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Water Cooling Regulations

Most Recent Action

The Obama administration has extended the deadline for setting a final rule on cooling water structures for industrial facilities to July 27, 2013.


Under a settlement agreement with environmental organizations, the EPA divided the section 316(b) rulemaking into three phases.

All new facilities except offshore oil and gas exploration facilities were addressed in Phase I in December 2001; all new offshore oil and gas exploration facilities were later addressed in June 2006 as part of Phase III. Existing large electric-generating facilities were addressed in Phase II in February 2004 and existing small electric-generating and all manufacturing facilities were addressed in Phase III in June 2006. However, Phase II and the existing facility portion of Phase III were remanded to EPA for reconsideration as a result of legal proceedings.

The April 2011 proposal combines Phases II and III into one rule, and provides a holistic approach to protecting aquatic life impacted by cooling water intakes at existing electric generating and manufacturing facilities.

The proposed rule covers roughly 1,260 existing facilities that each withdraws at least 2 million gallons per day of cooling water. The EPA estimates that approximately 590 of these facilities are manufacturers, and the other 670 are power plants.

A final rule is expected in 2013.

This rule is part of a group of rules known as the EPA’s Regulatory Train Wreck.


Clean Water Act Sec. 316. Thermal Discharges. (b) Any standard established pursuant to section 301 or section 306 of this Act and applicable to a point source shall require that the location, design, construction, and capacity of cooling water intake structures reflect the best technology available for minimizing adverse environmental impact.

Proposed Standard

Under the proposed rule, any water cooling intake structure that withdraws at least 2 million gallons per day of cooling water will have an upper limit on how many fish can be killed by being pinned against intake screens. Alternately, the facility could reduce their intake velocity to 0.5 feet per second, a rate at which most fish can avoid the cooling water intake.

Facilities that withdraw at least 125 million gallons per day would be required to conduct studies to help their permitting authority determine what controls would be required to reduce the amount of aquatic life drawn into the cooling water systems.

Finally, new units that add electrical generation capacity at an existing facility would be required to add technology equivalent to close-cycle cooling to reduce entrainment of aquatic life.

Related Documents

Final Deadline Extended to July 2013, July 2012

Notice of Data Availability, June 2012

Proposed Rules, April 2011

Proposed Rule Fact Sheet, March 2011

Press Release Announcing Proposed Rule, March 28, 2011

Settlement Agreement with Riverkeeper , November 2010

Environmental and Economic Benefits Analysis for Proposed Section 316(b) Existing Facilities Rule

Frequently Asked Questions

EPA Website