MS4 communities in the Bay watershed are required to screen their stormwater outfalls to detect illicit discharges of sewage and other pollutants and take actions to eliminate them. By taking certain actions above and beyond what is required in their MS4 permits to discover and eliminate dry weather pollutant discharges, communities can earn additional nutrient reductions that count toward their TMDL goals.

Below are several resources, including the Expert Panel report that defines the actions necessary to earn pollutant reductions, and CSN’s fact sheet that breaks down the most important information and tells you how to get started!

U-6 Eliminating Individual Nutrient Discharges from Gray Infrastructure
U-9 Advanced MS4 IDDE Programs


Expert Panel Report and Resources



Eliminating Nutrient Discharges from Gray Infrastructure Expert Panel Report: Final

Download “Profile Sheets for Crediting Nutrient Reductions from Grey Infrastructure” Appendix-A.-Profile-Sheets.pdf – Downloaded 727 times – 1 MB

Training Resources

[Webcast] Nutrient Discharges from Grey Infrastructure

[Webcast] Discharge Discovery Techniques

[Webcast] Tracking and Eliminating Illicit Discharges