The term “illicit discharge” is defined in EPA’s Phase II storm water regulations as “any discharge to a municipal separate storm sewer that is not composed entirely of storm water, except discharges pursuant to an NPDES permit and discharges resulting from fire-fighting activities.”
Illicit discharges can be categorized as either direct or indirect.
Examples of direct illicit discharges:
- sanitary wastewater piping that is directly connected from a building to the storm sewer
- materials (e.g., used motor oil) that have been dumped illegally into a stormdrain catch basin
- a shop floor drain that is connected to the storm sewer
- a cross-connection between the municipal sanitary sewer and storm sewer systems
Examples of indirect illicit discharges:
- an old and damaged sanitary sewer line that is leaking fluids into a cracked storm sewer line
- a failing septic system that is leaking into a cracked storm sewer line or causing surface discharge into the storm sewer
The Town of Bel Air is in the process of developing a comprehensive IDDE program beginning with the enactment of an Illicit Discharge and Connection ordinance passed by the Board of Town Commissioners on June 2, 2014.