Discharge Monitoring Report

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 U.S.” must obtain a National Pollution Discharge Elimination System (NPDES) permit from the appropriate agency, and many permittees are required to file DMRs.

NPDES permits and DMR reporting process

For permits other than stormwater permits, the agencies issue effluent limitations for specific pollutants, pursuant to the Clean Water Act (CWA). The basis for these limitations depends on the type of discharging facility, the discharge characteristics and status of the specific surface water body receiving the discharge.

National technology-based standards apply to many industries (these standards are called "effluent guidelines"), and to municipal sewage treatment plants.

Some dischargers are subject to water quality-based effluent limitations, derived from water quality standards for the adjacent water body.

For pollutants not covered by the above circumstances, the agency may set technology-based limitations based on its "best professional judgment" (BPJ).

Most NPDES permits require facilities to submit monthly DMRs, but some permits require seasonal or semi-annual reporting. Facilities may collect and analyze samples more frequently, e.g.