Aegis Regulatory Alert - May 1 2023

EPA Proposes Wastewater Discharge Standards for Coal-burning Electric Plants

What they’re saying: 

The EPA is proposing new limitations to wastewater discharge standards for coal-burning steam electric power plants (these regulations do not apply to natural gas burning plants) to reduce the release of toxic metals and other pollutants. 

  • These proposed limitations will target emissions from flue gas desulfurization wastewater, bottom ash transport water, and combustion residual leachate.
  • These proposals will also establish new definitions for legacy wastewaters.
  • These proposed limitations would include a zero-discharge limitation for pollutants in flue gas desulfurization wastewater and bottom ash transport water, and numeric discharge limitations for mercury and arsenic in Combustion residual leachate.

Regulation goals  In 2021, the EPA identified means to reduce pollutants via implementing available and affordable technologies. 

  • In exchange for promising to stop burning coal and to implement these technologies by 2028, the EPA will offer alternative/less stringent wastewater pollution limits.
  • Simultaneous to these proposed changes, the EPA has released a direct and final rule to extend the deadline for plants to opt-in to the 2028 early retirement provisions.
  • The EPA estimates that these regulations could reduce pollutants discharged by 584 million pounds per year, and hopes that by enacting more stringent wastewater limitations, more coal-burning plants will opt into the 2028 agreement.

What’s next: An online public hearing was held regarding these proposed changes on April 20th and 25th, but the EPA will accept public comments on the proposal through May 30th. To comment on the proposals, you may submit them online at and search by Docket Number EPQ-HQ-OW-2009-0819. 

Go deeper:   

Fact Sheet - 

Proposed Rule - 

EPA Summary Page for Proposed Rule -