On Monday, May 19, the United States Environmental Protection Agency (USEPA) issued final rules under Section 316(b) of the Clean Water Act for existing facilities that (a) use cooling water intake structures designed to withdraw at least 2 million gallons of water per day from waters of the U.S.; (b) have or are required to have a National Pollutant Discharge Elimination System (NPDES) permit; and (c) use at least 25 percent of the water they withdraw exclusively for cooling purposes. According to USEPA, the rules apply to more than 1,000 facilities in the following sectors:
- Electric generating plants
- Pulp and paper mills
- Chemical manufacturing plants
- Iron and steel manufacturing
- Petroleum refineries
- Food processing
- Aluminum manufacturing
Rather than require facilities to implement only the most stringent controls, the final rule allows flexibility to pick one of several different options to reduce both fish impingement (fish and other aquatic organisms getting trapped against an intake structure) and entrainment (fish, aquatic organisms, or their eggs getting drawn into the facility).
The rule will become effective 60 days after publication in the Federal Register and will be implemented through the NPDES permit program. Media reports that environmental groups were hoping for more stringent requirements and are expected to challenge the final rule. The full text of the pre-publication notice can be found here.
 New facilities are subject to the previously-promulgated Phase I rules found at 40 C.F.R. Subpart I. 66 Fed. Reg. 65256 (Dec. 18, 2001).