Discharge Monitoring Reports: No Discharge vs No Sample Taken

Stormwater monitoring requirements vary with each permit; therefore, monitoring may or may not be required for your facility. If stormwater samples are required, samples must be collected at each outfall representing the facility's discharge. The stormwater permit will indicate what type of monitoring is required, along with the frequency and submission of any monitoring data.

A Discharge Monitoring Report (DMR) contains the results of stormwater monitoring. The stormwater permit will outline how monitoring data needs to be submitted and the due dates for DMRs. Permittees are encouraged to sample early in the monitoring period in case the opportunity is not available later. Permittees can collect a stormwater sample and submit DMRs prior to the due date; however, extension and/or late reports are typically not allowed past the end of the monitoring period.

What happens if you don’t collect a stormwater sample during the monitoring period? You must still submit a DMR and mark the report as either “No Discharge” or “No Sample Taken.” What’s the difference? One is a legitimate reason the sample was not taken, and the other is not following the stormwater regulations.

Maybe it didn’t rain that much during the monitoring period, or your site is designed to hold water and there was no discharge at your outfall. In that case, you can submit the DMR as “No Discharge,” indicating there are no discharges that occurred during the monitoring period. Additional documentation will need to be submitted with the DMR and can include inspections, photographs, and precipitation information (e.g., rain logs) indicating there was no opportunity to collect the sample at any time during the entire monitoring period in which a sample could be taken (i.e., no measurable storm events occurred during the monitoring period or if there was a measurable storm event no discharge occurred).

What if you just forgot to take the sample, or there was no one qualified/trained to take the sample? If you cannot collect and report the stormwater sample, you must submit the DMR as "No Sample Taken.” You must also add comments to the DMR to explain the missing data. It is the permittee’s responsibility to ensure that there is a trained/qualified person to oversee the stormwater requirements. Permittees must emphasize to employees the importance of stormwater sampling and ensure the stormwater training program is up to date, conducted annually, and repeated more often if there are new employees.

The only time you can report “No Discharge” is when there has actually not been any discharge. A “No Discharge” report cannot be used if your facility was discharging stormwater but you were sick, out on vacation, busy, or just simply forgot to collect the sample. It’s not technically correct to report “No Discharge” if there, in fact, was a discharge. In many instances, severe enforcement actions occur because of incorrect reporting.

Stormwater permits require self-monitoring, and the regulatory authorities place the responsibility on you as the permittee to follow the regulations and take the stormwater samples within each monitoring period. If the facility fails to take a stormwater sample within the set monitoring period and therefore reports a DMR as “No Sample Taken,” this indicates a failure to comply with the permit conditions and, therefore, will likely result in a permit violation. The violation created for submitting as “No Sample Taken” is less significant than not submitting a DMR at all. Failure to submit a DMR creates a significant violation, which puts the facility on certain lists that can lead to enforcement.

DMRs will require the responsible official to “acknowledge” reported violations and missing fields prior to being signed and submitted. Therefore, it is important that the signatory authority review the DMR to verify that all required information has been successfully entered and submitted.

Need help with your stormwater permit program? Cornerstone EHS has been involved in helping facilities get and stay in compliance with stormwater permits across the United States since our founding in 1995. Our qualified professionals know the ins and outs of stormwater regulations and can help you. Contact us today.