Winter Is Coming and So Is the Deadline for Semi-Annual Stormwater Monitoring and Reporting (GP-0-23-001)

As the end of the year approaches, it’s time to complete semi-annual stormwater Discharge Monitoring Reports (DMR) in order to comply with New York’s State Pollutant Discharge Elimination System (SPDES) program requirements. Facilities that are covered under the New York State Department of Environmental Conservation (NYSDEC) Multi-Sector General Permit (MSGP) for Stormwater Discharges Associated with Industrial Activity (GP-0-23-001), as well as facilities that are covered under individual SPDES permits that include conditions related to stormwater discharges, have until December 31 to submit their testing results.

What’s new?

NYSDEC’s new five-year MSGP went into effect on March 8, 2023; the current MSGP, GP-0-23-001, replaces the previous general permit (GP-0-17-004). The purpose of the MSGP is to enforce stormwater control measures for industrial facilities. The permit includes updated water quality-based requirements that combine Best Management Practices (BMPs) to achieve a minimum level of treatment for industrial point sources. The general permit also continues to monitor the conditions based on the Clean Water Act (CWA), EPA 40 CFR Part 122 and 6 NYCRR Part 750.

What do I need to report?

All industrial facilities covered under the MSGP must report all prerequisites as stated in GP-0-23-001, including semi-annual monitoring and reporting for Benchmark Monitoring Cutoff Concentrations and Numeric Effluent Limitations, as well as quarterly monitoring and reporting for Discharges to Impaired Waterbodies. The results must be submitted electronically through the United States Environmental Protection Agency’s (EPA) DMR reporting system.

Exceedances and violations

Potential violations of the current general permit include: exceedance of a Numeric Effluent Limitation; failure to implement corrective actions; and failure to maintain proper documentation. All corrective actions implemented in response to benchmark concentration exceedances must be documented in the facility’s Stormwater Pollution Prevention Plan (SWPPP).

How long do I need to keep my records?

According to the NYSDEC, MSGP holders must retain records of all stormwater monitoring information for at least five years. These records must include all data used to complete the permit application and copies of all reports required by the MSGP. The monitoring information must include the date, the exact location and time of sampling, the individuals who performed the sampling, the names of the qualified individuals that performed the lab analyses, the results of such analyses, and quality control and quality assurance (QC/QA) documentation.

If you need help with any aspect of stormwater compliance and reporting, contact Walden at 516-271-1948 to speak with one of our stormwater experts today, before the next storm hits!