IDEM requests companies that report emissions of criteria pollutants under the emissions reporting rule, 326 IAC 2-6, to voluntarily report emissions of hazardous air pollutants (HAPS). The data is used to compile statewide emission inventories for HAPS to support different state initiatives and federal programs.
- Form for Reporting Hazardous Air Pollutants (available on the IDEM Forms page)
- U.S. EPA: Complete list of HAPs
Development of Regional and National Air Toxics Inventories
Although reporting of hazardous air pollutants is voluntary, IDEM uses the data for several on going emission inventory efforts. The HAP inventory is used to assist in state air toxics planning efforts, and is provided to the United States Environmental Protection Agency to support the development of the National Emissions Inventory (NEI) and federal programs for air toxics, such as the National-scale Air Toxics Assessment, a modeling study that estimates ambient levels of air toxics at the census tract level nationwide. IDEM will continue to make estimates, using information from the Emissions Statements and available emission factors, to develop Indiana's portion of the regional and national toxics inventories.
How to Estimate and Report HAPS
HAPs may be estimated a number of different ways. Estimates may be made by using continuous emissions monitoring data or stack test information, if available, or by using emission factors, speciation profiles, mass balance calculations, or other engineering calculations. Emissions for HAPS can be made at the segment level or at the plant level. Emission factors for many processes can be obtained from U.S. EPA's AP-42 and FIRE databases. These guidance materials, and others estimation tools, are available from U.S. EPA's Technology Transfer Network website.
Reporting of Hazardous Air Pollutants may be made using either the above form, or the Satellite program. IDEM prefers that HAPS be reported in Satellite the same way that criteria pollutants are reported. Submittals should include the HAP pollutant code, the material throughput, SCC code, emission factor, emission estimation method code, and control equipment information. Sources using the above form should remember to report plant total HAPS in tons per year. Please report using only one format.
If you have any questions on HAP reporting, or would like to see the current HAP estimates for your company, please contact OAQ staff.