EPA'S MACT RULE FOR HAZARDOUS WASTE COMBUSTORS

Note: The information and views contained in this paper are solely those of the author and do not represent any official information, views, positions, or policies of the U.S. Environmental Protection Agency. Further, because the final MACT rule for hazardous waste combustors has not yet received final Agency approval, all information on the contents of the rule is based on the proposals previously published in the Federal Register and on staff level evaluation. ABSTRACT In early 1999, U.S. EPA expects to promulgate final regulations controlling emissions of hazardous air pollutants (HAPs) from incinerators, cement kilns, and lightweight aggregate kilns that burn hazardous waste. DOE's mixed waste incinerators (as well as any privately-owned mixed waste incinerators) will also be subject to these regulations. Together, these facilities are responsible for about 80% of the hazardous waste burned each year in the U.S. EPA's final rule will impose a national set of technology-based emission standards. These standards will limit emissions of dioxins/furans, mercury, two semi-volatile metals (i.e., lead and cadmium), three low volatility metals (i.e., arsenic, beryllium, and chromium), particulate matter, total chlorine, carbon monoxide, and hydrocarbons. Emission standards and associated requirements on combustion operations will be regulated and permitted only under the Clean Air Act. Hazardous waste permits will continue to be required for other waste management activities conducted at these facilities (such as storage and corrective action). These hazardous waste permits, issued under authority of the Resource Conservation and Recovery Act (RCRA), can be expanded in unusual circumstances to include special emission standards needed to ensure full protection against potential risks to human health or the environment. BACKGROUND The U.S. Environmental Protection Agency (EPA or the Agency) intends in early 1999 to adopt a final rule that imposes national, technology-based emission standards on three categories of facilities that burn hazardous waste. These facilities include incinerators (both commercial and on-site), cement kilns, and lightweight aggregate kilns. EPA is doing so for several reasons. First, these standards will satisfy EPA's legal obligations under the Clean Air Act to control emissions of hazardous air pollutants (or HAPs) from hazardous-waste burning incinerators and portland cement kilns. In 1992, EPA published a list of categories of major and minor (or area) sources of HAPs, including hazardous waste incinerators and portland cement plants.(1) The Agency shortly thereafter committed to developing MACT standards for these two source categories within 10 years.(2) The expected final rule for hazardous waste combustors would fulfill most of this obligation, but some cement kilns do not burn hazardous waste. Therefore, to complete its task, the Agency has also proposed MACT standards for portland cement plants that do not combust hazardous waste.(3) (This proposal is not discussed in this paper.)