The Clean Water Act (CWA) and Environmental Protection Agency’s (EPA) National Pollutant Discharge Elimination System (NPDES) regulations require permitted facilities to monitor the quality of their wastewater discharge and report these wastewater monitoring data to their permitting authority on a Discharge Monitoring Report (DMR).

A Discharge Monitoring Report (DMR) is a United States regulatory term for a periodic water pollution report prepared by industries, municipalities and other facilities discharging to surface waters.  The facilities collect wastewater samples, conduct chemical and/or biological tests of the samples, and submit reports to a state agency or the United States Environmental Protection Agency (EPA). All point source dischargers to waters of the United States must obtain a  National Pollution Discharge Elimination System (NPDES) permit from the appropriate agency, and many permittees are required to file DMRs