EPA'S PARTICULATE MATTER (PM) AUGMENTATION TOOL: AUTOMATING QUALITY ASSURANCE AND PM SPECIATION TO GENERATE A MODEL-READY INVENTORY

The Consolidated Emissions Reporting Rule requires that state, local, and tribal agencies (SLT) submit particulate matter (PM) emissions for point and nonpoint sources to EPA’s National Emissions Inventory (NEI). Since PM is both a National Ambient Air Quality Standard (NAAQS) pollutant and a major contributor to visibility impairment, the PM2.5 NAAQS and the Regional Haze Rule each emphasize emissions inventory development for the PM species required in regional air quality modeling. While submission of PM emissions to the NEI by SLT agencies should include filterable and primary PM (PM10-PRI, PM10-FIL, PM25PRI, and PM25-FIL) along with condensible PM (PM-CON), SLT agencies often submit incomplete speciation. Augmentation of the PM species in the NEI point and nonpoint source inventories is necessary to ensure completeness of the PM inventories for air quality modeling and to ensure that SLT inventories do not contain erroneous pollutant reporting. This paper describes EPA’s PM Augmentation Tool used to correct inconsistencies in SLT-submitted PM data and to gap-fill missing PM data in version 1 of the 2011 NEI. One recent modification to the PM Augmentation Tool is the expansion of the augmentation procedure to cover nonpoint source categories. The tool involves three main steps: 1) pre-screening and self-consistency checks; 2) trivial updates, where missing data can be calculated using addition or subtraction of filterable or condensible PM; and 3) non-trivial updates, where missing data must be estimated using PM calculators. Each of these steps is described in more detail below.