Draft EIS Appendix 4 

APPENDIX 4—AIR QUALITY IMPACT TECHNICAL 

SUPPORT DOCUMENT 

The following technical support document describes the processes used to conduct the air quality impact

assessment for the air resources in the Rawlins Resource Management Plan Planning Area (RMPPA), and

provides summaries of relevant analysis data. This document will serve as the basis for subsequent air 

quality impact analyses of other alternatives and the preferred alternative. The contents of this document

are as follows: 

•

• 

•

• 

•

•

• Mitigation 

Regulatory Framework

Agency Roles and Authorities 

Existing Air Quality

Air Quality Impact Analysis 

Emission Calculations

Internet Resources

Copies of this technical support document and any data files are available upon request from—

Susan Caplan 

Physical Scientist: Air Quality

5353 Yellowstone 

PO Box 1828

Cheyenne, Wyoming 82003 

307-775-6031 Voice 

307-775-6082 Telefax 

susan_caplan@blm.gov 

REGULATORY FRAMEWORK

For quantitative analysis, the following air quality criteria apply. Although criteria listed below do not 

apply to the qualitative analysis presented in the Rawlins Air Quality Analysis, they are identified here for 

reference purposes. The basic framework for controlling air pollutants in the United States is mandated

by the 1970 Clean Air Act (CAA) and its amendments, and the 1999 Regional Haze Regulations. The

CAA addresses criteria air pollutants, State and national ambient air quality standards for criteria air 

pollutants, and the Prevention of Significant Deterioration program. The Regional Haze Regulations 

address visibility impairment. 

Ambient Air Quality Constituents 

Air pollutants addressed in this study include criteria pollutants; hazardous air pollutants (HAP); and 

sulfur and nitrogen compounds, which could cause visibility impairment or atmospheric deposition 

impacts. 

Criteria Pollutants 

Criteria pollutants are those for which national standards of concentration have been established. 

Ambient air concentrations of these constituents greater than the standards represent a risk to human

Rawlins RMP A4-1 
Appendix 4 Draft EIS 

health. Criteria pollutants include carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2),

ozone (O3), particulate matter (PM10, PM2.5), and lead (Pb). 

Carbon Monoxide. CO is an odorless, colorless gas formed during any combustion process, such as

operation of engines, fireplaces, and furnaces. High concentrations of CO affect the oxygen-carrying 

capacity of the blood and can lead to unconsciousness and asphyxiation. Wildfires are natural sources of

CO. 

Nitrogen Dioxide. NO2 is a red-brown gas formed during operation of internal combustion engines. 

Such engines emit a mixture of nitrogen gases, collectively called nitrogen oxides (NOx). NOx can

contribute to brown cloud conditions and can convert to ammonium nitrate particles and nitric acid, which 

can cause visibility impairment and acid rain. Bacterial action in soil can be a natural source of nitrogen 

compounds. 

Sulfur Dioxide. SO2 forms during combustion from trace levels of sulfur in coal or diesel fuel. It can 

convert to ammonium sulfate ((NH4)2SO4) and sulfuric acid (H2SO4), which can cause visibility 

impairment and acid rain. Volcanoes are natural sources of SO2. Anthropogenic sources include 

refineries and power plants. 

Ozone. O3 is a gas that is generally not emitted directly into the atmosphere but is formed from NOx and

volatile reactive organic compound (VOC) emissions. As stated above, internal combustion engines are 

the main source of NOx. Volatile organic compounds, such as terpenes, are very reactive. Sources of

VOCs include, but are not limited to, paint, varnish, and some types of vegetation. The faint acrid smell 

common after thunderstorms is caused by ozone formation by lightning. O3 is a strong oxidizing

chemical that can burn lungs and eyes, and damage plants. 

Particulate Matter. Particulate matter (e.g., soil particles, hair, pollen) is essentially small particles

suspended in the air that settle to the ground slowly and may be re-suspended if disturbed. Separate 

allowable concentration levels for particulate matter are based on the relative size of the particle: 

•

•

PM10 particles, particles with diameters of less than 10 micrometers, are small enough to be 

inhaled and can cause adverse health effects. 

PM2.5 particles, particles with diameters of less than 2.5 micrometers, are so small that they can 

be drawn deeply into the lungs and cause serious health problems. Particles in this size range are 

also the main cause of visibility impairment. 

Lead. Before use of unleaded fuel for automobiles became widespread, lead particles were emitted from 

automobile tailpipes. Lead is not considered in this environmental impact statement (EIS) because no 

proposed projects are expected to emit lead. The lead standard also will not be addressed in this Technical

Support Document because lead is not a current concern, but it will be considered in future projects. 

Hazardous Air Pollutants 

There are a wide variety of HAPs, including N-hexane, ethylbenzene, toluene, xylene, formaldehyde, and 

benzene. Although HAPs do not have ambient air quality standards, the U.S. Environmental Protection

Agency (EPA) has issued reference concentrations for evaluating the inhalation risk for cancerous and

noncancerous health effects, known as Reference Concentrations for Chronic Inhalation (RfC). 

The EIS associated with the Rawlins resource management plan (RMP) is a National Environmental 

Policy Act (NEPA) document and not a regulatory document, but the Record of Decision is binding and a

A4-2 Rawlins RMP 
Draft EIS Appendix 4 

"public record" (see 40 CFR 1505.2). Additionally, there are regulatory issues that should be taken into 

account in preparing this EIS and ensuing project-specific EISs. Actual regulation of HAPs is achieved

through compliance with the applicable maximum achievable control technology (MACT) standards and 

not through ambient air quality standards. Regulatory agencies implement control through Section 112 

programs, specifically Section 112(g) case-by-case MACT determinations based on 40 Code of Federal

Regulations (CFR) Part 63, Subpart B and Section 112(d) MACT emission standards. 

Any source that emits or has the potential to emit 10 tons per year or more of any HAP or 25 tons per year 

or more of any combination of HAPs is considered a major source and will require a Title V, Part 70 

operating permit review and permit. This may include either a case-by-case 112(g) MACT determination,

if the source is new or has had major modifications and no applicable MACT emission standard has been 

promulgated, or compliance with an applicable MACT emission standard. Specific regulations that apply 

in the Rawlins RMPPA include 40 CFR Part 63 Subpart HH, National Emission Standards for Hazardous 

Air Pollutants From Oil and Natural Gas Production Facilities; 40 CFR Part 63 Subpart HHH, National

Emission Standards for Hazardous Air Pollutants From Natural Gas Transmission and Storage Facilities;

and 40 CFR Part 63 Subpart ZZZ, National Emission Standards for Hazardous Air Pollutants for 

Stationary Reciprocating Internal Combustion Engines. This last regulation, new in 2004, affects source 

categories using reciprocating engines for gas compression. 

For quantifiable analysis, short-term (1-hour) HAP concentrations would be compared to acute Reference 

Exposure Levels (RELs). RELs are defined as concentrations at or below which no adverse health effects 

are expected. If no RELs were available for ethylbenzene and n-hexane, the available Immediately

Dangerous to Life or Health (IDLH) values would be used. These IDLH values are determined by the

National Institute for Occupational Safety and Health (NIOSH) and would be obtained from EPA’s Air 

Toxics Database. 

For quantifiable analysis, long-term exposure to HAPs emitted by the Proposed Action would be 

compared to RfCs. An RfC is defined by EPA as the daily inhalation concentration at which no long-term 

adverse health effects are expected. RfCs exist for both noncarcinogenic and carcinogenic effects on

human health. Annual modeled HAP concentrations for all HAPs emitted would be compared directly to 

the noncarcinogenic RfCs. RfCs for the suspected carcinogens benzene and formaldehyde are expressed

as risk factors. Accepted methods of risk assessment would be used to evaluate the incremental cancer 

risk from these pollutants. 

Annual modeled concentrations would be multiplied by EPA’s unit risk factors (URF) (based on 70-year 

exposure) for those pollutants, and then the product would be multiplied by an adjustment factor, which

represents the ratio of projected exposure time to 70 years. The adjustment factors represent two 

scenarios: a most likely exposure (MLE) scenario and one reflective of the maximally exposed individual

(MEI). 

The MLE duration would be assumed to be 9 years, which corresponds to the mean duration that a family

remains at a residence. This duration corresponds to an adjustment factor of 9/70 = 0.13. The duration of

exposure for the MEI is assumed to be 50 years (i.e., the Life of Project [LOP]), corresponding to an 

adjustment factor of 50/70 = 0.71. 

A second adjustment would be made for time spent at home versus time spent elsewhere. For the MLE 

scenario, the at-home time fraction is 0.64 (EPA 1993), and it would be assumed that during the rest of 

the day the individual remained in an area where annual HAP concentrations were one quarter as high as 

the maximum annual average concentration. Therefore, the MLE adjustment factor would be (0.13) x

[(0.64 x 1.0) + (0.36 x 0.25)] = 0.0949. The MEI scenario would assume that the individual was at home

100 percent of the time, for a final adjustment factor of (0.71 x 1.0) = 0.71. 

Rawlins RMP A4-3 
Appendix 4 Draft EIS 

HAP emissions are associated with industrial activities, such as oil and gas operations, refineries, paint 

shops, dry cleaning facilities, and wood working shops. 

Because this analysis is qualitative, no specific analysis of either short- or long-term HAP impacts is 

made. 

HAP emissions in the RMPPA are expected to be similar to those found in the Desolation Flats EIS and 

comprise of benzene, toluene, ethylbenzene, xylene, n-hexane, and formaldehyde. 

