Lives On The Line: Mercury Standard & Power Plants

The Mercury and Air Toxics Standards will annually prevent up to 11,000 premature deaths, and nearly 5,000 heart attacks and 130,000 asthma attacks.

Case Overview

The U.S. Environmental Protection Agency exempted power plants from Clean Air Act regulations, even though these power plants emit into the air tons of mercury and other toxins—known threats to human health.


In February 2008, a federal appeals court ruled that the EPA did not have the authority to exempt the power plants.


In 2012, after more than a decade of Earthjustice litigation on behalf of community, environmental and public health groups, the EPA released protections that will clean up toxic air emissions from power plants across the country, the Mercury and Air Toxics Standards (MATS).

MATS will annually prevent up to 11,000 premature deaths, nearly 5,000 heart attacks and 130,000 asthma attacks, and more than 540,000 missed days of work days. MATS will reduce mercury emissions by 75%, protecting babies and children from exposures to mercury than can damage their ability to develop and learn. The EPA has estimated that every year, more than 300,000 newborns face elevated risk of learning disabilities due to exposure to mercury in the womb.

In April 2014, the U.S. Court of Appeals for the D.C. Circuit upheld MATS. Industry appealed and on March 25, 2015, the U.S. Supreme Court heard arguments in industry’s challenge to MATS. The coal industry and its allies claimed that EPA cannot decide whether to protect the public and the environment from toxic air pollution without first considering the effect on the industry’s bottom line.


A decision for the coal industry would mean thousands of people across our country would continue to die unnecessary, premature deaths—all to protect the profits of the worst corporate polluters. Many responsible power plants have already reduced their pollution, and several of those companies are supporting MATS in court. As those companies said in a Supreme Court filing in EPA’s defense, MATS put an end to the “free ride” enjoyed by the worst polluters.


On June 29, in a 5–4 decision, the U.S. Supreme Court remanded MATS. Although EPA demonstrated that the health and environmental benefits of the standards far outweigh the costs to the industry, the Court found EPA should have considered industry’s costs earlier in the process, when it determined whether these emissions were worth controlling at all.

The Court left the standards in place pending further consideration by the U.S. Court of Appeals for the D.C. Circuit and the EPA. The majority of power plants are already in compliance with the standards, having met them without reported difficulty since April of this year. Because EPA has already evaluated the costs and benefits of the rule, the agency should be able to provide the cost analysis required by the Court in short order.

It is important to note that the Court did not reject the following key conclusions by EPA:

  • Power plants are far and away the worst industrial polluters.
  • Controlling toxic emissions is both technologically and economically feasible.
  • The resulting pollution reductions will yield between $37 billion and $90 billion in health benefits every year.
  • The public will receive $3–$9 in health benefits for every $1 that the protections cost the power industry.

On December 15, the U.S. Court of Appeals for the D.C. Circuit rejected a bid by the coal mining industry and its allies to throw out the standards. The Court’s decision will save thousands of lives, and avert long term environmental and public health damage.

Hear from attorney Jim Pew and two Pennsylvanians—Marti Blake and Martin Garrigan—who know first-hand what it means to live in the shadow of a smokestack and the specter of a plume.


A mother watches over her child during treatment for asthma.
A mother watches over her child during treatment for asthma. (Chris Jordan-Bloch / Earthjustice)

Case Updates

A coal-fired power plant in Pennsylvania, reflected in a neighboring home's window.
April 25, 2024 feature

The Mercury & Air Toxics Standards

When companies burn coal in the U.S., significant amounts of mercury spew into our air. Now, that mercury is controlled, thanks to a federal rule that Earthjustice and our clients fought for, defended, and successfully expanded.

A coal ash pond full of dead trees lies adjacent to Duke Energy's Buck Steam Station in Dukeville, N.C., in 2016.
April 25, 2024 Press Release: Victory

Earthjustice Applauds EPA for Historic Suite of Safeguards from Power Plant Pollution

Standards will tackle major sources of climate pollution and protect public health

Deadly fine particulate matter, also known as soot, is caused by pollution from tailpipes, smokestacks and industrial power plants.
November 8, 2023 Action Alert

Tell the EPA to protect us from mercury pollution

Controlling pollution from power plants improves public health for people across the country by reducing fatal heart attacks, reducing cancer risks and avoiding neurodevelopmental delays in children