USEPA Proposes Changes to March 2011 Rules for Boilers, Process Heaters and Incinerators
This post was written by Mark Mustian.
On December 2, the U.S. Environmental Protection Agency (USEPA) proposed revisions to a series of controversial regulations aimed at controlling emissions of hazardous air pollutants (HAPs) from industrial, commercial, and institutional boilers. These revisions are to regulations finalized in March, and then delayed in May. The regulations in question are actually three separate, but interrelated regulations. USEPA is proposing revisions to emission standards for (1) Major Source Industrial, Commercial, and Institutional Boilers and Process Heaters; (2)Area Source Industrial, Commercial, and Institutional Boilers; and (3) Commercial/Industrial Solid Waste Incinerators. By way of terminology, know that a major source is a stationary source which has the potential to emit 10 tons per year or more of any hazardous air pollutant or 25 tons per year or more of any combination of hazardous air pollutants. Also, an area source is a stationary source that is not a major source. And a commercial/industrial incinerator is any unit at a commercial or industrial facility which combust solid wastes.
The new proposed regulations are revisions to the regulations finalized back in March. USEPA is not proposing to revoke the previously finalized regulations. Instead, they are proposing to amend the existing regulations, based upon additional data and upon the input from the regulated community and interested parties. The impact of each proposal is discussed after the jump.
As you'll see below, USEPA is not proposing to significantly modify the structure of regulation developed for the March rulemaking but the proposed changes will increase flexibility and reduce some monitoring requirements and cost. Nonetheless, we still expect that many existing boilers will not be able to comply with the new requirements. In order to comply, they will likely need to look at alternatives, such as fuel switching, boiler rebuild or add-on controls, which will likely increase costs for the facility. The facilities most affected by these regulations will be major source facilities, facilities operating large solid fuel boilers, and solid waste incinerators. Those groups in particular need to start preparing for compliance. Unless the regulations get tossed out by the courts, it is likely that the requirements in their current form will be imposed upon the regulated community.
Major Source Industrial, Commercial, and Institutional Boilers and Process Heaters Requirements
Key Requirements in Rule Finalized in March 2011
In the March rulemaking, USEPA established significantly more stringent standards for major source boilers and process heaters, when compared to area source boilers. The March requirements were as follows:
- For all new and existing natural gas- and refinery gas-fired units, the final rule establishes a work practice standard, instead of numeric emission limits. The operator will be required to perform an annual tune-up for each unit. Units combusting other gases can qualify for work practice standards by demonstrating that they burn “clean fuel,” with contaminant levels similar to natural gas.
- For all new and existing units with a heat input capacity less than 10 million British thermal units per hour (MMBtu/hr), the final rule establishes a work practice standard instead of numeric emission limits. The operator will be required to perform a tune-up for each unit once every 2 years.
- The final rule establishes a work practice standard instead of numeric emission limits for all new and existing “limited use” boilers. The operator will be required to perform a tune-up for each unit once every 2 years. These units are operated less than 10 percent of the year as emergency and backup boilers to supplement process power needs.
The final rule establishes numeric emission limits for all other existing and new boilers and process heaters located at major sources (including those that burn coal and biomass). The final rule establishes emission limits for:
- Mercury
- Dioxin
- Particulate Matter (PM)
- Hydrogen Chloride (HCl)
- Carbon Monoxide (CO)
- The final rule requires monitoring to assure compliance with emission limits. The largest major source boilers must continuously monitor their particle emissions. All units larger than 10 MMBtu/hr must monitor oxygen as a measure of good combustion.
- Existing major source facilities are required to conduct a one-time energy assessment to identify cost-effective energy conservation measures.
Changes Proposed in December 2011
The proposed regulatory changes do not significantly modify the overall regulatory scheme from the March rulemaking. However, the proposed changes will allow for additional flexibility, and somewhat higher limitations in certain instances. The proposed changes include:
- New subcategories for light and heavy industrial liquid fuels.
- New PM emission limitations for each specific type of solid fuel (coal, biomass).
- New emission limitations for CO based upon newly submitted data.
- Alternative of using metals emission limitations in place of using PM as a surrogate.
- Replacement of the dioxin emissions limits with work practice standards.
- The removal of the requirement for continuous monitoring for biomass units.
- Allowing CO compliance based upon either stack testing or continuous monitoring.
- Removal of the hydrogen sulfide specification from the "clean fuel" standard.
Area Source Industrial, Commercial, and Institutional Boilers Requirements
In the rule finalized in March 2011, USEPA set emission standards for large coal-fired boilers. In particular, for new boilers, limitations were imposed for mercury, particulate matter (PM), and carbon monoxide (CO). For existing boilers, the rule established new limitations for PMs and CO. Also, new large biomass and oil fired boilers had new limitations for PMs only. All remaining area source boilers were subject to either a work practice standard or a management practice that required performing a boiler tune-up every 2 years. In the December proposed rulemaking, USEPA is not proposing major changes to these rules. The most significant change is to allow compliance determinations for CO to be based upon measurement of oxygen levels in the boiler stack, as opposed to the actual monitoring of CO levels. This will simplify the instrumentation requirements. USEPA also extended the initial compliance schedule for tune-ups, added an affirmative defense provision for malfunctions, added in a category for seasonal boilers, and included an exemption for temporary boilers.
Commercial/Industrial Solid Waste Incinerators Requirements
Key Requirements in Rule Finalized in March 2011
The category of commercial/industrial solid waste incinerators (CISWIs) is a much smaller category than the other two being regulated. EPA estimates that there are 95 CISWI units currently in operation in the United States. The March rulemaking imposed significant new requirements on these units, including the following:
- Emission limits for mercury, lead, cadmium, hydrogen chloride, particulate matter, carbon monoxide, dioxins/furans, nitrogen oxides and sulfur dioxide.
- New stack testing and monitoring requirements.
- Annual inspections of emission control devices
- Annual visible emissions test of ash handling operation.
USEPA expected that most units would be required to install add-on controls to comply with the new requirements. In some cases, USEPA expected the regulated community to select an alternate disposal option (landfill) as opposed to installing the necessary controls.
Changes Proposed in December 2011
In the proposed regulation, USEPA is requesting comments on various proposed changes to the March rulemaking. The proposed changes include:
- Revision of the subcategory of Energy Recovery Units (ERUs)
- Establishment of limitations on fuel switching provisions
- Revision of the definition of cyclonic burn barrels
- An affirmative defense for malfunction events
- Revisions to the CO monitoring requirements
- New stack test requirements for CO
- New definition of homogeneous waste
- Revised emission limits for waste-burning kiln and ERU subcategories
- Removal of CO monitoring with CO continuous emission monitoring systems (CEMS) requirements
- Removal of oxygen correction requirements for ERUs during startup/shutdown
- Replacement of continuous PM monitoring for large ERUs with other specific monitoring requirements
