The Environmental Protection Agency (EPA) on Dec. 20 finalized changes to a specific set of adjustments to the Clean Air Act that apply to coal, oil, natural gas, and biomass boilers and certain solid waste incinerators.
The rules seek to reduce mercury and particle pollution, in the same way as rules originally finalized in March 2011, but they increase the rules’ flexibility and address concerns raised by stakeholders, the EPA said. Major source and affected area source boilers will now have three years to comply and can be granted a fourth year if needed to install controls, it said.
More than 1.5 million boilers are operational in the U.S. Nearly 86% of these would be exempt from the rule because they burn natural gas at area source facilities and emit little pollution. For about 13% of the boilers, the EPA’s standards would “continue to rely on practical, cost-effective work practice standards to reduce emissions,” the agency said. And for the highest emitting 0.4% of all boilers in the U.S., the EPA is proposing more targeted revised emissions limits that will provide “industry practical, protective, cost-effective options to meet the standards.” The changes will require about 2,300 of the largest units to add pollution controls or take steps to reduce air pollution.
In a separate but related action, the EPA on Dec. 20 also revised the nonhazardous secondary materials rule (NHSM). That rule defines which materials are, or are not, “solid waste” when burned in combustion units. "The NHSM rule helps determine which standards, either boiler or [commercial and industrial solid waste incinerator (CISWI)] a unit that burns these materials will be required to meet."
The rules finalized on Dec. 20 stem from a reconsideration of the final rule that was adopted in February and published March 21, 2011—on the same day the EPA finalized the rules. The first Industrial Boiler MACT rule, adopted in 2005, was vacated by the U.S. Circuit Court of Appeals for the D.C. Circuit in 2007, leading to a re-proposal of the rule on June 4, 2010.
Industry pushback against that rule, and claims that limits set by the 2010 rule were unachievable, prompted the EPA to relax the rule. But a court-ordered consent decree required the EPA to publish the final rule at the beginning of 2012, forcing the agency to sign the final rule in February. However, the EPA promised to reconsider the rules because “certain issues of central relevance” arose after the period of public comment. It proposed adjustments in December 2011.
The EPA said that since proposing changes to the rules, it had received more than 50 petitions to reconsider, clarify, and amend certain provisions of the final rules.
This story first appeared in POWERnews, Jan. 3, 2013.
—Sonal Patel, Senior Writer (@POWERmagazine)