EPA Proposes Stringent New Emission Limits for Boilers

On April 29, 2010, the U.S. EPA issued four proposed new regulations that would impose stringent new emission limits on boilers.  EPA's proposals potentially affect every facility with a boiler.  Preliminary review by industry experts indicates that most affected boilers will need additional controls and/or operational changes to meet the new emission limits.  The four proposed new rules are described below.

1.         Background

Pursuant to Section 112 of the Clean Air Act, EPA is required to set Maximum Achievable Control Technology (MACT) standards for categories of major sources of hazardous air pollutants (HAPs) and Generally Available Control Technology (GACT) standards for certain categories of area (minor) HAP sources.  In an effort to implement these requirements, EPA has issued proposed MACT standards for industrial, commercial and institution boilers at major HAP sources, GACT standards for industrial, commercial and institutional boilers at area HAP sources, and standards for commercial and institutional solid waste incineration (CISWI) units (i.e., boilers combusting solid waste).  EPA has also proposed to define "solid waste" in an effort to clarify the types of secondary materials that constitute fuels subject to the MACT or GACT standards for boilers, as opposed to secondary materials that are considered solid waste and subject to the CISWI rule.  As explained below, the breadth of this definition of "solid waste" will startle many and, if adopted, will sweep many boilers under the proposed solid waste incineration rules. 

2.         Proposed Boiler MACT at Major HAP Sources, 40 C.F.R. Part 63, Subpart DDDDD

The proposed Boiler MACT regulation would apply to new and existing boilers at major HAP sources that do not combust solid waste.  The following types of boilers are exempt:

• A boiler specifically listed and subject to another MACT standard (such as the CISWI standard).
• Temporary boilers (boilers that are on site for less than 180 consecutive days).
• Boilers used specifically for research and development.
• Recovery boilers or recovery furnaces covered by 40 C.F.R. Part 63, Subpart MM.
• Fossil fuel-fired electric utility steam generating units > 25 megawatts.

Proposed emission limits are as follows.  Note that in addition to the standards summarized below, EPA has also proposed MACT emission limits for: existing coal boilers, new biomass boilers, new coal boilers, new liquid fuel boilers, new units designed to burn other gases and work practice standards for boilers < 10 MMBtu/hour.  The proposed MACT rule also includes testing, monitoring, recordkeeping requirements, and requirements that all affected facilities prepare a facility-wide energy management program in accordance with EPA ENERGY STAR guidelines.   

 

 

*      PM CEMs required for coal, biomass, or No. 6 oil boilers greater than or equal to 250 MMBtu/hr, daily averaging period.
**   CO and O2 monitors required for any boilers greater than or equal to 100 MMBtu/hr; 30-day averaging period.

3.         Proposed GACT Standards for Boilers at Area (Minor) HAP Sources, 40 C.F.R. Part 63, Subpart JJJJJ

The GACT standards would apply to new and existing boilers at minor HAP sources (i.e., boilers at virtually all sources other than major HAP sources), except for the following:

• Any natural gas-fired boiler.
• Boilers used specifically for research and development.
• Boilers used to burn solid waste.
• Boilers listed by another MACT standard in 40 C.F.R. Part 63.

Proposed emission limits for boilers at area HAP sources are as follows:

 

*      CO monitor required for coal, oil, or biomass boilers greater than or equal to 100 MMBtu/hr, daily averaging period.

1.     Coal subcategory includes any boiler that burns any coal alone or at least 10% coal on an annual heat input basis in combination with biomass, liquid fuels, or gaseous fuel.
2.     Biomass subcategory includes any boiler that burns any amount of biomass but no coal, either alone or in combination with liquid fuels or gaseous fuels.
3.     Oil subcategory includes any boiler that does not burn any solid fuel and burns any liquid fuel either alone or in combination with gaseous fuels.  Gas boilers that burn liquid fuel during periods of gas curtailment, gas supply emergencies, or for periodic testing are not included in this definition.

