This web feature service contains location and facility identification information from EPA's Facility Registry Service (FRS) for the subset of facilities that are Clean Water Act (CWA) National Pollutant Discharge Elimination System (NPDES) dischargers of pollutants into waters of the United States. These facilities are tracked in the NPDES module of the Integrated Compliance Information System (ICIS). For Publicly Owned Treatment Works (POTWs), Major dischargers include all facilities with design flows equal to or greater than one million gallons per day, or serve a population of 10,000 or more, or cause significant water quality impacts. Non-POTW discharges are classified as Major facilities on the basis of the number of points accumulated using a Rating worksheet, which evaluates the significance of a facility using several criteria, including toxic pollutant potential, flow volume, and water quality factors such as impairment of the receiving water or proximity of the discharge to coastal waters. FRS identifies and geospatially locates facilities, sites or places subject to environmental regulations or of environmental interest. Using vigorous verification and data management procedures, FRS integrates facility data from EPA's national program systems, other federal agencies, and State and tribal master facility records and provides EPA with a centrally managed, single source of comprehensive and authoritative information on facilities. This data set contains the subset of FRS integrated facilities that link to NPDES Major Facilities once the ICIS-NPDES data has been integrated into the FRS database. Additional information on FRS is available at the EPA website http://www.epa.gov/enviro/html/fii/index.html.