What the new rule actually requires
In April 2026, the Snohomish County Board of Health adopted a new point-of-sale septic inspection requirement. It takes effect November 1, 2026, and it exists to bring the county into compliance with a Washington State rule, WAC 246-272A-0270, that becomes mandatory for every county in the state by February 1, 2027. Snohomish is simply the first county to formalize it.
Board of Health Chair Megan Dunn described the intent behind the rule: it's meant to "protect our environment and public health, ensure septic systems are well maintained, and give homebuyers clear information about the condition" of the property. Ragina Gray, the county's Environmental Health Division Director, put the practical takeaway simply: "If you plan ahead, this requirement won't slow down a home sale."
The short version
If you're selling a property with a septic system in Snohomish County on or after November 1, 2026, a certified septic professional needs to inspect the system — and pump the tank if it's due — before the sale closes. The inspection is valid for 12 months, so if you're planning to list soon, you can get ahead of it now.
Who this applies to
- Sellers of any property served by a septic system, anywhere in Snohomish County — an estimated 2,785 septic-served properties change ownership in the county each year, out of roughly 84,000 private septic systems countywide.
- Systems installed within 12 months of the sale are exempt (they've already been inspected as part of installation).
- Inspections can be completed up to a year before closing — the report stays valid for 12 months "unless system conditions change."
Timing and cost at a glance
| Item | Detail |
|---|---|
| Effective date | November 1, 2026 |
| County application/report fee | $245 (2026–2027), rising to $255 (2027–2028) |
| Application review time | Up to 10 days |
| Report validity | 12 months from inspection date, unless conditions change |
| Exemption | Systems installed within 12 months of the sale |
The $245–255 figure is the county's application/report fee. Your certified inspector will also charge their own service fee for the actual site visit and pumping if needed — see the full cost guide for realistic all-in numbers.
What if the system doesn't pass?
Inspection reports generally rate a system as operational, marginal, or failing. What happens next — repair before closing, negotiate a credit, or disclose and move forward — depends on your specific situation and is genuinely the part most sellers and buyers get wrong. We cover it in detail on two dedicated pages: what a marginal or failing rating means, and who's actually responsible for the cost.
Plan around your closing date, not the deadline
An inspection can take up to 10 days to process, and a certified inspector's calendar can fill up fast once this rule is in full swing. If you're planning to list before or shortly after November 1, the smart move is scheduling your inspection now rather than waiting.
What to do next
- Check whether you're exempt. If your system was installed in the last 12 months, you likely don't need a new inspection — confirm with the county.
- Locate your system's as-built records. This saves your inspector time and helps you understand what type of system you have before they arrive. Here's how to find them.
- Get a certified inspector on the calendar well ahead of any planned listing date. Find one here.
- Understand your options if it doesn't pass before you're mid-negotiation with a buyer. Read what a marginal or failing rating means now, not after the inspection.
Sources: Snohomish County Health Department, HeraldNet, Lynnwood Times. This page summarizes public reporting on the rule and is not a substitute for the official county code — confirm current requirements directly with the Snohomish County Health Department before making decisions about a specific sale.