The U.S. Environmental Protection Agency has finalized standards to protect fish and other aquatic life drawn into cooling water systems at large power plants and factories. The final rule is required by the Clean Water Act to address site-specific challenges. It establishes a common-sense framework, putting a premium on public input and flexibility for facilities to comply.AquaticLife_IN

An estimated 2.1 billion fish, crabs and shrimp are killed annually by being pinned against cooling water intake structures (impingement) or being drawn into cooling water systems and affected by heat, chemicals or physical stress (entrainment). To protect threatened and endangered species and critical habitat, the expertise of the Fish & Wildlife Service and National Marine Fisheries Service is available to inform decisions about control technologies at individual facilities.

The final rule establishes requirements under the Clean Water Act for all existing power-generating facilities and existing manufacturing and industrial facilities that withdraw more than 2 million gallons per day of water from waters of the United States and use at least 25 percent of the water they withdraw exclusively for cooling purposes. This rule covers roughly 1,065 existing facilities; 521 of these facilities are factories and the other 544 are power plants. According to the EPA, the technologies required under the rule are well understood, have been in use for several decades and are in use at over 40 percent of facilities.

The national requirements, which will be implemented through National Pollutant Discharge Elimination System (NPDES) permits, are applicable to the location, design, construction and capacity of cooling water intake structures at these facilities and are based on the best technology available for minimizing environmental impact. The rule establishes a strong baseline level of protection and then allows additional safeguards for aquatic life to be developed through site-specific analysis. It puts implementation analysis in the hands of the permit writers so requirements can be tailored to the particular facility. The final regulation consists of three components.

Existing facilities that withdraw at least 25 percent of their water from an adjacent water body exclusively for cooling purposes and have a design intake flow of greater than two million gallons per day are required to reduce fish impingement. To ensure flexibility, the owner or operator of the facility will be able to choose one of seven options for meeting best-technology-available requirements for reducing impingement.

Facilities that withdraw very large amounts of water – at least 125 million gallons per day – are required to conduct studies to help the permitting authority determine what site-specific entrainment mortality controls, if any, will be required. This process will include public input.

New units at an existing facility that are built to increase the generating capacity of the facility will be required to reduce the intake flow to a level similar to a closed-cycle, recirculation system. Closed-cycle systems are the most effective at reducing entrainment. This can be done by incorporating a closed-cycle system into the design of the new unit, or by making other design changes equivalent to the reductions associated with closed-cycle cooling.

For more information about the new standards, visit here.