ACEEE Submits Comments for Boiler MACT

On August 23, 2010, ACEEE submitted comments to the U.S. Environmental Protection Agency (EPA) on the proposed National Emission Standards for Hazardous Air Pollutants for Area Sources and National Emission Standards for Hazardous Air Pollutants for Major Sources. These rules will promulgate standards for hazardous air pollutants (HAPs), which the EPA defines as those that "cause or may cause cancer or other serious health effects." These include pollutants such as mercury, carbon monoxide, and particulate matter. The above two rules specifically address standards for controlling HAPs from boilers and process heaters located in commercial, institutional, and industrial facilities. The Clean Air Act gives the EPA the authority to regulate these pollutants.

ACEEE's comments on the proposed rules addressed two issues: the use of energy assessments as a "beyond-the-floor" control measure, and the role of an output-based methodology for calculating emissions in the proposed rules.

In the proposed rules, the EPA suggests that energy assessments at impacted facilities could be a mechanism to yield emission reductions beyond those set by the "Maximum Achievable Control Technology (MACT) floor." For these proposed rules, the "MACT floor" — that is, the emissions level each affected source must meet — are based on the emissions of the lowest-emitting (best performing) 12% of similar units. ACEEE agreed with the EPA that energy assessments could encourage additional emissions reductions and reduce operating and maintenance costs at affected facilities.

ACEEE also encouraged the EPA to consider developing an output-based methodology when calculating emissions from affected sources. Several precedents indicate that the EPA recognizes that output-based emission standards encourage energy efficiency. Investments in energy efficiency reduce fuel consumption and thus could further reduce emissions at affected facilities.

View ACEEE's comments for the two rules:

The EPA home pages for each docket (which include additional information and documentation) can be found:

  • Here for the standard for Area Sources
  • Here for the standard for Major Sources