1 Regional NEPA Analysis of NOx Emissions from Potential Oil & Gas Development Scott F. Archer USDI - Bureau of Land Management March 11, 2004

2 This presentation describes the Montana and Wyoming Powder River Basin Oil & Gas Air Quality Impact Assessments’: Major Analytical Assumptions Major Emission Sources Analysis Methodology Summary of Major Findings Technical Support Document Outline

3 NEPA Air Quality Impact Analyses Key issues: Potential impacts to Standards, Increments, HAPs, visibility, atmospheric deposition Thresholds: Legal limits or “best science” Analysis and disclosure process (not decision) Focus on greatest potential impacts Affected Environment = Background Reasonably Foreseeable Future Activities No Action = Background + RFFA Potential Direct impacts = “Alternative” Potential Cumulative = No Action + “Alternative”

4 History WY PRBO&G Project Air Quality Analysis began in June 2000 Wyodak EIS was just completed DM&E Railroad Expansion was underway MT PRBO&G Project Air Quality Analysis began in April 2001 For a variety of reasons, both the MT and WY PRBO&G DEIS’ were delayed until January 2002

5 History Initial combined Air Quality modeling results became available in April 2002 May 2002 Comments on both DEIS’ The emissions inventory was updated through May 31, 2002 Significant re-modeling completed December 2002 Both the MT and WY PRBO&G FEIS’ were published January 2003

6 Major Analytical Assumptions Montana and Wyoming Study Area - New 5 State Domain (2.2 times larger than DM&E) Regional Meteorology MM5 (36km) CALMET Grid size - 4km CALPUFF Receptor Grid near-field: 0.1 and 1km far-field: 1km, + lakes

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10 Major Analytical Assumptions Wyoming Montana Max, % electric, “NA” Max, electric booster,“NA” ~40,000 new CBM wells ~26,000 new CBM wells ~1,000 “booster” comps ~1,000 “field” comps ~300 “recip” comps ~100 “sales” comps ~ 3,000 conventional ~2,500 conventional 10 year “LOP” 20 year “LOP”

11 Major Emission Sources Construction Activities –Road and pad clearing –Rig up and drilling –Rig down and testing Operation Activities –25 wells per field/booster compressor –250 wells per sales/reciprocating compressor

12 Construction Activities Access road and well pad construction (3 days) Rig-up and drilling (4 days) Rig-down and testing (5 days, including 1 day flaring) Compressor pads Coal Bed Methane Drill Rig

13 Operating Emissions Up to eight well pads per square mile, three wells per pad 90% of wells drilled assumed to produce Average 200 Mcf/day production over year “life of project” Two 380 horsepower, CBM-fired reciprocal field compressors

14 MT Emission Inventory Coal Bed Methane Sources

15 MT Emission Inventory Conventional Oil & Gas Sources

16 MT/WY Project Emissions

17 MT/WY New & RFFA Emissions

18 Analysis Methodology MM5/CALMET and CALPUFF Models Both near- and far-field analyses Maximum HAP, incremental MLE and MEI cancer risks based on a “reasonable, but conservative” well pad and compressor scenario Range of temporary generator impacts for power and pumping Post-processing for Atmospheric Deposition (USDA-FS protocol) and Regional Haze (FLAG protocol)

19 MT/WY Receptor Locations

20 Summary of Major Findings Montana FEIS (Alt E - Preferred) - Comply with State/National Standards - Comply with PSD Class I and II Increments - Above lowest State’s 8-hr formaldehyde AACL; well within range - Within incremental cancer risk thresholds - Within Atmos. Deposition/ANC thresholds - Exceed 1.0 dv “just noticeable change” at seven mandatory federal PSD Class I Areas for 0 to 3 days per year (not likely to actually occur)

21 Summary of Major Findings Wyoming FEIS (Alt 2A - Preferred) - Comply with State/National Standards - Comply with PSD Class I and II Increments - Above lowest State’s 8-hr formaldehyde AACL; well within range - Within incremental cancer risk thresholds - Within Atmos. Deposition/ANC thresholds - Exceed 1.0 dv “just noticeable change” at ten mandatory federal PSD Class I Areas for 0 to 4 days per year (not likely to actually occur)

22 Summary of Major Findings Cumulative Montana, Wyoming and Other New & RFFA - Potential to exceed 24-hr PM 2.5 and PM 10 NAAQS - Potential to exceed 24-hr PM 10 PSD Class II - Potential to exceed 24-hr PM 10 PSD Class I (2 areas) - Potential to exceed Annual NO 2 PSD Class I - Potential to exceed ANC thresholds (2 lakes) - Exceed 1.0 dv “just noticeable change” at all fourteen mandatory federal PSD Class I Areas for 2 to 32 days per year

23 What about Ozone?

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26 For More Information Please feel free to contact: Scott F. Archer Senior Air Resource Specialist USDI – Bureau of Land Management National Science and Technology Center Denver Federal Center, Building 50 P.O. Box Denver, Colorado USA

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28 Northern San Juan Basin Environmental Impact Statement for Coalbed Methane Development 3/1/2004

29 Existing Oil and Gas Development in the San Juan Basin

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31 Projected Timeline * … DateAction March 2004 Issue DEIS, 60-day comment period begins May 2004Close comment period September 2004Issue FEIS October 2004Issue ROD Mid-Nov 2004Appeal period closes * Schedule is dependent upon NOA approval and completion of air quality coordination.

32 For More Information Scott F. Archer Senior Air Resource Specialist USDI-Bureau of Land Management National Science and Technology Center Denver Federal Center, Building 50 P.O. Box 25047, ST-133 Denver, Colorado Fax

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