773 San Marin Drive, Suite 2115, Novato, CA 94998 415.899.0700 ENVIRON International Corporation



### DEVELOPMENT OF 2010 OIL AND GAS EMISSIONS PROJECTIONS FOR THE DENVER-JULESBURG BASIN

Prepared for Colorado Department of Public Health and Environment Air Pollut ion Control Division

Prepared by Amnon Bar-Ilan John Grant Ron Friesen Alison K. Pollack ENVIRON International Corporation

773 San Marin Drive, Suite 2115 Novato, CA 94998

Doug Henderer

Daniel Pring Buys & Associates 300 E. Mineral Ave., Suite 10 Littleton, CO 80122

Andrew Bremner Independent Petroleum Associati on of Mountain States (IPAMS) 410 17th Street, Suite 1920 Denver, CO 80202

Phase III Oil & Gas Emissions Inventory Project http://www.wrapair.org/forums/ssj f/documents/eictts/oilgas.html

April 30, 2008April 2008

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### i TABLE OF CONTENTS

Page

INTRODUCTION................................................................................................................... .......1

GEOGRAPHIC GROUPING.......................................................................................................1

PARAMETERS PROJECTED ....................................................................................................2

PROJECTION METHODOLOGIES FOR GEOGRAPHIC GROUPINGS.....................................................................................................4

Weld County .................................................................................................................... ....4 Yuma County.................................................................................................................... ...8 All Other Counties ............................................................................................................. 12

SCALING FACTOR DEVELOPMENT AND UNCONTROLLED 2010 EMISSIONS .....................................................................................15

Weld and Yuma County.....................................................................................................15 All Other Counties in the D-J Basin ..................................................................................16

CONTROLLED 2010 EMISSIONS...........................................................................................17

SUMMARY RESULTS...............................................................................................................1 8 TABLES

Table 1 Scaling parameter for each oil and gas source category considered in this inventory ...................................................................................................................... ..2 Table 2 Scaling factors for the four paramete rs used in the projection analysis for the three geographic groupings..........................................................................................17 Table 3 Summary of federal and state “on-the-books” regula tions affecting the oil and gas source categories consider ed in this inventory......................................................17 Table 4 2010 emissions of all criteria pollutants by county for the D-J Basin.........................21 Table 5 2010 NOx emissions [ton/yr] by count y and by source category for the D-J Basin .......................................................................................................................... ..22 Table 6 2010 VOC emissions [ton/yr] by count y and by source category for the D-J Basin. ......................................................................................................................... ..23

FIGURES

Figure 1 Gas production historic al data for Weld County (from the IHS database)....................4 Figure 2 Oil production historical data fo r Weld County (from the IHS database).....................5 Figure 3 Well count historic al data for Weld County (from the IHS database)...........................6 Figure 4 Spud count historical data for Weld County (from the IHS database) ..........................7April 2008

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### ii Figure 5 Gas production histor ical data for Yuma County (from the IHS database)..................8 Figure 6 Oil production historical data fo r Yuma County (from the IHS database)....................9 Figure 7 Well count historic al data for Yuma County (from the IHS database)........................10 Figure 8 Spud count historical data for Yuma County (from the IHS database) .......................11 Figure 9 Gas production hist orical data for all other counti es in the D-J Basin combined (from the IHS database)...............................................................................................12 Figure 10 Oil production historical data for all other counties in the D-J Basin combined (from the IHS database)...............................................................................................13 Figure 11 Well count historical data for al l other counties in the D-J Basin combined (from the IHS database)...............................................................................................14 Figure 12 Spud count historical data for al l other counties in the D-J Basin combined (from the IHS database)...............................................................................................15 Figure 13 2010 NOx emissions by source cate gory and by county in the D-J Basin ..................19 Figure 14 2010 VOC emissions by source cate gory and by county in the D-J Basin.................19 Figure 15 2010 NOx emissions proportional cont ributions by source category in the DJ Basin .......................................................................................................................... ..20 Figure 16 2010 VOC emissions proportional cont ributions by source category in the DJ Basin .......................................................................................................................... ..20April 2008

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### 1 INTRODUCTION

This document outlines the projection methodolog ies used in generating the 2010 model-ready emissions from oil and gas sources in the De nver-Julesburg (D-J) Basin to be used in the upcoming Denver metropolitan-area ozone SIP m odeling. These methodologies will use as a starting point the 2006 baseline D-J Basin oil and gas emissions inventory as approved by CDPHE.

