News | February 12, 2013

EPA Finally Amends Its Boiler MACT Regulations And Further Defines Fuels Versus Wastes

Boiler owners beware – EPA has “finalized” its Boiler MACT, GACT, CISWI and NHSM rules and the compliance clocks have begun ticking. EPA expects the rules to affect about 200,000 boilers and that annualized compliance costs will be $ billions/year.


EPA published its Boiler MACT (for major HAP sources), Boiler GACT (for minor or area HAP sources) and CISWI (incinerators) regulations in March 2011. At the same time, EPA also issued its Non-Hazardous Secondary Material (NHSM) regulation to define whether materials burned in units constitute a “fuel” (subjecting units to MACT/GACT standards for boilers) or a “waste” (subjecting units to the CISWI standards for incinerators). For a more complete discussion of these regulations as published in 2011, see our March 4, 2011, Alert here.

Immediately after publication, EPA announced that it would reconsider those regulations. After a lengthy reconsideration process, on December 23, 2011, EPA released proposed changes to the Boiler MACT/GACT, CISWI and NHSM rules. For a summary of the proposed changes, see our January 13, 2012, Alert here.

EPA published final amendments to the Boiler MACT rule on January 31, 2013; amendments to the Boiler GACT rule on February 1, 2013; amendments to the NHSM rule on February 7, 2013; amendments to the CISWI rule on February 7, 2013. Summarized below are the more significant recently published changes to the respective rules.

Boiler MACT

  • Compliance is required three years from the date of publication of the amendments (i.e., by January 31, 2016);
  • Sources may seek a one-year extension of compliance deadline;
  • Finalizes work practice standards for dioxin;
  • Adopts fuel variability factors for mercury and hydrogen chloride;
  • Revises CO limits for a number of subcategories;
  • Work practices for startup and shutdown, although procedures need to be site-specific;
  • Includes a limited-use category of subcategory (10% capacity factor);
  • Requires burning of “clean fuels” or use of control devices upon startup;
  • Particulate matter CEMs only required for units greater than 250 MMBtu in coal and heavy liquid subcategories; and
  • Includes affirmative defense for exceedances during SSM events.

Boiler GACT

  • Compliance date for existing sources is March 21, 2014;
  • Compliance date for new sources that began operations on or before May 20, 2011 is May 20, 2011 or, if start up occurred after that date, the date of startup;
  • List of subcategories is refined;
  • Adds subcategories for seasonal, temporary boilers and limited-use boilers subject to less stringent requirements; and
  • Reduces fuel sampling and performance testing requirements under certain circumstances;


  • Adjusted emission limits for all of the CISWI subcategories;
  • Adjusted monitoring provisions, particularly for carbon monoxide (CO) and particulate matter (PM);
  • Clarified which units qualify as CISWI units; and
  • CISWI units will need to comply with the CISWI standards no later than three years after EPA approves a state plan or five years after the publication date of these final amendments, whichever is earlier.


  • Revises four key definitions: “clean cellulosic biomass,” “contaminants,” “established tire collection program” and “resinated wood;”
  • Clarifies that certain materials are within the scope of clean cellulosic biomass and can be combusted as a non-waste fuel (e.g., hogged fuel, wood pallets, wood pellets);
  • Revises contaminant legitimacy criterion, allowing grouping of contaminants for comparison to traditional fuels and clarifies the term “design to burn;”
  • Lists materials that are non-waste fuels by category (i.e., resinated wood, tires under oversight of established tire collection programs, dewatered pulp and paper sludges generated onsite by pulp and paper mills that burn a significant portion of those materials, coal refuse recovered from legacy piles);
  • Includes rulemaking petition process for individuals seeking to list additional materials that are non-waste fuels under a categorical exemption determination;
  • Identifies other materials that are candidates for categorical listing in a future rulemaking: e.g., paper recycling residuals (including old corrugated cardboard (OCC) rejects); construction and demolition wood processed pursuant to best practices and produced and managed under the oversight of a comprehensive collection system or contractual agreement;
  • Notes that EPA is considering listing creosote-treated railroad ties as a non-waste fuel in a future rulemaking.

These interrelated regulations are complex and their impact will vary from boiler to boiler and compliance options may vary from site to site.

Source: Pierce Atwood LLP