Bothell guide
Snohomish County Now Requires a Septic Inspection Before You Sell. It Starts 1 November 2026.
If your property sits in unincorporated Snohomish County around 98012 and 98021, including Bothell East, Bothell West, Maltby and Clearview, this changes how you sell.
From 1 November 2026, every septic system in Snohomish County must be inspected by a certified professional before a property is sold, with the tank pumped if needed. The inspection can be done up to one year before closing, the report is valid 12 months, application review takes up to 10 days, and the fee is 245 dollars for 2026 to 2027. Systems installed within 12 months of sale are exempt. This implements WAC 246-272A-0270, which becomes mandatory statewide on 1 February 2027.
The rule
What changes, exactly
Snohomish County is implementing a Report of Property Transfer requirement for on site septic systems. Here is the whole thing in one table.
| Item | Detail |
|---|---|
| Effective date | 1 November 2026 |
| What is required | Inspection by a certified septic professional before the property is sold, with the tank pumped if necessary |
| How early you can do it | Up to one year before closing |
| Report validity | 12 months |
| Review time | Up to 10 days for application review |
| Exemption | Systems installed within 12 months of the sale |
| Fee, 2026 to 2027 | 245 dollars |
| Fee, 2027 to 2028 | 255 dollars |
| Underlying rule | WAC 246-272A-0270, mandatory statewide from 1 February 2027 |
Who this actually hits
Bothell East, Bothell West and the unincorporated fringe
A point of confusion worth clearing up immediately: this is a Snohomish County rule, and Bothell straddles two counties.
Roughly 60 percent of Bothell residents are in King County and about 40 percent in Snohomish, with the line running approximately along NE 205th Street on the King side, which becomes 240th Street SW on the Snohomish side.
The properties most likely to be affected are the ones outside city limits, where septic is common because there is no sewer connection. Two census designated places carry the Bothell name but sit in unincorporated Snohomish County:
- Bothell West, population 22,015 as of the 2020 census, 4.22 square miles.
- Bothell East, population 13,970 as of 2020, 2.05 square miles.
Both were carved out of the former North Creek census designated place, dissolved in 2010, with the remainder going to Maltby, Clearview, Martha Lake and Mill Creek East. Those are exactly the areas with meaningful septic density, along with the Maltby and Clearview corridor out along Maltby Road and SR 522.
Why the timing matters
The trap is the queue, not the fee
Two hundred and forty five dollars is not what makes this significant. The sequencing is.
What goes wrong
- You list in spring 2027 and book the inspection when the offer comes in.
- Application review takes up to 10 days on its own.
- The inspection finds a fault, which is common on a system nobody has looked at in fifteen years.
- Repair contractors are booked out, because the whole county hit this deadline simultaneously.
- Your closing date arrives with an unresolved report and the buyer walks or renegotiates.
What works
- Inspect in autumn 2026, up to a full year before you expect to close.
- The report is valid 12 months, so an early inspection still covers a spring or summer 2027 sale.
- Any fault surfaces while you have months rather than days to deal with it.
- You negotiate from a clean report instead of an open question.
- You are ahead of the countywide queue rather than inside it.
Getting ready
What to do before the inspector arrives
- Find your records. The as built drawing, the original permit, any repair history and the last pumping receipt. If you have never had any of it, the county health department holds records for permitted systems.
- Locate the tank lids and the drainfield. If they are under a deck, a shed or a decade of landscaping, that becomes your cost and your delay, not the inspector problem.
- Get it pumped if it is due. The rule says the tank is pumped if needed, so a system that plainly needs it will need it before the report can close out.
- Stop parking or driving on the drainfield. Compaction damages it, and it is one of the more common findings.
- Look at what goes down the drains. Wipes labeled flushable do not break down, and grease is as bad for a septic tank as it is for a sewer main. The City of Bothell runs a fats, oils and grease program for exactly this reason on the sewer side.
- Check your water use. A silent running toilet or a leaking supply line hydraulically overloads a drainfield. Run the food coloring test on every toilet and the meter test on the supply, both free, both explained on our leak detection page.
