,728 3,129 8,534 1,946 2,631 5,143 330 728,740 0 5,108 4,921 0 155,878 1,360 972 582,056 809,692 509 7 2,357,381

2010 0 10,042 284 51,960 4,196 11,450 2,609 3,530 4,996 359 791,890 0 5,055 5,345 0 228,942 1,478 1,056 582,056 809,692 438 7 2,515,386

2011 0 9,980 282 51,637 4,166 11,379 2,590 3,508 4,894 387 854,605 0 5,003 5,761 0 295,280 1,595 1,140 582,056 809,692 399 7 2,644,361

2012 0 9,793 276 50,669 4,082 11,166 2,538 3,442 4,842 415 916,548 0 4,954 6,166 0 356,450 1,711 1,222 855,056 853,327 391 8 3,083,058

2013 0 9,980 280 51,637 4,153 11,379 2,582 3,508 4,793 444 979,799 0 4,905 6,571 0 417,137 1,830 1,306 855,056 853,327 386 8 3,209,083

2014 0 9,886 277 51,153 4,108 11,272 2,554 3,475 4,722 472 1,042,396 0 4,857 6,966 0 467,844 1,947 1,390 855,056 853,327 367 8 3,322,079

2015 0 10,198 285 52,767 4,230 11,628 2,629 3,585 4,651 502 1,107,171 0 4,808 7,365 0 517,513 2,068 1,476 855,056 853,327 346 8 3,439,614

2016 0 7,968 222 41,229 3,299 9,085 2,050 2,801 4,584 524 1,156,376 0 4,760 7,657 0 554,427 2,161 1,542 855,056 853,327 328 8 3,507,406

2017 0 10,463 291 54,139 4,324 11,930 2,687 3,678 4,519 554 1,223,002 0 4,711 8,055 0 602,052 2,285 1,631 855,056 853,327 313 8 3,643,026

2018 0 11,508 319 59,544 4,747 13,121 2,949 4,045 4,458 588 1,296,922 0 4,663 8,492 0 676,563 2,424 1,729 855,056 853,327 299 8 3,800,764

2019 0 9,263 257 47,926 3,815 10,561 2,370 3,256 4,398 614 1,355,164 0 4,614 8,827 0 721,107 2,533 1,807 855,056 853,327 287 8 3,885,189

2020 0 9,271 256 47,966 3,812 10,570 2,368 3,259 4,343 641 1,413,996 0 4,570 9,160 0 762,258 2,643 1,885 855,056 853,327 275 8 3,985,666

2021 0 10,463 289 54,139 4,297 11,930 2,669 3,678 4,290 671 1,481,157 0 4,525 9,545 0 805,695 2,769 1,975 855,056 853,327 265 9 4,106,748

2022 0 9,925 272 51,355 4,061 11,317 2,522 3,489 4,232 700 1,544,562 0 4,481 9,841 0 859,866 2,888 2,060 855,056 853,327 251 9 4,220,213

2023 0 3,329 92 17,226 1,365 3,796 848 1,170 4,181 708 1,561,914 0 4,436 10,005 0 859,586 2,920 2,083 855,056 853,327 242 9 4,182,293

2024 0 0 0 0 0 0 0 0 4,130 705 1,556,023 0 4,392 9,934 0 821,421 2,909 2,075 855,056 853,327 234 9 4,110,215

2025 0 0 0 0 0 0 0 0 4,082 702 1,550,131 0 4,347 9,838 0 796,138 2,898 2,067 855,056 853,327 227 9 4,078,822

2026 0 0 0 0 0 0 0 0 4,033 700 1,544,239 0 4,303 9,772 0 777,764 2,887 2,059 855,056 853,327 220 8 4,054,370

2027 0 0 0 0 0 0 0 0 3,986 697 1,538,347 0 4,258 9,712 0 762,717 2,876 2,051 855,056 853,327 213 8 4,033,251

2028 0 0 0 0 0 0 0 0 3,904 692 1,527,100 0 4,173 9,617 0 749,782 2,855 2,036 855,056 853,327 207 8 4,008,758

2029 0 0 0 0 0 0 0 0 3,854 689 1,521,743 0 4,133 9,564 0 737,422 2,845 2,029 855,056 853,327 197 8 3,990,869

2030 0 0 0 0 0 0 0 0 3,811 687 1,516,387 0 4,093 9,512 0 727,118 2,835 2,022 855,056 853,327 192 8 3,975,049

2031 0 0 0 0 0 0 0 0 3,769 685 1,511,031 0 4,052 9,462 0 717,778 2,825 2,015 855,056 853,327 187 8 3,960,195

2032 0 0 0 0 0 0 0 0 3,727 682 1,505,675 0 4,012 9,413 0 709,140 2,815 2,008 855,056 853,327 182 8 3,946,045

2033 0 0 0 0 0 0 0 0 3,685 680 1,500,319 0 3,971 9,365 0 701,115 2,805 2,001 855,056 853,327 177 8 3,932,509

2034 0 0 0 0 0 0 0 0 3,644 677 1,494,963 0 3,931 9,318 0 693,648 2,795 1,993 855,056 853,327 173 8 3,919,533

2035 0 0 0 0 0 0 0 0 3,603 675 1,489,606 0 3,890 9,273 0 686,609 2,785 1,986 855,056 853,327 168 8 3,906,988

2036 0 0 0 0 0 0 0 0 3,563 672 1,484,250 0 3,850 9,229 0 679,998 2,775 1,979 855,056 853,327 165 8 3,894,873

2037 0 0 0 0 0 0 0 0 3,523 670 1,478,894 0 3,810 9,185 0 673,722 2,765 1,972 855,056 853,327 161 8 3,883,093

TOTAL 0 162,724 4,549 766,483 64,422 194,517 40,040 49,107 127,593 17,829 39,356,395 0 133,827 252,488 0 18,625,477 73,559 52,479 24,559,686 25,425,276 8,340 241 109,915,033

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2 [tpy]

Pollutant Year

Construction Drilling Completion

0

443,000

886,000

1,329,000

1,772,000

2,215,000

2,658,000

3,101,000

3,544,000

3,987,000

4,430,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well CO2 Emissions By Source Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-215

Table 283. Total New and Existing Wells CO2e - from CH4 Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 46. Total New and Existing Wells CO2e - from CH4 Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 14 1 34 6 0 4 12,830 454,768 66,108 275 0 1,228,142 8 1,321 665 1 216,897 7,391 18,182 57,368 24 2,064,038

2009 0 5 0 7 3 1 2 16 449,981 70,490 293 0 1,215,630 9 1,431 931 1 231,271 7,391 18,182 54,394 24 2,050,060

2010 0 6 0 9 4 2 2 22 444,904 76,598 319 0 1,203,117 9 1,643 1,354 1 251,313 7,391 18,182 47,684 24 2,052,584

2011 0 6 0 9 4 2 3 22 440,014 82,664 344 0 1,190,605 10 1,836 1,741 1 271,216 7,391 18,182 43,932 24 2,058,004

2012 0 6 0 9 4 2 3 21 435,718 88,656 369 0 1,179,055 11 2,024 2,099 1 290,874 8,257 18,277 43,186 25 2,068,596

2013 0 6 0 9 4 2 3 22 431,440 94,774 394 0 1,167,505 11 2,206 2,455 1 310,947 8,257 18,277 42,650 25 2,078,988

2014 0 6 0 9 4 2 3 22 427,042 100,829 420 0 1,155,955 12 2,301 2,757 1 330,813 8,257 18,277 40,741 26 2,087,476

2015 0 6 0 9 5 2 3 22 422,632 107,095 446 0 1,144,405 12 2,380 3,055 1 351,370 8,257 18,277 38,762 26 2,096,762

2016 0 5 0 7 4 1 2 17 418,238 111,854 465 0 1,132,855 13 2,425 3,277 1 366,986 8,257 18,277 37,027 26 2,099,737

