A new proposal from the U.S. Environmental Protection Agency (EPA) would strengthen discharge standards with the goal of reducing polluted wastewater generated from coal-fired power plants.

The EPA proposal takes aim at three types of wastewater generated at coal plants, from scrubbers that remove pollutants from exhaust systems; water used to flush out boilers at the bottom of a plant; and coal ash ponds that often leach into nearby waterways.

The types of wastewater affected would be flue gas desulfurization (FGD) wastewater, bottom ash (BA) transport water and combustion residual leachate (CRL).

Specifically, the proposal would implement “a zero-discharge limitation for all pollutants in FGD wastewater and BA transport water” and “numeric (non-zero) discharge limitations for mercury and arsenic in CRL.”

The proposal also encourages the plants to retire or switch to other fuels such as natural gas by 2028. It includes a carve-out for plants that plan to retire or stop burning coal by that year and would allow such plants to continue meeting older rules from 2015 and 2020.

Additionally, for some plants that are already in the process of installing treatment technologies to meet the 2015 and 2020 rules, the proposal would allow additional time for these plants to come into compliance with the new requirements.

EPA estimates its proposal would reduce pollutants discharged through wastewater from coal plants by approximately 584 million pounds per year.  

“The health and environmental protections of this action would especially benefit low-income communities and communities of color that are disproportionately impacted by pollution from coal-fired power plants,” the agency said.

EPA will conduct public hearings on the proposed rule on April 20 and 25, 2023.

While coal-fired generation in the U.S. has dropped dramatically because of competition from natural gas and renewables, the country still generated nearly 20% of its electricity from coal plants in 2022, according to the Energy Information Administration (EIA).

This article includes reporting from The Associated Press.

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