Semi-Annual Stormwater Sampling Deadline Approaching

General information

With the end of June approaching, make sure you don’t forget the upcoming deadlines to comply with New York State Pollutant Discharge Elimination System (SPDES) requirements! The New York State Department of Environmental Conservation (NYSDEC) administers the Multi-Sector General Permit (MSGP) for Stormwater Discharges Associated with Industrial Activity (GP-0-23-001), and June 30 marks the deadline for all facilities covered by this permit to complete stormwater monitoring activities for the first half of 2024.

The current permit and its purpose

Last year, the NYSDEC released the current MSGP, GP-0-23-001, which is the successor of the general permit GP-0-17-004 and is serving a typical five-year term. The permit is obtained by submitting a Notice of Intent (NOI) and subsequently preparing a Stormwater Pollution Prevention Plan (SWPPP) within 90 calendar days. Along with meeting the June 30 stormwater monitoring deadline, facilities must also submit Discharge Monitoring Reports (DMRs) by July 28.

Facilities covered by the general permit include industrial use facilities that discharge stormwater to surface waters of the State. The United States Clean Water Act (USCWA) institutes effluent limitations, which cap the amount of pollutants produced by a point source and into a body of water; the general permit helps both to enforce these standards (along with those enumerated in EPA 40 CFR Part 122 and 6 NYCRR Part 750) and to minimize pollutant discharge through Best Management Practices (BMPs).

Exceedances and violations

The current general permit cites violations as follows: 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 SWPPP.

What do I need to report and how long should I keep my records?

Holders of the MSGP must report all prerequisites 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.

Facility operator information, facility information, discharge information, monitoring information, and certification information are pertinent to completing the DMRs. Notably, all of a facility’s stormwater discharge points must be given a unique three-digit number and match all points identified in that facility’s NOI form. After the discharge points are sampled–and the date, location, and time of sampling, as well as the individuals who performed the sampling, are recorded–the samples must be sent to a lab to be analyzed by qualified individuals. The names of these individuals as well as the analysis results and Quality Control and Quality Assurance (QC/QA) documentation are included in the report as well.

These stormwater testing results are to be submitted electronically through the United States Environmental Protection Agency’s (EPA) DMR system by July 28. The NYSDEC mandates that records including both the data used to complete the permit application and copies of all reports required by the MSGP be kept by the permittee for a duration of five years.

Contact Walden at 516-588-6859 to speak with an experienced consultant about your stormwater permitting and compliance needs.