This methodology description is broken down into subsections which describe:

• Geographic grouping of data – regional differences in produc tion or activity are factored into the projection methodology by geographic region

• Projected parameters – four basic parameters are proj ected forward to 2010 for purposes of developing scaling factors: well counts, spud counts, gas produc tion and oil production

• Scaling factors and developing unc ontrolled emissions projections – the projected parameters are used to develop scaling f actors (incorporating ge ographic groupings), and these scaling factors are applie d to the 2006 baseline emissions

• Application of “on-the-books” re gulations and control measures – existing regulations are summarized for their impacts on the future year emissions and applied to adjust the 2010 inventory.

Projections for years beyond 2010 (not addresse d in this methodology) will likely include additional parameters and will be based on these 2010 projections as the start year.

Following the discussion of the methodology, the results of the 2010 emissions projections for the D-J Basin are presented in graphical and tabular formats.

GEOGRAPHIC GROUPING

The projections for 2010 have been conducted sepa rately for 3 geographic groupings in the D-J Basin:

1. Weld County 2. Yuma County 3. All other counties in the D-J Basin combined

The reason for conducting this grouping is that the majority of 2006 production, well counts and spud (drilling event) counts occur in Weld and Yuma County. We ld and Yuma Counties combined represent 94% and 87% of all gas and oil production respectively in the D-J Basin in 2006. Weld and Yuma Counties combined repr esent 87% and 95% of all wells and spuds respectively in the D-J Basin in 2006. Because oil and gas exploration and production activities differ significantly in Weld and Yuma Counties, these two counties are each treated separately.April 2008

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### 2 PARAMETERS PROJECTED

The 2010 projections for oil and gas emissions in the D-J Basin rely on scaling 4 parameters:

• Well counts

• Spud counts

• Gas production

• Oil production

These four parameters are considered because each parameter applies to the emissions projections of one or more s ource categories. The mapping of source category to projection parameter is shown below in Table 1.

Table 1. Scaling parameter for each oil and gas source category considered in this inventory.

Source SCC Description Projection Parameter Unpermitted 2310000100 Heaters well count Unpermitted 2310000220 Drill rigs spud count Unpermitted 2310000230 Workover rigs well count Unpermitted 2310000300 Pneumatic devices well count Unpermitted 2310000700 Fugitives well count Unpermitted 2310000800 Truck loading of condensate liquid oil production Unpermitted 2310001610 Venting - initial completions spud count Unpermitted 2310001620 Venting - recompletions spud count Unpermitted 2310001630 Venting - blowdowns gas production Unpermitted 2310002210 Small condensate tanks oil production Regulation 7 2310002220 Large condensate tanks oil production Unpermitted 2310002250 Condensate tank flaring oil production Unpermitted 2310003100 Exempt engines well count Unpermitted 2310003200 Pneumatic pumps well count Unpermitted 2310003300 Spills oil production Unpermitted 2310003400 Water tank losses oil production APENS 20200201 Compressor E ngines gas production APENS 20200202 Compressor E ngines gas production APENS 20200203 Compressor E ngines gas production APENS 20200209 Compressor E ngines gas production APENS 20200252 Compressor E ngines gas production APENS 20200253 Compressor E ngines gas production APENS 20200254 Compressor E ngines gas production APENS 31000101 Permitted Fugitives oil production APENS 31000102 Oil Production, Miscellaneous Well: General oil production APENS 31000123 Oil Production, Well Casing Vents oil production APENS 31000129 Oil Productio n, Gas/Liquid Separation oil production APENS 31000130 Oil Production, Fugitives: Compressor Seals oil production APENS 31000132 Oil Production, At mospheric Wash Tank: Fl ashing Loss oil production APENS 31000199 Oil Production, Pr ocessing Operations: Not Classified oil production

APENS 31000201 Natural Gas Production, Gas Sweetening: Amine Process gas production APENS 31000202 Natural Gas Production, Gas Stripping Operations gas productionApril 2008

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### 3 Source SCC Description Projection Parameter APENS 31000203 Compressor E ngines gas production APENS 31000205 Natural Gas Producti on, Flares gas production APENS 31000207 Permitted Fugitives gas production

