EPA Regional Modeling for National Rules (and Beyond) CAIR/ CAMR / BART 1
Emissions & Modeling Contacts Pat Dolwick Meteorology and Episodic Ozone Modeling Brian Timin Speciated Modeled Attainment Test for Projecting PM2.5 & BART/Visibility Modeling Sharon Phillips & Carey Jang CMAQ Evaluation & Science Issues Marc Houyoux, Ron Ryan & Madeleine Strum Emissions Inventories, Emissions Projections, Emissions Modeling Tom Braverman CAMR Mercury Modeling Kevin Culligan & Misha Adamantiades Integrated Planning Model (IPM) forecasts of emissions from electric generating units Norm Possiel CAIR AQ Modeling Team Lead 2
Additional Information CAIR Air Quality Modeling Tech Support Document (TSD) CAIR Emissions Inventory TSDs Updated CMAQ Model Evaluation Report Speciated Modeled Attainment Test Report CAIR Response to Comments Document CAIR Regulatory Impact Analysis (RIA) Reports on the Integrated Planning Model (IPM) CAMR AQ Modeling and EI TSDs and RIA CAIR: www.epa.gov/cleanairinterstaterule CAMR: www.epa.gov/cleanairmercuryrule 3
Briefing Outline Brief overview of CAIR, CAMR, BART rules Overview of CAIR/CAMR/BART Regional Modeling Air quality modeling platform & model performance evaluation Modeling to determine States covered by CAIR Expected impacts of CAIR Expected impacts of CAMR EPA s plans for additional regional modeling 4
CAIR Overview CAIR is designed to lower SO2 and NOx emissions in order to reduce interstate transport of PM2.5 and ozone in the East CAIR sets an emission reduction requirement for each State, based on capping power plant emissions collectively at levels that EPA believes are highly costeffective to achieve 5
CAMR Overview CAMR is oriented at lowering mercury emissions to reduce the harmful health effects of this pollutant There is a great deal of potential overlap in the source coverage of CAIR and CAMR o The optional CAIR trading programs cover all EGUs greater than 25 Mwe in CAIR affected States o CAMR covers all coal-fired EGUs greater than 25 Mwe in the 50 States and the US territories Both rules include similar trading rules The first phase reduction requirements of CAMR are based on co-benefits of CAIR 6
BART Overview See Presentation by Todd Hawes for more details Under 308, a source is BART eligible if: Major stationary source, including EGUs One of 26 non-egu source categories Placed into operation: 1962-1977 Potential to emit 250 tons of any pollutant reasonably anticipated to contribute to regional haze in any Class I area (modeling analysis helps determine cause or contribute) 7
Overview of CAIR/CAMR/BART Regional Modeling 8
AQ Modeling for CAIR/CAMR CAIR Identify which States to cover for emissions reductions in CAIR Forecast the improvements in air quality and other environmental benefits expected from implementation of each rule CAMR Forecast the environmental benefits of the rule 9
Regional Modeling to Support BART CMAQ used to model several BART control levels for the Regulatory Impact Analysis EGU and non-egu BART controls in 2015 Better than BART analysis of the CAIR rule Compared visibility improvements at Class I areas for a nationwide BART scenario vs. a CAIR + BART scenario (CAIR in the East, BART in the West) EGU controls only Purpose is to show that the CAIR trading program (for EGUs) is better than BART 10
Emissions Scenarios Modeled 2001 Base Year 2001 ab includes year-specific wild and prescribed fires (for model evaluation) 2001 ad includes 7-year avg wild and prescribed fires which were also used in future year scenarios 2010 Base and CAIR 2015 Base, CAIR, BART, CAIR+BART 2020 CAIR/CAMR 11
Air Quality Modeling Platform & Model Evaluation 12
Modeling Platform CMAQ used for modeling PM2.5, visibility, and nitrogen/sulfur deposition in CAIR and mercury modeling for CAMR Nationwide domain 36 x 36 km grid cell size;14 vertical layers Modeled 2001 meteorology (quarterly simulations with 10 day ramp-up) Boundary Conditions from global chemistry model (GEOSCHEM) 13
Modeling Platform CAMx used for modeling 8-hour ozone in CAIR Eastern US domain Nested 12 x 12 km within 36 x 36 domain; 9 layers Modeled meteorology for 30 days in the summer of 1995 (episodes in June, July, August w/ 3 day rampup for each episode) 14
