The Environmental Protection Agency on April 5 proposed to strengthen and update the Mercury and Air Toxics Standards for coal-fired power plants.
The agency released the pre-publication version of a proposed rule entitled “National Emission Standards for Hazardous Air Pollutants: Coal- and Oil-Fired Electric Utility Steam Generating Units Review of the Residual Risk and Technology Review.”
There will be a 60-day public comment period starting from the date the proposed rule is published in the Federal Register.
EPA, earlier in 2023, reinstated the appropriate and necessary finding under the Clean Air Act Section 112. That rulemaking process restored the legal underpinning for the agency’s MATS of hazardous air pollutant emissions from coal-fired plants, finding that it remains appropriate and necessary to regulate HAP emissions from electric generating units after considering cost.
With the new proposed rule, the agency would require that applicable facilities comply with the following changes within three years after the effective date of a final rule:
- Reduce the emissions standard for filterable particulate matter from 0.03 lb/MMBtu (pounds per million British thermal units) to 0.01 lb/MMBtu;
- Require that owners and operators of existing coal-fired plants only use continuous emission monitoring system to demonstrate compliance with the fPM standards; and
- Lower the mercury emissions standard for plants that burn low rank virgin coal from 4 lb/TBtu (pounds per trillion British thermal units) to 1.2 lb/TBtu, the same standard for plants that do not burn low rank virgin coal.
EPA also proposes to eliminate the alternative definition of startup. EPA proposes to no longer define startup period as lasting four hours after a unit starts to generate electricity. This provision would go into effect 180 days after the effective date of a final rule.
However, EPA is not proposing any changes to the current hydrogen chloride limits for coal-fired units. The agency has also not proposed any new standards that would apply to oil-fired units or integrated gasification combined cycle units.
According to EPA, 91 percent of the existing coal-fired power plants already meet the newly proposed fPM emissions standard. The agency does not expect the remaining units to have to incur significant costs to meet the new standard.
The agency is soliciting comments on the possibility of introducing an even lower fPM emissions standard at 0.006 lb/MMBtu.
EPA estimates that the cost of compliance for the entire industry will range from $33 million to $38 million on an annualized basis. On the other hand, the proposed rule is expected to yield $300 million to $350 million in annualized value net benefits, which includes $170 million to $220 million in health benefits and $170 million in climate benefits. EPA projects that retail electricity prices would increase by an average of less than 0.1 percent in 2028, 2030, and 2035.
These proposed amendments result from the EPA’s review of the May 22, 2020, residual risk and technology review (RTR) of MATS. EPA is only proposing changes to the MATS standards based on the technology review provisions of the Clean Air Act. The agency is not proposing any changes to the emissions standards as part of the residual risk review.
EPA is planning to host a virtual public hearing and registration details will be made available on its website.
