This Clean Water Act (CWA) regulation limits the discharge of pollutants into waters of the United States and the introduction of pollutants into publicly-owned treatment works by existing and new facilities in the coastal subcategory of the oil and gas extraction point source category. This regulation establishes effluent limitations guidelines and new source performance standards (NSPS) for direct dischargers based on ``best practicable control technology currently available'' (BPT), ``best conventional pollutant control technology'' (BCT), ``best available technology economically achievable'' (BAT), and ``best available demonstrated control technology'' (BADCT) for new sources. The regulation also establishes ``pretreatment standards for new sources'' (PSNS) and ``pretreatment standards for existing sources'' (PSES) discharging their wastewaters to publicly-owned-treatment works (POTWs). In essence, this final rule codifies the current permit requirements for coastal oil and gas dischargers--except that it also requires zero discharge of offshore produced water for discharges to the main passes of the Mississippi River, applies to discharges not currently authorized by permits, and establishes limitations in Cook Inlet, Alaska which are equal to those previously established for the offshore subcategory. The major wastestreams being limited are produced water, drilling fluids, and drill cuttings. These limitations are expected to reduce discharges of conventional pollutants by 2,780,000 pounds per year, nonconventional pollutants by 1,490,000,000 pounds per year, and toxic pollutants by 228,000 pounds per year, assuming a baseline of current permit requirements. The statutory term ``toxic pollutant'' refers to a substance identified as belonging to one of the 65 families of chemicals listed in the CWA as toxic.