Fish Impingement: Existing facilities that withdraw at least 25 % of their water exclusively for cooling purposes and have a design intake flow of greater than 2 million gallons per day (MGD) would be required to reduce fish impingement under the proposed regulations. The owner or operator of the facility will be able to choose one of two options for meeting best technology available requirements for reducing impingement. They may conduct monitoring to show the specified performance standards for impingement mortality of fish and shellfish have been met, or they may demonstrate to the permitting authority that the intake velocity meets the specified design criteria. EPA estimates that more than half of the facilities that could be impacted by this proposed rule already employ technologies that are likely to put them into compliance with the proposed standard.
Fish Entrainment: EPA is proposing a site-specific determination to be made based on local concerns and on the unique circumstances of each facility. This proposed rule establishes requirements for the facility owner to conduct comprehensive studies and develop other information as part of the permit application, and then establishes a public process, with opportunity for public input, by which the appropriate technology to reduce entrainment mortality would be implemented at each facility after considering site-specific factors. Because new units can incorporate the most efficient, best-performing technology directly into the design stage of the project, the proposed rule would require closed-cycle cooling (cooling towers) for new units at existing facilities, as is already required for new facilities. The public will be able to comment on the proposed rule upon its publication in the Federal Register. EPA will conduct a 90 day comment period, and consider comments before taking final action on the proposal. Final rules must be published by July 27, 2012.
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