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Illicit discharge

Steam cascading over rocks.

Illicit discharge

Illicit Discharge Elimination Program

Through MDOT's Illicit Discharge Elimination Program (IDEP), the department trains employees to identify improper connections or discharges into the drainage system. Common warning signs include dry‑weather flow, suds, sewage, oil or gas. Field crews also inspect point source discharges, which are locations where stormwater flows into state waters or into another public agency’s drainage system, as part of their dry‑weather screening.

IDEP Protocol Manual

  • Illicit discharge

    Any discharge (or seepage) to the separate stormwater drainage system that is not composed entirely of stormwater or uncontaminated groundwater.

  • Illicit connection

    Any direct or indirect connection to the MDOT drainage system that is not entirely composed of stormwater or is not permitted by MDOT.

Illicit discharge warning signs

  • Oil and gas

    An oil or gas sheen usually appears as a shiny film on the water. If you swirl it and it comes back together, it’s petroleum; natural sheens stay separated. These pollutants often enter waterways through stormwater runoff or illegal dumping.

  • Sanitary sewage

    Sewage may be present if there is black staining in the pipe or signs of sanitary waste like toilet paper or gray water. It can come from overflowing septic systems or improperly dumped trailer waste. Natural whiting can be mistaken for a sewage discharge.

  • Foam

    Foam can naturally occur or be a sign of pollution. Foam from illicit discharges can reduce oxygen in the water, and improper connections from car washes or washing machines often create foam at drainage outlets.

  • Dry weather flow

    Dry weather flow occurs when a storm drain has water or shows signs of intermittent flow, such as staining or odors, even though it has not rained for at least 72 hours.

Region IDEP coordinators

  • A map of MDOT's seven regions with Bay Region highlighted in blue.

    Bay Region

    Amanda Novak
    989-233-3687

  • A map of MDOT's seven regions with Grand Region highlighted in blue.

    Grand Region

    Tom Kitcey
    616-451-8881

  • A map of MDOT's seven regions with Metro Region highlighted in green.

    Metro Region

    Dave Dortman
    248-483-5157

  • A map of MDOT's seven regions with North Region highlighted in blue.

    North Region

    Doug Bates
    989-385-4608

  • A map of MDOT's seven regions with Southwest Region highlighted in blue.

    Southwest Region

    Rachael LeTourneau
    269-303-2529

  • A map of MDOT's seven regions with Superior Region highlighted in blue.

    Superior Region

    James Hanson
    906-786-1830

  • A map of MDOT's seven regions with University Region highlighted in blue.

    University Region

    Bob Batt
    517-750-0410