On January 31, 2013, the Environmental Protection Agency (EPA) published its new Boiler MACT (Maximum Achievable Control Technology) rule in the Federal Register. The next day, the agency published its new area-source rule. The publication of these two new rules in final form has set in motion a new regulatory regime that will impact hundreds of thousands of facilities nationwide that have a boiler or a process heater on site.
The new rules, which were a result of a decade of rulemaking attempts by the agency and related litigation, public comment, and political effort, appear in 78 Federal Register 7138 (Jan. 31, 2013 and 78 Federal Register 7488 (Feb. 1, 2013). The source of these new requirements lies in the Clean Air Act, which required the EPA to establish “National Emissions Standards for Hazardous Air Pollutants” for both “major” and “area” sources of hazardous air pollutants. A major source is a stationary source that emits or can emit 10 or more tons per year of any single hazardous air pollutant, or 25 tons or more per year of any combination of the 187 hazardous air pollutants subject to regulation. Major sources generally must install and operate maximum achievable control technology (MACT) to limit emissions.
For new sources, MACT-based emissions standards cannot be less stringent than the emissions control achieved in practice by the best-controlled similar source. An area source is a stationary source that does emit hazardous air pollutants, but not to the level that would make it a major source. The pollutants that will be controlled under the final rules include mercury, particulate matter (which is measured as a surrogate for non-mercury metals), and carbon monoxide (as a surrogate for organic air toxics). In addition, dioxin and hydrogen chloride are also controlled under the final rule for major sources.