NOx RACT Summary
The Clean Air Act amendments of 1990 introduced the requirement for existing major stationary sources of NOx in nonattainment areas to install and operate NOx RACT. Specifically, section 182(b)(2) of the CAA requires States to adopt RACT for all major sources of volatile organic compounds (VOC) in ozone nonattainment areas; and, section 182(f) requires the RACT provisions for major stationary sources of oxides of nitrogen.
Section 302 of the CAA defines major stationary source as any facility which has the potential to emit of 100 tons per year of any air pollutant. For serious ozone nonattainment areas, a major source is defined by section 182(c) as a source that has the potential to emit 50 tons of NOx per year. For severe ozone nonattainment areas, a major source is defined by section 182(d) as a source that has the potential to emit 25 tons per year.
The Ozone Transport Region (OTR) has special provisions for major sources since section 184(a) of the CAA requires areas in the OTR to be treated as moderate (or higher) ozone nonattainment. Therefore, in marginal and moderate nonattainment areas and attainment areas in the OTR, a major NOx source is one with the potential to emit 100 tons per year or more of NOx. The entire six State New England region is part of the OTR.
The CAA NOx RACT requirements are described by EPA in the "NOx Supplement" notice titled, "State Implementation Plans; Nitrogen Oxides Supplement to the General Preamble; Clean Air Act Amendments of 1990 Implementation of Title I; Proposed Rule," published November 25, 1992 (57 FR 55620). In the NOx Supplement notice EPA defined RACT as the lowest emission limitation that a particular source is capable of meeting by the application of control technology that is reasonably available considering technological and economic feasibility.
The EPA has not generally prescribed RACT requirements. In the NOx Supplement, however, EPA established emission limits for certain categories of utility boilers. The NOx Supplement set these emission limits on a 30-day rolling average basis. For those source categories for which the NOx Supplement specified a limit, States were required to define RACT at least as stringently.
Other non-EPA groups, such as the Northeast States For Coordinated Air Use Management (NESCAUM) Exitand State and Territorial Air Pollution Program Administrators/Association of Local Air Pollution Control Officials (STAPPA/ALAPCO) Exithave also developed NOx RACT guidance documents, including the joint NESCAUM and EPA December 1992 study entitled, Evaluation and Costing of NOx Controls For Existing Boilers in the NESCAUM Region (EPA 453/R-92-010) and STAPPA/ALAPCO's Controlling Nitrogen Oxides Under the Clean Air Act: A Menu of Options, published in July 1994. These documents also surveyed NOx emissions from various categories of sources, as well as the technically available controls and cost
In most New England States, the State has defined NOx RACT as category-wide emission rate limitations (e.g., on a part per million or pound NOx per million Btu basis) or control technology requirements (e.g., install and operate low-NOx burners). Additionally, all of the NOx RACT regulations in New England provide for case-specific NOx RACT determinations. Case-specific determinations were allowed either for sources that do not fall into one of the prescribed source-categories or cannot meet one of the presumptive emission limits.
In setting the NOx RACT standards, the States considered the total cost, total emission reductions, and cost effectiveness of controls needed to achieve the emission limits or equipment standards. Generally, the total NOx reductions achieved and the cost effectiveness of controls fell within the ranges articulated in EPA's Office of Air Quality Planning policy memoranda, such as the March 16, 1994 memorandum entitled, "Cost-Effective Nitrogen Oxides (NOx) Reasonably Available Control Technology (RACT), and the January 10, 1995 memorandum entitled, "De Minimis Values For NOx RACT." For example, the March 16, 1994 memorandum recommends that a NOx reduction of 30% to 50%, corresponding to a cost-effectiveness range of $160 to $1300, be considered in the setting of NOx RACT standards.
For more specific information on NOx RACT requirements please see the "NOx Supplement;" the EPA guidance memoranda included in compendium entitled, "NOx Policy Document for the Clean Air Act of 1990," (EPA-452/R-96-005, March 1996); and the Alternative Control Technologies documents (ACTs)for the following NOx sources: nitric and adipic acid manufacturing plants, stationary gas turbines, process heaters, stationary reciprocating internal combustion engines, industrial-commercial-institutional boilers, utility boilers, cement manufacturing, glass manufacturing, etc.