CMAQ Modeling Domain 15
CAMx Ozone Modeling Domain 16
Model Evaluation for CAMx Ozone CAMx 1995 evaluation performed in support of Nonroad Rule modeling Calculated model performance statistics by episode for 1-hour and 8-hour ozone for several geographic areas whole domain 4 quadrants 51 local areas Stats include Avg Accuracy of Peak; Normalized Bias; Normalized Gross Error 17
Model Evaluation for CAMx Ozone Model performance findings Performance similar to or improved compared to previous regional applications for Tier-2 and Heavy Duty Diesel rules Results compare favorably against performance goals recommended for urban scale modeling July episode had best performance; regional ozone in June episode tended to be under predicted; ozone was over predicted in the August episode in portions of the domain outside the Northeast 18
Model Evaluation for CMAQ PM2.5, Visibility, and Nitrogen/Sulfur Dep Scatter plots seasonal and annual average Statistical analysis FB, FE, NMB, NME, R 2 Spatial analysis Nitrate PM & Sulfate PM Time-series analysis daily, weekly, biweekly, monthly averages 19
Model Evaluation for CMAQ Ambient Monitoring Networks PM2.5 mass Particulate Species Gaseous Precursor Species Wet Deposition Species SO 4 NO 3 TNO 3 EC NH 4 OC O 3 SO 2 HNO 3 NO SO 4 NO 3 NH 4 IMPROVE X X X X X X CASTNet X X X X STN X X X X X X NADP X X X AIRS X SEARCH X X X X X X X X X X 20
Model Evaluation for CMAQ PM2.5 Eastern United States Fractional Bias (%) CMAQ 2001 Fractional Error (%) Sulfate (Summer) Nitrate (Winter) STN 14 44 IMPROVE 10 42 CASTNet 3 22 STN 15 43 IMPROVE 21 92 21
Model Evaluation for CMAQ PM2.5 General range of performance for summer sulfate and winter nitrate compares favorably with the better performing model applications by other groups in the modeling community, as follows: Summer sulfate FB: -10% to +30% ; FE: +35% to +50% Winter nitrate FB: +50% to +70% ; FE: +85% to +105% Current EPA CMAQ research is focused on: Organic carbon and particle nitrates Characterization of deposition, vertical mixing, and cloud processes 22
Model Evaluation for Mercury Model evaluation limited to wet deposition (MDN); currently no monitoring network to evaluate performance in estimating mercury dry deposition CMAQ underestimates annual wet deposition by ~23% in the East Current mercury research is focusing on: Air emission sources (natural and anthropogenic) Atmospheric transformations (chemical and physical) Deposition mechanisms (wet and dry) Re-emissions 23
Modeling to Determine States Covered by CAIR 24
Approach to Significant Contribution Modeling for Ozone and PM2.5 Step 1: Identify the counties in the East that are expected to be nonattainment in 2010 under projected future baseline emissions levels Step 2: Perform State-by-State modeling to quantify the contribution from 2010 baseline emissions in each State to nonattainment counties in other States Step 3: Evaluate the upwind State-to-downwind nonattainment contributions from Step 2 using significance metrics and criteria 25
Approach to Significant Contribution Modeling for Ozone and PM2.5 States that contribute amounts which exceed the significance criterion for PM2.5 are covered for annual SO2 and NOx emissions reductions States that contribute amounts which exceed the significance criteria for 8-hour ozone are covered for summer season NOx emissions reductions States that do not contribute in excess of our significance criteria for either PM2.5 or 8-hour ozone are not covered for regional controls as part of CAIR 26
2010 Base Nonattainment Counties used as Receptors in Significant Contribution Analyses The receptors in the significant contribution analysis are those counties that are currently measuring nonattainment based on 2001-2003 design values AND are also projected to be nonattainment in the 2010 Base Case scenario (i.e., modeled + monitored nonattainment) 27
Ozone and PM2.5 2010 Nonattainment Receptors Anchor Points for Upwind- Downwind Linkages 8-Hour Ozone Modeled + Monitored Nonattainment Counties (40 Counties) Annual Average PM2.5 Modeled + Monitored Nonattainment Counties (62 Counties) 28
