With much anticipation, on December 21, 2012 the Environmental Protection Agency (EPA) released a suite of air pollution rules regulating hazardous air emissions from combustion sources such as industrial boilers and process heaters. This package of combustion rules includes a revised version of the Industrial Boiler Maximum-Achievable Control Technology standard (Boiler MACT). The agency first finalized the Boiler MACT rule package in March 2011, but on the same day announced it would undertake an administrative reconsideration of the rule to address numerous concerns that had been raised by stakeholders. During the nearly two years it took EPA to reconsider the Boiler MACT rule, the agency collected additional emission information from certain categories of boilers and industrial incinerators which it used to better inform the rule revisions.

The final combustion rule package consists of more than 2,000 pages of administrative rules. The rule package specifically addresses major and area source industrial boilers, as well as commercial and industrial solid waste incinerators (CISWI). These rules provide new emissions limits, compliance dates and important clarifications on how the rules are to be implemented. The rule package also includes guidance for defining whether non-hazardous secondary materials (NHSM) are to be considered a solid waste or a fuel, which is a critical decision for determining whether combustion of such materials must be regulated under the generally more stringent incinerator CISWI rules or the revised Boiler MACT rules.

Given the volume of material released today, we will continue to review the revised rules and provide additional updates as appropriate. Compliance with the rules will be costly, especially when one considers cumulative costs of the other regulatory initiatives that are simultaneously impacting combustion sources. However, our initial impression is that the rule revisions, especially for Boiler MACT, are a marked improvement from the original rule. The principle changes from the March 2011 rules are summarized below.

Major Source Boilers

• Compliance date extended to early 2016, and subject facilities will have an opportunity to request an additional year if needed. The Boiler MACT rule includes language in the preamble to encourage states to grant this extra year.
• New subcategories were created for light and heavy industrial liquids and for coal fluidized bed units.
• Revised emission limits for units outside the continental U.S.
• New emission limits for particulate matter and carbon monoxide, allowing alternative total selective metals emission limits, and replacing numeric dioxin limits with work practice standards.
• Adding alternative monitoring approaches for demonstrating compliance with particulate matter limits.

 Area Source Boilers

• Initial compliance date is extended to March 21, 2014, and subject facilities will have an opportunity to request an additional year if needed.
• Initial notification must occur no later than January 20, 2014.
• New subcategories were created for seasonal and limited use boilers.
• Allowing existing dual-fuel fired units to retain the "existing unit" designation regardless of fuel switching.
• Periodic tune-ups for seasonal/limited use and small oil-fired units are required every five years, instead of every two years.
• Creating alternative compliance demonstrations for new boilers burning low sulfur oil and compliance incentives for boilers that perform well below emission standards.
• Adding alternative monitoring approaches for demonstrating compliance with carbon monoxide (CO) limits.

 CISWI

• Compliance date for existing units is 2018 (three years after EPA approves a state plan, or five years after the publication of EPA’s final rules, whichever is earlier).
• New incinerators need to meet the standards 180 days following publication of the rule in the Federal Register.
• New emission limits for dioxin and mercury which EPA believes will result in better-defined and more achievable standards.

 Non-hazardous Secondary Materials (NHSM)

• Provides new standards and procedures for determining if NHSMs are "solid waste" under the Resource Conservation and Recovery Act when used as fuels in combustion units.
• EPA notes the new standards and procedures should provide greater flexibility in the criteria for making non-waste determinations.

The full revised rule package can be found here.