Illicit Discharge Detection and Elimination

Where Does Your Stormwater Go?

Why is it important to keep pollutants and toxic chemicals out of the storm system? All stormwater that goes into the city’s storm conveyance system is somehow connected to a fish-bearing creek or river.  Even low concentrations of pollutants can cause harm to aquatic life.

IDDE Program

The city follows the guidance in the 2020 Illicit Connection and Illicit Discharge Field Screening and Source Tracing Guidance Manual (ICID Field Screening and Source Training Manual) for its IDDE program.

On average the city responds to 30-50 spills per year and reports approximately half of those to Ecology because the spill reached the city drainage system. In addition to responding to spills, the IDDE Program also includes the inspection of all outfalls from the city drainage system. There are approximately 90 outfalls in the city.

Non-permitted discharges are monitored and enforced through the IDDE program. Allowable discharges are listed in PMC 21.11.030 and enforcement action is conducted in accordance with PMC 21.11070.

IDDE Screening and Source Tracing

The city has hired a consultant to complete a full IDDE screening of Deer Creek and Meeker Creek. IDDE Screening and Source Tracing is a requirement set forth by the TMDL requirements in the NPDES Permit. For more information on TMDLs, click here. All screening and source tracing for these two basins are required to be completed by July 31st, 2024.

Reporting Spills

If you are aware of any spills or witness a spill, please call 253-770-3336 to report the spill or non-permitted discharges. A non-permitted discharge is anything other than surface and ground water into the City storm drain system. Life-threatening emergencies and hazardous materials should be reported by calling 911 immediately.
Non-permitted discharges could include a leaking garbage truck or dumpster, a carpet cleaning truck hose draining into a stormwater drain, hosing grass clipping into a storm drain, track out from a nearby construction site, or even soapy water from a car wash. If you see these types of activities, please remember to report:

  • When and where the incident occurred
  • Who is responsible for the spill/dumping? Include vehicle and license plate or personal description
  • What substance is being dumped/spilled