Frequent Questions on General Rule Information

The Hazardous Waste Combustion NESHAP is a set of national standards specifically established to limit the emissions of hazardous air pollutants (HAPs) from combustion devices that burn hazardous waste, e.g., incinerators, cement kilns, and lightweight aggregate kilns. The Clean Air Act (CAA) lists 188 HAPs, and requires EPA to develop a list of major industrial or "source" categories — categories of plants within an industry, at least one of which emits annually 10 tons or more of any single HAP, or 25 tons or more of any combination of HAPs. Many hazardous waste combustors (HWCs) are major sources under the CAA and emit HAPs, such as: cadmium, lead, hydrogen chloride, mercury, chlorinated dioxin and furans, benzene, and methylene chloride. As a result, HWCs are included on EPA's source category list. The CAA further requires that EPA establish national emission standards for each major source category, and any area source category that is of particular concern. These standards are referred to as national emission standards for hazardous air pollutants, or NESHAP. The standards must require the maximum degree of emission reduction that can be achieved for each source category. The standards for hazardous waste burning incinerators, cement kilns, and lightweight aggregate kilns are found in 40 CFR Part 63, Subpart EEE.

General information concerning the air toxic regulations, hazardous air pollutants, the difference between major and area sources, links to the most recently published source category list, and other subjects related to the NESHAP.

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We use the terms Hazardous Waste Combustion NESHAP and Hazardous Waste Combustion MACT standards interchangeably when discussing the national emission standards established under section 112(d) of the Clean Air Act (CAA) for hazardous waste combustion devices. Section 112(d) of the CAA requires that EPA establish national emission standards for each major source category and any area source category that is of particular concern. These standards are referred to as national emission standards for hazardous air pollutants, or NESHAP. The CAA further requires that the standards represent the maximum degree of emission reduction that can be achieved for each source category based on an analysis of the maximum achievable control technology, or MACT.

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What Clean Air Act source category do hazardous waste combustors fall under?

Hazardous waste combustors (HWCs) include several different types of combustion devices. As a result, HWCs fall under more than one Clean Air Act source category. The source categories pertaining to HWCs include: hazardous waste incineration, portland cement manufacturing, and clay products manufacturing.

Information regarding the Clean Air Act source category listings.

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The Hazardous Waste Combustion NESHAP limits emissions of the following Clean Air Act hazardous air pollutants (HAPs): chlorinated dioxins and furans, mercury, lead, cadmium, arsenic, beryllium, chromium, hydrochloric acid/chlorine gas, antimony, cobalt, manganese, nickel, selenium, and nondioxin and furan organic HAPs. For some of the above-listed HAPs, we chose to use surrogate emission limits. Specifically, antimony, cobalt, manganese, nickel and selenium emissions are controlled through a surrogate particulate matter standard; nondioxin and furan organic HAP emissions are controlled through surrogate carbon monoxide, hydrocarbon, and destruction and removal efficiency standards.

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Did the 1999 Hazardous Waste Combustion NESHAP set emission standards for all hazardous waste combustors?

No. The 1999 Hazardous Waste Combustion NESHAP set emission standards for a subset of the hazardous waste combustion universe. This is because we chose to promulgate the NESHAP in two phases. The first phase, or Phase 1, addressed hazardous waste burning incinerators, cement kilns, and lightweight aggregate kilns. The facilities that comprise these three categories burn over 80 percent of the total amount of hazardous waste combusted each year. We first promulgated the Phase 1 standards on September 30, 1999 (64 FR 52828). We later replaced them on February 13, 2002, with negotiated interim standards in response to a mandate issued by the Court of Appeals for the District of Columbia Circuit (67 FR 6792).

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What are the Interim Standards?

The Interim Standards are negotiated standards which temporarily replace the 1999-promulgated NESHAP for hazardous waste burning incinerators, cement kilns and lightweight aggregate kilns. On July 24, 2001, the Court of Appeals for the District of Columbia Circuit decided Cement Kiln Recycling Coalition v. EPA, 255 F.3d 855 (D.C. Cir. 2001) by vacating certain portions of the 1999 Phase 1 Hazardous Waste Combustion NESHAP. According to the court, the NESHAP "fail to reflect the emissions achieved in practice by the best performing sources as required by the Clean Air Act." Because the decision left the EPA without standards regulating hazardous waste combustor (HWC) emissions, the court invited EPA or any of the parties that challenged the regulation to file a motion to request that either the 1999 standards remain in place or that EPA be allowed time to develop interim standards until replacement standards could be put in place that would comply with the court's opinion. On October 19, 2001 EPA, together with all the other parties, requested the court stay its mandate until February 14, 2002 to allow EPA time to develop and promulgate interim standards. The court granted this motion on November 1, 2001. In turn, EPA promulgated negotiated interim standards on February 13, 2002 (67 FR 6792). The court issued its mandate on March 19, 2002. The negotiated interim standards temporarily replace the original Phase 1 standards.

