On December 20, the U.S. Environmental Protection Agency (EPA) finalized changes to Clean Air Act standards for boilers and certain incinerators (aka, Boiler MACT).

The adjustments were made in response to multiple requests for reconsideration of certain aspects of the 2011 rules and recognize the diverse and complex range of boiler uses and fuels.  EPA made data driven adjustments that reflect the real world operating conditions of specific types of boilers, while maintaining significant emission reductions.  The latest and best information provided during the rule development and reconsideration processes resulted in EPA:

• Adjusting emission limits for certain pollutants in certain categories of major boilers and CISWI. Because EPA followed the Clean Air Act, the changes resulted in both less and more stringent emission limits, depending on what the new data demonstrated.  A detailed summary of these changes is available in a fact sheet online.
• Adding to and refining the list of the subcategories of boilers that EPA uses to provide the right standards for the right boilers. Each subcategory has its own list of requirements that recognizes what is achievable.
• Allowing the necessary time to implement the standards by establishing the compliance deadlines for major boilers and CISWI units in 2016 and 2018, respectively.  These units will have three to five years, respectively, to comply with these adjusted standards, and can do so with proven, currently available technologies.
• Maintaining numerical emission limits for the highest emitting 0.4 percent of all boilers. These will not apply to 86 percent of all boilers in the United States because these boilers burn clean natural gas and emit little toxic air pollution.  The rest would need to follow work practice standards, such as annual tuneups, to minimize toxics.

The final adjustments to the standards are based on an analysis of data and input from states, environmental groups, industry, lawmakers and the public.  As a result of information gathered through this review, according to EPA, the final rule cuts the cost of implementation by individual boilers that EPA proposed in 2010. At the same time, the rules will continue to deliver public health benefits.  EPA estimates that for every dollar spent to reduce these pollutants, the public will see $13 to $29 in health benefits, including fewer instances of asthma, heart attacks and premature deaths.

The rules set numerical emission limits for less than one percent of boilers — those that emit the majority of pollution from this sector. For these high-emitting boilers and incinerators, typically operating at refineries, chemical plants and other industrial facilities, EPA is establishing more targeted emissions.

EPA has also finalized revisions to the Non-Hazardous Secondary Materials Rule to provide clarity on what types of secondary materials are considered non-waste fuels. This final rule classifies a number of secondary materials as categorical non-wastes when used as a fuel and allows for operators to request that EPA identify-specific materials through rulemaking as a categorical non-waste fuel.

More detailed information on the final standards for boilers and incinerators is available at www.epa.gov/airquality/combustion. The complete final rule, a 539-page PDF document, is online at Final Emissions Standards for Commercial/Industrial Solid Waste Incinerators (CISWI).