Understanding CWA Section 316(b) and Positive Impacts to Fish Populations

In April 2011, the United States Environmental Protection Agency (EPA) issued a draft rule that would impact an estimated 1,260 existing facilities that withdraw two million gallons of water or more per day and use at least 25 percent of that water for cooling purposes.  When this rule becomes final in June 2013, EPA estimates that 590 manufacturing facilities and 670 power plants will have to comply with the revised rules established in Section 316(b) of the Clean Water Act. Many plant owners are estimating costs to develop and implement possible engineering retrofits that will be needed to comply with the standards.  The modification costs for some facilities are in the billions of dollars and may lead industries such as fossil fuel plants towards closure or conversion to gas.  It is expected, however, that this rule will radically improve impingement and entrainment rates and ultimately decrease the total number of fish killed or injured each year, which in some cases is in the millions of fish.  We looked at several fossil plants and assessed the relative impingement and entrainment impacts to determine how fish communities may ultimately benefit from these protection standards.