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Water: Offshore Coastal Extraction Facilities

Proposed regulations for cooling water intake structures at phase III facilities

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

Fact Sheet, November 2004

On November 1, 2004, we proposed location, design, construction and capacity standards for cooling water intake structures at certain existing facilities and new offshore and coastal oil and gas extraction facilities. The Clean Water Act (CWA) calls us to establish the best technology available to minimize adverse environmental impact from cooling water intake structures. The proposed rule sets standards to protect fish, shellfish and other forms of aquatic life and provides flexibility by offering several alternatives for facilities to comply. This is the third in a series of rules designed to reduce harm to aquatic life that is taken up with cooling water. We seek public comment on this proposal and ask that comments be submitted no later than 120 days after the proposal is published in the Federal Register.


Section 316(b) of the Clean Water Act requires us to ensure that the location, design, construction, and capacity of cooling water intake structures reflect the best technology available to minimize adverse environmental impact. Such impacts include death or injury to aquatic organisms by impingement (being pinned against screens or other parts of a cooling water intake structure) or entrainment (being drawn into cooling water systems and subjected to thermal, physical or chemical stresses).

We divided this rulemaking into three phases. Phase I for new facilities was completed in December 2001. Phase II, for existing electric generating plants that use at least 50 million gallons per day (MGD) of cooling water, was completed in July 2004. Phase III addresses existing facilities not covered by the Phase II rule that withdraw cooling water above a certain regulatory threshold. The Phase III rulemaking would also address new offshore and coastal oil and gas extraction facilities that are designed to withdraw at least two MGD. Facilities with intakes below these thresholds will continue to be subject to 316(b) requirements set by the Director on a case-by-case basis.

The withdrawal of cooling water from waters of the U.S. harms billions of aquatic organisms each year, including fish, fish larvae and eggs, crustaceans, shellfish, sea turtles, and marine mammals. Most damage is done to early life stages of fish and shellfish.

When the quantity of water withdrawn is large relative to the flow of the source waterbody, more organisms will be affected. Intakes in coastal waters, estuaries, and tidal rivers tend to have greater ecological impacts than those in freshwater rivers and lakes, since these areas are usually more biologically productive and have more aquatic organisms in early life stages.

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Summary of the proposed rule

The proposed rule would require protection against these impacts. We are proposing the following three options that, based on design intake flow and source waterbody, define which existing facilities would be subject to new requirements:

  • The facility has a total design intake flow of 50 MGD or more, and withdraws from any waterbody type; or
  • The facility has a total design intake flow of 200 MGD or more, and withdraws from any waterbody type; or
  • The facility has a total design intake flow of 100 MGD or more and withdraws water from an ocean, estuary, tidal river, or one of the Great Lakes.

Because the lowest proposed threshold is 50 MGD and we already established standards for power producers over 50 MGD in the Phase II rule, only manufacturing facilities (not power producers) would be covered under the proposed rule.

The facilities subject to the rule would have to meet the same requirements as those established in the Phase II regulations for large-flow power plants. Requirements to reduce impingement mortality and/or entrainment would be determined based on waterbody type. For example, manufacturers on estuaries would be required to reduce impingement mortality by 80 to 95 percent and would have to reduce entrainment by 60 to 90 percent from uncontrolled levels. The proposed rule provides several compliance alternatives, such as using existing technologies, selecting additional fish protection technologies (such as screens with fish return systems), and using restoration measures.

The proposed rule would also establish requirements for new offshore and coastal oil and gas extraction facilities. These facilities would be required to design their cooling water intake structures to meet a through-screen velocity of 0.5 feet per second (ft/s) or less and, if they are located in estuaries or tidal rivers, they would also be required to meet proportional flow requirements. Facilities that do not employ seachests (openings in the hull of a vessel for withdrawing cooling water) would also be required to use fish protection technologies to reduce entrainment. As with other new facilities covered by the Phase I rule, fixed facilities could choose to demonstrate that alternative technologies (in this case, alternatives to meeting the 0.5 ft/s velocity standard) provide equivalent protection. (We did not extend this provision to mobile facilities as we do not believe that there are alternatives to the low-velocity standard for mobile facilities.) Facilities could also request alternative, less stringent requirements if their compliance costs would be wholly out of proportion to those we considered in establishing the requirements. In this case, the Permit Director would consider an applicant's cost estimates, information in EPA's record, other relevant information and, if warranted, require the facility to meet standards that are as close as possible to the national standards without resulting in costs that are wholly out of proportion to the costs in EPA's record.

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Environmental benefits and costs

We conducted rigorous scientific and economic analyses to develop the proposed rule. We worked with states, industry groups, and environmental organizations to identify how best to protect the aquatic life that are critical to the environment and to commercial and recreational activities. We considered the costs and financial impacts to industry in developing flexible compliance alternatives. The costs of this proposed rule would not cause any manufacturing facilities to close nor would it interfere with the supply, distribution, or use of energy produced by any of these facilities. We believe that the proposed requirements would not pose a barrier to new offshore oil and gas extraction facilities entering the market place.

We estimate that the proposed options would protect between 30 million and 50 million aquatic organisms annually from death or injury by cooling water intake structures. The use benefits range from $1.3 million to $1.9 million per year depending on the design intake flow threshold of the proposed options, and are primarily from improvements to commercial and recreational fishing. There are likely to be other benefits, for example, more robust and productive aquatic ecosystems, although these are harder to quantify. We estimate the proposed rule would affect between 19 and 136 existing facilities and have compliance costs between $17.4 million and $46.8 million per year, depending on the option. 124 new offshore and coastal oil and gas facilities would be regulated for a total compliance cost of $3.2 million. The rule would cost state and federal agencies between $500,000 and $1 million annually to administer, for a total annual cost of the rule of $21.3 million to $51 million, depending on the option.

How to get additional information

For more information, please call Paul Shriner (shriner.paul@epa.gov) at 202-566-1076. You can also learn more about this proposed rule, including how to submit comments by visiting the Phase III Web site.

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