APENS 31000209 Natural Gas Production, In cinerators Burning Waste Gas or Augmented Waste Gas gas production

APENS 31000215 Natural Gas Production, Flares Combusting Gases >1000 BTU/scf gas production

APENS 31000216 Natural Gas Production, Flares Combusting Gases <1000 BTU/scf gas production APENS 31000220 Natural Gas Product ion, All Equipt Leak Fugitives gas production APENS 31000225 Natural Gas Production, Co mpressor Seals gas production APENS 31000226 Natural Gas Production, Flange s and Connections gas production APENS 31000227 Glycol Dehydr ator oil production APENS 31000228 Glycol Dehydr ator oil production APENS 31000229 Natural Gas Production, Gathering Lines gas production APENS 31000230 Natural Gas Production, Hy drocarbon Skimmer gas production APENS 31000299 Natural Gas Production, Ot her Not Classified gas production APENS 31000301 Glycol Dehydr ator gas production APENS 31000302 Glycol Dehydr ator gas production APENS 31000303 Glycol Dehydr ator gas production APENS 31000304 Glycol Dehydr ator gas production

APENS 31000305 Natural Gas Processing Fac ilities, Gas Sweeting: Amine Process gas production APENS 31000306 Natural Gas Processing Facilit ies, Process Valves gas production APENS 31000307 Natural Gas Processing Facilit ies, Relief Valves gas production APENS 31000309 Natural Gas Processing Facilitie s, Compressor Seals gas production APENS 31000310 Natural Gas Processing Fac ilities, Pump Seals gas production

APENS 31000311 Natural Gas Processing Facilities, Flanges and Connections gas production APENS 31000404 Process H eaters well count APENS 31000405 Process H eaters well count APENS 31000406 Process H eaters well count
APENS 31000502 Liquid Separator well count APENS 31088801 Permitted Fugitives gas production APENS 31088802 Permitted Fugitives gas production APENS 31088803 Permitted Fugitives gas production APENS 31088804 Permitted Fugitives gas production APENS 31088805 Permitted Fugitives gas production APENS 31088811 Permitted Fugitives gas production APENS 40400301 Tank Loss es oil production APENS 40400302 Tank Loss es oil production APENS 40400304 Tank Loss es oil production APENS 40400305 Tank Loss es oil production APENS 40400311 Tank Loss es oil production APENS 40400312 Tank Loss es oil production APENS 40400315 Tank Loss es oil production APENS 40400322 Tank Loss es oil production APENS 40400332 Tank Loss es oil productionApril 2008

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### 4 PROJECTION METHODOLOGIES FOR GEOGRAPHIC GROUPINGS

For each geographic grouping, the methodology fo r obtaining the 2010 value of each projection parameter (well count, spud count, oil production and gas production) is described below. In general, the methodologies were developed by obtain ing the historical data for the parameter in the geographic grouping using the IHS database , and projecting a trend line forward from 2006 to 2010. The IHS database is a tool to query COGCC data, and previous work has confirmed that IHS data is consistent with COGCC’s da ta. In some cases, a different methodology was applied as noted below.

Weld County

Gas Production - Gas production in Weld County has been plotted for the years 1970 – 2006 below in Figure 1.

0 50,000,000 100,000,000 150,000,000 200,000,000 250,000,000

1970 1975 1980 1985 1990 1995 2000 2005

YearGas Production [mcf]



### Figure 1 . Gas production historical data for Weld County (from the IHS database).



### Because production activity differed greatly in We ld County in the years prior to 1997 from what has occurred from 1997 – 2006, only the period 1997 – 2006 is considered in this analysis. During this period, gas production peaked in 2004 and has been declining from 2004 – 2006. This decline is the result of th e depletion of the J Sands forma tion. New drilling in the Codell formation is producing significantl y higher oil production. However, the major companies in the D-J Basin have indicated that they intend to continue drilling activit ies in Weld County and expect gas production from their operations to continue to grow at 5% per year 1



### .

1 Data provided by Anadarko Petroleum Corp. and Noble Energy Inc.April 2008

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### 5 Based on this information, the methodology used to estimate 2010 gas production in Weld County was to grow 2006 gas production in the county by 5% per year for the years 2006 – 2010.

