Illicit discharges are the introduction of non-stormwater runoff, sewage, or hazardous materials into the public stormwater system. Studies have shown that pollutant discharge from stormwater systems in dry weather due to illicit discharges can exceed the total pollutant flow from storm event flows. Stormwater systems typically flow untreated to water bodies, thus the Department of Ecology places a significant emphasis on illicit discharge detection to protect water quality. Storm drains and dry wells are there to collect stormwater runoff only. The dumping of oil, grease, dirty wash water, or in most cases anything at all into a storm drain or dry well is illegal and may cause severe damage to the environment.

Illicit Discharges are: septic or sewer connections, liquid or solid wastes, operational wash water, hazardous waste.

With certain conditions, the following are not Illicit Discharges: water line or hydrant flush water, lawn water, swimming pool discharge, street/sidewalk wash water, dust control water, or permitted discharges covered under another permit.

Illicit Discharges are not: ground water, foundation drains, air conditioning condensate, irrigation water from agricultural sources, crawl space pump discharge, footing drains.

To report a suspected illicit discharge call: (509) 575-6077