2017 0 6 0 9 5 2 3 23 413,861 118,299 492 0 1,121,305 13 2,485 3,564 1 388,130 8,257 18,277 35,508 27 2,110,266

2018 0 7 0 10 5 2 3 25 409,497 125,449 522 0 1,109,756 14 2,721 4,000 1 411,589 8,257 18,277 34,164 27 2,124,324

2019 0 6 0 8 4 2 3 20 405,142 131,083 545 0 1,098,206 14 2,794 4,267 1 430,072 8,257 18,277 32,937 27 2,131,664

2020 0 6 0 8 4 2 3 20 401,147 136,773 569 0 1,087,618 15 2,842 4,516 1 448,743 8,257 18,277 31,808 28 2,140,635

2021 0 6 0 9 5 2 3 23 397,162 143,270 596 0 1,077,031 15 2,875 4,781 1 470,057 8,257 18,277 30,790 28 2,153,187

2022 0 6 0 9 4 2 3 22 393,132 149,403 622 0 1,066,443 15 3,001 5,102 1 490,179 8,257 18,277 29,421 29 2,163,927

2023 0 2 0 3 1 1 1 7 389,157 151,081 629 0 1,055,856 16 2,900 5,110 1 495,686 8,257 18,277 28,537 29 2,155,550

2024 0 0 0 0 0 0 0 0 385,187 150,511 626 0 1,045,268 15 2,604 4,905 1 493,817 8,257 18,277 27,709 28 2,137,206

2025 0 0 0 0 0 0 0 0 381,229 149,941 624 0 1,034,681 15 2,407 4,768 1 491,947 8,257 18,277 26,982 28 2,119,157

2026 0 0 0 0 0 0 0 0 377,271 149,372 622 0 1,024,094 15 2,262 4,669 1 490,077 8,257 18,277 26,267 28 2,101,210

2027 0 0 0 0 0 0 0 0 373,318 148,802 619 0 1,013,506 15 2,143 4,587 1 488,207 8,257 18,277 25,601 28 2,083,360

2028 0 0 0 0 0 0 0 0 365,852 147,714 615 0 993,294 15 2,040 4,517 1 484,637 8,257 18,277 24,937 27 2,050,182

2029 0 0 0 0 0 0 0 0 362,200 147,196 613 0 983,669 15 1,937 4,450 1 482,938 8,257 18,277 23,919 27 2,033,497

2030 0 0 0 0 0 0 0 0 358,609 146,677 610 0 974,044 15 1,854 4,394 1 481,238 8,257 18,277 23,357 27 2,017,359

2031 0 0 0 0 0 0 0 0 355,023 146,159 608 0 964,419 15 1,779 4,343 1 479,538 8,257 18,277 22,830 27 2,001,275

2032 0 0 0 0 0 0 0 0 351,438 145,641 606 0 954,794 14 1,710 4,296 1 477,838 8,257 18,277 22,318 27 1,985,217

2033 0 0 0 0 0 0 0 0 347,854 145,123 604 0 945,169 14 1,645 4,253 1 476,138 8,257 18,277 21,817 26 1,969,177

2034 0 0 0 0 0 0 0 0 344,274 144,605 602 0 935,544 14 1,584 4,212 1 474,439 8,257 18,277 21,349 26 1,953,183

2035 0 0 0 0 0 0 0 0 340,697 144,087 600 0 925,919 14 1,528 4,173 1 472,739 8,257 18,277 20,905 26 1,937,222

2036 0 0 0 0 0 0 0 0 337,127 143,569 597 0 916,294 14 1,474 4,137 1 471,039 8,257 18,277 20,503 26 1,921,315

2037 0 0 0 0 0 0 0 0 333,558 143,051 595 0 906,669 14 1,424 4,103 1 469,339 8,257 18,277 20,113 26 1,905,426

TOTAL 0 98 5 156 66 24 42 13,136 11,747,471 3,806,876 15,841 0 31,850,850 402 63,575 111,481 24 12,490,073 244,234 547,920 957,515 796 61,850,585

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2e-from 

CH4 [tpy]

Pollutant Year

Construction Drilling Completion

0

227,000

454,000

681,000

908,000

1,135,000

1,362,000

1,589,000

1,816,000

2,043,000

2,270,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well CO2e - from CH4 Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-216

Table 284. Total New and Existing Wells CO2e - from N2O Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 47. Total New and Existing Wells CO2e - from N2O Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 183 5 2,490 41 1,984 26 0 0 0 3,884 0 0 60 0 182 10 0 4,096 5,974 0 0 18,935

2009 0 59 1 305 19 67 12 9 0 0 4,142 0 0 64 0 295 11 0 4,096 5,974 0 0 15,053

2010 0 79 2 409 23 90 15 12 0 0 4,501 0 0 68 0 467 12 0 4,096 5,974 0 0 15,748

2011 0 79 2 406 22 90 14 12 0 0 4,857 0 0 72 0 628 13 0 4,096 5,974 0 0 16,263

2012 0 77 1 399 20 88 13 11 0 0 5,209 0 0 75 0 779 14 0 6,007 6,333 0 0 19,025

2013 0 79 1 406 19 90 12 12 0 0 5,569 0 0 77 0 930 14 0 6,007 6,333 0 0 19,548

2014 0 78 1 403 17 89 11 12 0 0 5,924 0 0 79 0 1,065 15 0 6,007 6,333 0 0 20,034

2015 0 81 1 415 16 91 10 12 0 0 6,292 0 0 80 0 1,201 16 0 6,007 6,333 0 0 20,557

2016 0 63 1 324 12 71 8 9 0 0 6,572 0 0 80 0 1,304 17 0 6,007 6,333 0 0 20,802

2017 0 83 1 426 15 94 9 12 0 0 6,951 0 0 81 0 1,438 18 0 6,007 6,333 0 0 21,467

2018 0 91 1 469 15 103 10 13 0 0 7,371 0 0 82 0 1,619 19 0 6,007 6,333 0 0 22,133

2019 0 73 1 377 11 83 7 11 0 0 7,702 0 0 81 0 1,741 20 0 6,007 6,333 0 0 22,448

2020 0 73 1 377 11 83 7 11 0 0 8,036 0 0 81 0 1,858 21 0 6,007 6,333 0 0 22,900

2021 0 83 1 426 11 94 7 12 0 0 8,418 0 0 81 0 1,986 22 0 6,007 6,333 0 0 23,481

2022 0 78 1 404 9 89 6 12 0 0 8,778 0 0 78 0 2,126 23 0 6,007 6,333 0 0 23,944

2023 0 26 0 136 3 30 2 4 0 0 8,877 0 0 81 0 2,145 23 0 6,007 6,333 0 0 23,668

2024 0 0 0 0 0 0 0 0 0 0 8,843 0 0 79 0 2,086 23 0 6,007 6,333 0 0 23,371

2025 0 0 0 0 0 0 0 0 0 0 8,810 0 0 75 0 2,047 23 0 6,007 6,333 0 0 23,295

2026 0 0 0 0 0 0 0 0 0 0 8,776 0 0 73 0 2,018 23 0 6,007 6,333 0 0 23,231

2027 0 0 0 0 0 0 0 0 0 0 8,743 0 0 72 0 1,995 23 0 6,007 6,333 0 0 23,172

2028 0 0 0 0 0 0 0 0 0 0 8,679 0 0 70 0 1,975 22 0 6,007 6,333 0 0 23,086

2029 0 0 0 0 0 0 0 0 0 0 8,649 0 0 68 0 1,956 22 0 6,007 6,333 0 0 23,035

2030 0 0 0 0 0 0 0 0 0 0 8,618 0 0 67 0 1,940 22 0 6,007 6,333 0 0 22,987

2031 0 0 0 0 0 0 0 0 0 0 8,588 0 0 66 0 1,925 22 0 6,007 6,333 0 0 22,941

2032 0 0 0 0 0 0 0 0 0 0 8,557 0 0 65 0 1,912 22 0 6,007 6,333 0 0 22,896

2033 0 0 0 0 0 0 0 0 0 0 8,527 0 0 64 0 1,899 22 0 6,007 6,333 0 0 22,852

2034 0 0 0 0 0 0 0 0 0 0 8,496 0 0 63 0 1,887 22 0 6,007 6,333 0 0 22,809

2035 0 0 0 0 0 0 0 0 0 0 8,466 0 0 63 0 1,876 22 0 6,007 6,333 0 0 22,767

2036 0 0 0 0 0 0 0 0 0 0 8,435 0 0 62 0 1,866 22 0 6,007 6,333 0 0 22,726

2037 0 0 0 0 0 0 0 0 0 0 8,405 0 0 61 0 1,856 22 0 6,007 6,333 0 0 22,684

TOTAL 0 1,286 21 8,172 264 3,236 168 163 0 0 223,676 0 0 2,168 0 47,003 580 0 172,558 188,565 0 0 647,859

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2e-from 

N2O [tpy]