Oil Production – Oil production in Weld County has been plotted for the years 1970 – 2006 below in Figure 2.

0 2,000,000 4,000,000 6,000,000 8,000,000 10,000,000 12,000,000 14,000,000

1970 1975 1980 1985 1990 1995 2000 2005

YearOil Production [bbl]



### Figure 2 . Oil production historical data for Weld County (from the IHS database).



### Similarly to gas production, oil activity has di ffered greatly from 1999 – 2006 than from past activity before 1999. Data from 1999 – 2006 is considered in this projection methodology.

Based on information from the major production companies in Weld County 2 

### , it was assumed conservatively that growth in oil production w ould continue following the trend observed from 1999 – 2006. A linear curve was best fit to the 1999 – 2006 oil production data, and this curve was extrapolated to 2010.

2 Data provided by Anadarko Petroleum Corp. and Noble Energy Inc.April 2008

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### 6 Well Count – Well counts in Weld County have been plotted for the years 1970 – 2006 below in Figure 3.

0 2000 4000 6000 8000 10000 12000 14000

1970 1975 1980 1985 1990 1995 2000 2005

YearWell Count



### Figure 3 . Well count historical data for Weld County (from the IHS database).



### Based on the historical data s hown in Figure 3, a second order cu rve was best fit to the 1999 – 2006 well count data for Weld C ounty and extrapolated to 2010.April 2008

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### 7 Spud Count – Spud counts in Weld County have been plotted for the years 1970 – 2006 below in Figure 4.

0 200 400 600 800 1000 1200

1970 1975 1980 1985 1990 1995 2000 2005

YearNumber of Spuds



### Figure 4 . Spud count historical data for Weld County (from the IHS database).



### Based on the increased activity from 1999 – 2006 as described above, only this data was considered for purposes of proj ecting Weld County spud counts. A linear curve was best fit to the spud count data from 1999 – 2006 and extrapol ated to 2010. For each year between 2006 – 2010, the spud count was evaluated and totaled a nd this total was comp ared to the 2010 well count projection to assess whethe r the total drilling ac tivity added to the 2006 existing well count matched reasonably well with the prediction fo r 2010 well count. It was found that spud count projections matched reasonably we ll with well count projections.April 2008

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### 8 Yuma County

Gas Production - Gas production in Yuma County has been plotted for the years 1970 – 2006 below in Figure 5.

0 5,000,000 10,000,000 15,000,000 20,000,000 25,000,000 30,000,000 35,000,000 40,000,000

1970 1975 1980 1985 1990 1995 2000 2005

YearGas Production [mcf]



### Figure 5 . Gas production historical data for Yuma County (from the IHS database).



### Production of gas in Yuma County has accelerate d recently, from 2004 – 2006 due to increased activity in this area. Theref ore gas production data from 2004 – 2006 was used for purposes of projecting gas production to 2010. A linear curve was best fit to the ga s production data from 2004 – 2006 and extrapolated to 2010. This is like ly to conservatively overestimate the gas production in this county for 2010.April 2008

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### 9 Oil Production - Oil production in Yuma County ha s been plotted for the years 1970 – 2006 below in Figure 6.

0 200 400 600 800 1,000 1,200 1,400 1,600

1970 1975 1980 1985 1990 1995 2000 2005

YearOil Production [bbl]



### Figure 6 . Oil production historical data for Yuma County (from the IHS database).



### Yuma County has had little or no oil pr oduction during the period 1970 – 2006, and no oil production from 1996 – 2006. It was assumed that th ere is no oil production in Yuma County in 2010.April 2008

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### 10 Well Count – Well counts in Yuma C ounty have been plotted for the years 1970 – 2006 below in Figure 7.

0 500 1000 1500 2000 2500 3000 3500

1970 1975 1980 1985 1990 1995 2000 2005

YearWell Count



### Figure 7 . Well count historical data for Yuma County (from the IHS database).



### Due to the increased recent activity in Yuma Co unty as described above, well count data from 2004 – 2006 was used to project 2010 well counts. A linear curve was best fit to the 2004 – 2006 well count data and projected to 2010.April 2008

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### 11 Spud Count – Spud counts in Yuma County have been plotted for the years 1970 – 2006 below in Figure 8.

