Illicit Discharge Detection and Elimination

What is an Illicit Discharge? It's stormwater pollution.

Stormwater is precipitation that falls and runs over land and eventually into a stream, river, lake, or ocean. When it rains, stormwater flows over the ground and picks up pollutants and carries them to the storm drainage system which goes directly into creeks, streams, and lakes without being treated. An illicit discharge is when various pollutants enter the stormwater drainage system. This may happen in two specific ways either directly through the spilling or dumping of pollutants or indirectly when pollutants are collected during a rain event and are carried the to storm drains that connect to underground pipes that lead directly to a near by stream or creek without being treated. Pollutants that would be considered illicit discharges include but are not limited to; sediment, soap, pet waste, litter, oil, fertilizer, pesticides, and raw sewage.

Stormwater Runoff Pollutes

The goal of an illicit discharge detection and elimination program is to identify and mitigate discharges that are not composed entirely of stormwater that enter the drainage system. This goal is achieved by routine inspections and monitoring as well as investigation following any observation or complaint, reliance on regulatory measures for abatement and enforcement, and to remedy any illicit connections when identified.


The program partners all share responsibility in implementing an IDDE program within the boundaries of their Municipal DSCN1109Separate Storm Sewer System also referred to as MS4s. Both the Cities of Burlington and Graham have regulatory authority through local ordinances to prohibit and eliminate illicit discharges and connections. NCDOT manages the potential for illicit discharges and connections through their Illicit Discharge Detection and Elimination (IDDE) and Encroachment Programs.The Cities of Graham and Burlington, as well as NCDOT have been implementing and reporting on illicit discharge detection and elimination programs over the tenure of their NPDES MS4 permits. These programs continue to be used to reduce non-stormwater discharges of toxins, fats, oils, greases, and heavy metals, and to prevent the cross-contamination of wastewater into the stormwater system both during wet weather and dry weather conditions.


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