Pollutant Year

Construction Drilling Completion

0

2,600

5,200

7,800

10,400

13,000

15,600

18,200

20,800

23,400

26,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well CO2e - from N2O Emissions By Source 

Category Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
TOTAL PROJECT EMISSIONS SUMMARY

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 L-217

Table 285. Total New and Existing Wells CO2e - total Emissions (tons/year) Contribution by Source Category and by Project Year.

Figure 48. Total New and Existing Wells CO2e - total Emissions (tons/year) Contribution by Source Category and by Project Year.

Construction 

Dust

Construction 

Equipment

Construction 

Traffic Drilling Drilling Traffic

Completion 

Equipment

Completion 

Traffic

Initial 

Completions Dehydrators

Fugitive 

Devices Heaters

Pneumatic 

Devices

Pneumatic 

Pumps

Production 

Traffic

Tank 

Loadout

Production 

Flaring Workovers

Well 

Venting Gas Plant

Compressor 

Station

Condensate 

Tanks

Evaporation 

Pond

2008 0 23,365 661 46,930 6,685 37,381 4,158 12,884 460,000 66,418 687,604 0 1,233,303 4,684 1,321 111,354 1,286 217,808 593,542 833,848 57,908 31 4,401,169

2009 0 7,549 213 39,039 3,151 8,603 1,960 2,656 455,124 70,820 733,175 0 1,220,738 4,993 1,431 157,104 1,371 232,243 593,542 833,848 54,903 31 4,422,494

2010 0 10,128 286 52,378 4,223 11,542 2,627 3,564 449,900 76,957 796,709 0 1,208,173 5,423 1,643 230,763 1,490 252,369 593,542 833,848 48,122 31 4,583,717

2011 0 10,065 284 52,052 4,191 11,470 2,607 3,541 444,908 83,052 859,806 0 1,195,608 5,843 1,836 297,649 1,609 272,355 593,542 833,848 44,331 32 4,718,628

2012 0 9,876 278 51,076 4,106 11,255 2,553 3,475 440,560 89,071 922,126 0 1,184,009 6,251 2,024 359,328 1,726 292,096 869,320 877,937 43,577 32 5,170,679

2013 0 10,065 282 52,052 4,176 11,470 2,597 3,541 436,233 95,218 985,762 0 1,172,411 6,659 2,206 420,522 1,845 312,254 869,320 877,937 43,037 33 5,307,620

2014 0 9,971 279 51,564 4,130 11,363 2,567 3,508 431,765 101,301 1,048,740 0 1,160,812 7,056 2,301 471,667 1,963 332,203 869,320 877,937 41,108 33 5,429,589

2015 0 10,285 287 53,191 4,251 11,721 2,642 3,619 427,283 107,596 1,113,909 0 1,149,214 7,458 2,380 521,769 2,086 352,846 869,320 877,937 39,108 34 5,556,934

2016 0 8,036 223 41,561 3,314 9,158 2,060 2,828 422,822 112,378 1,163,414 0 1,137,615 7,750 2,425 559,008 2,178 368,527 869,320 877,937 37,355 34 5,627,945

2017 0 10,552 293 54,574 4,343 12,026 2,699 3,713 418,380 118,853 1,230,445 0 1,126,017 8,149 2,485 607,054 2,304 389,760 869,320 877,937 35,821 35 5,774,759

2018 0 11,606 321 60,023 4,767 13,227 2,962 4,084 413,955 126,037 1,304,814 0 1,114,418 8,587 2,721 682,182 2,444 413,318 869,320 877,937 34,463 35 5,947,221

2019 0 9,342 258 48,311 3,830 10,646 2,380 3,287 409,540 131,697 1,363,411 0 1,102,820 8,922 2,794 727,115 2,554 431,879 869,320 877,937 33,224 36 6,039,302

2020 0 9,349 257 48,352 3,827 10,655 2,377 3,290 405,490 137,414 1,422,602 0 1,092,188 9,256 2,842 768,632 2,665 450,629 869,320 877,937 32,083 36 6,149,201

2021 0 10,552 290 54,574 4,313 12,026 2,679 3,713 401,452 143,941 1,490,171 0 1,081,556 9,641 2,875 812,462 2,791 472,032 869,320 877,937 31,055 37 6,283,417

2022 0 10,010 273 51,768 4,075 11,408 2,530 3,522 397,364 150,103 1,553,962 0 1,070,924 9,934 3,001 867,094 2,911 492,239 869,320 877,937 29,672 37 6,408,084

2023 0 3,358 92 17,364 1,370 3,826 851 1,181 393,338 151,789 1,571,420 0 1,060,292 10,102 2,900 866,841 2,944 497,769 869,320 877,937 28,779 37 6,361,511

2024 0 0 0 0 0 0 0 0 389,318 151,216 1,565,492 0 1,049,660 10,029 2,604 828,411 2,933 495,891 869,320 877,937 27,943 37 6,270,792

2025 0 0 0 0 0 0 0 0 385,311 150,644 1,559,565 0 1,039,028 9,928 2,407 802,953 2,922 494,014 869,320 877,937 27,209 37 6,221,273

2026 0 0 0 0 0 0 0 0 381,304 150,071 1,553,637 0 1,028,396 9,861 2,262 784,451 2,911 492,136 869,320 877,937 26,487 36 6,178,811

2027 0 0 0 0 0 0 0 0 377,304 149,499 1,547,710 0 1,017,765 9,799 2,143 769,300 2,900 490,258 869,320 877,937 25,814 36 6,139,783

2028 0 0 0 0 0 0 0 0 369,756 148,405 1,536,393 0 997,467 9,702 2,040 756,274 2,878 486,674 869,320 877,937 25,145 36 6,082,027

2029 0 0 0 0 0 0 0 0 366,054 147,885 1,531,004 0 987,802 9,647 1,937 743,827 2,868 484,967 869,320 877,937 24,117 35 6,047,401

2030 0 0 0 0 0 0 0 0 362,420 147,364 1,525,616 0 978,137 9,594 1,854 733,452 2,858 483,260 869,320 877,937 23,548 35 6,015,396

2031 0 0 0 0 0 0 0 0 358,792 146,844 1,520,227 0 968,471 9,543 1,779 724,046 2,848 481,553 869,320 877,937 23,017 35 5,984,411

2032 0 0 0 0 0 0 0 0 355,165 146,323 1,514,838 0 958,806 9,493 1,710 715,347 2,838 479,846 869,320 877,937 22,500 35 5,954,157

2033 0 0 0 0 0 0 0 0 351,539 145,803 1,509,449 0 949,140 9,444 1,645 707,266 2,828 478,139 869,320 877,937 21,994 34 5,924,538

2034 0 0 0 0 0 0 0 0 347,918 145,282 1,504,061 0 939,475 9,396 1,584 699,747 2,818 476,432 869,320 877,937 21,521 34 5,895,525

