Do I need a septic inspection to sell a house in Thurston County?

In most cases, yes. Thurston County’s Time of Transfer fact sheet says the county must issue a Time of Transfer Evaluation Report before a septic-served property sells or transfers, based on a component inspection and tank pumping by county-certified professionals. Exceptions exist for new permitted systems under 12 months old, foreclosures, court transfers, gifts, and inheritance.

How long is a Thurston County Time of Transfer report valid?

One year, per the county’s Time of Transfer fact sheet. The component inspection and the tank pumping behind it must each be completed within the 12 months before the application. If a sale drags past the report’s expiration the process starts over, so sellers usually time the inspection to the listing rather than to closing day.

What is Kitsap County’s property conveyance inspection?

Kitsap Public Health’s selling-property guidance directs owners to obtain a property conveyance inspection before the final sale of a home served by a septic system, under Board Ordinance 2025A-01, effective March 17, 2025. The district recommends starting at least 30 days before closing and needs a record drawing of the system on file.

Does Mason County require a septic inspection at the time of sale?

Not as a county mandate today. Mason County runs an operation and maintenance program instead: county-certified professionals file inspection and pumping reports, and those records get reviewed when a home sells. A statewide property transfer inspection requirement under chapter 246-272A WAC takes effect February 1, 2027, per the Washington State Department of Health.

Transfer inspections in Thurston, Kitsap, and Mason counties

The septic inspection that comes with selling a home

Q: Can a house still sell if the septic system fails the inspection?

Usually, yes. Thurston County’s Time of Transfer fact sheet states the county does not prohibit property sales. A failing system triggers compliance follow-up and can bring a Notice of Violation, so the problem has to be addressed. In practice, buyer and seller negotiate who pays for the repair and when the work happens.

Put a Thurston County home on the market with a septic system behind it and the sale carries a step that sewered houses skip. Before the property transfers, Thurston County Environmental Health must issue a Time of Transfer Evaluation Report on the system, a requirement in effect since September 1, 2010 per the county's Time of Transfer fact sheet (PDF). Kitsap County adopted its own conveyance-inspection rule in 2025, Mason County's maintenance records surface at sale time, and a statewide inspection-at-transfer requirement arrives in 2027. This page walks through each county's rule, the paperwork, the cost picture, and the order to do things in so the inspection is handled early instead of mid-escrow.

Verify the required transfer inspection

The rule depends on the county the property sits in. Each one is published by the agency that enforces it:

Thurston County: Time of Transfer program, in effect since September 1, 2010. See the county fact sheet (PDF) and the septic systems program page.
Kitsap County: Kitsap Public Health Board Ordinance 2025A-01, effective March 17, 2025. The district's selling-property guidance directs sellers to obtain a property conveyance inspection before final sale.
Mason County: operation and maintenance reporting under Mason County Code Chapter 6.76, administered by Mason County Environmental Health.
Statewide: the revised chapter 246-272A WAC adds a property transfer inspection requirement effective February 1, 2027, per the Washington State Department of Health.

How Thurston County's Time of Transfer works

Thurston County's program is the oldest of the three, so it sets the pattern. Per the county fact sheet, all components of the system must be inspected by a Thurston County certified pumper, monitoring specialist, or installer, and all tanks must be pumped by a certified pumper, each within the 12 months before the application. The county reviews the results and issues the Time of Transfer Evaluation Report, which is valid for one year.

Applications go through the Building Development Center at 3000 Pacific Ave SE, Suite 225 in Olympia, the same address as the Environmental Health Division that runs the program, and a county fee applies (amounts are on the county's pages). The current application packet (PDF) bundles the form with the fact sheet.

The fact sheet lists the exceptions: a brand-new permitted system under 12 months old, a foreclosure, sheriff's sale, court transfer, gift, or inheritance, a single mobile home in a mobile home park, a STEP system connected to city sewer, and large systems over 3,500 gallons per day, which the state Department of Health regulates directly. Everything else, which covers the typical rural or exurban home sale around Olympia and Lacey, goes through the program.

