Stormwater is rain and snowmelt that runs off paved streets, highways, and parking lots. As it runs off, it picks up pollution like oil, fertilizers, pesticides, soil, trash, etc. Most stormwater in Washington is not treated, even when it goes into a street drain and is the leading thread to our state’s urban waters, streambeds, banks, and habitats. What are we doing about this? Plenty! Read about the Dept. of Ecology’s efforts here: https://ecology.wa.gov/Water-Shorelines/Water-quality/Runoff-pollution/Stormwater