On August 31, 2020, the U.S. Environmental Protection Agency (EPA) Administrator, Andrew Wheeler, signed the final rule (referred to as the Steam Electric Reconsideration Rule) initially proposed last year to revise the technology-based effluent limitations guidelines and standards (ELGs) for common types of wastewater discharges from electric power generating facilities. This final rule rolls back the Obama-era effluent guidelines 2015 rule, which set the first federal limitations on toxic metal discharges from power plants. EPA touts that the new final rule will significantly reduce after tax compliance costs by $140 million per year.

New effluent standards

The Obama-era 2015 rule set requirements for wastewater streams associated with several processes and by-products of steam electric power generation: flue-gas desulfurization, fly ash, bottom ash, flue-gas mercury control and gasification of fuels such as coal and petroleum coke. However, EPA’s new final rule focuses on revisions to primarily two types: flue-gas desulfurization (FGD) wastewater and bottom ash (BA) transport water.

Specifically, the new final rule modifies the effluent limitations based on Best Available Technology Economically Achievable (BAT). For FGD wastewater, the rule establishes numeric BAT effluent limitations on mercury, arsenic, selenium, and nitrate/nitrite. For BA transport water, it establishes as BAT a high recycle rate system with a site-specific volumetric purge (defined in the as BA purge water). The new rule includes separate requirements for the following subcategories: high FGD flow plants, electric generating units (EGUs) that will permanently cease the combustion of coal by 2028, and low utilization EGUs (LUEGUs). In addition, the final rule extends the compliance by dates two years from Dec. 31, 2023, to Dec. 31, 2025.

New voluntary incentives program

Notably, the final rule establishes a voluntary incentives program that provides more time (until December 31, 2028) for plants to meet new standards and limitations, if they adopt additional process changes and controls that achieve more stringent limitations on mercury, arsenic, selenium, nitrate/nitrite, bromide, and total suspended solids in FGD wastewater.

Effective Date

The final rule becomes effective in 60 days after its publication in the Federal Register (i.e., November 2020). Several environmental groups have already expressed concerns regarding the less stringent effluent limitations, and will likely challenge the rule in court.