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Regional NEPA Analysis of NOx Emissions

from Potential Oil & Gas Development

Scott F. Archer

USDI - Bureau of Land Management

scott_archer@blm.gov

March 11, 2004

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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

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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”

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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

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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

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Major Analytical AssumptionsMontana and Wyoming

Study Area - New 5 State Domain

(2.2 times larger than DM&E)

Regional Meteorology - 1996 MM5 (36km)

CALMET Grid size - 4km

CALPUFF Receptor Grid

near-field: 0.1 and 1km

far-field: 1km, + lakes

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Major Analytical AssumptionsWyoming Montana

Max, 50-100% 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”

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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

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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 padsCoal Bed Methane Drill Rig

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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 10 - 20 year “life of project”

Two 380 horsepower, CBM-fired

reciprocal field compressors

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MT Emission InventoryCoal Bed Methane Sources

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MT Emission InventoryConventional Oil & Gas Sources

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MT/WY Project Emissions

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MT/WY New & RFFA Emissions

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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)

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MT/WY Receptor Locations

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Summary of Major FindingsMontana 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)

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Summary of Major FindingsWyoming 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)

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Summary of Major FindingsCumulative Montana, Wyoming and Other New & RFFA

- Potential to exceed 24-hr PM2.5 and PM10 NAAQS

- Potential to exceed 24-hr PM10 PSD Class II

- Potential to exceed 24-hr PM10 PSD Class I (2 areas)

- Potential to exceed Annual NO2 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

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What about Ozone?

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For More Information

Please feel free to contact:Scott F. Archer

Senior Air Resource SpecialistUSDI – Bureau of Land ManagementNational Science and Technology CenterDenver Federal Center, Building 50P.O. Box 25047Denver, Colorado 80225-0047USA+1.303.236.6400scott_archer@blm.gov

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Northern San Juan Basin Environmental Impact Statement for Coalbed Methane Development

3/1/2004

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Existing Oil and Gas

Development in the San Juan

Basin

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Projected Timeline * …

Date Action

March 2004 Issue DEIS, 60-day comment period begins

May 2004 Close comment period

September 2004

Issue FEIS

October 2004 Issue ROD

Mid-Nov 2004 Appeal period closes

* Schedule is dependent upon NOA approval and completion of air quality coordination.

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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 80225-0047

303.236.6400

303.236.3508 Fax

scott_archer@blm.gov

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