EPA releases proposed MACT rule changes

By Lisa Gibson
Posted May 11, 2010, at 9:16 a.m. CST

The U.S. EPA has released a set of proposed changes to the Maximum Achievable Control Technology rule that would reduce mercury emissions from industrial boilers, process heaters and solid waste incinerators by more than 50 percent.

The proposal would also considerably slash emissions of other pollutants from those technologies that are thought to cause cancer or other serious health problems, along with climate change, according to the EPA. The proposal, open for a 45-day comment period, includes emissions standards for three source categories: area source industrial, commercial and institutional boilers; major source industrial, commercial and institutional boilers; and commercial and industrial solid waste incinerators.

For area source boilers, the EPA recommends a rule with standards to address mercury, particulate matter and carbon monoxide, applicable to technologies based on whether they are coal or biomass-fired and new or existing, according to the proposal. Major source boilers would have a work practice standard instead of emission limits under the proposal and operators would be required to perform annual tune-ups for each unit. The major source standards would include limits for mercury, carbon monoxide, particulate matter, hydrogen chloride and dioxin. Finally, the proposal would limit nine pollutants from commercial and solid waste incinerators: mercury, lead, cadmium, hydrogen chloride, particulate matter, carbon monoxide, dioxin and furans, nitrogen oxides and sulfur oxides. The limits would require reductions at 172 of 176 operating solid waste incinerators, as four already meet the proposed standards, according to the EPA.

The agency also proposes a new definition to identify which nonhazardous secondary materials would be considered solid waste and which would be considered fuel. That distinction determines whether a facility burning the material would be considered a boiler or a solid waste incinerator pursuant to the proposed rule. The proposal states that the definition would not include, among other criteria, material that has been determined through a case-by-case petition process to not have been discarded and to be indistinguishable in all relevant aspects from a fuel product. The entire proposal can be found at www.epa.gov/airquality/combustion.

When fully implemented, the proposed rule would yield combined health benefits estimated between $18 billion and $44 billion annually, according to the EPA. That includes preventing between 2,000 and 5,200 premature deaths and about 36,000 asthma attacks per year. The estimated annual cost of installing and operating the pollution control equipment necessary to meet the proposed standards is $3.6 billion. The proposed rule comes after a D.C. Circuit Court vacated and remanded the original definition of commercial or industrial solid waste incinerator and the Boiler MACT rule in June of 2007.

Petition for Change

The original MACT rule was finalized in 2004 and consists of a floor limit for each pollutant and source category, below which the standard cannot be set; and a technology-based standard, which can be equal to or more stringent than the floor. Before establishment of the MACT rule, emissions standards had been risk based.

Some municipalities and environmental groups dissatisfied with the MACT rule petitioned the EPA to reconsider it in 2004, according to Anna Wildeman, a member of the Land and Resource Practice Group for law firm Michael Best & Friedrich LLP. The EPA granted the reconsideration and issued a revised rule in December of 2005. Still not pleased, the groups filed petitions with the D.C. Court of Appeals to review the final rule in February of 2006.

The petitions outlined a few issues challenging how reasonable the MACT rule was as it related to the requirements of the Clean Air Act. First, it said the definition of commercial and industrial waste was much too narrow, specifying only waste combusted at a facility that cannot or does not recover thermal energy for useful purpose. "The agency did not actually define waste," Wildeman said. "It defined waste by the process." That effectively limits the number of facilities that would fall under the definition of a commercial or industrial solid waste incineration unit-defined as a facility that combusts solid waste-and significantly increases the number of facilities that fall under the boiler rule, wherein lies the other issue outlined in the petition: The MACT floor for industrial boilers was a "no control" standard.

"The court agreed with the petitioners that EPA's definition of commercial or industrial waste was contrary to and in conflict with other definitions in the Clean Air Act and vacated that definition," Wildeman said. "The court further noted that, because a revised definition of commercial industrial waste would alter the number of facilities subject to the Boiler MACT rule, and because MACT standards are based on averages of similar facilities in the same source category, the Boiler MACT rule also had to be vacated."

The proposed rule would affect numerous biomass facilities, although some are still wading through the documents, numbering more than 1,200 pages. "We're still in the process of looking over the proposal and determining its impact," said Lynn Wallace, spokeswoman for Georgia Power, which is developing a 96-megawatt biomass power plant in Albany, Ga. The project is stalled on its timeline for operation before the summer of 2012, awaiting the MACT rule release. Wallace had previously said the company expects it will be affected, but has made arrangements to comply with any new standards and continue with the development of its wood-fired facility.