Atmospheric Deposition Constituents 

Sulfur and nitrogen compounds that can be deposited in terrestrial and aquatic ecosystems include nitric 

acid (HNO3), nitrate (NO3

-

), ammonium (NH4

+

), and sulfate (SO4

--). Nitric acid (HNO3), and nitrate 

(NO3

-

) are not emitted directly into the air but form in the atmosphere from industrial and automotive 

emissions of NOx. Sulfate (SO4

--) is formed in the atmosphere from industrial emission of sulfur dioxide

(SO2). Deposition of HNO3, NO3

-

, and SO4

-- can adversely affect plant growth, soil chemistry, lichens, 

aquatic environments, and petroglyphs. Ammonium (NH4

+

) is primarily associated with feedlots and

agricultural fertilization. Deposition of NH4

+

 can affect terrestrial and aquatic vegetation. Although

deposition may be beneficial as a fertilizer, it can adversely affect the timing of plant growth and

dormancy.

Although this analysis will be qualitative, future specific projects will require quantitative analyses using 

the following criteria. 

Wyoming and National Ambient Air Quality Standards 

Wyoming Ambient Air Quality Standards (WAAQS) and National Ambient Air Quality Standards

(NAAQS) are health-based standards for the maximum concentration of air pollutants at all locations to 

which the public has access. The WAAQS and NAAQS are legally enforceable standards. 

Concentrations above the WAAQS and NAAQS represent a risk to human health. State standards must

be as strict as, or more strict than, federal standards. 

EPA has developed standards for each criteria pollutant for a specific averaging time (see Table A4-1).

Short averaging times (1, 3, and 24 hours) address short-term exposure while the annual standards address 

long-term exposure. Longer term standards are set to lower allowable concentrations than are short-term

standards to recognize the cumulative effects of long-term exposure. 

Prevention of Significant Deterioration 

The goal of the Prevention of Significant Deterioration (PSD) program is to ensure that air quality in

areas with clean air does not significantly deteriorate, while maintaining a margin for future industrial 

growth. Under PSD, each area in the United States is classified by the air quality in that region according

to the following system: 

PSD Class I Areas. Areas with pristine air quality, such as wilderness areas, national parks, and 

some Indian reservations, are accorded the strictest protection. Only very small incremental 

increases in pollutant concentrations are allowed in order to maintain the very clean air quality in 

these areas. 

• 

• PSD Class II Areas. Essentially, all areas that are not designated as Class I are designated as

Class II. Moderate incremental increases in pollutant concentrations are allowed, although the 

A4-4 Rawlins RMP 
Draft EIS Appendix 4 

concentrations are not allowed to reach the concentrations set by Wyoming and federal standards

(WAAQS and NAAQS). 

PSD Class III Areas. No areas have yet been designated as Class III. Concentrations would be 

allowed to increase all the way to the WAAQS and NAAQS. 

• 

The incremental increases allowed for specific pollutants in Class I and Class II areas are provided in 

Table A4-2. 

Comparisons of potential PM10, NO2, and SO2 concentrations with PSD increments are intended only to 

evaluate a threshold of concern and do not represent a regulatory PSD increment consumption analysis. 

Regulatory PSD increment consumption analyses are solely the responsibility of the State of Wyoming, 

which has been granted primacy (with EPA oversight) under the CAA. 

In project-specific EISs, the Bureau of Land Management (BLM) does not expect that a PSD analysis will 

be performed. Rather the PSD standards are used only as a reference to give the public a better 

understanding of the level of potential impact. 

Regional Haze Regulations 

Visibility impairment in the form of regional haze obscures the clarity, color, texture, and form of what

we see. Haze-causing pollutants (mostly fine particles) are directly emitted into the atmosphere or are 

formed when gases emitted into the air form particles as they are carried downwind. Emissions from 

human-caused and natural sources can be carried great distances, contributing to regional haze. The

Wyoming Department of Environmental Quality–Air Quality Division (WDEQ-AQD) submitted its 

Regional Haze State Implementation Plan (SIP) in accordance with 40 CFR, Part 51.309, in December

2003. EPA has not yet taken action on this SIP. 

Visual range, one of several ways to express visibility, is the furthest distance at which a person can 

distinguish a dark landscape feature from a light background like the sky. Without human-caused

visibility impairment, natural visual range is estimated to average about 110–115 miles in the western 

United States and 60–80 miles in the eastern United States (Malm 1999). 

The Regional Haze Regulations were developed by EPA in response to the CAA Amendments of 1977 

and 1990. They are intended to maintain visibility on the least impaired days and to improve visibility on 

the most impaired days in mandatory federal Class I areas across the United States so that visibility in 

these areas is returned to natural conditions by the year 2064. These regulations require states to submit a 

regional haze SIP and progress reports to demonstrate reasonable progress toward the 2064 goal. 

Rawlins RMP A4-5 
Appendix 4 Draft EIS 

Table A4-1. National and Wyoming Ambient Air Quality Standards 

NAAQS WAAQS Pollutant Averaging 

Time (μg/m3) (ppm) (ppb) (μg/m3) (ppm) (ppb) 

Carbon 1 hour 40,000 35 35,000 40,000 35 35,000

Monoxide 

CO 8 hour 10,000 9 9,000 10,000 9 9,000

Lead 

Pb 

Calendar 

quarter 1.5 1.5 

Nitrogen 

Dioxide 

NO2

Annual 100 .053 53 100 .053 53

Ozone 1 hour 235 .12 120 235 .12 120

O3 8 hour 157 .08 80 157 .08 80

Particulate 24 hour 150 150 

Matter 

PM10

Annual 50 50 

Particulate 24 hour 65 65 

Matter 

PM2.5

Annual 15 15 

3 hour 1300 .5 500 695 .266 266 

24 hour 365 .14 140 260 .099 99 

Sulfur 

Dioxide 

SO2 Annual 80 .030 30 60 .023 23

Table A4-2. PSD Increments 

PSD Increment 

Pollutant Class I Class II Averaging 

Time

(μg/m3) (ppm) (ppb) (μg/m3) (ppm) (ppb) 

Nitrogen 

Dioxide 

NO2

Annual 2.5 .0013 1.3 25 .013 13

Particulate 24 hour 8 30 

Matter 

PM10 Annual 4 17 

3 hour 25 .0096 9.6 512 .1956 196 

24 hour 5 .0019 1.9 91 .0348 35 

Sulfur 

Dioxide 

SO2 Annual 2 .0008 .8 20 .0076 8

APPLICABILITY TO THE RAWLINS AREA

Air pollution impacts are limited by local, state, tribal, and federal air quality regulations, standards, and 

implementation plans established under the CAA and administered by the WDEQ-AQD with oversight 

from EPA. Air quality regulations require that proposed new, or modified existing, air pollutant emission 

stationary sources (including oil and gas compression facilities) undergo a permitting review before their 

construction can begin. Therefore, the WDEQ-AQD has the primary authority and responsibility to

review permit applications and to require emission permits, fees, and control devices, before construction 

or start of operation. 

Fugitive dust and exhaust from construction activities, along with air pollutants emitted during operation 

(e.g., well operations, booster [field] and pipeline [sales] compressor engines), are potential causes of air

quality impacts. These issues are more likely to generate public concern where natural gas development 

activities occur near residential areas or near sensitive Class I and Class II areas. 

The Forest Service (FS), the National Park Service (NPS), and the Fish and Wildlife Service (FWS) have

also expressed concerns about potential atmospheric deposition (acid rain) and visibility impacts within

A4-6 Rawlins RMP 
Draft EIS Appendix 4 

downwind PSD Class I and PSD Class II sensitive areas under their administration, located throughout 

Wyoming. 

The NAAQS and the WAAQS are health-based standards for the maximum acceptable concentrations of

air pollutants at locations to which the public has access. The analysis of the proposed alternatives must 

demonstrate continued compliance with all applicable local, state, tribal, and federal air quality standards. 

Existing air quality throughout the project area is in attainment of all ambient air quality standards, as 

demonstrated by the relatively low concentration levels presented in Table A4-3. 

Air quality regulations require that stationary proposed new, or modified existing air pollutant emission 

sources (including oil and gas compression facilities) undergo a permitting review before their 

construction can begin. Therefore, the WDEQ-AQD has been given primary authority over and

responsibility for reviewing permit applications and for requiring emission permits, fees, and control 

devices, before construction and/or operation. In addition, the U.S. Congress (through the CAA Section

116) authorized local, state, and tribal air quality regulatory agencies to establish air pollution control 

requirements more (but not less) stringent than federal requirements. Also, under both the Federal Land

Policy and Management Act (FLPMA) and the CAA, BLM cannot authorize any activity that would not 

conform to all applicable local, state, tribal, and federal air quality laws, regulations, standards, and

implementation plans. 

Given the project area’s current attainment status, future development projects that have the potential to

emit more than 250 tons per year of any criteria pollutant (or certain listed sources that have the potential

to emit more than 100 tons per year) would be required to undergo a site-specific regulatory PSD

increment consumption analysis under the federal New Source Review permitting regulations. 

Development projects that require PSD permits may also be required by the applicable air quality 

regulatory agencies to incorporate additional emission control measures (including a Best Available

Control Technology [BACT] analysis and determination) to ensure protection of air quality resources and 

to demonstrate that the combined impacts of all PSD sources will not exceed the allowable incremental

air quality impacts for NO2, PM10, and SO2. Minor sources having emissions below the cutoff rates 

mentioned above do not require PSD permits; nevertheless, their emissions consume increment. 

A regulatory PSD increment consumption analysis may be conducted, either as part of a New Source

Review or independently. The determination of PSD increment consumption is a legal responsibility of 

the applicable air quality regulatory agencies, with EPA oversight. In addition, an analysis of cumulative 

impacts due to all existing sources and the permit applicant’s sources is required during New Source

Review to demonstrate that applicable ambient air quality standards will be met during the operational

lifetime of the permit applicant’s operations. 

