Today's final rule establishes Clean Water Act effluent limitations guidelines and new source performance standards for concentrated aquatic animal production facilities. The animals produced range from species produced for human consumption as food to species raised to stock streams for fishing. The animals are raised in a variety of production systems. The production of aquatic animals contributes pollutants such as suspended solids, biochemical oxygen demand, and nutrients to the aquatic environment. The regulation establishes technology-based narrative limitations and standards for wastewater discharges from new and existing concentrated aquatic animal production facilities that discharge directly to U.S. waters. EPA estimates that compliance with this regulation will affect 242 facilities. The rule is projected to reduce the discharge of total suspended solids by about 0.5 million pounds per year and reduce the discharge of biochemical oxygen demand (BOD) and nutrients by about 0.3 million pounds per year. The estimated annual cost for commercial facilities is $0.3 million. The estimated annual cost to Federal and State hatcheries is $1.1 million. EPA estimates that the annual monetized environmental benefits of the rule will be in the range of $66,000 to $99,000.