Developing a Local-Scale Nonpoint Area Source Emissions Inventory: Cuyahoga County, Ohio

The development of a nonpoint area source emissions inventory is often dictated by the time and resources available. As part of the National Emissions Inventory (NEI), EPA has developed county-level emission inventories of criteria and hazardous air pollutants (HAPs) for nonpoint area sources in the United States for the 1996 and 1999 base years using top-down methodologies. State, local, and tribal agencies have periodically had opportunity to provide comment s, corrections, and bottom-up supplemental data to these inventories. The incorporation of bottom-up emissions data has always been encouraged by EPA to improve the NEI. Although the trend for data submissions increased from 22 agencies in 1996 to 40 agencies in 1999, lack of time and resources have been limiting factors for several agencies, preventing development of a bottom-up nonpoint area sources inventory for NEI submission