0 100 200 300 400 500 600 700

1970 1975 1980 1985 1990 1995 2000 2005

YearNumber of Spuds



### Figure 8 . Spud count historical data for Yuma County (from the IHS database).



### There has been a substantial increase in the number of annual spuds in Yuma County from 2004 – 2005, however there were fewer spuds recorded in 2006. Based on information from the major producing companies 3 

### this is likely due to the lack of av ailability of drilling equipment in Yuma County as activity in other major basins in Colo rado and other states is utilizing much of the available drilling capacity. Ther efore the number of spuds was projected to remain constant from 2006 – 2010.

3 Data provided by Anadarko Petroleum Corp. and Noble Energy Inc.April 2008

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### 12 All Other Counties

Gas Production - Gas production in all other D-J Basin counties combined has been plotted for the years 1970 – 2006 below in Figure 9.

0 5,000,000 10,000,000 15,000,000 20,000,000 25,000,000 30,000,000 35,000,000 40,000,000

1970 1975 1980 1985 1990 1995 2000 2005

YearGas Production [mcf]



### Figure 9 . Gas production historical data for all other counties in the D-J Basin combined (from the IHS database).



### Figure 9 shows that from 1992 – 2006 gas production has declined in this geographic grouping. An exponential curve was best fit to the gas produc tion data in all other counties combined in the years 1992 – 2006, and extrapolated to 2010.April 2008

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### 13 Oil Production – Oil production in all ot her D-J Basin counties combined has been plotted for the years 1970 – 2006 below in Figure 10.

0 1,000,000 2,000,000 3,000,000 4,000,000 5,000,000 6,000,000 7,000,000 8,000,000 9,000,000 10,000,000

1970 1975 1980 1985 1990 1995 2000 2005

YearOil Production [bbl]



### Figure 10 . Oil production historical data for all other counties in the D-J Basin combined (from the IHS database).



### Figure 10 shows that from 1985 – 2006 oil producti on has declined in this geographic grouping. An exponential curve was best fit to the oil production da ta in all other coun ties combined in the years 1985 – 2006, and extrapolated to 2010.April 2008

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### 14 Well Count – Well counts in all other D-J Basin counties combined have been plotted for the years 1970 – 2006 below in Figure 11.

0 500 1,000 1,500 2,000 2,500

1970 1975 1980 1985 1990 1995 2000 2005

YearWell Count



### Figure 11 . Well count historical data for all other counties in the D-J Basin combined (from the IHS database).



### Well counts in the combined other counties in D-J Basin is primarily driven by activity in Adams county, which borders the large oil and gas deve lopment area in Weld County. As described above, a significant increase in activity in this area has been observed since 1999. Based on this information, a linear curve was best fit to the we ll count data for all other counties in the D-J Basin combined for the years 1999 – 2006, and extrapolated to 2010.April 2008

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### 15 Spud Count – Spud counts in all other D-J Basin coun ties combined have been plotted for the years 1970 – 2006 below in Figure 12.

0 100 200 300 400 500 600 700 800 900

1970 1975 1980 1985 1990 1995 2000 2005

YearNumber of Spuds



### Figure 12 . Spud count historical data for all other counties in the D-J Basin combined (from the IHS database).



### Figure 12 shows that from 1985 – 2006 spud counts have declined in this geographic grouping. An exponential curve was best fit to the spud coun t data in all other counties combined in the years 1985 – 2006, and extrapolated to 2010.

SCALING FACTOR DEVELOPMENT AND UNCONTROLLED 2010 EMISSIONS

Scaling factors were generated for each geograp hic grouping for each parameter considered here: gas production, oil production, well count and spud c ount. The ratio of the value of each of these parameters in each geographic grouping in 2010 to their values in 2006 is the scaling factor for that parameter for purposes of th is projection. A more detailed description is given below for each geographic grouping.

