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MCM 3: IDDE Program


Unusual cloudiness can be an indicator of an illicit discharge.

The Virginia Tech Illicit Discharge Detection & Elimination (IDDE) Program establishes methods for controlling the introduction of pollutants into the Municipal Separate Storm Sewer System (MS4) in order to comply with the requirements of the Virginia Pollutant Discharge Elimination System (VPDES) permit.

Implementation Guidelines

  1. Locate Problem Areas: The EPA recommends priority areas be identified for detailed system screening.
  2. Find the Source: Once the problem area or discharge is found, additional steps must be taken to find the location of the discharge.
  3. Remove/Correct Illicit Connections: Once the source is identified, the offending discharger should be notified and directed to correct the problem.
  4. Document Actions Taken: All actions taken under the plan should be documented.

Outfall Reconnaissance Inventory (ORI)

ORI testing follows these Water Quality Guidelines.

ORI is a field screening technique utilized in Virginia Tech’s IDDE Program. ORI is designed to inventory and measure flow from outfalls from storm conveyance systems and to find and correct continuous and intermittent non-stormwater discharges without in depth laboratory analysis.