Reporting spills & eliminating illicit discharges

Identifying and reporting spills, illicit discharges and unauthorized connections that might affect the stormwater drainage system helps keep pollutants out of receiving waterbodies. We do not allow the discharge of anything other than stormwater into our stormwater drainage system, nor do we allow any pipe, ditch or other manmade structure to connect to our stormwater drainage system without authorization.

Reporting procedures

Report spills and illicit discharges that are not comprised entirely of stormwater on or along state highways or WSDOT properties, as well as connections to our stormwater drainage system, to the appropriate authorities listed below.

Emergency or hazardous spills

Call 911 for spills on state highways or WSDOT properties that may impact the safety of the travelling public or the environment. These could include spills related to vehicle collisions, fires, unknown chemicals or explosive hazards. 

Non-emergency spills and illicit discharges that could reach WSDOT’s stormwater drainage system

Call the closest Department of Ecology office.

Department of Ecology Region offices

Central Washington: 509-575-2490

  • Counties: Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan and Yakima

Eastern Washington: 509-329-3400

  • Counties: Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla and Whitman

Northwest Washington: 425-649-7000

  • Counties: Island, King, Kitsap, San Juan, Skagit, Snohomish and Whatcom

Southwest Washington: 360-407-6300

  • Counties: Clallam, Clark, Cowlitz, Grays Harbor, Jefferson, Mason, Lewis, Pacific, Pierce, Skamania, Thurston and Wahkiakum

Illicit connections or non-emergency spills and illicit discharges that do not reach WSDOT’s stormwater drainage system

Call the WSDOT Region Illicit Discharge Detection and Elimination (IDDE) contact. Contacts are available during normal business hours only. Leave a message if contacting outside of business hours.

Use the map below to find the WSDOT region/IDDE contact phone number:

WSDOT Regions and illicit discharge detection and elimination contacts map.

WSDOT regions/IDDE contact phone numbers:

  • Eastern Region: 509-323-8402
  • Olympic Region: 360-570-6748
  • North Central Region: 509-667-2989
  • Northwest Region: 206-440-4900
  • South Central Region: 509-577-1759
  • Southwest Region: 360-905-2015

How to identify illicit discharges, connections and spills

Use the definitions, warning signs and examples below to help determine if you have identified an issue that needs to be reported. Keep this information in mind and be on the lookout for issues to report.


Use these explanations to determine if you have identified an issue to report and how to categorize it.

  • Illicit discharge – any discharge to WSDOT property or stormwater drainage system that is not comprised entirely of stormwater.
  • Illicit connection – any unauthorized pipe, ditch or other manmade structure that is physically connected to WSDOT’s property or stormwater drainage system.
  • Spill – unintentional release of a non-stormwater substance to WSDOT's stormwater drainage system or property related to a single event. Spills often occur in emergency situations, such as a collision causing oil or other automotive fluids to spill onto the highway surface.

Indications and warning signs

The following conditions have the potential to be bigger issues and should be reported following the procedures on this page:

  • Staining.
  • Residues.
  • Oily substances.
  • Odors.
  • Abnormal flow during dry weather.
  • Turbid (murky) water.
  • Suds.
Dry weather flow from drainage system.


Oil or gas sheem flowing into curbside drainage.


Suds flowing into a storm drain on roadway.


Pipe discharging into storm drain


Sewage in drainage pipes from improper disposal.


Suds from clothing or car washing activities flowing down pavement.


Murky and turbid water exiting a culvert.


Water draining to roadside system.



14 fish passage projects were completed in 2020

improving access to 54.2 miles of upstream habitat.

11,959 incidents responded to

by WSDOT’s incident Response teams during second quarter of 2021, 15% more than same quarter in 2020.

41 Pre-existing Funds Projects Advertised

during the eighth quarter of the 2019-2021 biennium.