USEPA Cooling Water Intake Structure Regulations — CWA §316(b)

Phase I : New facilities (promulgated November 9, 2001)

The USEPA established location, design, construction and capacity standards for cooling water intake structures at new facilities (power plants and manufacturing facilities). This rule applies to all new facilities that withdraw > 2 MGD, if they use > 25% of their intake water for cooling. New facilities with smaller cooling water intakes are to be regulated on a site-by-site best professional judgment (BPJ) basis. Phase I provides 2 paths for compliance. The first requires compliance using default technologies that address intake capacity, such as cooling towers (as opposed to a once-through system). The second track would utilize a site-specific study to determine suitable controls that would achieve comparable performance to the first track. For more information, go to the USEPA website: http://www.epa.gov/waterscience/316b/phase1/

Phase II : Existing Power Plants > 50 MGD (promulgated July 9, 2004)

Phase II addresses large existing power plants that are designed to withdraw > 50 MGD and that use > 25% of their withdrawn water for cooling. The final rule required protection against environmental losses. For example, requirements call for the number of organisms harmed when pinned against parts of an intake structure (i.e., “impingement mortality”) to be reduced by 80 to 95 percent from uncontrolled levels. Requirements also call for the number of aquatic organisms drawn into the cooling system (“entrainment”) to be reduced by 60 to 90 percent from uncontrolled levels. The rule provides several compliance alternatives, such as using existing technologies, selecting additional fish protection technologies (such as screens with fish return systems), using restoration measures, and others.

The Phase II rule was challenged by a number of parties and the 2nd Circuit Court of Appeals issued a decision in January 2007 (Riverkeeper vs. EPA, No. 04-6692, 2d Cir. Jan. 25, 2007). The court's decision remanded several provisions of the Rule on various grounds. The provisions remanded include: EPA's determination of the Best Technology Available under section 316(b):

With so many provisions of the Phase II rule affected by the decision, USEPA decided to suspend the entire rule. USEPA has stated that it intends to re-write the Phase II rule to address all of the issues identified by the court and that, in the meantime, all permits for Phase II facilities must address 316(b) requirements on a BPJ basis (see WDNR BPJ guidance below). For more information, go to the USEPA website: http://www.epa.gov/waterscience/316b/phase2/

Phase III : New Offshore Oil and Gas Extraction Facilities (promulgated June 16, 2006)

The final "Phase III" rule established categorical requirements for new offshore oil and gas extraction facilities. For more information, go to the USEPA website: http://www.epa.gov/waterscience/316b/phase3/

If you have any questions regarding the WDNR's intake structure guidance or this website, please email Kari Fleming.