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Water: Offshore Coastal Extraction Facilities

Final Rule for Cooling Water Intake Structures at Phase III Facilities

Fact Sheet; EPA-821-F-06-007; June 2006

EPA is publishing the third and final part of regulations designed to minimize harmful impacts on aquatic life caused by cooling water intake structures. This "Phase III" rule establishes categorical requirements under section 316(b) of the Clean Water Act for new offshore oil and gas extraction facilities that have a design intake flow threshold of greater than 2 million gallons per day (MGD) and that withdraw at least 25 percent of the water exclusively for cooling purposes.

EPA decided that uniform national standards are not the most effective way at this time to address cooling water intake structures at existing facilities that were not covered under the earlier Phase II rule. Instead, we will continue to rely upon the existing National Pollutant Discharge Elimination System (NPDES) program, which implements section 316(b) for these facilities on a case-by-case, best professional judgment basis. This rule does not change the regulatory requirements for facilities subject to the Phase I or Phase II regulations.


Background

Section 316(b) of the Clean Water Act requires NPDES permits 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).

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Rulemaking in Three Phases

EPA divided this rulemaking into three phases.

  1. Phase I for new facilities was completed in December 2001.
  2. Phase II, for existing electric generating plants that use at least 50 MGD of cooling water, was completed in July 2004.
  3. Phase III addresses other existing facilities, as well as new offshore and coastal oil and gas extraction facilities that are designed to withdraw at least two MGD. Any facility not covered by these national categorical rules will continue to be subject to 316(b) requirements set by the NPDES Permitting Director on a case-by-case, best professional judgment basis.

Phase III Proposal

EPA proposed the following three options that, based on design intake flow and source waterbody, define three different instances in which existing facilities would be subject to new requirements. Either:

  • 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 EPA already established standards for power producers over 50 MGD in the Phase II rule, EPA only considered requirements for existing manufacturing facilities (not power producers) and new oil and gas extraction facilities under the proposed Phase III rule.

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Final Phase III Action

EPA has decided to establish categorical regulations for new offshore oil and gas extraction facilities that have a design intake flow threshold of greater than 2 MGD and that withdraw at least 25 percent of the water exclusively for cooling purposes. Based on available data, analyses, and comments, the Agency decided not to promulgate a national categorical rule for Phase III existing facilities. In light of the ratio of the costs of any of the three proposed regulatory options to their benefits, the best approach for existing facilities is through conditions established by NPDES permit directors on a case-by-case basis using best professional judgment.

For More Information

For more information, please call Paul Shriner (shriner.paul@epa.gov) at 202-566-1076. You can also learn more about this rule by visiting EPA's Section 316(b) web site.

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