DEVELOPING A TOOL TO ESTIMATE NONPOINT EMISSIONS FROM INDUSTRIAL, COMMERCIAL, AND INSTITUTIONAL FUEL COMBUSTION

Emissions from Industrial, Commercial, and Institutional (ICI) fuel combustion are often a significant portion of most areas’ total emissions inventory. Unless all ICI combustion emission sources are covered in a geographic area’s point source inventory, it is necessary for inventory preparers to estimate ICI combustion nonpoint source emissions. Because there are specific challenges associated with estimating ICI nonpoint source emissions, the U.S. EPA in conjunction with Abt Associates developed a Microsoft® Access-based ICI Combustion Tool to assist State, Local, and Tribal agencies in estimating nonpoint emissions from ICI fuel combustion for the 2014 National Emission Inventory. The primary data source behind the ICI Combustion Tool is total state-level ICI energy consumption data released annually as part of the Energy Information Administration’s State Energy Data System (SEDS). The ICI Combustion Tool processes the SEDS data and adjusts the data to account for the fraction of fuel consumed by nonroad mobile sources whose emissions are included in the nonroad inventory and by non-fuel combustion uses of energy, such as product feedstocks. Through a user-friendly interface, users can update the underlying assumptions in the adjustment methodology. The ICI Combustion Tool also includes a nonpoint source to point source crosswalk and allows the user to perform point source activity subtractions to avoid double counting of emissions between their point and nonpoint inventories. The ICI Combustion Tool generates outputs in EPA’s Emissions Inventory System (EIS) format, ready for submission to the EIS. This paper will provide an overview of the ICI Combustion Tool and the procedures for developing a credible estimate of nonpoint emissions from ICI fuel-combustion sources.