State-by-State Modeling Techniques Zero-Out Modeling Contributions are calculated as the difference in concentration between the 2010 Base Case and another 2010 model run in which manmade emissions in a particular State are removed For PM2.5 modeling we removed emissions of SO2 and NOx For Ozone modeling we removed emissions of NOx and VOC Source Apportionment Modeling Contributions are calculated internally within the model run using chemical and non-reactive tracers Zero-Out and Source Apportionment techniques were used in the ozone contribution analysis Only Zero-Out modeling was performed for PM2.5 since Source Apportionment for PM2.5 is still being developed and tested 29
CAIR PM2.5 and Ozone Significance Criteria PM2.5 Single bright-line criterion based on the magnitude of the contribution from an upwind State to downwind nonattainment receptor A State is significant if it contributes 0.2 ug/m3 or more to annual average PM2.5 nonattainment in another State 8-Hour Ozone Multi-factor test which considers the magnitude, frequency, and relative amount of contribution Same approach as used in the NOx SIPCall A State is significant if it contributes large and/or frequent amounts of ozone to 8-hour ozone nonattainment in another State 30
CAIR Region and Emission Caps Emission Caps* (million tons) 2009/2010 2015 Annual SO 2 3.6 2.5 (2010) Annual NOx 1.5 1.3 (2009) Seasonal NOx.58.48 (2009) States controlled for fine particles (annual SO 2 and NOx) States controlled for ozone (ozone season NOx) States controlled for both fine particles (annual SO 2 and NOx) and ozone (ozone season NOx) States not covered by CAIR *For the affected region. 31
Expected Impacts of CAIR on PM2.5 and Ozone 32
Emissions Reductions Expected from CAIR CAIR emissions reductions are based on a two Phase cap and trade program The net effect of CAIR on emissions: Total SO2 emissions reduced by 28% in 2010 and 32% in 2015 across CAIR region Total NOx emissions reduced by 11% in 2010 and 14% in 2015 across CAIR region 33
Impacts of CAIR on PM2.5 Reduction in Annual Average PM2.5: 2010 Reduction in Annual Average PM2.5: 2015 34
Expected Impacts of CAIR, plus other Clean Air Programs, on PM2.5 and 8-Hr O3 Nonattainment in 2010 in the East 8-Hr O3 & PM2.5 Nonattainment Areas Projected Nonattainment Areas in 2010 104 ozone nonattainment areas with 408counties 43 PM 2.5 nonattainment areas with 211 counties 14 ozone nonattainment areas 20 PM 2.5 nonattainment areas Nonattainment areas for 8-hour ozone pollution only Nonattainment areas for fine particle pollution only. Nonattainment areas for both 8-hour ozone and fine particle pollution Projections concerning future levels of air pollution in specific geographic locations were estimated using the best scientific models available. They are estimations, however, and should be characterized as such in any description. Actual results may vary significantly if any of the factors that influence air quality differ from the assumed values used in the projections shown here. 35
Expected Impacts of CAIR, plus other Clean Air Programs, on PM2.5 and 8-Hr O3 Nonattainment in 2015 in the East 8-Hr O3 & PM2.5 Nonattainment Areas Projected Nonattainment Areas in 2015 104 ozone nonattainment areas with 408 counties 43 PM 2.5 nonattainment areas with 211 counties 5 ozone nonattainment areas 14 PM 2.5 nonattainment areas Nonattainment areas for 8-hour ozone pollution only Nonattainment areas for fine particle pollution only Nonattainment areas for both 8-hour ozone and fine particle pollution Projections concerning future levels of air pollution in specific geographic locations were estimated using the best scientific models available. They are estimations, however, and should be characterized as such in any description. Actual results may vary significantly if any of the factors that influence air quality differ from the assumed values used in the projections shown here. 36
Expected Impacts of CAMR 37
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EPA s Plans for Additional Regional Modeling 39
Nested 12 km Modeling 36 km 2001 & 2002 Met 12 km East 2001 & 2002(?) Met 12 km West 2002 Met - WRAP - CMAQ 4.4 w/possible science updates / CAMx? - 2001 Base Year - Future Year Forecasts of National Rules - Results at 12 km for East in Fall 2005 40