Selling a home with a septic system in Snohomish County? New property-transfer requirements took effect November 1, 2026. Sellers need a current septic inspection, appropriate system records, and a completed property-transfer process with the Snohomish County Health Department. Here is what to plan for before closing.
What Changed for Home Sellers?
The new requirements help buyers understand the condition of the septic system they are purchasing. For sellers, that means making septic service and records part of the sale preparation. Starting early gives you time to locate paperwork, schedule service, and work through questions with your septic professional and real estate team.
Start With a Current Septic Inspection
A certified septic professional must complete a full septic system inspection within the 12 months before the sale closes. A Wesco Septic is a certified septic service provider with Snohomish County. Our licensed professionals are held to the highest standards when performing septic inspections. Let your service provider know that the inspection is for a property sale so you can discuss the records needed for the transfer.
Does the Tank Have to Be Pumped?
Pumping is required if the certified septic contractor recommends it on the inspection report. Most systems typically need service every 1 to 2 years, depending on usage and the age of the system. The inspection determines whether pumping is needed, and recommended pumping must be completed before closing.
A septic inspection and a tank pump-out are different services. A pumping receipt alone does not replace the full inspection required for a property transfer.
Check for an As-Built Record
An as-built is a record drawing showing the septic system layout. If one is already on file with the Health Department, you do not need a new drawing simply because you are selling. If no as-built exists, a certified septic contractor qualified for your system type must prepare the County's On-Site Sewage System Site Plan. A Wesco Septic can prepare the required system Site Plan if one is needed for your property transfer. Include that Site Plan with the property-transfer application.
Plan Ahead for Closing
Keep the process manageable by working through these steps with your service provider and real estate team:
Gather your paperwork
Find your inspection report, service history, and system drawing. Keep everything together so it is easy to share and review.
Schedule service early
Explain your expected closing date when arranging an inspection. Leave room in the schedule for any recommended pumping or follow-up work.
Keep your real estate team informed
Share updates as records and reports become available. Discuss any findings promptly so everyone understands the next steps.
Recently installed system? The County lists an exemption for septic systems installed within the past 12 months. Confirm how that exemption applies to your property with the Health Department.