Section 316(b) of the Clean Water Act requires that National Pollutant Discharge Elimination System (NPDES) permits for facilities with cooling water intake structures ensure that the location, design, construction, and capacity of the structures reflect the best technology available (BTA) to minimize harmful impacts on the environment.
According to EPA, the rule covers roughly 1,260 existing facilities that each withdraw at least 2 million gallons per day of cooling water. EPA estimates that approximately 590 of these facilities are manufacturers, and the other 670 are power plants, including electric cooperatives.
The proposed rule does not require existing power plants with once-through cooling to retrofit cooling towers where they do not make economic sense when other less-expensive alternatives exist. EPA is not presuming that cooling towers are BTA; however, the proposed rule appears to allow for site-specific analysis and for permitting agencies to consider costs when making BTA determinations. (National Rural Electric Cooperative Association, 4/1/2011)
More information on EPA’s proposed Clean Water Act Section 316(b) rule