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Unified Agenda 2040-AE95

Criteria and Standards for Cooling Water Intake Structures


Section 316(b) of the Clean Water Act (CWA) requires EPA to ensure that the location, design, construction, and capacity of cooling water intake structures reflect the best technology available (BTA) for minimizing adverse environmental impacts. Under a consent decree with environmental organizations, EPA divided the 316(b) rulemaking into three phases. All new facilities except offshore oil and gas exploration facilities were addressed in Phase I in December 2001. In July, 2004, EPA promulgated Phase II which covered large existing electric generating plants. In July 2007, EPA suspended the Phase II rule following the Second Circuit decision. Several parties petitioned the U.S. Supreme Court to review that decision, and the Supreme Court granted the petitions, limited to the issue of whether the Clean Water Act authorized EPA to consider the relationship of costs and benefits in establishing 316(b) standards. On April 1, 2009, the Supreme Court reversed and remanded the case to the Second Circuit. The Second Circuit subsequently granted a request from EPA that the case be returned to the Agency for further consideration. In June 2006, EPA promulgated the Phase III regulation, covering existing electric generating plants using less than 50 MGD of cooling water, new offshore oil and gas facilities, and all existing manufacturing facilities. Petitions to review this rule were filed in the U.S. Court of Appeals for the Fifth Circuit. In July 2010, the U. S. Court of Appeals for the Fifth Circuit issued a decision upholding EPA's rule for new offshore oil and gas extraction facilities. The court also granted the request of EPA and environmental petitioners to remand the existing facility portion of the rule to the Agency. EPA entered a settlement agreement with the plaintiffs in two lawsuits related to Section 316(b) rulemakings. Under the settlement agreement EPA agreed to sign a notice of a proposed rulemaking implementing section 316(b) of the CWA at existing facilities no later than March 28, 2011 and to sign a notice taking final action on the proposed rule no later than November 4, 2013 as discussed below. Plaintiffs agreed to seek dismissal of both their suits, subject to a request to reopen one of the lawsuits in the event EPA failed to meet the deadlines. EPA's proposed regulation includes uniform controls at all existing facilities to prevent fish from being trapped against screens (impingement), site-specific controls for existing facilities other than new units to prevent fish from being drawn through cooling systems (entrainment), and uniform controls equivalent to closed cycle cooling for new units at existing facilities (entrainment). Other regulatory options analyzed included similar uniform impingement controls, and progressively more stringent requirements for entrainment controls. Another option considered would imposed the uniform impingement controls only for facilities withdrawing 50 or more MGD of cooling water, with site-specific impingement controls for facilities withdrawing less than 50 MGD. EPA issued two Notices of Data Availability in June 2012 that described measures to provide additional flexibility that EPA is considering as part of the impingement mortality standard and that described the preliminary results of surveys of households' willingness to pay for incremental reductions in fish mortality. In light of the Supreme Court 2009 decision and its recognition that EPA has broad discretion in its 316(b) regulations, EPA initiated consultation with the Fish and Wildlife Service and the National Marine Fisheries Service under Section 7 of the Endangered Species Act. EPA and the Services began informal consultation in 2012, but concluded in 2013 that formal consultation was necessary. In order to accommodate the regulatory 135-day time frame for formal consultation, plaintiffs agreed to a modification to the settlement agreement, extending final rule deadline to November 4, 2013.

Statement of need

Cooling water is withdrawn for the purpose of dissipating waste heat from industrial processes. Over half of all water withdrawn in the United States each year is for cooling purposes. The withdrawal of cooling water removes and kills hundreds of billions of aquatic organisms from waters of the United States each year, including plankton, fish, crustaceans, shellfish, sea turtles, and marine mammals. In addition to direct loss of organisms, a number of indirect, ecosystem-level effects may also occur, and environmental degradation can result from the cumulative impacts. The long life of the capital equipment in industries withdrawing cooling water implies that these adverse environmental impacts could continue for decades. Private decision making at facilities that use cooling water may not take society's preferences for fish protection into account. The beneficiaries of fish protection at cooling water intakes include fisherman, and citizens interested in well-functioning and healthy aquatic ecosystems. In addition, deregulation in the electric industry has made it more difficult for merchant power producers to both remain competitive and pass along to consumers costs associated with fish protection, putting them at a disadvantage to rate-regulated electric utilities that are vertically integrated.

Legal Basis

The Clean Water Act requires EPA to establish best technology available standards to minimize adverse environmental impacts from cooling water intake structures. On February 16, 2004, EPA took final action on regulations governing cooling water intake structures at certain existing power producing facilities under section 316(b) of the Clean Water Act (Phase II rule). 69 FR 41576 (July 9, 2004). These regulations were challenged, and the Second Circuit remanded several provisions of the Phase II rule on various grounds. Riverkeeper, Inc. v. EPA, 475F.3d83, (2d Cir., 2007). EPA suspended most of the rule in response to the remand. 72 FR 37107 (July 9, 2007). The remand of Phase III does not change permitting requirements for these facilities. Until the new rule is issued, permit directors continue to issue permits on a case-by-case, Best Professional Judgment basis for existing facilities.


This analysis will cover various sizes and types of potentially regulated facilities and control technologies. EPA is considering whether to regulate on a national basis, by subcategory, by broad water body category, or some other basis.

Costs and Benefits

The technologies under consideration in this rulemaking are similar to the technologies considered for the original Phase II and Phase III rules, and costs have been updated to 2009. The annual social costs associated with EPA's proposed regulation are $384 million, plus an additional $15 million in costs associated with the new units provision. The annual social costs of the other options ranged from $327 million to $4.63 billion. EPA monetized only a portion of the expected annual benefits of the rule, amounting to $18 million. The monetized benefits for the other options ranged from $17 million to $126 million. EPA also conducted a stated preference survey to provide a more comprehensive estimate of the monetized benefits and expects to have the Science Advisory Board review this study.


Cooling water intake structures may pose significant risks for aquatic ecosystems.


5 actions from April 20th, 2011 to January 2014


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