Sources subject to the PSD permit review procedure are also required to demonstrate potential impacts on

air quality–related values (AQRV). These include visibility impacts, degradation of mountain lakes due 

to atmospheric deposition (acid rain), and effects on sensitive flora and fauna in Class I areas. The CAA

also provides specific visibility protection procedures for the mandatory federal Class I areas designated

by the U.S. Congress on August 7, 1977, which included wilderness areas greater than 5,000 acres in size, 

as well as national parks and national memorial parks greater than 6,000 acres in size as of that date. 

Rawlins RMP A4-7 
Appendix 4 Draft EIS 

AGENCY ROLES AND AUTHORITIES

EPA 

EPA administers the Federal CAA (42 U.S. Code [U.S.C.] 7401 et seq.) to maintain the NAAQS that 

protect human health and to preserve the rural air quality in the region by ensuring the PSD Class I and 

Class II increments for SO2, NO2, and PM10, are not exceeded. EPA has delegated this CAA authority to 

the State of Wyoming. 

Wyoming DEQ

Wyoming regulates pollutants emitted into the air through the Wyoming Environmental Quality Act

(W.S. 35-11-101 et seq.). Wyoming is also authorized by an approved SIP to administer all requirements 

of the PSD permit program under the CAA. In addition, the approved Wyoming SIP contains a number 

of programs that provide for the implementation, maintenance, and enforcement of the NAAQS, 

including a New Source Review program for minor source permitting that requires, among other things,

application of BACT for all new or modified sources, regardless of size or source category. Included as

well are authorities for the control of particulate emissions, including fugitive particulate emissions from 

haul roads, access roads, or general facility boundaries. Wyoming is also delegated responsibility for 

operating an approved ambient air quality monitoring network for the purpose of demonstrating 

compliance with the NAAQS and the WAAQS. 

Bureau of Land Management 

NEPA requires that federal agencies consider mitigation of direct, indirect, and cumulative impacts 

during their preparation of an EIS (BLM Land Use Planning Manual 1601). Under the CAA, federal 

agencies are to comply with SIPs regarding the control and abatement of air pollution. Before approval of

RMPs or amendments to RMPs, the state director is to submit any known inconsistencies with SIPs to the 

governor of that state. If the governor of the state recommends changes in the proposed RMP or

amendment to meet SIP requirements, the state director shall give the public an opportunity to comment 

on those recommendations. (BLM Land Use Planning Manual, Section 1610.3-2.) 

Forest Service 

The FS administers national forests, which include several wilderness areas (WA) that could be affected

by direct effects associated with the project: Bridger WA; Fitzpatrick WA; Rawah WA; and Mount Zirkel

WA with mandatory federal Class I designation. In addition, Washakie, Teton, and Savage Run WAs and

the Class II Popo Agie must be included in the RMPPA analysis. As federal land mangers, the USFS

could act in a consultative role to recommend that the BLM impact analysis results, or any future EPA- or 

state-administered PSD refined impact analysis results (if justified), trigger adverse impairment status. If

the FS determines impairment of WAs, BLM, the state, and/or EPA might need to mitigate this predicted 

adverse air quality effect. 

National Park Service 

One area administered by the NPS with a mandatory federal Class I area designation, Rocky Mountain 

National Park, could be affected by direct effects associated with the Rawlins Field Office BLM

emissions. As federal land mangers, the NPS could act in a consultative role to recommend that the BLM 

impact analysis results, or any future EPA- or state-administered PSD refined impact analysis results (if

A4-8 Rawlins RMP 
Draft EIS Appendix 4 

justified), trigger adverse impairment status. If the NPS determines impairment of NPS-administered

Class I areas, BLM, the state, and/or EPA might need to mitigate this predicted adverse air quality effect. 

EXISTING AIR QUALITY

As described in Chapter 3.2, Affected Environment (Air Resources), specific air quality monitoring is not

conducted throughout most of the project area, but air quality conditions are likely to be very good, as 

characterized by limited air pollution emission sources (few industrial facilities and residential emissions 

in the relatively small communities and isolated ranches) and good atmospheric dispersion conditions,

resulting in relatively low air pollutant concentrations. Table A4-3 summarizes the ambient air quality 

background concentrations in the RMPPA. This information was provided by WDEQ. Although 

monitoring is primarily conducted in urban or industrial areas, the data selected are considered to be the

best available representation of background air pollutant concentrations throughout the project area. The 

assumed background pollutant concentrations are below applicable ambient air quality standards for all 

pollutants and averaging times (although ozone levels approach the standards). These national and

Wyoming standards, and PSD increment values are also presented in Tables A4-1 and A4-2. 

Table A4-3. Assumed Background Concentrations and Applicable Ambient Air 

Quality Standards and PSD Increment Values (in μg/m3

) 

Percent of Standards

Averaging (%) 

Time

Measured

Background 

Concentration

(μg/m3) NAAQS WAAQS

Data Source

Carbon Monoxide (CO) 

1-hour 3,336 8 8

8-hour 1,381 14 14

Data collected by Amoco at 

Ryckman Creek for an 8-month 

period during 1978–1979, 

summarized in the Riley Ridge

EIS 

Nitrogen Dioxide (NO2) 

Annual 3.4 3 3

Data collected at Green River 

Basin Visibility Study Site, 

Green River, Wyoming, during 

January–December 2001 (ARS

2002) 

Ozone 

1-hour 169 72 72

8-hour 147 94 94

Data collected at Green River 

Basin Visibility Study Site, 

Green River, Wyoming, during 

June 10, 1998, through 

December 31, 2001(ARS 2002) 

Particulate Matter (PM10) 

24-hour 47 31 31

Annual 16 32 32

Data collected by WDEQ at 

Emerson Building, Cheyenne, 

Wyoming, Year 2002 (WDEQ)

Particulate Matter (PM2.5) 

24-hour 15 23 23

Annual 5 33 33

Data collected by WDEQ at 

Emerson Building, Cheyenne, 

Wyoming, Year 2002 (WDEQ)

Sulfur Dioxide (SO2) 

3-hour 132 10 19

24-hour 43 12 17

Annual 9 11 15

Data collected at LaBarge

Study Area at the Northwest 

Pipeline Craven Creek site 

1982–1983 

Data provided by the WDEQ-AQD 

Note: μg/m3 = micrograms per cubic meter

Rawlins RMP A4-9 
Appendix 4 Draft EIS 

Air Quality Impact Assessment 

As described in Chapter 4, Environmental Consequences (Air Quality), a qualitative emission comparison 

approach was used. A qualitative method was selected because of (1) lack of specific project information 

on location, types, and magnitude of potential projects and (2) time constraints in completing the analysis. 

Emissions calculations were based on the best available engineering data and assumptions; air, visibility, 

and atmospheric deposition data; and emission inventory procedures, as well as on professional and

scientific judgment. However, where specific data or procedures were not available, assumptions were

incorporated. 

Maximum potential near-field particulate matter emissions from traffic on unpaved roads and during well 

pad construction were used to estimate emissions for PM2.5 and PM10 impacts. Maximum air pollutant

emissions from each oil and gas well would be temporary (i.e., occurring during an average of a 12-day

construction period) and would occur in isolation, without significantly interacting with adjacent well

locations. Particulate matter emissions from well pad and resource road construction would be minimized

by application of water and/or chemical dust suppressants. The control efficiency of these dust 

suppressants was computed at 50 percent during construction. During well completion testing, natural

gas could be burned (flared) on an average of 2 days (refer to emission CD for details). 

For any future projects, significance criteria for potential air quality impacts will include local, state,

tribal, and federally enforced legal requirements to ensure that air pollutant concentrations remain within 

specific allowable levels. These requirements and legal limits are presented in Table A4-1. Because 

neither the WDEQ-AQD nor EPA has established ambient HAP standards, only emissions were

calculated. 

Because the potential air pollutant emission sources comprise many small sources spread out over a very

large area, discrete visible plumes are not likely to impact the distant sensitive areas, but the potential for 

cumulative visibility impacts (increased regional haze) is a concern. Regional haze degradation is caused

by fine particles’ and gases’ scattering and absorbing light. Potential changes to regional haze are

calculated in terms of a perceptible “just noticeable change” (1.0 deciview [dv]) in visibility when 

compared to background conditions. A 1.0 dv change is considered potentially significant in mandatory 

federal PSD Class I areas as described in the EPA Regional Haze Regulations (40 CFR 51.300 et seq.), 

and as originally presented in Pitchford and Malm (1994). A 1.0 dv change is defined as about a 10 

percent change in the extinction coefficient (corresponding to a 2 to 5 percent change in contrast, for a 

black target against a clear sky, at the most optically sensitive distance from an observer), which is a 

small but noticeable change in haziness under most circumstances when viewing scenes in mandatory

federal Class I areas. 

It should be noted that a 1.0 dv change is not a “just noticeable change” in all cases for all scenes.

Visibility changes of less than 1.0 dv are likely to be perceptible in some cases, especially where the 

scene being viewed is highly sensitive to small amounts of pollution, as in the case of preferential forward

light scattering. Under other view-specific conditions, such as where the sight path to a scenic feature is 

less than the maximum visual range, a change of greater than 1.0 dv might be required to produce a “just

noticeable change.” However, any future project-specific NEPA analyses will not be designed to predict

specific visibility impacts for specific views in specific mandatory federal Class I areas based on specific 

project designs but to characterize reasonably foreseeable visibility conditions that are representative of a 

fairly broad geographic region, based on emission source assumptions. This approach is consistent with 

both the nature of regional haze and the requirements of NEPA. At the time of a preconstruction air 

quality PSD permit review, the WDEQ-AQD may require a much more detailed visibility impact 

analysis. Factors such as the magnitude of change, frequency, time of year, and meteorological 

A4-10 Rawlins RMP 
Draft EIS Appendix 4 

conditions during times when predicted visibility impacts are above the 1.0 dv threshold (as well as 

inherent conservatism in the impact analyses) should all be considered in assessing the significance of 

predicted impacts. 

