This layer displays a point layer depicting Facilities that Discharge to Water indexed to NHDPlus version 2.1. National Pollutant Discharge Elimination System (NPDES) is used by EPA programs, regions, states, and water programs for monitoring water quality. Discharge of pollutants into waters of the United States is regulated under the NPDES, a mandated provision of the Clean Water Act. To assist with the regulation process, state and federal regulators use an information management system called the Integrated Compliance Information System (ICIS-NPDES). ICIS-NPDES stores data about NPDES facilities, permits, compliance status, and enforcement activities. ICIS-NPDES replaces the legacy Permit Compliance System (PCS). The NPDES permit program addresses water pollution by regulating point sources that discharge pollutants to waters of the United States.