Weld County and Yuma County

The projected 2010 values of each of the four pa rameters for each of these two counties were ratioed to the value of the respective parameter in 2006, following Equation (1):

Equation (1)

2006 2010 

### W W f

i 

### =April 2008

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### 16 where: f

i 

### is the scaling factor for either Weld or Yuma County for parameter i (gas production, oil production, well count or spud count) W

2006 

### is the value of parameter i in 2006 W

2010 

### is the projected value of parameter i in 2010

All Other Counties in the D-J Basin

Because all other counties were combined for purposes of projecting gas production, oil production, well count, and spud count, the project ed parameters were apportioned to each county in this grouping based on the 2006 frac tions of that county’s gas production, oil production, well count or spud count. The scaling factors for each county in this grouping are estimated according to Equation (2):

Equation (2) ⎟ ⎠ ⎞ ⎜ ⎝ ⎛

× =
2006 2010

, 

### Q Q c f county i i



### where: f

i 

### is the scaling factor for each county in the “other counties” grouping for parameter i (gas production, oil production, well count or spud count)

c i,county 

### is the fraction of parameter i for all combined counties that is assigned to each specific county based on 2006 data Q 2006 

### is the value of parameter i in 2006 for all other combined counties Q 2010 

### is the projected value of parameter i in 2010 for all other combined counties

Emissions were therefore projected to 2010 for each county in the D-J Basin using the scaling factors derived above for each county. Uncont rolled 2010 emissions were estimated according to Equation (3):

Equation (2) 2006

, , , 2010

, , county j county i county j 

### E f E × =

where:


### E

j,county,2010 

### are the projected emissions in a sp ecific county in 2010 for source category 

### j E

j,county,2006 

### are the 2006 baseline emissions in a specific county for source category 

### j f

i 

### is the scaling factor for each county for parameter 

### i (gas production, oil production, well count or spud count)

The scaling factor based on the appropriate parameter (gas pr oduction, oil production, well count or spud count) is selected for each source category as described in Table 1. The scaling factors for the four parameters used in this analysis for each of the three geographic groupings is presented in Table 2 below.April 2008

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### 17 Table 2. Scaling factors for the four parameters used in the projection analysis for the three geographic groupings.
Metric Gas Production Oil Production Well Count Spud Count
Weld 1.216 1.302 1.288 1.413
Yuma 1.721 0.000 1.758 1.000
All other DJ counties 0.732 0.730 0.970 0.452



### CONTROLLED 2010 EMISSIONS

This methodology considered any “on-the-books” fede ral or state regulations that would affect the uncontrolled 2010 emissions pr ojections described above.

Table 3 below lists the “on-the-book s” federal and state regulations that affect emissions source categories in the oil and gas indus try, and the action taken to adju st the 2010 emissions inventory appropriately.

Table 3 . Summary of federal and state “on-the-books” regulations affecting the oil and gas source categories considered in this inventory.

Source Category Regulation Enforcing Agency Effective Date Implementation in the 2010 D-J Basin Emissions Projections Federal

Drill Rigs Nonroad engine Tier standards (1-4) US EPA Phase in from 1996 - 2014 None – turnover of drill rig engines is considered too slow to be affected by Tier standards. Drill Rigs, Workover Rigs Nonroad diesel fuel sulfur standards US EPA Phase in beginning in 2010 Assume 50 ppm sulfur in nonroad diesel fuel throughout D-J Basin.

All New Nonroad Engines New Source Performance Stds. (NSPS) US EPA Phase in beginning 2006 None – although some new compressors will be put into the field in the D-J Basin, this methodology conservatively estimates no application of this rule to these engines. State Natural Gas Engines Regulation 7 * CDPHE Phase in from 2007 - 2011 None – see above on compressor engines.

Glycol Dehydrators Regulation 7 * CDPHE May 2008 Apply a rule-effectiveness of 83% to the 90% control required for any glycol dehydrator emitting more than 15 tpy VOC. Condensate Tanks Regulation 7 * CDPHE May 2008 Apply 95% control to any tank emitting more than 20 tpy VOC.

Condensate Tanks with APENs in the EAC Regulation 7 * CDPHE May 2007 Apply a rule-effectiveness of 83% to the 75% control required of total VOC emissions in the front range early action compact area (EAC) from these tanks. * Information about the State of Colorado’s Regulation 7 concerning oil and gas emissi ons sources can be found at

(http://www.cdphe.state.co.us/ap/oilgas.html)April 2008

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### 18 The uncontrolled 2010 emissions were adjusted ba sed on the proposed action described in Table 3 to account for each regulation that may affect any oil and gas source category considered in this inventory.

The methodology recognizes that there are a number of volunt ary and/or required control measures that have been partially implem ented since 2006, and/or will be implemented completely by the calendar year 2010. However, th ese controls were not incorporated into this base case 2010 projection, but rather could form part of the c ontrols to be included in a control scenario.

