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National Standards Announced for Cooling Water Intake Structures at Large Existing Power Plants

Release Date: 02/17/2004
Contact Information:

Contact: Cathy Milbourn, 202 564-7824 /

02/17/2004 - On February 16, Administrator Mike Leavitt signed a final rule to protect fish, shellfish and other aquatic life from inadvertently being killed by cooling water intake structures at large power plants. This is the first time in the 32-year history of the Clean Water Act that EPA has established a systematic way to comprehensively address the environmental consequences of power plants that withdraw more than 50 million gallons of water per day.

EPA estimates that the rule will affect about 550 facilities and will cost approximately $400 million annually to implement and administer. EPA estimates that this rule will protect more than 200 million pounds of aquatic organisms annually from impingement mortality (when fish are trapped on intake screens) and entrainment (when they are drawn through the cooling system).

“This rule sets an important national standard to protect fish, shellfish, and other forms of aquatic life from death or injury,” said Leavitt. “The environmental benefits of this rule include improvements to recreational and commercial fishing and are valued at about $80 million annually.”

About 220 billion gallons of water are withdrawn each day for cooling large power plants. Withdrawing so much cooling water inadvertently draws many aquatic organisms into the intake structures. This water contains aquatic organisms (fish, shellfish, fish larvae and eggs, sea turtles and others) that are pulled into cooling water intake structures, where many are killed or injured.

The new rule will require all large existing power plants to meet performance standards to reduce the number of organisms pinned against parts of the cooling water intake structure by 80 to 95 percent. Depending on location, the amount of water withdrawn, and energy generation, certain facilities will also have to meet performance standards to reduce the number of aquatic organisms drawn into the cooling system by 60 to 90 percent. These ranges represent differences among facilities and nearby aquatic environments. To offer these large power plants flexibility to comply and to ensure energy reliability, facilities will have several compliance alternatives to meet the performance standards. The alternatives include using existing technologies, selecting additional fish protection technologies (such as screens with fish return systems), and using restoration measures.

This new final rule, often called the 316(b) Phase II regulations, directs EPA to establish the “best technology available” for cooling water intake structures to minimize adverse effects to fish and shellfish from cooling water intake structures at large power plants. The rule fulfills a consent decree filed in 1995 as a result of a lawsuit brought by several environmental groups.

The national standards EPA is announcing today are the second of three rules for cooling water intake structures being developed under the consent decree. The first rule was for new facilities and was completed in December 2001. The rule announced today is for existing electric generating plants that use large amounts of cooling water. Scheduled for proposal in November 2004, the third rule will be for existing electric generating plants using smaller amounts of cooling water and for other manufacturers.