National Menu of Best Management Practices (BMPs) for Stormwater-Illicit Discharge Detection and Elimination
Disclaimer: The BMP examples and references included on these fact sheets are not intended to be comprehensive. Additionally, the list of BMPs is not all-inclusive, and it does not preclude MS4s from using other technically sound practices.
In general, illicit discharges include any discharge into a storm drain system that is not entirely composed of stormwater. The exceptions include water from firefighting activities and discharges from facilities already covered under a National Pollutant Discharge Elimination System (NPDES) permit. Illicit discharges are a problem because, unlike wastewater, which flows to a treatment plant, stormwater generally flows to waterways without any additional treatment. Illicit discharges often contain pathogens, nutrients, surfactants, and various toxic pollutants.
Phase II MS4s are required to develop a program to detect and eliminate these illicit discharges. This primarily includes developing:
- a storm sewer system map,
- an ordinance prohibiting illicit discharges,
- a plan to detect and address these illicit discharges, and
- an education program on the hazards associated with illicit discharges.
An effective illicit discharge program needs to be both reactive and proactive. The program is reactive in addressing spills and other illicit discharges to the storm drain system that are found. The program is proactive in preventing and eliminating illicit discharges through education, training, and enforcement.
BMP Fact Sheets
The fact sheets describe the BMPs and generally provide applicability, implementation, and effectiveness information to help municipal stormwater and construction site operators comply with the stormwater Phase II requirements.
Developing an IDDE Program
- Illicit Discharge Detection and Elimination Program Development (pdf)
- Preventing Stormwater Contamination from Sanitary Sewage (pdf)
- Reducing the Occurrence of SSOs (see Preventing Stormwater Contamination from Septic System Failure (pdf) )
Trash and Illegal Dumping
- Developing a Used Oil Recycling Program (pdf)
- Illegal Dumping Control (pdf)
- Trash and Debris Management (see Public Education Trash and Debris Management)
Decentralized Wastewater
- Preventing Septic System Failure (see Preventing Stormwater Contamination from Septic System Failure (pdf) )
- Preventing Stormwater Contamination from Septic System Failure (pdf)
- Sewage from Recreational Activities (discontinued)
Public Reporting
Resources
- Stormwater Phase II Fact Sheet on the IDDE Minimum Measure
- Illicit Discharge Detection and Elimination: A Guidance Manual for Program Development and Technical Assessments - Center for Watershed Protection's comprehensive manual that includes details on creating and managing an IDDE program, implementation timelines, information on estimating program costs in terms of capital and personnel expenses, and types of testing used to detect stormwater illicit discharges.
- EPA Region 1 Resources – Includes links to instructional video for EPA MS4 General Permits in Massachusetts and New Hampshire, webinars, tool related to catchment delineation and outfall prioritization, and technical documents.
- Trash Free Waters website - Resources to educate the public about the impact of trash and ways to prevent marine debris.
- Non-Stormwater Discharges - Fact sheet on controlling Non-Stormwater Discharges to the storm drain system.
- Model Illicit Discharge Ordinances
- Wastewater Education Materials - Materials to help municipal officials educate citizens on important wastewater issues.