The proposed regulation also includes more stringent limits for new boilers at area HAP sources and testing, monitoring, and recordkeeping requirements. 

Existing boilers less than or equal to 10 MMBtu/hr are not subject to the numerical limits, but must perform tune-ups as defined in the rule every two years.

4.         MACT Requirements for CISWI Units, 40 C.F.R. Part 60, Subpart CCCC and DDDD

New and existing boilers that burn any amount of solid waste (as defined under RCRA and discussed further below) would be subject to the CISWI standards instead of the Boiler MACT standards.  Exemptions include solid waste incineration units that are covered under other Clean Air Act Section 129 categories, such as, for example, municipal waste combustors, medical waste incinerators, certain qualifying small power producers, and qualifying cogeneration units.

EPA's proposed CISWI standards are as follows.  Note that the below summarizes only the limits for the "incinerator" and "energy recovery unit" subcategories.  The proposed CISWI regulation also includes separate emission limits for additional subcategories, including "waste-burning kilns," "burn off ovens," and "small remote incinerators" and yet more stringent requirements for new CISWI units. 

5.         EPA Proposed Definition of "Solid Waste" Under RCRA

In conjunction with the three Clean Air Act regulations summarized above, EPA is also proposing to make changes to its definition of "solid waste" under RCRA for use in the context of determining whether a material constitutes a fuel (boilers subject to MACT/GACT standards) or a "solid waste" (units subject to CISWI standards).  EPA's proposal would establish that the following types of secondary materials, when used as fuels in combustion units, would not be considered solid waste:

• Nonhazardous secondary materials used as fuels that remain within and are combusted within the control of the generator and that meet the "legitimacy criteria."
• Nonhazardous secondary materials that meet the legitimacy criteria and have been processed into a fuel.
• Nonhazardous secondary materials used as a fuel that do not remain within the control or generator but for which EPA grants a facility's petition for a non-solid waste determination. 

EPA sets forth the following "legitimacy criteria":

• Contain contaminants at levels comparable to those in traditional fuels.
• Have a meaningful heating value.
• Used in a combustion unit that recovers energy.
• Handled as a valuable commodity.

As noted above, a source can petition EPA for determination that a nonhazardous secondary material that has not been discarded is not a solid waste. 

Based on the EPA Frequently Asked Questions document, the following are materials that fall into the following categories (though EPA is taking comments on several of these proposed positions):

• Generally not considered solid waste:
  • Pulp and paper mill residuals (e.g., wastewater treatment plant sludge) within the control of the generating mill.
  • Wood product mill residuals (sander dust, trim, resonated wood) within the control of the generator plant.
  • Tire-derived fuel with steel belts and wire have been removed.
  • On-specification used oil.
  • Clean biomass.
  • Clean biofuels process from solid waste.
• Generally considered solid waste:
  • Contaminated construction and demolition debris.
  • Sewage sludge (unless processed).
  • Off specification used oil.
  • Whole tires or shredded tires where significant portion of the wire has not been removed.
  • Painted wood.
  • Pentachlorophenol, copper-based and borate-based treated wood.
• Materials that may not be considered solid waste if generated onsite, meet the legitimacy criteria and have undergone processing if generated off site or subject to an EPA-approved non-solid waste determination
  • Pulp and paper wastewater treatment residuals from another generator.
  • Biomass that is not "clean" and is generated offsite.
  • Creosote treated wood (e.g., railroad ties).

6.         Next Steps

The four regulations above have not yet been published in the Federal Register.  Once published in the Federal Register (expected any day now), EPA will be accepting public comments on the proposed rules for a 45-day period.  Sources concerned about the potential impacts of these regulations on their facilities, or who have specific questions regarding the potential categorization of certain materials as fuels, as opposed to solid waste, should consider submitting comments to EPA during the upcoming public comment period.  EPA is expected to issue final rules by the end of the year and to require compliance within three years thereafter (compliance by the end of 2013).

If you have any questions regarding the EPA's proposed regulations, please  contact Brian Rayback at207-791-1188 or brayback@pierceatwood.com.