For a comparison of the 1999 Phase 1 standards to the 2002 negotiated interim standards, see the Standard for Existing and New Units Guide (PDF) (6 pp, 90K) located in the Checklists and Guidelines module of the Toolkit.

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Yes. Since 1999 we have issued several technical corrections and amendments to the Phase 1 Hazardous Waste Combustion NESHAP to improve its implementation. We have also revised specific sections in response to the mandates issued by the Court of Appeals for the District of Columbia Circuit. Most notably, we promulgated negotiated interim emission standards that temporarily replace the 1999-promulgated standards that were challenged, and we extended the compliance date by one year.

For more specific information regarding changes to the Phase 1 NESHAP since its original publication in 1999, see the Corrections and Amendments to the Phase 1 Hazardous Waste Combustion NESHAP Fact Sheet (PDF) (6 pp, 322K) located in the Fact Sheet module of the Toolkit.

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The Hazardous Waste Combustion NESHAP achieves two primary goals. First, it establishes emission standards for hazardous waste burning incinerators, cement kilns and lightweight aggregate kilns based on performance of control technology. Second, it meets our commitment under the RCRA Hazardous Waste Combustion Strategy, first announced in 1993, to upgrade the emission standards for hazardous waste burning facilities through the use of best available technologies and the most current science. The NESHAP also provides an opportunity for EPA to integrate the CAA and RCRA monitoring, compliance testing, recordkeeping and permitting requirements for combustor emissions so as to minimize regulatory duplication to the extent possible. Thus, once a facility has demonstrated compliance with the HWC NESHAP by conducting a comprehensive performance test and submitting a Notification of Compliance documenting compliance, the RCRA emission requirements of 40 CFR Part 264, 265 and 266 no longer apply for hazardous waste incinerators, cement kilns and lightweight aggregate kilns. The RCRA combustion permitting requirements in 40 CFR Part 270 similarly no longer apply after a facility has demonstrated compliance with the HWC NESHAP. However, your regulatory authority may apply certain RCRA combustion permitting provisions on a case-by-case basis for purposes of information collection under 40 CFR 270.10(k) and 270.32(b)(2). You should also note that any emission-related conditions in a RCRA permit will remain in effect even after compliance with the NESHAP, unless they are removed from the permit or subject to a sunset clause, or the permit is terminated or revoked.

For information regarding transitioning from the RCRA permitting requirements after compliance with the HWC NESHAP, see the Toolkit's Permitting FAQs and the Permit Transition: Moving from RCRA to the CAA Fact Sheet (PDF) (8 pp, 569K) located in the Fact Sheet module.

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What are the Replacement Standards?

The Replacement Standards are national emission standards that EPA must issue to replace the negotiated Interim Standards for hazardous waste burning incinerators, cement kilns and lightweight aggregate kilns. On July 24, 2001, the Court of Appeal for the District of Columbia Circuit decided Cement Kiln Recycling Coalition v. EPA, 255 F.3d 855 (D.C. Cir. 2001) by vacating certain portions of the 1999 Phase 1 Hazardous Waste Combustion NESHAP. According to the court, the NESHAP "fail to reflect the emissions achieved in practice by the best performing sources as required by the Clean Air Act." Because the decision left the EPA without standards regulating hazardous waste combustor emissions, the court invited EPA or any of the parties that challenged the regulation to file a motion to request that either the 1999 standards remain in place or that EPA be allowed time to develop interim standards until replacement standards could be put in place that would comply with the court's opinion. On October 19, 2001 EPA, together with all the other parties, requested the court stay its mandate until February 14, 2002 to allow EPA time to develop and promulgate interim standards. The court granted this motion on November 1, 2001. In turn, EPA promulgated negotiated interim standards on February 13, 2002 (67 FR 6792). On March 4, 2002, the court followed with an order that EPA promulgate a Permanent Replacement Standards Rule by June 14, 2005. The Replacement Standards will supersede the interim emission standards that have been in effect since February 13, 2002.

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