The resulting controlled 2010 emissions are cons idered the final 2010 oil and gas emissions inventory projection for purposes of the Denver metropolitan area ozone SIP modeling.

SUMMARY RESULTS

The scaling factors were applied to the baseli ne 2006 inventory, and “on- the-books” regulations were applied to the uncontrolled 2010 emissions pr ojections to generate the final 2010 emissions projections and results are presented below.

Figure 15 shows that compressor engines and drilling rigs combined account for almost 80% of NOx emissions in 2010. Similarly, Figure 16 shows that permitted and unpermitted condensate tanks and pneumatic devices account for a pproximately 77% of VOC emissions in 2010.G:\IPAMS\Technical_Reports\D-J_Basin\CDPHE _Submission\2010_Proj_Emiss_D-J_Basin_043008.doc 

### 19 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000

Adams

Arap a hoe

B

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C

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D

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rt Frem ont Je

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L ari

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M

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P h i lli

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P

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Weld Y

uma

County2010 NOx Emissions (tons/year) Other Categories

Glycol Dehydrator

Compressor Engines

Workover rigs

Venting - recompletions Pneumatic devices

Permitted Fugitives

Exempt engines

Drill rigs



### Figure 13. 2010 NOx emissions by source category and by county in the D-J Basin.

0 10,000 20,000 30,000 40,000 50,000 60,000 70,000 80,000

Ada m

s Arapahoe Bo

uld

er Broo mfl

d Crowley Denver El

be

rt

F

r e mo

nt Jef

f erson

Kit Cars La

ri

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Lincoln
L

og

an M

organ Phillip s Pue b lo

S

e dg

w i ck Washngt n We

ld Y

uma

County2010 VOC Emissions (tons/year) Other Categories Glycol Dehydrator Compressor Engines Workover rigs Venting - recompletions Venting - initial completions Venting - blowdowns Truck loading of condensate liquid

Small condensate tanks Pneumatic pumps

Pneumatic devices Large condensate tanks

Heaters Permitted Fugitives Unpermitted Fugitives Exempt engines Drill rigs



### Figure 14. 2010 VOC emissions by source category and by county in the D-J Basin.April 2008

G:\IPAMS\Technical_Reports\D-J_Basin\CDPHE _Submission\2010_Proj_Emiss_D-J_Basin_043008.doc 

### 20 Drill rigs

26%

Exempt engines 15% Other Categories 1%

Workover rigs 3% Heaters 3% Compressor Engines 52%



### Figure 15. 2010 NOx emissions proportional contributions by source category in the DJ Basin



### .

Large condensate tanks 45% Other Categories 1%

Pneumatic devices 17% Permitted Fugitives 1% Venting - recompletions 1%

Truck loading of condensate liquid 1% Venting - initial

completions 1%

Small condensate tanks 14%

Pneumatic pumps 1% Venting - blowdowns 2% Unpermitted Fugitives 11% Drill rigs

0% Glycol Dehydrator 0% Compressor Engines 3%



### Figure 16. 2010 VOC emissions proportional contributions by source category in the DJ Basin



### .April 2008

G:\IPAMS\Technical_Reports\D-J_Basin\CDPHE _Submission\2010_Proj_Emiss_D-J_Basin_043008.doc 

