August 14, 2013

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## Air Quality and Emissions Data **; Supporting Information for the**  **Residential Wood Heater**  **New Source Performance Standard** This spreadsheet includes recent fine particulate matter (PM2.5) emissions from residential wood smoke combustion (RWC) and PM2.5 air quality design values (DVs ) by state and county. The emissions data are expressed in terms of tons per year (tpy) and are taken from EPA's preliminary 2011 National Emissions Inventory (NEI). The NEI contains emissions data submitted by the states and augmented by EPA if no state data are available. Th is inventory is expected to be finalized in September. Currently, the NEI includes emissions data for point source s, nonpoint (or area) sources, and nonroad mobile sources. Onroad mobile source emi ssions were not available for this analysis. We believe that t he impact of not including onroad mobile source emissions in the total PM2.5 emissions is relatively small given that onroad mobile sources contribute d only 6% to the total PM2.5 emissions in t he 2008 NEI . Also, w ildland fire emissions were not included in the total PM2.5 emissions here because the impact of these em i ssions can be excluded under our exceptional events rule in determining a n area’s attainment status. Also please note that a lthough this is the most up to date inventory available for RWC, we are continuing to improve our emissions inventories. For example, we b elieve that the relative PM2.5 RWC contributions are overestimate d in some areas and underestimated in others. The DVs shown here are based on the 3 -year period 2009 - 2011 and are computed using Federal Reference Method or equivalent data reported by states, t ribes, and local agencies to EPA's Air Quality System as of July 26, 201 2. 1  C ounties with annual DVs between 10 micrograms/cubic meter (μg/m3) and 11.9 μg/m3 are highlighted in yellow in column 6. This range of values was chosen to include areas that are roughly within 10% of the annual national ambient air quality standard (NAAQS) . 2  C ounties with annual DVs equal to or greater than the annual NAAQS are highlighted in red.  C ounties with 24 - hour DV's between 30 μg/m3 and 34.9 μg/m3 are highlighted in yellow in column 7 . This range of values was chosen to include areas that are roughly within 10% of the 24 - h ou r NAAQS . 3  C ounties with 24 - hour DVs equal to or greater than the 24- h ou r NAAQS are highlighted in red.

1 Please note t he DVs shown are the highest of the valid , complete site - level values in each county. R eported value s of - 999 or - 999.0 re flect that there are i nsufficient data to compute a DV . Blank cells in columns 6 and 7 indicate that no monitoring data are available in that county. Concentrations flagged by states, tribes, and local agencies as exceptional events (e.g., high winds, wildfires, volcanic eruptions, constructio n), and concurred by the associated EPA Regional Office, are not included in the calculation of these DV s. 2 The level of the 2012 annual NAAQS for PM2.5 is 12.0 micrograms per cubic meter (μg/m3). The design value for the annual PM2.5 NAAQS is the 3 -yea r average annual mean concentration. 3 The level of the 2006 24- hour NAAQS for PM2.5 is 35 micrograms per cubic meter (μg/m3). The design value for the 24- hour PM2.5 NAAQS is the 3 -year average 98th percentile concentration.August 14, 2013

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Sheet 1 in the spreadsheet contains counties with a % RWC contribution > 10% in column 5 , annual DV ≥ 10 μg/m3 in column 6, or 24- hour DV ≥ 30 μg/m3 in column 7. Sheet 1 is sorted on c olumn 5 from highest to lowest. Sheet 2 contains counties with a % RWC contribution > 10% in column 5 , but have no monitoring data and , therefore , no DVs .