​What Is A Discharge Monitoring Report (DMR) Report And How is It Used In New Jersey

A Discharge Monitoring Report (DMR) is a regulatory document required for facilities that discharge wastewater, stormwater, or other effluents to ground water, surface water, or stormwater systems in New Jersey. Its preparation is a critical process that ensures environmental compliance and public transparency.

​What Is A Discharge Monitoring Report (DMR) Report And How is It Used In New Jersey

What is DMR Preparation?

DMR preparation involves collecting data on pollutant levels and flow from permitted outfalls and treatment systems, whether they discharge to ground water, surface water bodies, or via stormwater systems. Permit holders, including municipal and industrial treatment plants, must routinely sample, analyze, and record values such as pH, biochemical oxygen demand (BOD), total suspended solids (TSS), metals, and other regulated parameters depending on permit requirements.

Reporting and Submitting to the State

All self-monitoring data is documented on DMR forms supplied or approved by the NJ Department of Environmental Protection (NJDEP), with frequency dictated by the facility’s permit—typically monthly, but sometimes quarterly or after specific weather events. Completed forms must be submitted to the NJDEP, either by mail or electronically, within the required reporting period. The highest-ranking facility official is responsible for certifying and signing each submission, bearing legal accountability for its accuracy.

Data Collection and Sharing

Collected monitoring data includes sample values for each outfall or discharge point, the type of sampling (grab, composite, continuous), dates, analytical methods, and relevant comments. Once submitted, this data is reviewed by the state for compliance and potential enforcement. Additionally, DMR results are shared with federal databases such as the EPA’s ECHO system, making them accessible for stakeholders and the public.

Permit Requirements and Who Needs Them

Any facility discharging water that reaches a groundwater, stormwater system, or surface water—including municipal, industrial, and certain construction sites—must obtain a New Jersey Pollutant Discharge Elimination System (NJPDES) permit from the DEP. Permit obligations are scaled to the size and nature of the operation. Facilities with larger or more complex discharges require more frequent and extensive monitoring; small facilities may have reduced requirements but still must submit valid DMRs as scheduled.

Which samples require grab versus composite sampling

Grab samples are used for parameters that fluctuate quickly, such as pH, temperature, chlorine residual, dissolved oxygen, nitrites, and bacteria. These require a representative snapshot from a single point in time because concentrations may change rapidly and won’t be reliably captured in an average.

Composite samples are required for most stable parameters that are averaged over time, such as BOD (biochemical oxygen demand, eg. CBOD5), total suspended solids (TSS), total nitrogen (TN), metals, and nutrients. These samples consist of aliquots collected at intervals or flow-proportional increments over several hours—usually 24 hours—to reflect average conditions and performance during the sampling period.

Summary Table

Sampling Type Typical Parameters

Grab pH, temperature, chlorine, DO, bacteria, nitrites

Composite BOD/CBOD5, TSS, TN, metals, nutrients

Always check the specific requirements in the facility’s permit, which lists which parameters require grab or composite sampling for compliance monitoring.

Summary Table

Requirement Details

Data Collected Pollutant levels, flow, dates, methods

Submission Monthly, quarterly, or as required

Responsible Party Highest-ranking facility official

Shared Data NJDEP, EPA ECHO, public disclosure

Permit Needed Any ground, storm, or surface discharge

In summary, DMR preparation and submission is essential for regulatory compliance in New Jersey, protecting water quality, and maintaining transparency in all situations where water leaves a facility and reaches the environment.