Snohomish

The City of Snohomish's treatment plant serves homes inside the incorporated city boundaries — but the unincorporated Snohomish area around it is on septic, and so are many existing homes north of Blackmans Lake and east of State Route 9, in the former NE Sewer Area. If your home is outside the city limits, or in that north-of-the-lake area and not yet connected to the city's extended sewer system, septic is the service you need.

We serve the unsewered parts of the Snohomish area: the unincorporated Snohomish mailing area outside the city and its Urban Growth Area — the SR-9 corridor, Machias, Cathcart, Three Lakes, and the Snohomish River valley — and existing homes north of Blackmans Lake and east of SR-9 that are not yet connected to the city's sewer system. The city's North Sewer Trunkline, completed in 2025, removed the capacity limit that kept that north-of-the-lake area on septic, and the City Council repealed the NE Sewer Area restrictions in October 2025 — but the trunkline ends at Lakemount Drive, and homes there are only sewered once a line is extended to them, so many existing homes in the area are still on septic. We do not target historic downtown Snohomish or the sewered northern city neighbourhoods. Connection status for a specific home should be checked per parcel with the city.