Air Quality Dispersion Modeling on the Alaska OCS

Transcription

1 Air Quality Dispersion Modeling on the Alaska OCS Wednesday, April 24, :45 a.m. 11:15 a.m. presented by Virginia Raps Meteorologist BOEM Alaska Region

2 Thank you!

3 Overview - Purpose Explain what BOEM does and why dispersion analysis is necessary Describe unique conditions of the Arctic OCS List the modeling capabilities needed List of the models being used now What alternatives are available 3

4 Overview - Goals Familiarize modelers with needs of the Arctic Increase understanding of BOEM s regulatory responsibilities Learn fate of models Receive recommendations: Should we consider using different methods? What options should we engage? 4

5 BOEM Alaska Region Alaska OCS Region (AOCSR) Oversees more than one billion acres of the OCS 5

6 Federal Oil & Gas Leases 50 km line 6

7 Surfaces: Open water Partial ice Frozen-over seas Frozen tundra Dry land Sea-land interface Regional Conditions 7

8 Regional Conditions Over-water uses: Subsistence hunting and fishing Recreation Time frame for oil and gas drilling: Summer open-water season for exploration (July November) Year-round for development and production 8

9 Environmental Review Proposed drilling plans initiate the environmental review process Exploration Plans (EPs) e.g. drillships & jack-up rigs Development and Production Plans (DPPs) e.g. platforms etc. Kulluk Drillship is a stationary source on OCS while drilling Discoverer 9 Jack-up Rig

10 Air Quality Approach BOEM Alaska uses a three-pronged approach when evaluating air quality on the Alaska OCS: NEPA Assessment Regulation (30 CFR Part 550 Subpart C) Special Studies Regulation (30 CFR Part 550 Subpart C) NEPA Assessment Special Studies The use of all three methods provides a holistic understanding of the air quality impacts over the water and onshore from activities on the OCS. 10

11 NEPA Assessments National Environmental Policy Act (NEPA) Applicable to all Federally-authorized projects in the Alaska OCS Planning Areas Requires evaluation and disclosure of all emissions that are project-related NEPA Assessment Dispersion analysis: Total emission inventory exceeds 250 tons per year Assess control measures Mitigation measures 11

12 Source Types Offshore sources: Stationary drillship or platform Drillship while underway Support vessels; ice breakers Over-flights by fixed-wing aircraft for marine mammal observations Helicopters for crew changes and supply deliveries Onshore sources: Crew-related (buses/vans) Aircraft LTOs (landing and takeoff cycles) NEPA Assessment 12

13 Regulation BOEM Air Quality Regulatory Program (AQRP) In Alaska, applicable to just the Arctic OCS Planning Areas 30 CFR Part 550 Subpart C Authority to control OCS emission sources Separate analysis from the NEPA process Dispersion analysis: When impacts onshore are significant May require BACT & additional analysis, or Additional controls, or Redesign of the plan or Offsets, onshore and/or offshore Regulation (30 CFR Part 550 Subpart C) 30 Part

14 Scope of Jurisdiction Change in Authority to Control Air Pollution Sources on the Arctic OCS (Dec. 2011) Jurisdiction transferred from EPA to BOEM for the Beaufort Sea and Chukchi Sea OCS Planning Areas only. Beaufort Sea and Chukchi Sea Planning Areas All other Alaska OCS Planning Areas Different Goals for Control of Arctic OCS Air Pollution Sources BOEM requires demonstration of no significant impact on the nearest onshore area EPA requires air permit based on size of the OCS source. Regulation (30 CFR Part 550 Subpart C) 14

15 Special Studies Arctic Air Quality Impact Assessment Modeling Study FY Investigate existing & predict future sources Develop offshore/onshore meteorological datasets Using photochemical models (v5.0.1) THE UNIVERSITY of NORTH CAROLINA at CHAPEL HILL Special Studies (v5.41) 15

16 Standards Considered Pollutants and Averaging Periods Disclose NEPA Regulate BOEM AQRP Investigate Artic AQ Study CO 1-hr 8-hr NO 2 1-hr Annual SO 2 1-hr 3-hr PM hr Annual 2 nd PM hr Annual PM hr Lead 3-month Ozone 8-hr 16

17 Near- & Far-Field Needs Offshore 500-meter-radius from the drillship: Serves as the facility fence-line Enforceable by the Coast Guard, with approval Offshore 25-mile-radius: Consistent with EPA stationary source (PSD) rules for offshore Includes emissions from other support vessels and aircraft Onshore area: Nearest onshore area Nearest onshore communities 17

18 Current Models Available A suite of models is available for regulatory compliance on the OCS: Model Offshore and Coastal Dispersion Model with Weather Research & Forecasting (WRF) modeling system American Meteorological Society and EPA Regulatory Model, coupled with the meteorological preprocessor AERMET AERMOD with the meteorological preprocessor Coupled Ocean Atmosphere Response Experiment (COARE) California PUFF model, with the meteorological preprocessor CALMET Model Identification OCD-WRF AERMOD-AERMET AERMOD-COARE CALPUFF-CALMET 18

19 Near-Field Modeling Over open water and frozen seas Use OCD-WRF Coastal interface 500-meter radius 25-mile radius Use AERMOD-AERMET Onshore sources Uses FAA EDMS 19

20 Far-Field Modeling Over open water and frozen seas Use OCD-WRF Source to 50 km 500-meter radius 25-mile radius Use CALPUFF-CALMET 50 km and beyond to shoreline No coastal interface capability Use AERMOD-AERMET Onshore sources Uses FAA EDMS 20

21 Alternative Methods Lease blocks within 50 km from shore Use AERMOD-COARE to replace OCD-WRF Conditionally approved by EPA for use on the Arctic OCS Approval for other OCS areas is being considered Lease blocks greater than 50 km from shore Use COARE option in CALPUFF-CALMET CALPUFF not approved by EPA for near-field impacts COARE not preferred or approved 21

22 Modeling Questions OCD Suitable for partial-ice conditions? Evaluates all the standards? AERMOD-COARE Should this replace OCD? Need EPA approval for use outside Arctic OCS? COARE Can this meteorological preprocessor be approved by EPA for use with CALPUFF? 22

23 Modeling Questions CALPUFF Can this model be approved by EPA for assessing near-field impacts? Coastal interface capability? Suitable for partial-ice conditions? Future of CALPUFF? CAMx and CMAQ Suitable for partial-ice conditions? Approved as one atmosphere models for nearfield? Coastal interface capability? 23

24 Contact BOEM is interested in your opinion! Please contact us: Virginia Raps Meteorologist Bureau of Ocean Energy Management Anchorage, Alaska