The FS, NPS, and FWS have published their Final FLAG Phase I Report (Federal Register, Vol. 66, No. 

2, January 3, 2001), providing “...a consistent and predictable process for assessing the impacts of new 

and existing sources on AQRVs...” including visibility. For example, the FLAG report states, “A 

cumulative effects analysis of new growth (defined as all PSD increment-consuming sources) on visibility 

impairment should be performed,” and further, “If the visibility impairment from the proposed action, in 

combination with cumulative new source growth, is less than a change in extinction of 10% [1.0 dv] for

all time periods, the FLMs will not likely object to the proposed action.” 

Estimation of Emission Factors 

For natural gas compressor engines, the emissions of nitrogen oxides, CO, and formaldehyde are 

determined by the average permitted emission rate allowed by the state under BACT processes. For

fugitive dust impacts, emission rates are obtained from EPA’s AP-42 document titled A Compilation of

Air Pollutant Emission Factors. An AP-42 emission factor is a representative value that attempts to relate

the quantity of a pollutant released into the atmosphere with an activity associated with the release of that

pollutant. Emission factors may be appropriate to use in a number of situations, such as in making 

source-specific emission estimates for areawide inventories. These inventories have many purposes,

including ambient dispersion modeling and analysis, control strategy development, and screening sources 

for compliance investigations. In most cases, these factors are simply averages of all available data of

acceptable quality and are generally assumed to be representative of long-term averages for all sources in

a specific category. 

Emission Assumptions 

When reviewing the emission inventory it is important to understand that assumptions were made 

regarding development. For example, there is uncertainty regarding ultimate development of energy

resources (e.g., number of wells, equipment to be used, specific locations of wells). 

For the qualitative emission comparison approach, the following assumptions were used: 

• 

• 

• 

• 

All emission sources were assumed to operate at their reasonably foreseeable maximum emission

rates (as identified in the other resource sections of this document) simultaneously throughout the 

area. Given the number of sources included in this analysis, the co-probability of such a scenario

actually occurring over an entire year (or even 24 hours) is small. 

In developing the emissions inventory, there is uncertainty regarding ultimate development (e.g.,

number of wells, equipment to be used, specific locations). All proposed coalbed natural gas and

conventional wells were assumed to be fully operational and to remain operating, except for 

normal well closures throughout the area (well numbers were provided by the BLM RMG 

Group). 

The emissions inventory uses peak years of construction and peak years of operation, which 

would not occur throughout the entire development region at the same time. However, it is

possible that conditions close to this could occur in some isolated areas. Further, it is assumed 

that the maximum cumulative emissions will occur in the last year (2023) of the analysis. 

Mitigation measures are included in the emissions inventory that may not be achievable in all

circumstances. However, actual mitigation actions decided on by the developers and local and 

Rawlins RMP A4-11 
Appendix 4 Draft EIS 

state authorities may be greater or less than those assumed in the analysis. For example,

maintaining a construction road speed limit of 15 miles per hour (mph) might be reasonable in a 

construction zone but difficult to enforce elsewhere. Full (100 percent) mitigation of fugitive 

dust from disturbed lands might not be achievable. Further, although 50 percent reduction in

fugitive emissions is assumed based on construction road wetting on the unimproved access road 

to the pad and at the pad, this level of effectiveness is characterized as the maximum possible. 

Wetting was assumed for maintenance traffic. 

• 

• 

• 

• 

• 

• 

• 

• 

• 

Induced or secondary growth related to increases in vehicle miles traveled (VMT) is not included 

in the emissions inventory. Only activities directly related to BLM actions are considered. 

The major assumptions used in developing the emissions calculations are as follows: 

Except for those emission factors that have been lowered through the WDEQ-AQD BACT 

requirements, EPA-recommended emission factors (AP-42) are appropriate for all activities 

The base year is 2003 

Activity factors (or the quantification of activity for each resource area as provided by the 

Rawlins Field Office) are appropriate for the base year and future time frames 

Any anticipated recreational growth would follow growth trends for Wyoming over the past 10

years 

For the qualitative analysis, only emissions from Rawlins Field Office BLM administered 

activities are included. (For the cumulative analysis, emissions calculated by TRC are included 

for other federal and nonfederal actions throughout the state.) 

Criteria pollutants and HAPs are included in the calculations 

Coal mining activity is 1.2 million tons per year production, and coal activity will cease in the

year 2004 

No trona mining activity occurs on Rawlins Field Office BLM land. 

Emissions were calculated for the following activities: coalbed natural gas (CBNG), coal mining, lands 

and realty, livestock grazing, off-highway vehicles (OHV), resource roads, salable minerals, vegetation, 

fire, and natural gas development. Activities related to weed control, wildlife and fisheries, and wild 

horses are assumed to be insignificant sources of air emissions. 

A qualitative emission comparison approach was selected for this RMP air quality analysis. This

approach was used because (1) sufficient specific data were not available on future projects, (2) there was 

limited time available to complete the analysis, (3) as projects are defined quantitative analysis will be

required, and (4) WDEQ-AQD will require demonstration of compliance for any future specific projects. 

There are limitations associated with this approach. However, given the uncertainties concerning the

number, nature, and specific location of future sources and activities, the emission comparison approach 

is defensible and provides a sound basis for comparing alternatives. 

It is important to note that before actual development could occur, the applicable air quality regulatory

agencies (including the state, tribe, or EPA) would review specific air pollutant emissions preconstruction 

permit applications that examine potential project-specific air quality impacts. As part of these permit 

reviews (depending on source size), the air quality regulatory agencies could require additional air quality

impact analyses or mitigation measures. Thus, before development occurred, additional site-specific air

A4-12 Rawlins RMP 
Draft EIS Appendix 4 

quality analyses would be performed to ensure protection of air quality. Federal land managers would

require a demonstration that potential impacts from proposed projects would not adversely impact AQRV 

(including visibility) in sensitive Class I and Class II areas. 

Emissions Calculations 

Emissions for All Activities Except Fire 

Summary emission inventories for each of the BLM activities for the base year short-term and long-term 

scenarios for all of the alternatives are found in Chapter 4.2, Air Quality Impact Assessment. These 

emissions were calculated from data provided by the Rawlins Field Office and used best available 

information, BACT, AP-42, and the emission studies from other BLM documents. 

The numbers of oil and gas wells estimated are provided by the Rawlins Field Office and are shown in

Table A4-4. (This table accounts for net wells in operation and subtracts wells that are abandoned.) 

Table A4-4. Numbers of Oil and Gas Wells for the Rawlins Field Office 

Well Type

Existing Wells

Through 2003 

2008 Operational 

Wells 

2023 Operational 

Wells 

No Action Alternative

Coalbed Natural Gas (development) 62 943 3586 

Coalbed Natural Gas (exploratory) 7 94 355 

Total CBNG Wells 69 1037 3941 

Natural Gas (development) 2439 3150 5285 

Natural Gas (exploratory) 182 253 463 

Total Conventional Gas Wells 2621 3403 5748 

Total Combined Wells 2690 4440 9689 

Alternative 2 

Coalbed Natural Gas (development) 62 989 3769 

Coalbed Natural Gas (exploratory) 7 99 374 

Total CBNG Wells 69 1088 4143 

Natural Gas (development) 2439 3180 5404 

Natural Gas (exploratory) 182 275 544 

Total Conventional Gas Wells 2621 3455 5948 

Total Combined Wells 2690 4543 10091 

Alternative 3 

Coalbed Natural Gas (development) 62 758 2843 

Coalbed Natural Gas (exploratory) 7 76 282 

Total CBNG Wells 69 834 3125 

Natural Gas (development) 2439 2952 4487 

Natural Gas (exploratory) 182 251 464 

Total Conventional Gas Wells 2621 3203 4951 

Total Combined Wells 2690 4037 8076 

Alternative 4 

Coalbed Natural Gas (development) 62 907 3474 

Coalbed Natural Gas (exploratory) 7 108 416 

Total CBNG Wells 69 1015 3890 

Natural Gas (development) 2439 3127 5255 

Natural Gas (exploratory) 182 251 470 

Total Conventional Gas Wells 2621 3378 5725 

Total Combined Wells 2690 4393 9615 

Rawlins RMP A4-13 
Appendix 4 Draft EIS 

Using the well numbers, individual tables of air emissions for all BLM activities were calculated in linked 

spreadsheets. These spreadsheets are available on an emissions CD. 

Because oil and gas field activities consist of many phases (i.e., exploration, development, production, 

and closure), the components that need to be included in emission calculations are complex. To

understand the elements and assumptions used in the emissions calculations in the emissions CD, the 

following summary is provided. 

Table of Contents for Emissions CD 

A list of the detailed spreadsheets, including a short description of some of the spreadsheets, is included 

below. (A brief description of the contents is included in the first several titles of natural gas development

to provide a roadmap of the titles for the other resource areas.) In addition, a gas process flow diagram is 

included as a pdf file in the emissions CD. 

