EPA Revises Air Quality Regulations for Boilers, Incinerators, and Non-Hazardous Secondary Materials

Posted Friday, January 11th, 2013

On December 20, 2012, the U.S. Environmental Protection Agency (EPA) issued final revisions to several rules intended to reduce emissions of hazardous air pollutants from boilers and incinerators: the national emission standard for hazardous air pollutants (NESHAP) for major and area source boilers (also known as the Boiler MACT), the commercial/industrial solid waste incinerators (CISWI) rule, and the Identification of Non-Hazardous Secondary Materials That are Solid Wastes rule (NHSM rule).  In comparison to emission reductions under the original rules, EPA projects less emissions reductions for non-mercury metals and particulate matter (PM), but more emission reductions for mercury, hydrogen chloride, and sulfur dioxide.  Overall, EPA anticipates higher total emissions reductions and a more efficient cost-benefit ratio in terms of control measures and public health.  EPA notes that the U.S. Department of Energy and U.S. Department of Agriculture will provide technical and practical assistance for boiler compliance.

Boiler MACT

Final revisions to the area source and major source Boiler MACT address a range of issues, including changes to unit subcategories, emission limits, monitoring requirements, and work practice standards.  EPA emphasized that eighty-eight percent of major source boilers burn clean fuel and qualify for work practice standards, while twelve percent must satisfy numeric emission standards.  Among area source boilers, less than one percent must meet numerical emission limits. 

For major sources, notable revisions include:

• Adding a new subcategory for certain coal fluidized bed units;
• Adding new subcategories for light and heavy industrial liquids;
• Establishing new emission limits for PM for each biomass subcategory;
• Establishing new emission limits for carbon monoxide (CO) based on boiler variability;
• Allowing an alternative total selective metals emission limit for metallic air toxics instead of using PM as a surrogate;
• Replacing numeric dioxin emission limits with work practice standards;
• Adding alternative monitoring approaches for PM;
• Reducing the frequency of required tune-ups for some units, including those with continuous oxygen and CO trim systems; and
• Amending definitions of “startup,” “shut down,” and certain averaging periods.

For area sources, notable revisions include:

• Establishing seasonal use and limited use subcategories;
• Extending tune-ups to every five years instead of every two years for certain units;
• Establishing burning low sulfur oil as an alternative method of compliance for new oil-fired units to meet the PM emission standard;
• Amending provisions for existing dual-fired boilers that switch from gas to coal, biomass, or oil;
• Reducing fuel sampling and performance test requirements for certain boilers subject to mercury and PM limits;
• Providing for continuous emissions monitoring to demonstrate compliance with CO emission limits; and
• Changing energy assessment provisions and related definitions.

Existing major source boilers must comply within three years of publication of the final rule in the Federal Register but may request an additional year.  Existing area source boilers must comply by March 21, 2014 but may request an additional year.  For existing affected area source boilers, the deadline for EPA initial notification is January 20, 2014.

Further information on the revised Boiler MACT and the text of the final rules (not yet published in the Federal Register) is available here.

CISWI Rule Revision

The final CISWI rule revises subcategories of CISWI and the new source performance standards (NSPS) and emissions guidelines for all CISWI subcategories.  In particular, EPA revised monitoring provisions for CO and PM, as well as the methodology for establishing and monitoring oxygen levels.  The revised rule also clarifies which units qualify as CISWI units.  For all subcategories of CISWI, EPA extended the deadline for existing CISWI units to comply with the revised rule to no later than three years after EPA approves a state implementation plan or five years after publication of the final rule in the Federal Register, whichever is earlier.  EPA estimates using an alternative disposal option will be most cost effective for certain regulated CISWI units.

NHSM Rule Revision

In addition, EPA finalized several revisions to the NHSM rule codified at 40 C.F.R. pt. 241.  These changes include:

• Amending the definitions of “clean cellulosic biomass,” “contaminants,” “established tire collection programs,” and “resinated wood” for clarification and accuracy;
• Revising contaminant legitimacy criterion for non-hazardous secondary materials used as fuels;
• Codifying certain non-hazardous secondary materials as non-wastes when used as fuels;
• Finalizing a rulemaking petition process for determining additional non-hazardous secondary materials are non-waste fuels; and
• Streamlining the public participation process for non-waste determinations. 

EPA also noted other NHSMs  that may be addressed in future rulemaking for categorical listing.  These include paper recycling residuals, construction & demolition wood processed under best practices, and potentially creosote-treated railroad ties. 

Notably, under the Resource Conservation and Recovery Act (RCRA), the NHSM rule identifies which non-hazardous secondary materials are solid wastes when burned in combustion units.  If a combustion unit burns secondary material identified as solid waste according to the NHSM rule, EPA regulates the unit under Clean Air Act (CAA) section 129 as a CISWI.  However, if the same combustion unit burns secondary material not identified as solid waste according to the NHSM rule, EPA regulates the unit under CAA section 112, which applies to air toxics from sources such as boilers and process heaters.

EPA set forth revisions to both the CISWI and NHSM rules in a combined action (not yet published in the Federal Register) available here. Further information on the revised CISWI rule is available here, and further information on the revised NHSM rule is available here.

For additional information contact Jon Harris Maurer

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