MERPs View Qlik
EPA released the “Guidance on the Development of Modeled Emission Rates for Precursors (MERPs) as a Tier 1 Demonstration Tool for Ozone and PM2.5 under the PSD Permitting Program”(74 pp, 3 MB, 04/30/2019, 454-R-19-003) to provide a detailed framework for permit applicants to estimate single source impacts on secondary pollutants under the first tier (or Tier 1) approach put forth in the 2017 final revisions to the EPA's Guideline on Air Quality Models(54 pp, 761 K, 01-17-2017) (published as Appendix W to 40 CFR part 51). For Tier 1 assessments, it is generally expected that PSD permit applicants would use existing empirical relationships between precursors and secondary impacts (e.g., O3 and PM2.5). EPA has generated empirical relationships between single sources and O3 and PM2.5 impacts for hundreds of hypothetical sources that vary in stack height, emission rate, and geographic location. The MERPs VIEW Qlik applications provide EPA Regional offices, permit review authorities, and applicants easy access to EPA’s hypothetical single source modeled impacts of O3 and PM2.5 to support appropriate PSD applications.
Specifically, the tools provide: (1) Class II NAAQS Tier 1 demonstrations for PSD permits, illustrative hypothetical single source modeled impacts for annual and daily maximum average PM2.5 and annual maximum daily 8-hr O3 and (2) Class I PSD increment Tier 1 demonstration for PSD permits, illustrative hypothetical single source modeled impacts of maximum daily average PM2.5 concentrations provided by distance from the source.
Please contact George Bridgers (bridgers.george@epa.gov) if there are any questions or feedback for the MERPs VIEW Qlik applications below.
Emission rates are tons per year. Stack heights are provided in meters and represent actual stack height. The "MaxConc" value is the maximum concentration predicted by the model in ppb for ozone and ug/m3 for PM2.5. Facility latitude and longitude are provided in decimal degrees. The near-source average terrain (Terr Avg) is the average terrain (meters) within 50 km of the source. The "urban max" represents the maximum grid cell urban landcover fraction within 50 km of the source.
Information intended to support Class II NAAQS Tier 1 demonstrations for permit related programs - Illustrative hypothetical single source modeled impacts for annual and daily maximum average PM2.5 and annual maximum daily 8-hr O3
Information intended to support Class I PSD increment Tier 1 demonstration for permit related programs - Illustrative hypothetical single source modeled impacts of maximum daily average PM2.5 concentrations provided by distance from the source