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MATS for Power Plants EPA Proposal

MATS for Power Plants EPA Proposal

MATS for Power Plants EPA Proposal

Power Industry Successes Key to Strengthening Standards


Exceeding standards for the greater good is evidence of companies taking action beyond what is regulated and expected. The April 3, 2023, Environmental Protection Agency (EPA) proposal for strengthening Mercury and Air Toxic Standards (MATS) reflects advancements in control technologies and levels achieved by best-performing plants.

Embracing MATS, along with significant advancements in the power sector, has realized significant health and environmental benefits by reducing a broad range of hazardous air pollutants.  According to EPA monitoring, “by 2017 mercury emissions had dropped by 86 percent – down to approximately 4 tons.  Acid gas HAP and non-mercury metals are down 96 percent and 81 percent respectively when compared to 2010 levels.”

Fulfilling a responsibility under the Clean Air Act to periodically re-evaluate MATS for power plants, the EPA is proposing strengthening as well as updating the National Emission Standards for Hazardous Air Pollutants for Coal- and Oil-Fired Electric Utility Steam Generating Units (EGUs).

The current MATS established standards to limit emissions of mercury; acid gas hazardous air pollutants (HAP) such as hydrogen chloride (HCl) and hydrogen fluoride; non-mercury HAP metals such as nickel, lead, and chromium; and organic HAP such as formaldehyde and dioxin/furan from coal- and oil-fired power plants. MATS as well as other changes to the power sector resulted in reductions in air pollutants from coal- and oil-fired power plants. For example, 2021 industry reported mercury emissions data as required by MATS, coalfired EGUs were 90 percent lower than pre-MATS levels. Similarly, health-protective reductions in acid gas and HAP non-mercury metals including nickel, arsenic, and lead have been reported.

Based on the health protective reductions of air pollutants and advances in pollution control technologies, EPA has several proposed actions that build upon the highly successful and cost-effective health protections realized from MATS:

  • Reducing the non-mercury HAPs emissions: By significantly reducing the sta
  • ndard for filterable particulate matter (fPM) by 2/3rds within existing coal-fired plants, this action will further limit the emission of non-mercury HAP metals. EPA also proposes removal of low-emitting EGU provisions for fPM and non-mercury HAP metals.
  • Lowering the emission limit for mercury: For existing lignite-fired power plants, lowering the emission limit for mercury by 70 percent will be making standards and performance consistent with the mercury standard that other coal-fired power plants have been achieving.
  • Enhancing emissions monitoring and compliance: Requiring coal fired EGUs to comply with the fPM standard using PM continuous emission monitoring systems (CEMS) will strengthen emissions monitoring
  •  practices across the industry.
  • Revising startup requirements: To assure better emissions performance during start-up, the EPA is proposing to remove one of the two options for defining the start-up period for MATS-affected EGUs, based on its determination that the option being eliminated is not widely utilized or necessary and removing it would better secure good emissions performance during start-up periods.


Impact to Energy Prices

EPA contends that the proposed actions would have a small impact on energy prices. In EPA’s analysis, about 500 megawatts of coal-fired capacity would retire by 2028 and does not project coal production for use in the power sector to change significantly by 2028.  Together with other EPA proposed rules, EPA believes the actions will “protect communities across the nation from the various health and environmental impacts of power plant pollution” and allow “states, grid operators, and power companies to make good investments and planning decisions, while preserving the industry’s ability to deliver reliable and affordable electricity.”

This proposal reflects the most significant improvements and updates to MATS since EPA first issued these standards in February of 2012. In addition, the proposal aligns with President Biden’s January 20, 2021, Executive Order 13990 “Protecting Human Health and the Environment and Restoring Science to Tackle the Climate Crisis.”

A virtual public hearing will be announced with further details at:


QTS continuously monitors opportunities for advancement and best practices in MATS and all areas of toxic and hazardous materials impacting client industries. With more than three decades of expertise in the utility/power sectors, we are helping our clients lead the industry in safety, healthy working environments, and environmental stewardship.