2035 0 0 0 0 0 0 0 0 344,300 144,762 1,498,672 0 929,810 9,350 1,528 692,658 2,808 474,725 869,320 877,937 21,073 34 5,866,977

2036 0 0 0 0 0 0 0 0 340,690 144,241 1,493,283 0 920,144 9,305 1,474 686,002 2,798 473,018 869,320 877,937 20,668 34 5,838,914

2037 0 0 0 0 0 0 0 0 337,081 143,721 1,487,894 0 910,479 9,260 1,424 679,681 2,788 471,311 869,320 877,937 20,274 34 5,811,203

TOTAL 0 164,108 4,575 774,811 64,753 197,778 40,249 62,406 11,875,065 3,824,705 39,595,911 0 31,984,677 255,058 63,575 18,783,960 74,163 12,542,552 24,976,478 26,161,761 965,855 1,037 172,413,477

Production Total (Costruction + 

Drilling + Completion 

+ Production)

CO2e-total 

[tpy]

Pollutant Year

Construction Drilling Completion

0

672,900

1,345,800

2,018,700

2,691,600

3,364,500

4,037,400

4,710,300

5,383,200

6,056,100

6,729,000

2008 2012 2016 2020 2024 2028 2032 2036

Emissions (TPY)

All Well CO2e - total Emissions By Source 

Category

Evaporation Pond

Condensate Tanks

Compressor Station

Gas Plant

Well Venting

Workovers

Production Flaring

Tank Loadout

Production Traffic

Pneumatic Pumps

Pneumatic Devices

Heaters

Fugitive Devices

Dehydrators

Initial Completions

Completion Traffic

Completion Equipment

Drilling Traffic

Drilling

Construction Traffic

Construction Equipment

Construction Dust
Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016

Appendix M

Supplemental Analysis of Continental Divide-Creston FEIS Ozone Modeling 

to Address the 2015 Revision to the National Ambient 

Air Quality Standard for Ozone
APPENDIX M – SUPPLEMENTAL ANALYSIS OF CD-C FEIS OZONE MODELING TO ADDRESS THE 

2015 REVISION TO THE NAAQS FOR OZONE

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 M-2

M1. INTRODUCTION

The far-field air quality impact assessment for the Continental Divide-Creston Final 

Environmental Impact Statement (CD-C FEIS) was performed with the photochemical grid 

model CAMx (Comprehensive Air quality Model with Extensions; ENVIRON, 2010; 

www.camx.com). The modeling and analyses were completed in early 2014. The modeling 

results were presented to the Inter-Agency Review Team in April, 2014 and were documented 

in the CD-C FEIS and Air Quality Technical Support Document (AQTSD), which was completed in 

June, 2014. 

At the time the CD-C FEIS modeling was performed and documented, the primary and 

secondary National Ambient Air Quality Standards (NAAQS) for 8-hour ozone were set at 75 

ppb. The primary ozone standard is designed to protect human health and the secondary 

standard is aimed at protecting visibility, animals, crops, vegetation, and buildings1. The 75 ppb 

primary and secondary ozone NAAQS were set in 2008. Under the Clean Air Act, the EPA is 

required to review the NAAQS periodically. On November 26, 2014, the EPA announced their 

intention to lower the eight-hour ozone primary and secondary NAAQS to values in the 65-70 

ppb range (EPA, 2014). EPA also sought comments on a primary NAAQS set at 60 ppb as well as 

on leaving the 2008 75 ppb NAAQS in place.

EPA’s analysis indicated that a secondary 8-hour standard of the same form as the primary 

standard and set in the range 65-70 ppb would provide the same level of protection as a 3-year 

average W126 index value set at or below a range of 13-17 ppm-hours2. The W126 index is a 

seasonal measure of ozone that is used to assess the impact of ozone on ecosystems and 

vegetation. EPA proposed to set the secondary standard in the same form as the primary 

standard, but took comments on a secondary standard in the form of a W126 index in the range 

13-17 ppm-hours, averaged over three years. 

On October 1, 2015, the EPA lowered the primary ozone NAAQS from 75 ppb value to a more 

stringent value of 70 ppb. As in 2008, the secondary NAAQS was set to be identical to the 

primary NAAQS. The EPA expects to issue detailed guidance on the designation process in early 

2016, but has indicated that attainment designations for the 2015 NAAQS will be based on 

2014-2016 data3. State recommendations for designations of attainment and nonattainment 

areas are due to EPA by October 1, 2016 and EPA will finalize designations by October 1, 2017.

The lower 2015 NAAQS enhances the importance of background ozone in contributing to high 

ozone in southwest Wyoming. In Section M2 of this Appendix, we consider the relative 

importance of contributions from the CD-C Project emissions, regional emissions sources and 

the transported ozone background to 8-hour ozone in the CD-C air quality impact assessment 

study area. 

Although EPA decided not to set a secondary ozone standard in the form of a 3-year average 

W126, we evaluate the CD-C future year ozone modeling results against a W126 index in the 

 

1 www3.epa.gov/ttn/naaqs/criteria.html

2

http://www.gpo.gov/fdsys/pkg/FR-2014-12-17/pdf/2014-28674.pdf

3

http://www.gpo.gov/fdsys/pkg/FR-2015-10-26/pdf/2015-26594.pdf
APPENDIX M – SUPPLEMENTAL ANALYSIS OF CD-C FEIS OZONE MODELING TO ADDRESS THE 

2015 REVISION TO THE NAAQS FOR OZONE

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 M-3

range 13-17 ppm-hours. The purpose of this analysis, which is presented in Section M3, is to 

evaluate the impact of ozone associated with emissions from the CD-C Project Alternatives on 

ecosystems and vegetation in the CD-C study area.

M2. BACKGROUND OZONE ANALYSIS

Ozone monitored in a given location can be thought of as the sum of ozone formed from local 

emissions of ozone precursors and a transported ozone background from more distant sources 

of emissions. As the ozone standard becomes more stringent, the role played by transported 

ozone from outside Southwest Wyoming becomes more important as the area can more easily 

be brought to the brink of an ozone exceedance through the effect of transport alone. In 

addition to U.S. sources of ozone and precursors, sources outside the U.S. (e.g. Asia) may also 

contribute to ozone in Southwest Wyoming. 

The North American Background (NAB) ozone (formerly referred to as the policy-relevant 

background [PRB]) is defined by the EPA to be “the distribution of ozone concentrations that 

would be observed in the U.S. in the absence of anthropogenic (man-made) emissions of 

precursor emissions (e.g., VOC, NOx, and CO) in the U.S., Canada, and Mexico”4, and is 

equivalent to the lowest ozone that could possibly be achieved by air quality management 

efforts within North America. The NAB includes ozone formed from anthropogenic precursors 

emitted outside the U.S., Canada and Mexico. The NAB also includes ozone formed from 

emissions from natural sources such as wildfires, lightning and biogenics both within and 

outside the U.S., as well as the downward transport of stratospheric ozone. 

For the CD-C air impact analysis, it is important to understand the relative importance of the 

CD-C Project Alternative emissions, the transported ozone background, non-Project 

anthropogenic emissions and emissions from natural sources in contributing to ozone 

exceedance days in Southwest Wyoming at different potential levels of the ozone NAAQS. For 

the purposes of this analysis, we define a background that includes ozone and precursors that 

are:

1. Due to natural and anthropogenic sources and transported into the 12/4 km domain 

through the lateral boundaries (Figure M2-1)

2. Due to natural and anthropogenic sources and transported through the model’s top 

boundary within the 12/4 km domain

3. Emitted by wildfires or prescribed burns within the 12/4 km domain

4. Emitted by biogenic sources within the 12/4 km domain

We refer to the sum of the contributions to ozone from sources 1-4 as the total background 

(BKGTOT). Note that BKGTOT is different from the NAB because it includes the contribution 

from anthropogenic emissions sources located outside the 12/4 km modeling domain but 

within the U.S., Canada and Mexico. BKGTOT is therefore expected to be larger than the NAB

 

4 http://www.epa.gov/ttn/naaqs/standards/ozone/fr/20080327.pdf
APPENDIX M – SUPPLEMENTAL ANALYSIS OF CD-C FEIS OZONE MODELING TO ADDRESS THE 

2015 REVISION TO THE NAAQS FOR OZONE

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 M-4

values described in, for example, McDonald-Buller et al. (2011). Below, we summarize the 

modeling of ozone and precursor emissions for sources that form the background affecting the 

CD-C modeling.

