Illicit Discharge Detection and Elimination

The IDDE program consists of outfall inspections and sampling of dry weather flows (i.e. water flowing in storm drains during dry weather), as well as identifying and eliminating source flow.

Outfall Inspections

  • City has identified over 800 outfalls.
  • Outfalls are inspected over the permit term.
  • Outfalls with flow are inspected annually.
  • When an outfall has flow, the sampling crew will conducts a field screening.
ESDSW015_outfallsampling2.jpg ESDSW014_outfallsampling.jpg
Sampling crew collecting a water sample. Sampling crew performing a field screening analysis.

Tracking the Source of Flow

  • If an outfall is observed to have a dry weather flow, an investigation is initiated.
  • Inspections use visual observations, open manholes and televise the storm drain to identify source of flows.
ESDSW067_IDDE.jpg ESDSW066_IDDE.jpg ESDSW069_truckIDDE.jpg
Inspector using the camera tractor to televise storm drain. Inspector operating the camera tractor and televising the storm drain. Storm drain investigation in front of City Hall.