Conventional Natural Gas—Exploratory, Development, and Operations 

• 

• 

• 

• 

• 

• 

• 

• 

• 

•

•

• 

•

• 

•

• 

• 

• 

•

• 

• 

• 

•

• 

•

•

• 

• 

Table ZZ—major oil and gas assumptions 

Assumptions—secondary level of assumptions 

Compressor Horsepower (HP) Estimates 

ng-pad const.-fug dust (conventional natural gas fugitive dust from construction)

Well Field Gas Charac (well field gas characteristics) 

ng-pad const.-exh &flare-shrt (conventional natural gas construction traffic exhaust and flaring 

short term) 

ng-pad const.-exh &flare-long (conventional natural gas construction traffic exhaust and flaring

long term) 

ng-commuting veh-fug dust-shrt (conventional natural gas fugitive dust from commuting 

vehicles short term) 

ng-commuting veh-fug dust-long 

ng-commuting veh-exhaust-shrt

ng-commuting veh-exhaust-long

ng-Operations-NG compress-shrt (natural gas operations compressors short term) 

ng-Operations-NG compress-long

ng-Op NG Dehyd&Flash&Flare (VOC emissions natural gas operations dehydrators, flashing and 

flaring) 

ng-Ops-Dehyd&Sep-Heaters-shrt&long (natural gas operations dehydrator and separators 

heaters) 

ng-Ops-sta. vis-dust&exh-short (natural gas operation station visits vehicular emission short 

term) 

ng-Ops-sta. vis-dust&exh-long (natural gas operation station visits vehicular emission long term) 

ng-Ops-WO-dust&exh-short (natural gas well operations vehicle dust and exhaust short term) 

ng-Ops-WO-dust&exh-long2

ng-Ops W&P vis-dust&exh-shrt (well and pipe station visits vehicular emissions) 

ng-Ops W&P vis-dust&exh-long 

ng-Road maint-dust&exh-shrt (road maintenance vehicular dust and exhaust short term) 

ng-Road maint-dust&exh-long

ng-Comp maint-dust&exh-short (compressor maintenance vehicular dust and exhaust short term) 

ng-Comp maint-dust&exh-long

Tanks-Condensate&Loadout (emissions from tanks and truck loadout) 

ng-summary-criteria-short (summary of all natural gas emissions short term) 

Annual Summary 2008 

A4-14 Rawlins RMP 
Draft EIS Appendix 4 

• 

•

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

•

•

•

•

• 

• 

•

•

• cbng-Ops-WO-dust&exh-short 

• cbng-Ops-WO-dust&exh-long 

• 

• 

•

•

•

•

• 

•

• 

• 

•

• 

•

•

•

•

•

•

•

•

Annual Summary 2023 

ng-summary-criteria-long

(Same analysis and tabs for Base Year as above for 2003). 

Coalbed Natural Gas—Exploratory, Development, and Operations 

Table ZZ—major oil and gas assumptions 

Assumptions—secondary level of assumptions 

Compressor Horsepower (HP) Estimates 

cbng-pad const.-fug dust 

cbng Well Field Gas Charac-(well field gas characterisitics) 

cbng-pad const. traffic-exh-shrt (Heavy equipment and traffic exhaust short term) 

cbng-pad const. traffic-exh-long 

cbng-commuting veh-fug dust-shrt 

cbng-commuting veh-fug dust-long 

cbng-commuting veh-exhaust-shrt

cbng-commuting veh-exhaust-long

cbng-operations-NG compress-shrt

cbng-operations-NG compress-long

cbng Dehyd shrt&long-(dehydrators short and long term emissions) 

cbng-Ops-Sep-shrt&long (coalbed natural gas operational separators) 

cbng-Ops-sta. visits-dust&exh-short

cbng-Ops-sta. visits-dust&exh-long

cbng-Ops W&P vis-dust&exh-shrt- (well and pipe visits fugitive and vehicular emissions) 

cbng-Ops W&P vis-dust&exh-long 

cbng-Road maint-dust&exh-shrt

cbng-Road maint-dust&exh-long

cbng-Compress maint-dust&exh-short

cbng-Compress maint-dust&exh-long

CBNG Water Reinjection (Coalbed Natural gas water reinjection pumps short and long) 

cbng-summary-criteria-short

Annual NG Emissions 2008 

Annual NG Emissions 2023 

cbng-summary-criteria-long

(same analyis and tabs for Base Year 2003 as above). 

Coal Development 

Coal emissions

Lands and Realty

L&R-heavyequip-dust-shrt&long

L&R-heavyequip-exh-shrt&long

L&R-Commuting-FugDust-short

L&R-Commuting-FugDust-long

L&R-Commuting-exhaust-short

L&R-Commuting-exhaust-long

Summary-short

Rawlins RMP A4-15 
Appendix 4 Draft EIS •••••••••••

• ATVs •••••••

• sg-batchdrop 

• 

• gran-crush,screen,tx,etc •

• granite-batchdrop ••

• limestone-batchdrop ••••••••• Summary-long.

Livestock Grazing LG-heavyequ

ip-dust-shrt&long

LG-heavyequip-exh-shrt&long

LG-Commuting-FugDust-shortunpav

LG-Commuting-FugDust-shortpaved

LG-Commuting-FugDust-longunpav

LG-Commuting-FugDust-longpaved

LG-Commuting-exhaust-short

LG-Commuting-exhaust-long

Summary-short

Summary-long.

Off-Highway Vehicles OH Motorcycle

s

Snowmobiles

OHV-Summary.

Resource Roads res road-du

st&exh-short

resroad-dust&exh-long.

Salable Minerals sg-dry,hand,screen,load,etc

.

sg-unpavedroads

heavy equipment-all operations 

gran-unpavedroads

lime-crush,screen,tx,etc

lime-unpavedroads

saleable-summary.

Vegetation Veg

-heavyequip-dust-shrt&long

Veg-heavyequip-exh-shrt&long

Veg-Commuting-FugDustshort

Veg-Commuting-FugDustlong

Veg-Commuting-exhaust-short

Veg-Commuting-exhaust-long

Summary-short

Summary-long.

A4-16 Rawlins RMP 
Draft EIS Appendix 4 

The tables are linked spreadsheets with emissions calculations for short-term and long-term time frames. 

Each set of calculations for the non-oil and non-gas spreadsheets is cumulative, that is, the total emissions 

for all activities are cumulative for 5 and 20 years, respectively. The beginning of each spreadsheet

identifies the emission factors and activity factors, in tabular format. 

The detailed emissions tables identified above are on an emissions CD and are available by request from 

Susan Caplan. 

Prescribed Fire Emissions Estimation 

To estimate the total emissions of particulate matter and carbon monoxide from prescribed fires, the 

Simple Approach Smoke Estimation Model (SASEM) was used. SASEM is a simple screening-level 

Gaussian dispersion model designed to predict ground-level particulate matter impacts from a single 

source (fire) in generally flat terrain for the western United States. 

When available, site-specific information provided by the Rawlins Field Office was used as input to the 

model. When such information was not available, either built-in model defaults or professional judgment 

was used to supply missing data. 

A total of three scenarios were run according to the information provided by the Rawlins Field Office for 

Alternative 1. These are as follows: 

• Fire RFA. Wildland/Urban Interface; five 20-acre treatments; total of 300 tons burned 

• 

• 

Timber Harvest Residue. Ten 10-acre burns, total of 160 tons burned 

Vegetation RFA. 4,000 acres per year of prescribed fire treatments. 

It should be noted that the emission production module of SASEM was used only to estimate total 

emissions for each event as input to the qualitative air quality assessment. (See references in Chapter 4,

Sestak and Riebau 1988.) The detailed results for these model runs are available from Susan Caplan

(contact information provided above). 

Rawlins RMPPA BLM Emissions 

Tables A4-5 through A4-7 show summaries of total BLM emissions, estimated for the base year (2003), 

the short-term (2008), and the long-term (2023). The tables are broken down by activity and show

emissions for the time frame referenced (i.e., base year, short-term, and long-term). Emissions are 

calculated on an annual basis (tons per year). In addition, for both the short-term and the long-term time 

frames (Tables A4-6 and A4-7, respectively), emissions were calculated for each alternative. (Because the

base year is the same for all alternatives, only one set of base year emissions was needed.) These tables

were used to generate the summary tables and figures presented in Chapter 4. 

Rawlins RMP A4-17 
Appendix 4 Draft EIS 

Table A4-5. Base Year (2003) Emissions Inventory for BLM-Administered Lands 

Within RMPPA (tons per year) 

Base Case 

Activity PM10 Tons PM2.5 Tons NOx

Tons

SO2 

Tons

CO 

Tons

VOC 

Tons

HAPs

Tons b

 

Coalbed Natural Gas 137 27 125 5 99 52 8 

 

Coal Mining 32 32 a 41 5 72 4 0

Lands and Realty 44 7 2 0 1 0 0 

Livestock Grazing 52 8 3 0 3 1 0 

OHV 4 4 2 0 256 135 14

Resource Roads 2 0 1 0 0 0 0 

Salable Minerals 762 200 0 0 0 0 0

Vegetation 9 1 0 0 0 0 0

Fire 170 142 0 0 0 0 0

 

Subtotal: Other Activities 1120 401 47 5 330 139 14 

 

Conventional Natural Gas 594 195 3,060 51 1,632 13,564 1,407

 

Total Base Year 2003 1,851 623 3,232 61 2,061 13,755 1,429

a PM2.5 assumed = PM10 for this activity. Coal mining will cease after 

2004 b HAP assumed = VOC × 0.1 for non-gas activities 

Table A4-6. Short-Term (2008) Emissions Inventory for BLM-Administered Lands 

Within RMPPA (tons per year) 

Activity

PM10 

Tons

PM2.5 

Tons

NOx 

Tons

SO2

Tons

CO 

Tons

VOC 

Tons

HAPs

Tons b

Alternative 1 (No Action Alternative) 

Coalbed Natural Gas 536 137 1,313 24 1,406 791 120 

 