Figure M2-1. 36 km, 12 km, and 4 km modeling domains.

M2.1 STRATOSPHERIC OZONE

The stratosphere is a layer of air that extends from approximately 10-50 km above the earth’s 

surface. Ozone concentrations in the stratosphere are far higher than in the troposphere. Due 

to the absorption of solar radiation by ozone, temperature increases with increasing altitude in 

the stratosphere which gives the stratosphere a strong static stability that inhibits the transport 

of air from the stratosphere to the troposphere. However, under certain weather conditions, 

ozone-rich air from the stratosphere can intrude into the troposphere and can be mixed down 

to the Earth’s surface. 

Analysis of ambient ozone data and modeled back trajectories (e.g. Lefohn et al., 2012) has 

shown that stratospheric air can influence surface ozone in the western U.S. One such ozone 

intrusion occurred during the CD-C modeling period and was observed by aircraft and satellite 
APPENDIX M – SUPPLEMENTAL ANALYSIS OF CD-C FEIS OZONE MODELING TO ADDRESS THE 

2015 REVISION TO THE NAAQS FOR OZONE

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 M-5

and ambient data during the INTEX-B field study5. Stratospheric ozone intrusions have been 

observed over the western U.S. during the CalNex Study (Langford et al., 2012) as well as over

the eastern U.S. during the DISCOVER AQ study6. 

Attempts to model surface ozone impacts of stratospheric ozone intrusions have met with 

mixed success. Surface ozone impacts of stratospheric ozone intrusions during the spring of 

2006 were underestimated in both global (Zhang et al., 2011) and regional (Emery et al., 2011)

models. Emery et al. used the CAMx model in a configuration that is similar to that used in the 

CD-C modeling and found that the model simulated enhanced ozone at times and locations 

when ambient data indicated the presence of stratospheric air at the ground in the western 

U.S.; however, CAMx underestimated the observed surface ozone values. 

The CD-C CAMx modeling configuration was similar to the configuration of Emery et al., in that 

it used a zero gradient mixing ratio assumption at the model’s top boundary to characterize 

stratospheric ozone concentrations. Stratospheric ozone can enter through the model’s top 

boundary when the vertical velocity is downward, but the value of ozone entering the model is 

constrained to be the same that in the top model layer. This assumption can easily cause an 

underestimation of ozone entering the model as the tropopause in reality is a region of strong 

vertical gradients in ozone. The CD-C CAMx model has no layer collapsing (see Section 4.2.1.3 

of the AQTSD) and good resolution at the tropopause. The effects of stratospheric ozone 

intrusion events outside the 12/4 km domain can enter the 12/4 km domain through the 

model’s lateral boundary condition. The CD-C CAMx model could potentially simulate 

stratospheric ozone intrusion events. However, given the results of Emery et al. (2011), Zhang 

et al., (2011) and the CD-C modeling configuration, it is likely that the effects of stratospheric 

ozone on surface ozone are underestimated in the CD-C future year modeling. 

M2.2 EMISSIONS FROM NATURAL SOURCES

Three main emissions sources make the most important natural contributions to the NAB: 

lightning, fires, and biogenic sources. 

NOx is formed in lightning channels as the heat released by the electrical discharge causes the 

conversion of N2 and O2 to NO. The modeling of lightning and its emissions is an area of active 

research. For example, the mechanism for the buildup of electric potential within clouds is not 

well understood and modeling the production, transport and fate of emissions from lighting is 

complicated by the fact that the cumulus towers where lightning occurs may be sub-grid scale 

depending on the resolution of the model. Given the importance of lightning NOx in the 

tropospheric NOx budget and in understanding its effect on upper tropospheric ozone and OH, 

lightning NOx is typically incorporated in global modeling (e.g. Emmons et al., 2010), and has 

recently been integrated into some regional modeling studies (e.g. Allen et al. 2012). Lightning 

emissions were not accounted for in the CD-C regional emission inventory and so ozone 

impacts from this natural source are underestimated in the CD-C air quality impact analysis. 

 

5

http://airs.jpl.nasa.gov/documents/science_team_meeting_archive/2007_10/slides/Wicks_AIRSmeeting_200710

10.pdf

6 http://acmg.seas.harvard.edu/presentations/aqast/jun2014/Day1_AM/1-

Duncan_AQAST_June17_Tues_10am.pdf
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Wildfires can emit large quantities of trace gases and aerosols into the atmosphere, and these 

emissions undergo chemical and physical changes as they are transported away from the active 

fire region. Primary emitted species are depleted as they are deposited and/or chemically 

processed and secondary species such as ozone and secondary organic aerosols form within the 

plume. Both primary and secondary species can influence air quality at local and regional scales 

and can affect human health (e.g., Jaffe et al., 2008, Hu et al., 2008.) Ozone and particulates 

formed in wildfire plumes can be transported to populated regions and can influence measured 

concentrations at air quality monitors (e.g. Jaffe and Wigder, 2012). Day-specific wildfire 

emissions were used in the CD-C modeling, as described in AQTSD section 2.3.1.5 and Appendix 

G. For the 2005 and 2006 calendar years, fire emissions from the National Center for 

Atmospheric Research (NCAR) were used and these emissions were used in the future year 

simulations that included the CD-C Project Area year 2022 emissions and the 2005 and 2006 

meteorology (2022met05 and 2022met06). The fire emission estimates are derived from 

analysis of fire locations determined by satellite-borne detectors. 

As described in Appendix G, biogenic emissions were modeled using the Model of Emissions of 

Gases and Aerosols from Nature (MEGAN) version 2.03 with modifications made by ENVIRON 

(Guenther et al, 2006; Guenther and Wiedinmyer, 2007). MEGAN was used to prepare gridded 

hourly biogenic emissions inventories suitable for input to CAMx and incorporates the full range 

of ozone and PM precursor species. MEGAN accounts for the spatial variability of biogenic 

emissions through the use of high resolution estimates of vegetation type and quantity. 

MEGAN requires as input weather data, Leaf Area Index (LAI), plant functional type (PFT) cover 

and compound-specific emission factors that are based on plant species composition.

M2.3 TRANSPORT FROM OUTSIDE THE U.S.

Ozone formed from anthropogenic sources outside the U.S. has been shown to affect the U.S. 

Ozone has a lifetime of on the order of weeks to months in the free troposphere and can be 

transported across the Pacific Ocean and reach the U.S.7Recent measurements suggest that 

ozone transport from sources outside the U.S. in increasing. Parrish et al. (2009) measured the 

ozone mixing ratio in the onshore flow of marine air at the North American west coast and at 

higher elevation sites (e.g. Lassen National Park). Parrish et al. determined that along the U.S. 

west coast, springtime ozone has increased by ~0.5 ppbv/yr, i.e. ~10 ppbv in 20 years. This 

trend suggests that the NAB may be increasing. If the background ozone transported into the 

United States increases and the NAB continues to approach the level of the NAAQS, it may be 

increasingly hard for areas affected by intercontinental transport to attain the ozone standard.

