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. This inventory is expected to be finalized in 

September. Currently, the NEI includes emissions data for point sources, nonpoint (or area) sources, 

and nonroad mobile sources. Onroad mobile source emissions were not available for this analysis. We 

believe that the impact of not including onroad mobile source emissions in the total PM2.5 emissions is 

relatively small given that onroad mobile sources contributed only 6% to the total PM2.5 emissions in 

the 2008 NEI. Also, wildland fire emissions were not included in the total PM2.5 emissions here because 

the impact of these emissions can be excluded under our exceptional events rule in determining an 

area’s attainment status. Also please note that although this is the most up to date inventory available 

for RWC, we are continuing to improve our emissions inventories. For example, we believe that the 

relative PM2.5 RWC contributions are overestimated 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, tribes, and local agencies to EPA's Air Quality 

System as of July 26, 2012.1 

 Counties 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).

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 Counties with annual DVs equal to or greater than the annual NAAQS are highlighted in red. 

 Counties 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-hour NAAQS.

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 Counties with 24-hour DVs equal to or greater than the 24-hour NAAQS are highlighted in red. 

 

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Please note the DVs shown are the highest of the valid, complete site-level values in each county. Reported 

values of -999 or -999.0 reflect that there are insufficient 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, construction), and concurred by the 

associated EPA Regional Office, are not included in the calculation of these DVs.

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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-year average annual mean concentration.

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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 column 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.