What the county requires before sale
In King County, Public Health – Seattle & King County administers the on-site sewage system program under the county Board of Health Code. Before a property with a septic system is sold, the system must be inspected by a maintainer certified by King County, and the maintainer files the inspection report with the health department through its online reporting system. The report documents the type and condition of the system, whether it was pumped, and whether any components failed. A copy goes to the buyer.
In Snohomish County, the Snohomish County Health Department, which took over the former Snohomish Health District, runs a time-of-transfer program with its own inspection form and filing requirement. If your home is in Bothell, Woodinville, or elsewhere north of the county line, your agent confirms which jurisdiction applies from the parcel number.
These are county requirements, separate from your contract. Form 22S puts them into the agreement by stating who orders the inspection, who pays, and by when, but the county's rule applies whether or not the form is attached.
Form 22S: what your contract says
The Septic Addendum has checkboxes and blanks that assign the work. The common arrangement is that the seller has the system inspected and pumped, if pumping is recommended, at the seller's expense, and delivers the report and the county's records to the buyer within a number of days written on the form. The addendum also gives the buyer a period to review the report and, depending on how it is filled in, to request repairs or terminate if the system fails.
Read your 22S with your agent for four dates: when the inspection must be done, when the report must be delivered, how long the buyer has to respond, and whether repairs, if any, must be completed before closing. Jennifer, RexMont's transaction administrator, calendars each one.
If you had the system inspected and pumped before listing, the report may still be current. King County's rule sets how recent the inspection must be relative to the transfer; the maintainer who did the work can confirm whether a new visit is needed or the earlier report can be filed for this sale.
Pumping, the inspection visit, and what the maintainer looks at
Schedule the inspection with a maintainer on the county's certified list. The visit takes an hour or two. The maintainer locates and opens the tank, measures sludge and scum, checks baffles and the outlet filter, inspects the pump and alarm if the system has them, and probes or observes the drainfield for surfacing effluent or saturation. If the tank is due, it is pumped on the same visit, and the maintainer notes it on the report.
The maintainer needs access to the tank lids and the drainfield. If your lids are buried, ask the company about locating and exposing them before the appointment; risers installed now save the next owner the same trouble and are a small cost. Do not run heavy water loads the morning of the inspection, and keep vehicles off the drainfield.
If your system is a pressure distribution, mound, sand filter, or aerobic treatment unit, the county requires more frequent maintenance than a gravity system, and the inspection is more detailed. Have the name of the company that has been servicing it ready.
If the system fails
A failed inspection means the maintainer found a condition the county code does not accept: a saturated or surfacing drainfield, a cracked or collapsing tank, a failed pump without a working alarm, or an illegal connection. The maintainer reports it to the health department, and the county expects the failure to be corrected. Selling the property does not make the requirement go away; it decides who is responsible for the fix.
What happens next is governed by your Form 22S. Depending on how it was completed, the buyer may request repairs, the parties may negotiate a credit with the county's permit requirements in mind, or the buyer may terminate. Repairs that involve replacing a drainfield require a design by a licensed designer, a county permit, and an installer; that process runs weeks, not days, so the conversation about closing timing starts immediately.
Your agent handles the exchange with the buyer's side. Your part is to authorize the maintainer to speak with the designer or installer and to decide, with your agent, between fixing before closing and a negotiated alternative if the form allows one.
Pulling your as-built and maintenance records
Two records travel with a septic system. The as-built is the drawing filed when the system was installed or last repaired, showing tank and drainfield locations, sizes, and setbacks. The operation and maintenance record is the history of inspections and pumping filed by maintainers over the years. Buyers, maintainers, and any future designer all rely on them.
In King County, both are available through Public Health's on-site sewage system records search, which lets you look up a parcel and download the as-built and past maintenance reports. If your system predates the county's electronic records or the as-built is missing, the maintainer can prepare a record drawing during the inspection, and the county has a process for filing it.
In Snohomish County, the Health Department provides as-built and permit records by parcel through its online records or on request. Gather these now, put them in your transaction file, and leave copies for the buyer along with the name and phone number of your maintainer. Form 17 asks about the system; having the records makes your disclosure accurate and complete.
Your checklist
- 1Confirm with your agent which county program applies and what your Form 22S assigns to you, with each date.
- 2Book a King County-certified or Snohomish County-approved maintainer for the inspection and pumping right away.
- 3Locate the tank lids and drainfield; expose buried lids or authorize the maintainer to do so.
- 4Download the as-built and operation and maintenance record from the county's parcel search and add them to your file.
- 5Deliver the filed inspection report and the records to the buyer by the Form 22S deadline, through your agent.
- 6If the report notes a failure, meet with your agent the same day to review your options under the addendum.
- 7Leave the maintainer's contact information and the records for the buyer at possession.
What RexMont tracks for you
- Which county program applies to your parcel and the maintainer's appointment date.
- Each Form 22S deadline: inspection, report delivery, buyer response, and any repair completion date.
- Confirmation that the maintainer filed the report with the health department, with a copy in your file.
- The as-built and maintenance history pulled from county records and delivered to the buyer.
- Any failure finding and the design, permit, and repair timeline it triggers against the closing date.
Jennifer Johansen, RexMont’s transaction administrator, coordinates every date and document from mutual acceptance to keys. Questions on price, terms, or strategy go to your RexMont agent.
Sources
This guide explains the process and the standard NWMLS forms in general terms. It is not legal, tax, or lending advice, and your contract controls. Talk to your RexMont agent, escrow officer, lender, or attorney about your specific situation.