In the CD-C modeling, transport from outside the U.S. is accounted for through the boundary 

conditions (BCs) on the 36 km grid shown in Figure M2-1. BCs for the outer lateral edges of the 

36 km continental U.S. modeling domain for the CD-C base case CAMx run were developed 

using the global 3-D chemical transport model GEOS-Chem (Bey et al., 2001). Future year BCs

were identical to the base years BCs. For the 2005 and 2006 modeling years for both the base 

case and the 2022 future year modeling, diurnally varying monthly average BCs from a 2002 

GEOS-Chem simulation were used along the boundaries of the 36 km modeling domain. BCs for 

the 12 km domain were derived from the results of the 36 km CAMx simulation. The 12 km and 

 

7 http://www.htap.org/publications/2010_report/2010_Final_Report/HTAP%202010%20Part%20A%20110407.pdf
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4 km grids were run in two-way nested mode with the 36 km run used only to supply boundary 

conditions to the 12 km grid (i.e., one-way grid nesting between the 36 km and 12 km 

domains).

M2.4 CD-C BACKGROUND ANALYSIS

In this section, we examine the contribution of BKGTOT, the CD-C Project Alternative year 2022

emissions, and other anthropogenic emissions to the daily maximum 8-hour average (DM8) 

ozone for all grid cells and times during the 2022met05 and 2022met06 CAMx runs when the 

total modeled DM8 ozone ≥ 60 ppb. We also assess the ozone impacts of the CD-C Project 

Alternative emissions when the observed and/or modeled DM8 ozone exceeds the 70 ppb 2015

NAAQS.

A photochemical model can be used to determine the relative contributions of source regions 

both near and distant, and can quantify the importance of locally-formed and transported 

ozone in causing high ozone days. The following analysis addresses the influence of 

anthropogenic sources outside Southwest Wyoming and all natural sources in causing 

exceedances of the 70 ppb NAAQS in the CD-C FEIS modeling. The ozone source apportionment 

analysis was performed with the CAMx Anthropogenic Precursor Culpability Assessment (APCA) 

tool described in Section 4.4.2 of the CD-C AQTSD. 

The main study area for the analysis is the 4 km modeling domain shown in Figure M1-1. The 4 

km domain includes the CD-C Project Area and most PSD Class I and sensitive Class II (Class I/II) 

areas for which the far-field air quality and AQRVs assessment was performed. Although the 

main focus of the analysis is the 4 km grid, the modeling strategy accounts for the fact that 

pollutant concentrations within the 4 km domain may be influenced by transport of pollutants 

and their precursors from outside the 4 km domain. The nested model grid system was 

designed to account for the effects of transport on determining pollutant concentrations and 

atmospheric background reactivity within the 4 km domain.

The primary function of the continental-scale 36 km grid domain shown in Figure M1-1 is to 

provide lateral boundary conditions to the 12/4 km nested grids. This was accomplished by 

running CAMx for the 36 km domain and processing the hourly model output to define 

Boundary Conditions (BCs) for the 12 km domain (i.e., one-way nesting between the 36 km and 

12 km domains). The 12/4 km CAMx simulation was then run with two-way interactive grid 

nesting where pollutants flow between the 12 km and 4 km grid domains in the simulation.

Figure M2-2 shows the contribution of the CD-C Proposed Action Alternative year 2022

emissions to the DM8 ozone at all monitors within the 4 km domain. Each point represents one 

day at one monitor. The plot shows all monitors and all days from April 1-October 31 for the 

2022met05 and 2022met06 simulations. For each Alternative, 2022met05 simulation results 

are shown in left panels and 2022met06 results are shown in right panels. In this figure, the 

abbreviation MDA8 is used to indicate the daily maximum 8-hour average ozone (referred to as 

DM8 elsewhere in this document).

Figure M2-2 indicates that in both the 2022met05 and 2022met06 simulations, the CD-C 

Proposed Action and No Action contributions generally diminish with increasing total DM8
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ozone for DM8 ozone >70 ppb. Using 2005 meteorology in the 2022 future year emissions 

scenario, the CD-C Proposed Action contribution to DM8 ozone is 1.6 ppb or less when DM8 

ozone is > 70 ppb, the level of the 2015 NAAQS. Modeled ozone was higher using 2006 

meteorology, with the CD-C Proposed Action contribution amounting to 3.4 ppb or less for all 

monitors/days with total DM8 ozone >70 ppb. The No Action Alternative contribution is smaller 

than that of the Proposed Action and is less than 1 ppb for all total DM8 ozone >70 ppb using 

2005 meteorology and less than 1.6 ppb using 2006 meteorology. In both simulations, the CD-C 

Proposed Action and No Action Alternatives have their maximum contribution at total DM8

ozone values between 65-75 ppb when only values of the total DM8 ozone>60 ppb are 

considered.

Figure M2-2 indicates that the impacts for the CD-C Project new wells on Federal lands 

(Proposed Action – No Action) are smaller than those of the Proposed Action Alternative, but 

have a similar distribution, with maximum contribution occurring for total DM8 ozone in the 

range 65-73 ppb and with CD-C contribution diminishing with increasing total DM8 ozone for 

DM8 ozone>70 ppb. Impacts for monitors/days with total DM8 ozone >70 ppb are less than 1 

ppb using 2005 meteorology and less than 1.7 ppb using 2006 meteorology.

Next, we compare the ozone contribution to grid cells and times with DM8 ozone>60 ppb from 

the CD-C Project Alternative emissions, the transported background (BKGTOT), Reasonably 

Foreseeable Development emissions sources (RFD), and all other anthropogenic sources within 

the 4 km grid (Anthro). Figure M2-3 shows that the background contribution BKGTOT far 

exceeds the CD-C Proposed Action contribution to the DM8 ozone for all days and grid cells 

with DM8 ozone > 60 ppb. BKGTOT also exceeds the contribution from the RFD and Anthro 

emissions for all days and grid cells. The very highest values of the DM8 ozone in both runs are 

driven almost entirely by the BKGTOT contribution. Figure M2-3 points out the importance of 

the transported background and natural emissions sources in determining ozone levels in 

Southwest Wyoming.

There are a number of days (especially in the 2022met05 run) in which the Anthro component 

contributes more than 20 ppb and the total DM8 ozone was in the 70-80 ppb range. These 

days with highest Anthro contribution had a relatively small BKGTOT contribution (~45 ppb). 

This type of event with relatively high Anthro contribution and relatively low BKGTOT 

contribution is consistent with stagnation event typical of summer ozone in an urban area. The 

Anthro contribution was typically larger than the RFD contribution as well as the CD-C Project 

emissions contribution.

Next, we use the APCA results to evaluate the effect on surface DM8 ozone of ozone 

transported downward through the model’s top boundary. Figure M2-4 shows the 

contributions to the DM8 ozone from the top boundary condition (TC) for all days and grid cells 

with DM8 ozone>60 ppb within the 4 km modeling domain during the 2022met05 and 

2022met06 simulations. The contributions from top conditions are generally small (< 3 ppb). 
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Figure M2-2. Incremental contribution to the DM8 ozone for all days and grid cells within the 

4 km domain with DM8 ozone>60 ppb from: (upper panels) the CD-C Proposed Action,

(middle panels) CD-C New Project wells (the difference between the CD-C Proposed Action 

emissions and the CD-C No Action emissions) and (lower panels) the No Action Alternative. 
APPENDIX M – SUPPLEMENTAL ANALYSIS OF CD-C FEIS OZONE MODELING TO ADDRESS THE 

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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 M-10

Here follows a summary of the scatter plot results: 

 CD-C Proposed Action and No Action Alternatives contributions diminish with increasing 

DM8 ozone for total DM8 ozone values higher than ~73 ppb.

 CD-C Proposed Action and No Action Alternatives have their maximum contribution at 

DM8 ozone between 65-75 ppb.

 The BKGTOT contribution far exceeds the CD-C contribution for all days and grid cells > 60 

ppb.

