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Snohomish County Time-of-Sale Septic Inspection

Snohomish County Time-of-Sale Septic Inspection

Selling a Home With Septic in Snohomish County? There’s a New Inspection Rule (Here’s What It Means for You)

If you’re buying or selling a house with a septic system in Snohomish County, there’s a new item on the closing checklist. Starting November 1, 2026, every septic system has to be inspected before the property changes hands.

No, it’s not a reason to panic. And no, it doesn’t have to slow your sale down. But it does mean the old “we’ll deal with the septic later” approach is officially retired.

We’re Above Grade Septic, a family-owned crew that’s been doing septic inspections across Snohomish and King County since 2010. Time-of-sale inspections are a big part of what we do, so here’s the plain-English rundown of the new rule: what it requires, what it costs, and how to keep it from becoming a last-minute headache.

What’s Changing: The Short Version

In April 2026, the Snohomish County Board of Health adopted a new rule requiring a septic inspection on every property with a septic system before it sells. It takes effect November 1, 2026.

This isn’t the county going rogue. Washington’s state septic code (WAC 246-272A-0270) now requires counties to have time-of-sale inspections in place by February 1, 2027. Snohomish County is simply getting there a few months early.

The key points:

  • Every septic system gets inspected before closing. Gravity, pressure, mound, ATU — if it’s septic, it’s included.
  • The inspection has to be done by a certified septic professional. Not a general home inspector, not a handy neighbor.
  • The tank gets pumped if the inspection calls for it.
  • You can inspect up to one year before closing. The report is good for 12 months, so you can get ahead of it before you even list.
  • There’s a county fee: $245 for 2026–2027 and $255 for 2027–2028. That’s the county’s review fee, and it’s charged on top of the cost of the inspection itself, so budget for both.
  • The county takes up to 10 days to review. Build that into your timeline.
  • Brand-new systems get a pass. A system installed within 12 months of the sale is exempt.

Why now? The county has roughly 84,000 private septic systems, and about 2,800 homes with septic change hands every year. A failing system pollutes groundwater, streams and Puget Sound, and it’s a nasty surprise for a new owner who inherits it. As the county’s Environmental Health Director put it, planning ahead means this requirement won’t slow down a home sale.

What the Inspection Actually Looks At

A time-of-sale inspection is a full check-up of the whole system, not a quick peek under the lid. Here’s what we look at on a typical visit:

  • The records. We pull the county as-built so we know what’s supposed to be in the ground: tank size, system type, drainfield layout.
  • The tank. Liquid levels, sludge and scum buildup, baffles, lids and risers, and any signs of cracks or leaks.
  • Pumps, floats and alarms on pressure, mound and ATU systems: does everything turn on, shut off, and alarm when it should?
  • The drainfield. Surfacing effluent, soggy ground, suspiciously green grass, and anything that says the soil isn’t absorbing like it should.

If the tank needs pumping as part of the inspection, we’ll coordinate that with one of our trusted pumping partners so the process stays on schedule.

What If the Inspection Finds a Problem?

This is the question every seller asks, so here’s the honest answer: a problem in the report doesn’t automatically kill a deal.

Under the new rule, the seller can repair the issue and get an updated report. If the seller doesn’t fix it, the unresolved issue transfers to the buyer to handle after closing. Either way, everyone at the table knows exactly what they’re dealing with — which is kind of the whole point.

That’s also why inspecting early pays off. A seller who finds a failing pump three months before listing has time to get quotes and fix it on their terms. A seller who finds it three days before closing is negotiating with their back against the wall.

Tips for Sellers, Buyers and Agents

Sellers: Schedule the inspection before you list. The report is good for a year, so there’s no downside to getting it done early, and you’ll walk into negotiations knowing exactly where you stand. Bonus: “septic inspected and clean” looks great on a listing.

Buyers: Read the report, not just the summary line. Ask how old the system is, when it was last pumped, and whether any issues were flagged and left for you to handle. If something was passed along unrepaired, factor it into your offer.

Agents: Add the septic inspection to your listing checklist right alongside photos and disclosures. Between scheduling, a possible pumping, and the county’s review window of up to 10 days, waiting until you’re under contract is the fastest way to a delayed closing.

How We Make This Easy

Time-of-sale inspections aren’t new to us. We’ve been doing them since 2010, long before the county made them mandatory. We know the paperwork, we know the timelines, and we know how to keep a closing on track.

When you book with Above Grade Septic, we look up your county records, inspect the full system, coordinate pumping with our partners if it’s needed, and give you a clear, plain-English report. No scare tactics, no upsells, just an honest picture of what’s in the ground (we’re basically underground detectives at this point).

Buying or selling a home with septic in Snohomish County? Call us at (425) 954-7233 or email solutions@abovegradeseptic.com to schedule your time-of-sale inspection. The earlier you call, the smoother your closing.

Above Grade Septic proudly serves Snohomish and King County, WA, with routine and time-of-sale inspections, septic repairs and maintenance, drainfield repair, system installations, and emergency service.

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