EPA Finalized New Wastewater Treatment Standards for Coal-fired Power Plants

A 15-year legal fight to curb toxic wastewater to protect drinking water.

Some good news today out of EPA! EPA just finalized more stringent wastewater treatment standards for coal-fired power plants that will reduce the amount of toxic pollutants such as arsenic, mercury, and selenium that power companies dump into U.S. waterways. Once this rule is implemented, coal-fired power plants will have to either use cost-effective technologies to clean up their mess or stop burning coal altogether.

In protecting surface waters from power plant pollution, today’s announcement complements other important new protections that EPA announced today for power plants, including strengthened standards to address toxic coal ash waste, mercury and other hazardous air pollutants, and greenhouse gas emissions.

For decades, coal-fired plants have polluted water bodies supplying drinking water to millions of people across the United States. Even though the Clean Water Act requires polluters to use the most modern and effective pollution control technology available to treat wastewater, prior to 2015 most coal plants had no limits on toxic pollutants in their wastewater discharges.

Coal-fired power plants are one of the largest sources of toxic pollutants in our rivers, lakes, and streams. EPA estimates that 42 million people rely on drinking water sources likely contaminated with wastewater from coal fired power plants. At one time, over 23,000 miles of waterways were contaminated, including nearly 400 water bodies used as drinking water sources. According to EPA, the new rule would prevent over 660 million pounds of pollutants from being dumped into U.S. waterways each year.

Finally, EPA is forcing coal-fired power plants to clean up their act, by requiring the best available technology, including a zero-discharge requirement for power plants’ three largest wastestreams. EPA also established the first-ever national treatment standards for existing wastewater stored in coal ash impoundments that is discharged during closure.

Significant benefits and cost savings for drinking water

EPA’s new coal-fired plant wastewater standards are good news for drinking water utilities, some of which have been forced to install expensive new treatment systems to remove toxic contaminants from upstream coal-fired power plants from their source water. Municipal drinking water utilities across the country have pressed EPA to ensure strong guidelines to control discharges of toxic chemicals from coal-fired power plants.

The standards will significantly reduce toxic metals and other harmful pollutants such as bromide that are difficult and costly to remove from our drinking water. During drinking water treatment, the presence of bromide can create carcinogenic byproducts that utilities would need expensive treatment equipment to avoid. The zero-discharge standards in the new rule are supported by a wide variety of groups, including the American Water Works Association and Brewers for Clean Water.

EPA estimates its proposal would provide $3.2 billion in annual benefits to society. In addition to reduced drinking water treatment costs, these benefits include: reduction in cancer and other health problems, improved recreational opportunities, and protection of threatened and endangered species.

Less toxic pollution from coal plants means improved water quality for humans and wildlife. EPA estimates that as a result of the final rule there will be:

  • a 63% reduction in the number of receiving waters that exceed levels of pollutants deemed unsafe for human health; and
  • a 69% reduction in the number of receiving waters that are unsafe for fishing.

A long legal fight to curb toxic wastewater from coal plants

EPA’s new coal-fired power plant wastewater standards are the culmination of over 15 years of efforts and litigation to push the EPA to update and strengthen wastewater standards to protect our drinking water and the health and safety of our waterways.

In 2015, in response to an Earthjustice suit filed in 2010 with the Environmental Integrity Project, representing Sierra Club and Defenders of Wildlife, the Obama administration revised the coal plant wastewater standards for the first time in over 30 years. Power plants were required to install state-of-the-art wastewater treatment technology and monitor local water quality. But EPA in 2020 under then-Administrator Andrew Wheeler — a former coal lobbyist — finalized a weaker rule in 2020 that pushed back compliance dates and exempted some power plants, while rolling back necessary treatment technologies to let older coal-fired plants keep burning. This happened even as courts were telling EPA that the standards needed to be made stronger; in 2019, a federal appeals court held that EPA’s failure to set more stringent national standards for leachate and legacy wastewater was unlawful.

EPA’s most recent coal plant wastewater rule comes in response to a 2020 lawsuit challenging that weakening of the rules, which Earthjustice filed on behalf of the Center for Biological Diversity, Clean Water Action, Natural Resources Defense Council, Sierra Club, and Waterkeeper Alliance, in partnership with Environmental Integrity Project, the Southern Environmental Law Center, and additional groups. With the current proposed rule, EPA is addressing both our 2019 legal victory and the legal and technical deficiencies of the 2020 Trump-era rule, and also further strengthening standards to reflect that the technology to treat coal plant wastewater continues to improve over time.

New requirements to achieve zero discharge

The EPA’s new rule requires power plants to upgrade their wastewater treatment technology to eliminate discharges of pollutants from their three largest toxic wastewater streams: wastewater generated by power plant air pollution scrubbers, water used to flush out coal ash that accumulates at the bottom of the coal boiler (known as bottom ash), and leachate from coal ash surface impoundments and landfills. EPA added the zero-discharge requirement for leachate to the final rule in response to comments from Earthjustice and our partners that the same cost-effective technologies that are available to eliminate FGD wastewater can also be used to eliminate leachate.

Coal plant owners who have declared that they intend to retire or stop burning coal by 2028 can avoid installing improved pollution controls. Since 2020, the utility owners of dozens of aging, uneconomic coal power plants have announced that they will retire their plants in favor of other, less costly energy sources.

Some plants that have already installed less effective treatment technologies may be allowed to continue operating until as late as 2034 without installing the best available technologies if they commit to retiring by that date.  At Earthjustice, we will be taking a close look at this exemption in the final rule, which we believe is broader than is necessary or legally justifiable.

The new standards will eliminate water pollution from coal-fired plants to safeguard our drinking water. EPA has the authority and obligation to continue strengthening these protections.  The Clean Water Act requires more stringent discharge limits on pollutants over time as new and better technologies to control pollution are developed.

By implementing more stringent wastewater treatment standards, we can safeguard our drinking water, rivers, lakes, streams, and most importantly, our health, from the harmful effects of these pollutants and ensure a healthier future for all communities.

Based in Cincinnati, Ohio, Thomas is a senior attorney for the Clean Energy Program.

Earthjustice’s Clean Energy Program uses the power of the law and the strength of partnership to accelerate the transition to 100% clean energy.

The sun peeks over the horizon next to the Brayton Point Power Station in Somerset, Mass., in 2012.
Brayton Point Power Station in Somerset, Mass., in 2012. (Denis Tangney Jr. / Getty Images)