Two Thurston-specific wrinkles are worth knowing before you list. First, if the property sits in the Henderson Inlet or Nisqually Reach watershed protection area, the septic system carries a renewable operational certificate, and the fact sheet says a seller must show that certificate is current before submitting the Time of Transfer application. The county's November 2025 on-site sewage management plan update (PDF) counts 16,203 systems countywide on renewable operational certificates, concentrated in the Henderson Inlet and Nisqually Reach watershed protection areas plus complex systems countywide. Second, a failing result does not block the sale: the county states it does not prohibit property sales, but a failing system triggers compliance follow-up and can bring a Notice of Violation, which usually means a repair gets negotiated into the deal.

None of this is exotic in Thurston County. The same plan update estimates the division oversees roughly 55,400 on-site sewage systems, so the Time of Transfer process is routine business for the county and for the professionals who perform the inspections.

Kitsap County: the property conveyance inspection

Kitsap County's rule is the most recent of the three. Kitsap Public Health Board Ordinance 2025A-01 took effect March 17, 2025, and the district's selling-property guidance directs owners to obtain a property conveyance inspection, arranged through Kitsap Public Health, before the final sale of a property served by a septic system, citing Section 13.D of the ordinance. The district recommends starting at least 30 days before closing and needs a record drawing of the system, so the paperwork lead time matters as much as the inspection itself.

The district operates from 345 6th Street, Suite 300 in Bremerton and covers the whole county, so the same process applies whether the sale is in Bremerton, Silverdale, or Port Orchard. When it comes time to choose who works on the system, the district publishes a certified on-site sewage system contractor list.

Mason County: maintenance records instead of a sale mandate, for now

Mason County does not impose its own time-of-sale inspection requirement today. What it runs instead, under Mason County Code Chapter 6.76, is an operation and maintenance program: county pages require septic professionals to be certified through the county and to file every inspection and pumping report within 30 days through the OnlineRME system, and many alternative systems, such as aerobic treatment units and Glendon-style units, carry annual maintenance requirements. Those filed records are what a buyer's agent, a lender, or the county pulls when a home around Shelton changes hands, so a thin maintenance file shows up at the worst possible time.

The statewide backstop arriving in 2027

The county rules are about to stop being local quirks. The State Board of Health adopted a revision of chapter 246-272A WAC on January 10, 2024, per the Department of Health's rule revision page, which lists a property transfer inspection requirement effective February 1, 2027, performed by an inspector authorized by the local health officer; the rule text is at leg.wa.gov. Thurston County's November 2025 management plan update puts it plainly: the state now requires an inspection at property transfer, and the county's existing Time of Transfer program already requires this. The West Sound counties are simply early. The full county-by-county walkthrough lives in our Washington time-of-sale septic guide.

What the inspection and the pumping cost

No agency sets a fixed price for the inspection itself; companies price by system type and scope. Published local figures give a usable anchor. Contractor-published pricing from Clean Septic Pumping, which serves Thurston County, lists a routine inspection at $175 for a gravity system or $225 for a pressure system, plus $85 if pumping is not performed with it. Contractor-published pricing from Premier Septic Services in Yelm lists an inspection at $95 when performed with pumping.

Because Thurston's program also requires the tank pumped by a certified pumper, budget for pumping too: the same two published price lists show Thurston County pumping at $535 plus a $25 county pump report fee (Clean Septic Pumping) to $600 plus $25 (Premier, for tanks to 1,200 gallons; larger or overfull tanks add $0.50 per gallon, and digging to a buried lid runs $60 per foot of depth per lid). The county application fee is separate; amounts are on the county's own pages. And if the inspection finds a failure, contractor-published Washington ranges from Sterling Septic and Plumbing put extensive repairs at $1,000 to $5,000 and beyond, with a full replacement able to pass $15,000, which is why the smart money gets the system looked at before the listing goes live.

When to schedule it

Work backward from the county clocks. In Thurston County the report is valid one year and the inspection and pumping behind it must each fall within the 12 months before the application, so ordering the work when you decide to sell, rather than when you accept an offer, costs nothing and removes the deadline pressure. In Kitsap County the district recommends starting the application at least 30 days before closing, a window that is easy to miss in a fast sale. Buyers have the mirror-image interest: the report tells you what you are actually purchasing. Either way, the professional you are matched with handles the on-site work and the paperwork trail it feeds.