 BKGTOT is the largest contributor to ozone within 4 km domain for all days and grid cells 

with total DM8 ozone> 60 ppb

 Contribution from the model top boundary conditions is small (< 3 ppb). No large 

stratospheric ozone intrusion events affected surface DM8 ozone within the 4 km domain, 

but stratospheric ozone impacts can enter the 12/4 km domain via the lateral boundary 

conditions and can affect surface concentrations. The impact of the stratosphere on 

surface ozone is likely underestimated in the CD-C modeling.

 Days with highest Anthro contribution have the smallest BKGTOT contribution (consistent 

with stagnation event)

 For grid cells and days with DM8 ozone > 60 ppb, the contribution from BKGTOT made the 

largest contribution to the total DM8 ozone, follow by Anthro sources and RFD, with the 

CD-C Project Alternative emissions making a far smaller contribution to the DM8 ozone

that was always <3 ppb.
APPENDIX M – SUPPLEMENTAL ANALYSIS OF CD-C FEIS OZONE MODELING TO ADDRESS THE 

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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 M-11

Figure M2-3. Contributions to the DM8 ozone from background, CD-C Proposed Action 

emissions (CDC PRO), RFD emissions (RFD) and all other anthropogenic sources (Anthro) for 

all days and grid cells within the 4 km domain with DM8 ozone>60 ppb for the 2022met05 

(left panel) and 2022met06 (right panel) simulations. Red dotted line is the total DM8 ozone

value shown in the horizontal axis. In this figure, the abbreviation MDA8 is used to indicate 

the daily maximum 8-hour average ozone (referred to as DM8 elsewhere in this document).

Figure M2-4. Contributions to the DM8 ozone from top boundary conditions (TC)) for all days 

and grid cells within the 4 km domain with DM8 ozone>60 ppb for the 2022met05 (left panel) 

and 2022met06 (right panel) simulations. Red dotted line is the total DM8 ozone value 

shown in the horizontal axis. In this figure, the abbreviation MDA8 is used to indicate the 

daily maximum 8-hour average ozone (referred to as DM8 elsewhere in this document).
APPENDIX M – SUPPLEMENTAL ANALYSIS OF CD-C FEIS OZONE MODELING TO ADDRESS THE 

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M3. W126 ANALYSIS

In this section, we present an analysis of the W126 index focused on the range 13-17 ppmhours for the CD-C future year modeling. We show plots of the W126 index across the 4 km 

modeling domain and calculate the CD-C Project Alternative emissions’ contribution to the 

W126 index throughout the 4 km domain as well as at ozone monitors in Southwest Wyoming 

and northern Utah and Colorado.

First, we describe the W126 index, which was calculated using hourly values of total modeled 

ozone (i.e. not APCA contributions) for the 2022 future year. We used modeled ozone data for 

each month from April-October, corresponding to the Wyoming ozone and growing seasons, 

for the two meteorological years 2022met05 and 2022met06. For each year, we started with 

the modeled hourly ozone value for each grid cell, O3i, for each hour (i) within the 12-hour 

period 8 am-8 pm local time, and calculated the W126 value for that hour. The W126 index 

weights higher values of ozone more heavily than lower values, and is defined:

W126 = O3i

1

1 + (4403e

−126O3i)

Next, we added the weighted hourly W126 ozone values for each day to produce a daily total 

W126 value. Then, we added the daily values for each month to form a monthly total W126 

value for each month. The monthly values for each 3-month period from April-September were 

then calculated by adding the monthly values for each 3-month period. 

The EPA specifies that the W126 index is formed by taking the highest 3-month sums from each 

of three consecutive years of data. For the CD-C analysis, we had only two years of model 

output, so we formed an average for the 2022met05 and 2022met06 simulations. We present 

data from the two individual years, as well, in order to examine differences between the two 

years that contribute to the average W126 calculation. 

We calculated the W126 index for all grid cells within the 4 km domain, and the results are 

shown in Figure M3-1. The 2022met05 and 2022met06 run W126 index plots show a similarity 

in pattern to the absolute modeled values for these two runs shown in Section 4.5.4.4 of the 

AQTSD. For the 2022met05 run, relatively high W126 values are shown within and east of Fort 

Collins and over the high terrain of the Uinta Mountains in northeastern Utah. The W126 index 

is less than 13 ppm-hours for all grid cells within the 4 km domain. In the vicinity of the CD-C 

Project, the W126 index ranges from 9-12 ppm-hours, which is less than the 13-17 ppm-hour 

range that EPA considered for the 2015 secondary NAAQS.
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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 M-13

Figure M3-1. W126 index for the 2022met05 (upper left panel) and 2022met06 (upper right 

panel) simulations and the two year average of 2022met05 and 2022met06 (lower panel).

Comparison of the upper panels of Figure M3-1 shows that although patterns of high and low 

W126 values in the 4 km domain are similar between the two years, the W126 index is 

generally higher using 2006 meteorology than with 2005 meteorology. This is consistent with 

the absolute modeling results shown in Section 4.5.4.4 of the AQTSD. With 2006 meteorology, 

broad areas of the domain (e.g. Fort Collins Area, Uinta Mountains, Bridger-Fitzpatrick 

Wilderness) exceed 13 ppm-hours, while with 2005 meteorology, the entire domain has W126 

index < 13 ppm-hours. In the vicinity of the CD-C Project, the W126 index in the 2022met06 run 

ranges from 10-13 ppm-hours, and for some grid cells exceeds the lower bound of the 13-17 

ppm-hour range EPA considered for the 2015 secondary NAAQS.

The 2022met05 and 2022met06 W126 values were averaged to approximate the form of the 3-

year average proposed by the EPA (lower panel of Figure M3-1). In the two-year average, the 

W126 index exceeds 13 ppm-hours only in the Fort Collins Area and in the vicinity of Salt Lake 
APPENDIX M – SUPPLEMENTAL ANALYSIS OF CD-C FEIS OZONE MODELING TO ADDRESS THE 

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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 M-14

City. In the vicinity of the CD-C Project, the W126 index ranges between 9-12 ppm-hours, and 

would not exceed a W126 secondary NAAQS in the 13-17 ppm-hour range.

We calculated the W126 index for grid cells in the 4 km modeling domain that contain the 

monitoring sites shown in Figure M3-2. The results are shown in Table M3-1 and in bar chart 

form in Figure M3-3.

Figure M3-2. Locations of monitoring sites within the 4 km grid domain used in the W126 

analysis shown in Table M3-1

The CD-C Project Proposed Action contribution to the W126 index in all grid cells in the 4 km 

domain was determined using the CAMx APCA source apportionment capability. The APCA 

contribution from the CD-C Proposed Action Alternative was subtracted from the full CAMx 

2022 run output (W126 base, results shown in Figure M3-1). The contribution from the CD-C 

Proposed Action Alternative was obtained by taking the difference:

W126(CD-C Proposed Action) = W126(Base) – W126(Base - CD-C Proposed Action)

An analogous procedure was followed to get the contribution from the CD-C No Action 

Alternative and the difference between the Proposed Action and the No Action.
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Table M3-1. CD-C Project emission impacts on W126 index for monitoring sites within the 12/4 km modeling domains for the 2022 future year 

simulations using 2005 and 2006 meteorology. 
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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 M-16

Figure M3-4. Graphical representation of the data in Table M3-1. CD-C Project Alternative 

impacts on W126 index for monitoring sites within the 12/4 km modeling domains for the 

2022 future year simulations using 2005 and 2006 meteorology. Top panel: CD-C Proposed 

Action, middle panel: CD-C new wells on Federal lands (Proposed Action–No Action), lower 

panel: No Action.
APPENDIX M – SUPPLEMENTAL ANALYSIS OF CD-C FEIS OZONE MODELING TO ADDRESS THE 

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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 M-17

For all monitors, the impacts on the W126 index from the CD-C Proposed Action emissions 

were less than 1 ppm-hour. The largest W126 impacts due to CD-C Project emissions occurred 

at monitors closest to the CD-C Project Area: Wamsutter, Sun Dog and Atlantic Rim. 2-year 

average impacts from the CD-C Proposed Action emissions for these three monitors ranged 

from 0.29-0.66 ppm-hours, which correspond to 2-5% of a W126 index value of 13 ppm-hours. 