### 21 Table 4. 2010 emissions of all criteria pollutants by county for the D-J Basin.

County NOx [tons/yr] VOC [tons/yr] CO [tons/yr] SOx [tons/yr] PM [tons/yr] Adams 1,718 2,246 716 9 15 Arapahoe 546 299 187 0 3 Boulder 174 594 135 0 3 Broomfield 13 143 9 0 0 Crowley 46 1 62 0 0 Denver 29 76 13 0 1 Douglas 0 0 0 0 0 Elbert 34 282 22 0 1 El Paso 0 0 0 0 0 Fremont 12 250 7 0 0 Jefferson 4 0 7 0 0 Kit Carson 6 104 3 0 0 Larimer 35 471 22 0 1 Lincoln 10 341 8 0 0 Logan 357 104 133 1 6 Morgan 583 728 541 97 3 Phillips 28 39 18 0 1 Pueblo 0 0 0 0 0 Sedgwick 1 9 0 0 0 Teller 0 0 0 0 0 Washington 212 3,309 156 0 6 Weld 15,768 71,930 10,688 19 555 Yuma 4,832 7,127 2,684 4 176 Totals 24,408 88,989 15,412 131 771April 2008G:\IPAMS\Technical_Reports\D-J_Basin\CDPHE_Submission\2010_Proj_Emiss_D-J_Basin_043008.doc22Table 5.2010 NOx emissions [ton/yr] by county and by source category for the D-J Basin.CountyDrill rigsExemptenginesHeatersWorkoverRigsCompressorEnginesGlycolDehydratorOtherCategoriesTotalsAdams 11 147 29 29 1,494 0 81,718Arapahoe 5 17 3 3 518 0 0546Boulder 14 38 8 7 107 0 0174Broomfield 0 10 2 2 0 0 013Crowley 0 0 0 0 46 0 046Denver 11 6 1 1 11 0 029Douglas 0 0 0 0 0 0 00Elbert 2 10 2 2 19 0 034El Paso 0 0 0 0 0 0 00Fremont 3 6 1 1 0 0 012Jefferson 0 0 0 0 4 0 04Kit Carson 3 2 0 0 0 0 06Larimer 0 22 4 4 4 0 035Lincoln 2 2 0 0 6 0 010Logan 14 19 4 4 317 0 0357Morgan 2 11 2 2 468 6 93583Phillips 5 3 1 1 19 0 028Pueblo 0 0 0 0 0 0 00Sedgwick 0 1 0 0 0 0 01Teller 0 0 0 0 0 0 00Washington 36 75 15 15 71 0 0212Weld 4,255 2,598 514 504 7,734 6 15715,768Yuma 1,906 803 159 156 1,808 0 04,832Totals 6,267 3,769 746 731 12,625 12 259 24,408April 2008G:\IPAMS\Technical_Reports\D-J_Basin\CDPHE_Submission\2010_Proj_Emiss_D-J_Basin_043008.doc23Table 6.2010 VOC emissions [ton/yr] by county and by source category for the D-J Basin.CountyDrillrigsFugitivesLargecondensatetanksPneumaticdevicesPneumaticpumpsSmallcondensatetanksTruckloading ofcondensateliquidVenting -blowdownsVenting -initialcompletionsVenting -recompletionsCompressorEnginesGlycolDehydratorOtherCategoriesTotalsAdams 1 450 729 595 43 127 17 37 1 1 155 32 582,246Arapahoe 0 59 100 68 5 18 2 2 1 1 13 16 14299Boulder 1 102 238 167 11 41 5 13 1 2 9 0 4594Broomfield 0 25 57 42 3 10 1 4 0 0 0 0 1143Crowley 0 0 0 0 0 0 0 0 0 0 1 0 01Denver 1 15 26 23 2 5 1 1 1 1 0 0 176Douglas 0 0 0 0 0 0 0 0 0 0 0 0 00Elbert 0 26 0 40 3 156 2 1 0 0 1 0 53282El Paso 0 0 0 0 0 0 0 0 0 0 0 0 00Fremont 0 16 0 25 2 204 2 0 0 0 0 0 1250Jefferson 0 0 0 0 0 0 0 0 0 0 0 0 00Kit Carson 0 5 0 8 1 87 1 2 0 0 0 0 0104Larimer 0 59 153 90 7 154 5 1 0 0 0 0 2471Lincoln 0 5 0 8 1 318 3 0 0 0 0 0 5341Logan 1 49 0 74 5 847 9 1 1 2 33 7 10104Morgan 0 32 0 44 3 376 4 2 0 0 108 17 143728Phillips 0 8 0 13 1 0 0 3 1 1 6 6 039Pueblo 0 0 0 0 0 0 0 0 0 0 0 0 00Sedgwick 0 1 0 2 0 5 0 0 0 0 0 0 09Teller 0 0 0 0 0 0 0 0 0 0 0 0 00Washington 3 200 0 303 22 2,690 27 12 4 5 9 6 293,309Weld 295 7,317 38,985 10,513 761 7,784 902 1,654 413 556 2,155 127 46971,930Yuma 132 2,128 0 3,225 235 0 0 475 185 249 296 121 827,127Totals 434 10,498 40,288 15,238 1,104 12,821 980 2,208 608 819 2,786 33287288,989