Site-Specific Compliance Demonstration For Hydrochloric Acid Emissions For Non-Utility Boilers Subject To 40 CFR 63 Subpart DDDDD (Boiler MACT)

摘要

A Site-Specific Compliance Demonstration per 40 CFR 63 Subpart DDDDD, Appendix A for hydrochloric acid (HCl) was completed for a major mid-western university. 40 CFR 63 Subpart DDDDD, also known as the Boiler MACT, requires subject boilers meet HCl emission limits set forth in the rule through stack testing or fuel monitoring. The rule also provides an alternate compliance demonstration approach for hydrochloric acid, outlined in Subpart DDDDD, Appendix A. This alternate approach offers two methods to determine eligibility for the health-based compliance alternative for HCl: a Look-Up Table Analysis based on a calculated HCl-equivalent emission rate from all subject sources, and also a Site-Specific Compliance Demonstration where the facility is eligible if the compliance demonstration indicates that the maximum chronic hazard index (HI) value for HCl and Cl2 from the subject sources is less than or equal to 1.0 at locations where people live or congregate. This paper provides details on methodologies evaluated and includes results of the health-based eligibility demonstration and basis for evaluation. All of the utility plant boilers at the university are subject to the Boiler MACT. Therefore, all hydrochloric acid and chlorine emissions associated with combustion of coal and fuel oil in the subject boilers were included in this demonstration. The EPA-required methodology resulted in a total hazard index of less than 1.0, i.e., the noncarcinogenic effects of the individual chemical concentrations and the noncarcinogenic effects of the combined chemical concentrations are protective of human health. This entailed the use of a fate and transport model to estimate ambient air concentrations, followed by an exposure assessment and risk characterization. The approach used to perform this analysis followed the risk assessment methodology found in the U.S. EPA/OAQPS Air Toxics Risk Assessment Library, Volume 2, Facility-Specific Assessment (U.S. Environmental Protection Agency, EPA-453-K-04-001B, April 2004).