Proposed Action emissions impacts at the other monitors were all less than 1% of 13 ppmhours. For the New CD-C wells only (Proposed Action – No Action), 2-year average impacts on 

the W126 index at the three monitors ranged from 0.16-0.37 ppm-hours, which is 1-3% of 13 

ppm-hours. For the No Action Alternative, 2-year average impacts on the W126 index at the 

three monitors ranged from 0.13-0.31 ppm-hours, which is 1-2% of 13 ppm-hours.

A spatial map of the CD-C Project Alternatives’ contribution to the W126 value for the 

2022met05 and 2022met06 simulations is shown in Figure M3-5. W126 index impacts from the 

CD-C Project Alternative emissions are largest within the Project Area and in the region that is 

east (generally downwind) of the Project Area. For all three Alternatives, the peak W126 values 

are higher using 2006 meteorology than with 2005 meteorology. The magnitude of the peak 

W126 index is correlated with the number of wells and corresponding emissions for each 

Alternative. The highest impacts are seen in the Proposed Action (0.89 ppm-hours), followed

by the increment due to new CD-C wells (Proposed Action – No Action; 0.49 ppm-hours) and 

the No Action (0.41 ppm-hours). CD-C Project Alternative impacts on the W126 index in the 

non-attainment areas in Sublette, Lincoln, and Sweetwater Counties in Wyoming are too small 

to be visible on this scale.
APPENDIX M – SUPPLEMENTAL ANALYSIS OF CD-C FEIS OZONE MODELING TO ADDRESS THE 

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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 M-18

CD-C Proposed Action: 2022met05 CD-C Proposed Action: 2022met06

CD-C Proposed Action–No Action: 2022met05 CD-C Proposed Action–No Action: 2022met06

No Action: 2022met05 No Action: 2022met06

Figure M3-5. CD-C Project Alternative impacts on the W126 index within the 4 km modeling 

domains for the 2022 future year simulations using 2005 and 2006 meteorology. Top panel: 

CD-C Proposed Action, middle panel: CD-C new wells on Federal land (Proposed Action–No 

Action), lower panel: No Action.
APPENDIX M – SUPPLEMENTAL ANALYSIS OF CD-C FEIS OZONE MODELING TO ADDRESS THE 

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Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 M-19

M4. REFERENCES

Allen, D. J., K. E. Pickering, R. W. Pinder, B. H. Henderson, K. W. Appel, and A. Prados. 2012. 

Impact of lightning-NO on eastern United States photochemistry during the summer of 

2006 as determined using the CMAQ model. Atmos. Chem. Phys., 10, 107–119.

Bey, I., D. J. Jacob, R. M. Yantosca, J. A. Logan, B. Field, A. M. Fiore, Q. Li, H. Liu, L. J. Mickley, 

and M. Schultz. 2001. Global modeling of tropospheric chemistry with assimilated 

meteorology: Model description and evaluation, J. Geophys. Res., 106, 23,073-23,096.

Emery, C., et al. 2011. Regional and global modeling estimates of policy relevant background 

ozone over the United States, Atmos. Env., doi:10.1016/j.atmosenv.2011.11.012

Emmons, L. K., S. Walters, P. G. Hess, J.-F. Lamarque, G. G. Pfister, D. Fillmore, C. Granier, A. 

Guenther, D. Kinnison, T. Laepple, J. Orlando, X. Tie, G. Tyndall, C. Wiedinmyer, S. L. 

Baughcum, and S. Kloster. 2010. Description and evaluation of the Model for Ozone and 

Related Tracers, version 4 (MOZART-4), Geosci. Model Dev., 3, 43–67.

EPA. 2007. Guidance on the Use of Models and Other Analyses for Demonstrating Attainment 

of Air Quality Goals for ozone, PM2.5, and Regional Haze. U.S. Environmental Protection 

Agency, Office of Air Quality and Planning Standards, Research Triangle Park, North 

Carolina.(EPA-454/B-07-002). April.

EPA. 2014. National Ambient Air Quality Standards for Ozone: A Proposed Rule by the 

Environmental Protection Agency on 12/17/2014. www.gpo.gov/fdsys/pkg/FR-2014-12-

17/pdf/2014-28674.pdf.

ENVIRON. 2010. User’s Guide Comprehensive Air Quality Model with Extensions (CAMx) 

Version 5.40. ENVIRON International Corporation, Novato, California. (www.camx.com). 

September.

Guenther, A., T. Karl, P. Harley, C. Wiedinmyer, P. I. Palmer, and C. Geron. 2006. Estimates of 

global terrestrial isoprene emissions using MEGAN (Model of Emissions of Gases and 

Aerosols from Nature). Atmos. Chem. Phys., 6, 3181-3210.

Guenther, A. and C. Wiedinmyer. 2007. MEGAN Homepage. http://lar.wsu.edu/megan/. 

Hu, Y., Odman, M. T., Chang, M. E., Jackson, W., Lee, S., Edgerton, E. S., Baumann, K., and 

Russell, A. G. 2008. Simulation of air quality impacts from prescribed fires on an urban 

area. Env. Sci. & Tech, 42(10), 3676-3682.

Jaffe, D., D. Chand, W. Hafner, A. Westerling, and D. Spracklen. 2008. Influence of fires on O(3) 

concentrations in the western US, Env. Sci. & Tech., 42(16), 5885-5891.

Jaffe, D. and Wigder, N. 2012. Ozone production from wildfires: A critical review. Atmos. Env., 

51 (2012) 1-10.

Langford, A.O., J. Brioude, O. R. Cooper, C. J. Senff, R. J. Alvarez, R. M. Hardesty, B. J. Johnson 

and S. J. Oltmans. 2012. Stratospheric influence on surface ozone in the Los Angeles 

area during late spring and early summer of 2010. J. Geophys. Res. 117 (D21).

Lefohn, A.S., Wernli, H., Shadwick, D., Oltmans, S.J., Shapiro, M. 2012. Quantifying the 

Importance of Stratospheric-Tropospheric Transport on Surface Ozone Concentrations 
APPENDIX M – SUPPLEMENTAL ANALYSIS OF CD-C FEIS OZONE MODELING TO ADDRESS THE 

2015 REVISION TO THE NAAQS FOR OZONE

Continental Divide-Creston Natural Gas Development Project Final EIS • April 2016 M-20

at High- and Low-Elevation Monitoring Sites in the United States. Atmos. Env. 62:646-

656.

McDonald-Buller, E.C., D.T. Allen, N. Brown, D.J. Jacob, D. Jaffe, C.E. Kolb, A.S. Lefohn, S. 

Oltmans, D.D. Parrish, G. Yarwood, and L. Zhang. 2011. Establishing Policy Relevant 

Background (PRB) Ozone Concentrations in the United States, Environ. Sci. & Tech., 

2011, 45, 9484-9497, dx.doi.org/10.1021/es2022818.

Parrish, D.D., D. B. Millet, and A. H. Goldstein. 2009. Increasing ozone in marine boundary layer 

inflow at the west coasts of North America and Europe. Atmos. Chem. Phys., 9, 1303–

1323.

Zhang, L., Jacob, D.J., Downey, N.V., Wood, D.A., Blewitt, D., Carouge, C.C., van Donkelaar, A., 

Jones, D.B.A., Murray, L.T., Wang, Y. 2011. Improved estimate of the policy-relevant 

background ozone in the United States using the GEOS-Chem global model with 1/2°x 

2/3° horizontal resolution over North America. Atm. Env. 

doi:10.1016/j.atmosenv.2011.07.054.

.