Surface Water Discharges Section
Compliance Training, Assistance, and Enforcement

Each National Pollutant Discharge Elimination System (NPDES) permit includes requirements that the discharger must collect representative samples of the discharge, analyze specified parameters, and report the results. Surface Water Discharges Section staff review the data submitted, conduct their own surveillance and monitoring program, and provide both assistance and oversight to ensure facilities regain or maintain compliance. Individual permittees must report monitoring results monthly, using the Discharge Monitoring Report (DMR) form developed specifically for each facility and test methods specified by federal regulations.

The DMR lists parameters in the discharge that have a reasonable potential to cause or contribute to water quality problems in receiving waters. Example parameters are nitrogen, phosphorus, temperature, total suspended solids (TSS), 5-day biological oxygen demand (BOD₅), dissolved oxygen, pH, copper, oil & grease, benzene, and PCBs. Although DMRs are submitted monthly, actual monitoring frequency ranges from continuously to once per year, depending on the sensitivity of the receiving waters, the discharge’s characteristics, and its volume relative to the receiving waters.