Coal Mining 0 0 a 0 0 0 0 0

Lands and Realty 44 7 2 0 1 0 0 

Livestock Grazing 52 8 3 0 3 1 0

OHV 7 7 3 0 574 209 21

Resource Roads 2 0.1 1 0.1 0.2 0.05 0

Salable Minerals 762 200 NA NA NA NA NA 

Vegetation 64 10 2 0 3 1 0

Fire 170 142 0 0 0 0 0

Subtotal: Other Activities 1100 374 10 1 581 211 0 

Conventional Natural Gas 734 247 4,137 65 2,148 17,584 1825 

Total Short Term 2,370 758 5,460 90 4,135 18,586 1,966

Alternative 2 

Coalbed Natural Gas 564 144 1,382 26 1,480 833 126 

 

Coal Mining 0 0 a 0 0 0 0 0

A4-18 Rawlins RMP 
Draft EIS Appendix 4 

Activity

PM10 

Tons

PM2.5 

Tons

NOx 

Tons

SO2

Tons

CO 

Tons

VOC 

Tons

HAPs

 b Tons

Lands and Realty 44 7 2 0 1 0 0 

Livestock Grazing 52 8 3 0 3 1 0

OHV 7 7 3 0 574 209 21

Resource Roads 2 0 1 0 0 0 0

Salable Minerals 762 200 NA NA NA NA NA 

Vegetation 64 10 2 0 3 1 0

Fire 170 142 0 0 0 0 0

Subtotal: Other Activities 1100 374 10 1 581 211 0 

Conventional Natural Gas 763 256 4,280 67 2,206 18,080 1,876

Total Short Term 2427 774 5672 94 4267 19,124 2,023 

Alternative 3 

Coalbed Natural Gas 424 109 1040 19 1112 626 95 

 

Coal Mining 0 0 a 0 0 0 0 0

Lands and Realty 44 7 2 0 1 0 0 

Livestock Grazing 52 8 3 0 3 1 0

OHV 7 7 3 0 574 209 21

Resource Roads 2 0 1 0 0 0 0

Salable Minerals 762 200 NA NA NA NA NA 

Vegetation 64 10 2 0 3 1 0

Fire 170 142 0 0 0 0 0

Subtotal: Other Activities 1100 374 10 1 581 211 0 

Conventional Natural Gas 616 213 3596 54 1933 14,871 1549 

Total Short Term 2140 696 4646 74 3626 15,708 1665 

Alternative 4 

Coalbed Natural Gas 530 136 1,298 24 1,391 783 118 

 

Coal Mining 0 0 a 0 0 0 0 0

Lands and Realty 44 7 2 0 1 0 0 

Livestock Grazing 52 8 3 0 3 1 0 

OHV 7 7 3 0 574 209 21

Resource Roads 2 0 1 0 0 0 0 

Salable Minerals 762 200 NA NA NA NA NA

Vegetation 64 10 2 0 3 1 0

Fire 170 142 0 0 0 0 0

Subtotal: Other Activities 1100 374 10 1 581 211 0 

Conventional Natural Gas 632 222 3,747 55 2,038 17,357 1,802

Total Short Term 2,262 732 5,055 80 4,010 18,351 1,941

a PM

2.5

 assumed = PM

10

 for this activity. Coal mining will cease after 2004

b HAP assumed = VOC × 0.1 for non-gas activities

Rawlins RMP A4-19 
Appendix 4 Draft EIS 

Table A4-7. Long-Term (2023) Emissions Inventory for BLM-Administered Lands 

Within RMPPA (tons per year) 

Activity

PM10 

Tons

PM2.5 

Tons

NOx 

Tons

SO2 

Tons

CO 

Tons

VOC 

Tons

HAPs

Tons b

Alternative 1 (No Action Alternative) 

 

Coalbed Natural Gas 877 324 4,648 47 5,427 3,084 470 

 

Coal Mining 0 0 a 0 0 0 0 0

Lands and Realty 61 9 4 0 2 1 0 

Livestock Grazing 47 7 3 0 3 1 0 

OHV 11 11 5 0 889 326 33

Resource Roads 2 0.1 1 0.12 0.2 0.05 0

Salable Minerals 762 200 NA NA NA NA NA 

Vegetation 64 10 2 0 3 1 0

Fire 170 142 0 0 0 0 0

 

Subtotal: Other Activities 1117 378 14 1 898 329 33 

 

Conventional Natural Gas 904 318 5,502 77 3,169 17,451 1,847

 

Total Long Term 2,898 1,020 10,164 125 9,494 20,864 2,350

Alternative 2 

 

Coalbed Natural Gas 922 341 4,892 49 5,712 3,246 495 

 

Coal Mining 0 0 a 0 0 0 0 0

Lands and Realty 61 9 4 0 2 1 1 

Livestock Grazing 47 7 3 0 3 1 0 

OHV 11 11 5 0 889 326 33

Resource Roads 2 0 1 0 0 0 0 

Salable Minerals 762 200 NA NA NA NA NA 

Vegetation 64 10 2 0 3 1 0

Fire 170 142 0 0 0 0 0

 

Subtotal: Other Activities 1117 378 14 1 898 329 34 

 

Conventional Natural Gas 944 333 5,759 80 3,307 19,028 2009 

 

Total Long Term 2,983 1,052 10,665 130 9,917 22,603 2538

Alternative 3 

 

Coalbed Natural Gas 692 256 3,672 37 4,287 2,438 371 

 

Coal Mining 0 0 a 0 0 0 0 0

Lands and Realty 61 9 4 0 2 1 0 

Livestock Grazing 47 7 3 0 3 1 0 

OHV 11 11 5 0 889 326 33

Resource Roads 2 0 1 0 0 0 0 

Salable Minerals 762 200 NA NA NA NA NA 

Vegetation 64 10 2 0 3 1 0

Fire 170 142 0 0 0 0 0

 

Subtotal: Other Activities 1117 378 14 1 898 329 33 

 

Conventional Natural Gas 741 264 4,592 63 2,682 13,719 1,459

 

A4-20 Rawlins RMP 
Draft EIS Appendix 4 

Activity

PM10 

Tons

PM2.5 

Tons

NOx 

Tons

SO2 

Tons

CO 

Tons

VOC 

Tons

HAPs

 b Tons

Total Long Term 2,550 898 8,278 101 7,867 16,486 1,863

Alternative 4 

Coalbed Natural Gas 867 320 4,602 46 5,374 3,054 466 

 

Coal Mining 0 0 a 0 0 0 0 0

Lands and Realty 61 9 4 0 2 1 0 

Livestock Grazing 47 7 3 0 3 1 0 

OHV 11 11 5 0 889 326 33

Resource Roads 2 0 1 0 0 0 0

Salable Minerals 762 200 NA NA NA NA NA 

Vegetation 64 10 2 0 3 1 0

Fire 170 142 0 0 0 0 0

Subtotal: Other Activities 1117 378 14 1 898 329 33 

Conventional Natural Gas 801 293 5,116 67 3,062 16,957 1,797

Total Long Term 2,785 991 9,732 114 9,334 20,340 2,296 a PM2.5 assumed = PM10 for this activity. Coal mining will cease after 2004 b HAP assumed = VOC × 0.1 for non-gas activities

RESULTS OF IMPACT ANALYSIS

Table A4-8 summarizes the existing conditions described in Chapter 3, Affected Environmental (Air

Quality). 

Table A4-8. Existing Conditions 

Air Quality Value

Air Pollutant Concentrations

Criteria Air 

Pollutants 

Concentrations

Base year: in compliance with NAAQS and WAAQS 

Visibility (Rocky Mountain National Park [RMNP] and Centennial) 

Visual Range 20% cleanest: 

Base year 150–173 miles (RMNP) and 178 (Centennial 2001) 

Average: 

Base year 112–126 miles (RMNP) and 117 (Centennial 2001) 

20% haziest: 

Base year 71–88 miles (RMNP) and 81 Centennial 2001) 

Visibility Guidelines 

Base year: Within guidelines 

Atmospheric Deposition (Centennial, Wyoming) 

Precipitation pH Base year: 4.9–5.2 

Total Deposition Total nitrogen depositiona

Base year: 4.3 kg/ha/year 

Total sulfur depositionb

Base year: 2.5 kg/ha/year 

Total nitrogen deposition guidelines

Base year: Not within guidelines 1999: otherwise, within 

Total sulfur deposition guidelines 

Base year: Within guidelines 

Rawlins RMP A4-21 
Appendix 4 Draft EIS 

Air Quality Value

Air Pollutant Concentrations a Proposed acceptable total annual loading nitrogen deposition is 3 to 5 kg/ha/year (USFS 

1989)

b

Proposed acceptable total annual loading sulfur deposition is 5 kg/ha/year (USFS 1989) 

The emission inventory results and qualitative impacts for the alternatives are included in Chapter 4.2, Air 

Quality Assessment, and total emissions are shown in Table A4-9. Table A4-10 shows the increases in

emissions from alternative to alternative, and year to year. 