Where we fit
What a plumber can and cannot do for you here
We want to be precise about this rather than sell you something.
What we handle
- The building sewer from the house to the tank, which is ordinary side sewer work.
- Camera inspection of that run, with the footage handed to you.
- Clearing roots and blockages between house and tank.
- Fixing the water side problems that overload a drainfield, such as running toilets and supply leaks.
- Repairs identified in a report that fall on the plumbing side of the tank.
What needs a certified septic professional
- The Report of Property Transfer inspection itself.
- Tank pumping.
- Drainfield assessment and repair.
- System design and replacement.
- Anything that has to be signed off to the county on the transfer report.
The rule requires a certified septic professional specifically. A plumbing contractor license is not that credential, and any plumber telling you they can sign your transfer inspection is either certified separately or overstating. Ask which certification they hold, the same way you would verify any contractor at secure.lni.wa.gov/verify.
Straight answers
Snohomish County septic inspection questions
When does the Snohomish County septic inspection requirement start?
1 November 2026. From that date every septic system must be inspected by a certified professional before a property is sold, with the tank pumped if needed. It implements WAC 246-272A-0270, which becomes mandatory statewide on 1 February 2027.
How much does the Snohomish County septic transfer inspection cost?
The fee is 245 dollars for 2026 to 2027, rising to 255 dollars for 2027 to 2028. That is the county fee. Pumping, any repairs and the inspector own charges are separate. Verify the current figure with the county health department before budgeting a transaction on it.
How long is a septic inspection report valid for?
Twelve months. The inspection may be carried out up to one year before closing, so an autumn 2026 inspection still covers a sale that closes in summer 2027. Application review takes up to 10 days on top of that.
Does this apply to my Bothell address?
Only if you are in unincorporated Snohomish County on a septic system. Bothell straddles two counties, so a Bothell mailing address does not settle it. Bothell East and Bothell West are census designated places outside city limits in Snohomish County, along with Maltby, Clearview, Martha Lake and Silver Firs. If you are inside city limits and connected to sewer, it does not apply.
Is there any exemption from the rule?
Yes, systems installed within 12 months of the sale are exempt. Otherwise the requirement applies to the transfer of any property served by an on site septic system in the county.
Why should I inspect early rather than when I get an offer?
Because the queue is the real risk. Snohomish County has roughly 84,000 septic systems and about 2,785 septic properties change hands each year, and every one of them hits this requirement from the same start date. Review alone takes up to 10 days, and if the inspection finds a fault you need repair capacity in a market where everyone is looking for it at once.
Can a plumber do my septic transfer inspection?
Not unless they separately hold the certified septic professional credential the rule requires. A plumbing contractor license is a different thing. A plumber handles the building sewer from the house to the tank, camera inspection of that run, and the water side problems that overload a drainfield. The tank, the drainfield and the signed transfer report need a certified septic professional.
What most commonly causes a septic system to fail an inspection?
Hydraulic overload from leaking fixtures, drainfield compaction from parking or driving on it, tanks that have not been pumped, and solids carryover from grease and non degradable items. Several of those are cheap to correct if you find them a year out rather than ten days before closing.
Related
Other things we fix in Bothell
Sewer Repair & Side Sewer Replacement
Camera first, permit pulled, and the footage handed to you before anyone quotes a replacement.
Drain Cleaning & Clogged Drains
Cleared through a cleanout, then cameraed so you see the line is actually clear.
24 Hour Emergency Plumber
Burst pipes, sewer backups and no-water calls, answered around the clock across 98011, 98012 and 98021.
Leak Detection & Pipe Repair
Pinhole leaks, crawlspace leaks, and the free meter test you can run yourself first.
Sump Pumps & Crawlspace Water
Is it groundwater or a broken supply line? We answer that before anyone sells you a drainage system.
Water Pressure, PRV & Expansion Tanks
The Alderwood pressure reduction project, and why your relief valve drips.
Service area
- 98011
- 98012
- 98021
- Kenmore
- Woodinville
- Mill Creek
- Brier
- Lynnwood
- Bothell East
- Bothell West
Selling in the next two years?
Start this in autumn 2026 rather than ten days before closing.