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Press Statement

Press Statement  Statement from AG Healey on U.S. Supreme Court Remanding EPA's Rule to Reduce Toxic Power Plant Emissions

AG Healey Led Coalition of States in Defending EPA’s Rule to Reduce Mercury and Other Harmful Emissions that Endanger Public Health
  • Office of Attorney General Maura Healey

Media Contact   for Statement from AG Healey on U.S. Supreme Court Remanding EPA's Rule to Reduce Toxic Power Plant Emissions

Chloe Gotsis

Boston — Attorney General Maura Healey today issued the following statement in response to the U.S. Supreme Court’s decision remanding the U.S Environmental Protection Agency’s (EPA) Mercury and Air Toxics Standards (MATS) rule.

“The MATS Rule is already working to reduce the toxic air emissions from power plants that harm our residents and natural resources. The benefits of the MATS rule – which include preventing thousands of premature deaths annually and reducing exposure of pregnant women and developing fetuses to mercury – far outweigh the costs of controlling toxic power plant emissions.  Given the decades-long delay in promulgating this rule, I urge the D.C. Circuit Court of Appeals and the EPA to swiftly complete the necessary additional proceedings so that residents across Massachusetts and the nation will continue to be protected from these dangerous air pollutants.”


The Supreme Court’s decision leaves the MATS rule in effect and requires the EPA to undertake additional proceedings for the limited purpose of further evaluating the costs of the rule. The MATS rule is the first federal limit on the emission of toxic air pollutants by electric power plants.

The MATS rule represents the culmination of more than two decades of study and rule-making by the EPA and was triggered by Congress’s 1990 amendments to the Clean Air Act.  Issued in 2012, the MATS rule will reduce power-plant mercury emissions by 75 percent in 2015, and will substantially cut emissions of other toxic metals, fine particulate matter and acid gases, through the implementation of pollution-control technology already widely used in the electric power industry. These pollutants pose serious health harms, including neurological damage, cancer and acute and chronic respiratory diseases.

The AG’s Office led 15 other states, as well as the District of Columbia and the cities of Baltimore, Chicago, and New York City, and Erie County, New York, in defending the EPA’s long-overdue standards to reduce mercury and other hazardous air pollutant emissions from coal and oil-fired electric power plants. The MATS rule is an important step to protect the public, in particular children and women of child-bearing age, from harmful exposure to mercury. The states joining Massachusetts were California, Connecticut, Delaware, Illinois, Iowa, Maine, Maryland, Minnesota, New Hampshire, New Mexico, New York, North Carolina, Oregon, Rhode Island and Vermont.

The Supreme Court heard oral arguments in the case on March 25, 2015. On February 25, 2015, AG Healey filed a multi-state Supreme Court brief on behalf of the state intervenors in support of the MATS rule.  Various industry groups – including the National Mining Association and the Utility Air Regulatory Group – along with a number of states, challenged the MATS rule in federal appeals court. The AG’s Office intervened in that challenge and argued in support of the EPA on behalf of the coalition of states and local governments supporting the MATS rule.

In April 2014, the U.S. Court of Appeals for the District of Columbia upheld the MATS rule and the validity of the EPA’s determination that regulation of hazardous air pollutant emissions from electric power plants is “appropriate and necessary.”

In November 2014, the Supreme Court agreed to hear petitions filed by the same industry groups and a coalition of states that argued the EPA had erred by focusing on public health impacts and not considering costs when making its threshold determination whether it was “appropriate” to regulate hazardous air pollution from power plants. AG Healey argued in her brief that the EPA properly considered the costs of regulating toxic power-plant emissions when it established the technology-based emission standards that the MATS rule requires power plants to meet, and that Congress required EPA to focus on public health, not costs, when making its initial decision whether to regulate.

The brief also argued that power plants, using readily-available, cost-effective control technologies, have successfully complied with mercury reduction requirements that are already in place in a number of states and are typically more stringent than the proposed MATS rule, without adverse economic effects or impacts on electric system reliability.

Mercury is a potent neurotoxin that poses serious danger to people, especially to developing fetuses and children, and to wildlife. When airborne mercury from power plants is deposited into the water, it can change into methylmercury, a highly toxic form of mercury that accumulates in the food chain, particularly in fish. A child exposed to methylmercury consumed by her mother during pregnancy can suffer lifelong adverse developmental effects including impaired attention, fine motor function, visual-spatial abilities and verbal memory. Currently, all 50 states have fish consumption advisories in place related to mercury contamination.

As a sector, electric power plants are the largest source of mercury emissions and other hazardous air pollutants in the United States – emitting thousands of tons of those pollutants each year. EPA estimates that the MATS rule will prevent up to 11,000 premature deaths each year, and that the monetized health benefits of the rule will range from $37 to $90 billion annually, meaning that for every $1 spent by electric power plants to reduce toxic air emissions, the public will receive $3 to $9 back in health benefits.

Media Contact   for Statement from AG Healey on U.S. Supreme Court Remanding EPA's Rule to Reduce Toxic Power Plant Emissions

  • Office of the Attorney General 

    Attorney General Maura Healey is the chief lawyer and law enforcement officer of the Commonwealth of Massachusetts.
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