On February 23, 2011, the U.S. EPA released its much-anticipated Industrial Boiler MACT, which was actually finalized on February 21, 2011 pursuant to a federal court order. The rule package, which actually includes four rules, was promulgated under Section 112 of the Clean Air Act which requires national emission standards for hazardous air pollutants (HAPs). These emission standards must include Maximum Achievable Control Technology (MACT). The new rule, collectively known as the National Emission Standard for Hazardous Air Pollutants (NESHAP) for Industrial, Commercial and Institutional Boilers, addresses two primary areas: 1.) industrial, commercial and institutional boilers and process heaters for “major” sources; and 2.) industrial, commercial and institutional boilers for “area” sources. The original Industrial Boiler MACT was issued in 2004 but was vacated by a federal court of appeals in 2007. The U.S. EPA was ordered to re-write the rule and issued a new draft rule in April 2010, and was under a court order to finalize the rule by December 16, 2010. Because of numerous comments, the U.S. EPA sought extensions of the deadline, but the court eventually ordered the U.S. EPA to issue the final rule by February 21, 2011.

According to the U.S. EPA, the final Industrial Boiler MACT will result in a 50% reduction of implementation costs for industry from the April 2010 draft. Major changes include the addition of “work practice standards” (e.g., periodic maintenance tune-ups), instead of numeric emission standards, for small new boilers (i.e., heat input capacity less than 10 MMBtu/hr), limited-use boilers (i.e., emergency backup units used less than 10% a year), and for periods of startup, shutdown and maintenance. Because of the rush to release the Industrial Boiler MACT to satisfy the court-imposed deadline, the U.S. EPA could not entertain public comments on the revised rule. As a result, the U.S. EPA also simultaneously issued a Notice of Reconsideration of the final Industrial Boiler MACT rule, which will allow the public to comment on certain aspects of the final rule. Details of the reconsideration process will be forthcoming.

The rules set emission standards based on the heat input of the combustion unit, fuel source, whether it’s new or existing, and whether it’s an “area” source or a “major” source. Depending upon these various factors, a boiler could be subject to emission limits for mercury, particulate matter, carbon monoxide, hydrogen chloride and dioxin/furan. The complete rules can be found at www.epa.gov/airquality/combustion/actions.html#feb11 and consist of 276 pages for area source rule and 490 pages for major source rule. The rule package also includes emissions standards for Commercial/Industrial Solid Waste Incinerators and emission standards for Sewage Sludge Incinerators. As part of this rule package, the U.S. EPA also issued a final rule relating to the definition of “solid waste” as it relates to the Industrial Boiler MACT rule. This definition determines whether a combustion unit is required to meet the emissions standards for solid waste incineration units or the emissions standards for commercial, industrial, and institutional boilers.

While the Industrial Boiler MACT rule was just recently released and the public is still trying to review and decipher the more than 750 pages that make up the primary rules, early commentators note the favorable treatment of biomass. Boilers that burn any solid fossil fuel and no more than 15% biomass are in the coal subcategory, whereas the same boiler that burns at least 15% biomass is in the biomass subcategory, which could have a significant impact on whether the combustion unit has emission limitations or periodic tune-ups. According to Gina McCarthy, assistant administrator for the U.S. EPA Office of Air and Radiation, “the final rule does provide some incentive to look at coal-fired with biomass as part of a compliance suggestion.”

Various aspects of the Industrial Boiler MACT become effective at different dates. Generally, emission limits for existing units will not become effective until 2014, but work practice standards for existing sources will become effective in 2012 (one year from the date of publication of the rule in the Federal Register). As noted previously, some parts of the Industrial Boiler MACT are being “reconsidered” by the U.S. EPA, and the foregoing standards, requirements and dates may change in the future.