Wastewater discharge from power plants

Wastewater discharges from industrial and commercial sources could contain pollutant levels that alter water quality or interfere with publicly owned treatment works (POTWs) that receive those discharges. Effluent guidelines are federal technology-based requirements for discharges of over 50 categories of industrial and commercial activity.

Since requirements vary for different categories of activity, some such as coal-fired power plants are more stringent than others. Even considering that, on March 8, 2023, the Biden-Harris Administration announced plans to further strengthen these standards that apply to coal-fired power plants.

A proposed rule from the Environmental Protection Agency (EPA) would set stricter discharge standards for the following three types of wastewaters generated at coal fired power plants:

1. Flue gas desulfurization wastewater,
2. Bottom ash transport water, and
3. Combustion residual leachate.

The proposed rule would also address wastewater produced by these power plants that is stored in surface impoundments like ash ponds. It would define legacy wastewaters and look for public comments on whether to create stricter discharge standards for them.

EPA believes the proposed rule would lower power plant pollutants discharged through wastewater by almost 584 million pounds per year.

Who else do these guidelines impact?

Regulations apply to nearly 40,000 facilities that discharge directly into waters of the United States like streams, lakes, or oceans. They also apply to about 129,000 facilities that discharge to POTWs or municipal sewage treatment plants.

The EPA issues effluent guidelines for industrial categories based on the performance of treatment and control technologies. The guidelines are implemented through the National Pollutant Discharge Elimination System (NPDES) Permit Program. These guidelines prevent the discharge of over 700 billion pounds of toxic pollutants each year. EPA identified 65 pollutants and classes of pollutants as toxic under these regulations. Some of the pollutants on EPA’s toxic list include:

• Benzene,
• Chloroform,
• Cyanides,
• Copper,
• Lead,
• Nickel, and
• Zinc.

The Integrated Compliance Information System is the national database used to track compliance with NPDES permit requirements for major dischargers. It shows when a permit was issued and expires, how much each company is allowed to discharge, and the monitoring data explaining what each company has discharged.