The emission inventory is a compilation of pollutant-emission estimates from facility and equipment operations. Mills can employ continuous emissions measurement in any scenario where instrument systems are applicable. EPA requirements for CEMS have applied to specific equipment operations and typically have allowed long compliance averaging periods, often up to 30 days. But under new-source permitting guidelines, agencies have the latitude to require CEMS for what some believe are inappropriate source applications. There also is the potential for regulatory abuse by imposing compliance averaging periods that are unreasonably short.
Companies then use the emission factor to estimate emissions based on the measured source parameter.
In the third method, a firm uses average emission factors from measurements at numerous similar facilities. These general emission factors then are applied to specific source operations to estimate average emissions. Regulatory agencies use emission-inventory data in a variety of ways. Perhaps you're most keenly aware of requirements to pay annual emission fees based on your estimated amount of emitted pollutants. To estimate the total pollutant burden on an exposed population, agencies combine industrial-source inventories with those for utilities, natural sources, and pollutants transported to a geographic area.