Discharge Monitoring Report (DMR)

What is a DMR?

A Discharge Monitoring Report (DMR) is a periodic compliance report required for any facility discharging pollutants from a point source into waters of the United States under the Clean Water Act (CWA). These reports are submitted monthly, quarterly, or semi-annually depending on permit conditions. DMRs are mainly submitted electronically through the EPA’s NetDMR platform or state-equivalent system.

Who Requires DMR Submission?

DMR Submission is required for facilities operating under a valid National Pollutant Discharge Elimination System (NPDES). This generally includes sewage treatment plants and industrial facilities, which encapsulates:

• • Multi-Sector General Permit (MSGP) holders
  • Construction Stormwater General Permit (CSGP) permittees
  • Municipal Separate Storm Sewer Systems (MS4s)
  • Publicly Owned Treatment Works (POTWs)
  • Facilities with State Disposal System (SDS) or Water Quality Management permits (WQM)

Note: Even if facility has no discharge during a reporting period, a DMR submission indicating “no discharge” may still be required.

Types of DMR

DMR encompasses various types of monitoring activities depending on the nature of discharge and type of permit. The main categorizations include:

1. 1. Periodic monitoring
      1. Grab samples – Collected at a single point in time
      2. Composite samples – Collected over set period of time and takes the average value
      3. Common Parameters: pH, biochemical oxygen demand, total suspended solids, nutrients, toxic pollutants, temperature, etc.
   2. Continuous monitoring
      1. Continuous Water Monitors (CWMs) – Real time automated measurement of water quality
   3. Visual assessment – Required for some states such as Virginia, Michigan, etc.
      1. Stormwater monitoring (e.g. color, odor, floating solids, etc.)
   4. Other
      1. Biosolids/Sewage Sludge Reports
      2. Sewer Overflow/Bypass Event Reports
      3. Residual Transfer Reports (RTRs)
      4. Waste Characterization Reports (WCRs)

Key Aspects of DMR Reporting Process

The key components of the DMR process include:

• • Sampling & Testing – Based on permit-specific frequency and parameters
  • Reporting Period Closure (i.e. End of Monitoring Period) – Marks end of sampling cycle and references to reporting deadlines
  • Submission Timeline – Usually due on the 15th of the month following the End of Monitoring Period, or Annually by March 31st.
  • Permit Feature Codes – Unique 3-digit codes identifying each outfall or monitoring location
  • Location Codes – Indicate nature of sampling point (e.g. 0: intake, 1: effluent gross, etc.)
  • No Data Indicator (NODI) codes – Used to explain why parameters aren’t reported (i.e. no data)

Avoiding DMR Non-Compliance

DMR violations are automatically tracked in the EPA’s Integrated Compliance Information System (ICIS-NPDES). Common violations include:

• • D80 – Failure to report monitoring data
  • D90 – Failure to report data for parameters with effluent limit data
  • Late Submissions – Report not submitted within 31 days of their due date are flagged
  • Federal Violation Trigger – States have up to 40 days to enter values before EPA flags are generated

It is essential for facilities to proactively plan DMR to avoid enforcement actions, ensure compliance, and maintain permit eligibility. Our SEC experts help clients implement Best Management Practices (BMPs) to help streamline monitoring schedules and develop comprehensive DMRs.