Table A4-9. Total Emissions for Alternatives (tons per year) 

Alternative 2003 2008 2023 

Alternative 1 (No Action Alternative) 20,960 30,641 43,545

Alternative 2 20,960 31,585 46,298 

Alternative 3 20,960 26,194 35,282 

Alternative 4 20,960 29,758 42,305 

Note: Totals are all pollutants minus PM2.5 and HAPs 

Table A4-10. Increase in Annual Air Emissions from Base Year Conditions on 

BLM-Administered Lands Within the RMPPAa

Time

Frame 

PM10 PM2.5 NOx SO2 CO VOC HAP 

Alternative 1 (No Action Alternative) 

2008 519

(28%) 

135 

(22%) 

2,228 

(69%) 

29 

(48%) 

2,074 

(101%) 

4,831 

(35%) 

537 

(38%) 

 2023 1,047

(57%) 

397 

(64%) 

6,932 

(214%) 

64 

(105%) 

7,433 

(361%) 

7,109 

(52%) 

921 

(64%) 

Alternative 2 

2008 576

(31%) 

151 

(24%) 

2,440 

(76%) 

33 

(54%) 

2,206 

(107%) 

5,369 

(39%) 

594 

(42%) 

2023 1,132

(61%) 

429 

 (69%) 

7,433 

(230%) 

69 

(113%) 

7,856 

 (381%) 

8,848 

(64%) 

1,109 

(78%) 

Alternative 3 

2008 289

(16%) 

73 

(12%) 

1414 

(44%) 

13 

(21%) 

1,575 

(76%) 

1953 

(14%) 

236 

(17%) 

2023 699

(38%) 

275 

(44%) 

5,046 

(156%) 

40 

(66%) 

5,806 

(282%) 

2431 

(20%) 

434 

(30%) 

Alternative 4 

2008 411

(22%) 

109 

(17%) 

1,823 

(56%) 

19 

(31%) 

1,949 

(95%) 

4,596 

(33%) 

512 

(36%) 

2023 934

(50%) 

368 

(59%) 

6,500 

(201%) 

53 

(87%) 

7,273 

(353%) 

6,585 

(48%) 

867 

(61%) a

 Constituents increase in tons per year and (in percentage change from base year emissions) 

OTHER EMISSIONS DATA

Although only BLM activities were included in the qualitative analysis, other emissions data are being 

developed for areas that include the Rawlins District. These data were provided by TRC Environmental

Corp (TRC, 2004), using State of Wyoming air permit information and other information, including all 

potential (PTE) and some actual emissions for point sources throughout Wyoming that were permitted 

between January 1, 2001, and June 30, 2003. Tables A4-11 and A4-12 show the calculations of the

A4-22 Rawlins RMP 
Draft EIS Appendix 4 

incremental increase (i.e., change from the base year) in emissions from January 1, 2001 (the base year), 

through June 30, 2003, for permitted sources. 

The Wyoming statewide emission inventory conducted by TRC indicates that there will be a change in 

future emissions of NOx, SO2, PM10, and PM2.5 in the RMPPA and for the State of Wyoming. This study

uses different base year dates. The Wyoming statewide complete emissions increases (or decreases) were

calculated (1) from all permitted sources, from January 1, 2001, through June 30, 2003; (2) all new oil 

and gas commission sources from 2002; and (3) all NEPA authorized and other quantifiable emissions 

from June 30, 2003. (This last case is referred to as the Wyoming statewide Reasonable Forseable 

Development [RFD]). It should be noted that not all emissions permitted or authorized during this period 

are occurring yet. 

The RFD case refers only to oil and gas projects and covers the change in emissions after June 30, 2003, 

for authorized NEPA and other quantifiable emissions. (Specifically, the RFD case is defined by TRC as 

“...1) the NEPA-authorized but not yet developed portions of the Wyoming NEPA projects and 2) not yet

authorized NEPA projects for which air quality analyses were in progress and for which emissions had 

been quantified.)” Also, complete (total) emissions are calculated. Table A4-12 shows these emissions.

It is expected that these data will someday be integrated with the BLM emissions data to depict all 

emissions in the Rawlins District and can be used for cumulative analysis. Also, this information will be 

needed if air dispersion modeling is performed in the area. 

Table A4-11. Incremental Emissions From Permitted Sources, January 2001 

through June 2003, for the RMPPA 

WDEQ-AQD Permitted Sources WOGCC Permitted Oil and Gas Wellsa

Change In Emissions (tpy) Change In Emissions (tpy)

Area NOx SO2 PM10 PM2.5 NOx SO2 PM10 PM2.5

Rawlins FOb 281 (1,002) (49) (49) 9.5 -- -- --

Wyoming 20,344 (85) (1,812) (1,539) 150.9 -- -- --

a Emission factors per well were assumed according to the following: 0.045 tons per year (tpy) of NOx per 

producing natural gas or coalbed natural gas well, equivalent to well emission rates calculated for the Jonah 

Infill Project, 2004, and 0.3 tpy NOx per producing oil well (obtained from Denise Kohtala, WDEQ-AQD). b

 Permitted oil and gas wells category includes Carbon, Albany, and Laramie counties. 

Table A4-12. RFD and Complete Emissions for the RMPPAa 

RFDb Complete Inventory

 Change In Emissions (tpy) Change In Emissions (tpy)

Area NOx SO2 PM10 PM2.5 NOx SO2 PM10 PM2.5

Rawlins FOc 1,147 0 6.8 6.8 1,438 (1,002) (43) (43)

Wyoming 6,016 115 741 195 26,510 30 (1,072) (1,343) a Emission factors per well were assumed according to the following: 0.045 tpy of NOx per producing 

natural gas or coalbed natural gas well, equivalent to well emission rates calculated for the Jonah Infill 

Project, 2004, and 0.3 tpy NOx per producing oil well, obtained from Denise Kohtala, WDEQ-AQD. b

 RFD defined as authorized NEPA projects and NEPA projects not yet authorized but for which air 

emissions have been quantified. c

 Permitted oil and gas wells category includes Carbon, Albany, and Laramie counties. 

The data in Table A4-11 indicate that permitted sources from January 1, 2001, through June 30, 2003, 

have contributed additional NOx emissions of 281 tons per year and that emissions of other pollutants 

were reduced for the RMPPA. However, because the base year for the emissions calculations for the 

Rawlins RMP A4-23 
Appendix 4 Draft EIS 

Rawlins RMPPA is for 2003, the RFD values in Table A4-12 are more appropriate for comparison of

cumulative impact. In Table A4-12, the RFD NOx emissions for the Rawlins Field Office are about onehalf the NOx calculated for the RMP (see Table A4-10) for the short term and about one-sixth of the 

emission differences projected for the long term (see tables above for comparisons). The RFD values for 

the State of Wyoming are a little less than long-term BLM RMP emissions, except for particulates. (This 

is to be expected because much of the BLM RMP particulate emissions sources, such as construction 

activities, do not require a permit.) 

CONCLUSIONS AND RECOMMENDATIONS

A qualitative emission comparison approach was selected for analysis of impacts on air quality. This

approach was used because (1) sufficient specific data were not available on future projects, (2) there was 

limited time available to complete the analysis, (3) quantitative analysis will be required as development

projects are defined in the future, and (4) WDEQ-AQD will require demonstration of compliance with

federal and state air quality regulations and standards for any future development projects. Given the 

uncertainties regarding the number, nature, and specific location of future emission sources and activities, 

the emission comparison approach is defensible and provides a sound basis for comparing the potential

impacts under the various alternatives. Federal land managers will require a demonstration that potential 

impacts from proposed projects will not adversely impact AQRV (including visibility) in sensitive Class I

and Class II areas. 

For the RMP-specific air quality analysis, the BLM concludes the following: 

Under Alternative 1, emissions have been calculated for the base year and for 5-year and 20-year time

horizons. These will serve as the basis for comparisons of alternatives. Information in Tables A4-7

through A4-9 indicates that the total emissions of criteria pollutants increase from 20,960 tons per year in 

the base year (2003) to 43,545 tons per year by 2023. Most of the increase is due to oil and gas

exploration and development. Alternative 2 produces higher emissions than Alternative 1 (emissions of

46,298 ton per year in 2023), and Alternative 3 produces lower emissions estimates for 2023 (35,282 tons

per year). Alternative 4 produces emission levels between those of Alternatives 2 and 3 (42,305 tons per 

year). 

Given the low ambient concentrations that exist in the Rawlins area for all of the pollutants except ozone,

it is expected that the increase in emissions, under any alternative, of carbon monoxide (CO), nitrogen 

oxides (NO2), sulfur dioxide (SO2), PM10, and PM2.5 will not cause any exceedance of state or federal

ambient air quality standards. Because a quantitative relationship between the expected air emissions 

calculated above and the subsequent potential impacts on ambient criteria pollutant concentrations, 

visibility, atmospheric deposition, or ozone are not known, it is not possible to draw any conclusions as to

potential expected impacts on these air quality values from any alternative. BLM intends to make

quantitative estimates of these impacts for project-specific EISs and in the statewide air quality analysis. 

For the cumulative analysis, BLM concludes the following: 

Given the low ambient concentrations that exist in the Rawlins RMPPA for criteria pollutants except

ozone, it is expected that the cumulative increase in emissions for all of sources in the region of influence

(ROI) of carbon monoxide (CO), nitrogen oxides (NOx), sulfur dioxide (SO2), PM10, and PM2.5 would not

cause any exceedance of state or federal ambient air quality standards. 

Because a quantitative relationship between the expected air emissions calculated above and the 

subsequent potential cumulative impacts on the air quality values of visibility, atmospheric deposition, or

ozone are not known, it is not possible to quantify potential impacts on these air quality values from the 

A4-24 Rawlins RMP 
Draft EIS Appendix 4 

sources in the ROI. However, because air quality analyses from recent energy development projects, such

as the Desolation Flats project (BLM 2003), estimate potential impacts on visibility, the possibility that

the emissions described in Section 4.2 may contribute to significant impacts on visibility must be

considered. Results of a quantitative analysis using modeling performed for the Desolation Flats EIS

suggest that RMPPA activities could contribute to a significant impact on visibility in the Bridger, 

Fitzpatrick, Mount Zirkel, and Rawah WAs. 

In addition to these findings, monitoring of total nitrogen deposition in the Snowy Range shows

deposition loading above the Forest Service LOC. Accordingly, emissions described in Section 4.2 may

contribute to significant impacts on total nitrogen deposition. BLM intends to make quantitative 

estimates of these impacts for project-specific EISs and in the statewide air quality analysis. 

Given the qualitative nature of the emission comparison approach, it is recommended that the following 

actions be performed: 

• 

• 

• 

A more sophisticated air quality set of tools should be considered for future analysis of specific 

projects (i.e., modeling) 

Additional monitoring for ambient criteria pollutants, visibility, and atmospheric deposition 

should be conducted in the area. 

Mitigation measures, such as those discussed in this AQTSD, should be considered. Some of 

these measures include dust suppression and control during construction, electric power

generation for natural gas compressor engines, flareless completion, and natural gas compressor

engine nitrogen oxide controls. 

INTERNET RESOURCES

Numerous Internet resources were accessed to develop the data used in this document. Key information

concerning emission factors and emissions was obtained from EPA Web sites.

Climate 

Western Regional Climate Center:http://www.wrcc.sage.dri.edu/climsum.html/

NOAA: http://www.noaa.gov

Stagnation Index: http://www.ncdc.noaa.gov/oa/climate/research/stagnation/stagnation.html

Air Quality: Emissions 

EPA: http://www.epa.gov/ttn/chief/ap42

Air Quality: Concentrations 

EPA: http://www.epa.gov/air/data/geosel.html

CASTNet: EPA: http://www.epa.gov/castnet

NPS: http://www2.nature.nps.gov/ard/gas/airatlas-du/viewer_index.htm

Rawlins RMP A4-25 
Appendix 4 Draft EIS 

BLM: http://www.blm.gov

BLM: http://www.wy.blm.gov

Air Quality: Atmospheric Deposition 

NADP: http://nadp.sws.uiuc.edu/

CASTNet: EPA: http://www.epa.gov/castnet

NPS: http://www2.nature.nps.gov/ard/gas/airatlas-du/viewer_index.htm

Air Quality: Visibility

IMPROVE: http://vista.cira.colostate.edu/improve

IMPROVE: http://vista.cira.colostate.edu/views

FLAG: http://www.WDEQ-AQD.nps.gov/ard/flagfree

Wyoming Visibility Monitoring Network: http://www.wyvisnet.com

MITIGATION OPTIONS

Mitigation may be applied to fugitive dust and NOx impacts. Fugitive dust refers to any particulate matter 

that is not deliberately emitted by a well-defined source. Fugitive dust sources typically include 

windblown dust from unvegetated lands, construction, and unpaved roads. Table A4-13 shows several 

available fugitive dust mitigation options. 

A4-26 Rawlins RMP 
Draft EIS Appendix 4 

Table A4-13. Fugitive Dust Mitigation Measures (PM10), Effectiveness and Cost 

Dust Sources

Disturbed Areas Unpaved Roads a,b,c

Effectiveness Level proportional

to percentage of land cover 

0 to 50% reduction in uncontrolled dust emissions

33% to 100% control efficiency 

80% for 15 mphc

65% for 20 mphc25% for 30 mphc

30% reduction 

90% reduction 

Estimated Cost 

Unknown $4,000/mile $2,000 to

$4,000/mile per year 

Unknown $9,000/

mile 

$11,000 to $60,000/mile

aImproved and county roads bWetting of construction roads during the construction period. Wetting of construction roads not required for once-amonth maintenance trips to well pads. cReductions assume a 40-mile-per-hour base speed. 

Rawlins RMP A4-27 
Appendix 4 Draft EIS

Nitrogen oxide emissions are associated with combustion. Table A4-14 shows several potential 

mitigation measures that could reduce impacts from NOx emissions. The appropriate level of control will 

be determined by the WDEQ-AQD during the construction permit process. 

Table A4-14. Nitrogen Oxides (NOx) Mitigation Measures Efficiency

NOx Emissions Sources 

Field 

Compressors

Sales 

Compressors

Temporary

Diesel 

Generatorsa

Heavy 

Equipment 

Mitigation 

Options/Efficiency

Implement Best 

Available Control 

Technology 

Typically results in 

a NOx emission

rate of about 1 

g/bhp-hr 

Implement Best 

Available Control 

Technology 

Typically results

in a NOx

emission rate of 

about 1 g/bhp-hr 

Register with 

State; WDEQ 

regulate as 

appropriate 

Voluntary use of 

electric 

enginesb

 aWyoming is currently registering these generators to determine whether NOx emissions are 

significant. bBACT could include electric compression. 

In addition, Table A4-15 shows additional mitigation measures to be considered in the Rawlins impact 

assessment. These are general mitigation opportunities that should be considered and applied as 

appropriate. BLM has no authority to require any application of these measures, although industry is 

encouraged to implement these measures on its own before it is required to by WDEQ. Advances in

technology are likely to offer new mitigation options during the time covered by the RMP. Under NEPA, 

the planners of individual projects in the RMPPA must recommend mitigation measures that are 

appropriate for the projects. The Wyoming DEQ, as the permitting authority, will review permit

applications and require specific emission control devices and measures. All costs shown in Table A4-15 

are approximate. 

Table A4-15. Additional Mitigation Measures With Approximate Costs and 

Benefits 

Type of 

Mitigation 

Approximate

Cost 

Environmental 

Cost 

Potential 

Limitations

Environmental 

Benefit 

Selective 

Catalytic 

Reduction for 

Compressor 

Emissions 

$4,000 to $27,000 

per NOx ton-year 

Possible NH3

releases 

Cost may be 

prohibitive for 

oil and gas 

applications 

NOx emission rate 

reduced to 0.1 g/hphr; decreased 

visibility impact

“Green 

Completions” 

and 

Flowback Units

Capital cost ranges 

from $1,000 to 

$10,000. 

Operating cost is 

$1,000/year. 

Payback 1–3 years 

Moving equipment 

to and from well 

completions; 

fugitive dust from 

truck 

Saves 100,000 cubic 

feet of gas per well 

per year; 

reduces flaring

emissions by 70% to 

90% at completion 

Condenser on 

Glycol 

Dehydrator

$1,000 to $10,000 Unknown 1% to 10% VOC 

reduction 

Activated 

Carbon Filter 

on Condensate

Storage Tank 

$1,000 and up Energy required to 

recycle filter

50% to 80% VOC 

reduction 

A4-28 Rawlins RMP 
Draft EIS Appendix 4 

Type of Approximate Environmental Potential Environmental 

Mitigation Cost Cost Limitations Benefit 

Electrical 

Compressors 

Capital cost is 40% 

of gas turbine cost. 

Operating costs 

depend on location 

of transmission

lines 

Displaced air 

emissions from

compressor unit to 

electric power 

plant 

Moving air emissions 

away from sensitive 

Class I areas 

Fugitive Dust 

Road

Treatment 

$2,400 to $50,000 

per mile 

Possible 

vegetation effects 

20% to 100% dust 

control 

Fugitive Dust 

Administrative 

Control 

$13,000 per well 

for remote 

telemetry. A few

added work hours 

per year traveling 

at enforced speed 

limits 

Minor/unknown Hard to

enforce 

Reduced VMTs with 

related emission

reductions. Slower 

speeds give 20% to 

50% reductions in 

dust emissions

Larger 

Diameter Sales 

Pipeline 

Capital costs 

increase with 

larger pipes. 

Operating costs 

decrease with 

larger pipes 

Larger trench for 

burying line. 

Slightly more 

surface 

disturbance 

Probably 

applicable 

only for large 

producing 

operations 

Lower gas pressures 

with resulting lower 

compressor 

emissions 

Microhole 

drilling 

Cost of technology

transfer, then 

potentially less

than conventional 

drilling 

Additional impacts 

if duplicate drilling 

is necessary

Lighter equipment on 

roads, smaller 

drilling sites, reduced

gaseous emissions 

during drilling 

Condensate 

Pipelines 

Cost of pipe and 

installation minus 

cost of eliminated 

storage tank and 

trucking 

Trench for burying 

line 

Cost may

outweigh 

benefit 

Reduce emissions 

from storage 

vessels; reduce

miles traveled by

vacuum trucks 

Stage I Vapor 

Controls for 

Condensate 

Transfer for 

Truck Loading

$1,000 to $3,000 Potential fire risk 

with improper 

operation 

90% VOC emission 

reduction during

transfer 

Wind Farm 

Electric 

Generation 

4 to 5 cents/kW-hr. 

Capital costs are 

large 

Visual impacts, 

impacts on raptors, 

maintenance 

Large capital 

costs required

Reduced power 

plant emissions. 

(VOC, NOx, SO2, 

CO, CO2) 

Phased Oil and 

Gas 

Development 

Short-term loss of 

state and federal 

royalties 

Emissions 

averaged over a 

longer period 

Peak emissions and 

impacts are reduced

Rawlins RMP A4-29 
Appendix 4 Draft EIS

LITERATURE CITED

Air Resource Specialists, Inc. (ARS). 2002. Green River Basin Visibility Study. 

Malm, W.C. 1999. Introduction to Visibility. Air Resource Division National Park Service and 

Cooperative Institute for Research in the Atmosphere (CIRA) Colorado State University, Fort 

Collins, CO. 

Pitchford, M.L., & W.C. Malm. 1994. Development of a standard visual index. Atmospheric 

Environment 28(5) 1049–1054. 

TRC, 2004. Regional Air Emissions Inventory Methodology Summary. Prepared for Booz Allen 

Hamilton, United States Department of Interior Bureau of Land Management Wyoming State 

Office, Rawlins Field Office, and Pinedale Field Office. TRC Environmental Corporation, 605 

Skyline Drive, Laramie, Wyoming. April, 2004. 

U.S. Department of the Interior. BLM Rawlins and Rock Springs Field Offices. 1993. Draft 

Environmental Impact Statement Desolation Flats Natural Gas Field Development Project. 

April. 

U.S. Environmental Protection Agency (EPA), Office of Pollution Prevention and Toxics. 1993. Status 

Report on the Use of Environmental Labels Worldwide, Washington, DC. EPA 741-R-0-93-001 

A4-30 Rawlins RMP