The septic side of buying or selling a Seattle property, in the order it has to happen. In King County, Washington, which covers Seattle, we have measured 84,437 parcels on septic and 486,662 on sewer. That is a county measurement. We do not hold a septic count for Seattle on its own and this page does not estimate one.
The cheapest diligence happens before there is a contract. Two questions come first: is the property on septic at all, and does the county hold a record for it. A property with a filed as-built is a materially easier purchase, because tank size, field layout and permitted flow are visible before you commit.
| County | Records we hold | County records portal | Searchable without an account | Parcels on septic |
|---|---|---|---|---|
| King County | 184,607 | county portal | no account needed | 84,437 |
King County, Washington is one of the more heavily documented counties in our collection: we hold 184,607 septic records for it, so the odds that a specific Seattle address already has a filed document we can point you at are good. The county is predominantly sewered: only 84,437 of 571,099 classified parcels are on septic. Septic properties near Seattle are the exception, which is exactly why owners often do not know they have one. The county publishes a records portal that we were able to search without creating an account, which makes checking a specific parcel something you can do yourself in a few minutes.
| Document | What it settles |
|---|---|
| As-built drawing | Where the tank and field are, tank capacity, and the design flow the system was permitted for. Compare that flow against the bedroom count being advertised: a three-bedroom permit under a four-bedroom listing is a real problem, not a technicality. |
| Permit file | That the system was legal when built, and what the soil evaluation found. Also reveals permitted repairs. |
| Recent pumping receipts | Evidence of maintenance, and a rough interval. A tank nobody can show a receipt for is a tank nobody can show was pumped. |
| Inspection report | Condition now. Insist it is a full inspection with the tank opened and the field loaded, not a visual. |
Pull the county record first, then inspect. An inspector working from the as-built covers the whole system; one working blind covers what he can find. Where the tank also needs pumping, having it pumped as part of the inspection lets the inspector see the tank empty, which is when structural problems are visible. Book that as one visit rather than two.
Leave room in the contingency period: a competent inspector is not always available at three days’ notice, which is how buyers end up accepting a visual inspection they did not want.
The seller’s advantage is time. Pulling the record and fixing component faults before listing turns a mid-transaction discovery, negotiated at the buyer’s number, into a disclosed and resolved item.
Disclosure duties around septic condition and known defects are set by state law and vary substantially. This page does not restate them, and the state rules page linked below is the right place to start.
Raw land asks a different question: not the system’s condition but whether the ground will take one at all. Write the soil and site evaluation into the contract as a contingency. A lot that cannot pass one is not a discount, it is a different product.
These are real businesses we hold an address for, not a ranked or paid list. We take no fee and list nobody preferentially. Confirm current licensing with your county or state before hiring.
With an address in Seattle itself
| Business | Town on file | Phone | Rating |
|---|---|---|---|
| 5 Star Septic Sewer & Storm | Seattle | (206) 484-1905 | — |
| Brandon’s Plumbing Services | Seattle | (206) 240-2366 | — |
| Cascade Septic Service | Seattle | (206) 243-2809 | — |
| Clearline Sewer Repair | Seattle | (206) 759-7162 | 3.7 (3) |
| Drain Cleaning Septic Services | Seattle | (253) 838-2359 | — |
| Economy Septic Service Inc. | Seattle | (206) 248-2213 | 4.2 (5) |
| Full Bore | Seattle | (206) 259-0415 | 2.7 (7) |
| Green Latrine | Seattle | (206) 397-0336 | 5.0 (7) |
| Jafco Plumbing and Sewer | Seattle | (206) 552-3560 | 4.6 (286) |
| Long Septic Service | Seattle | (206) 774-4546 | 1.0 (1) |
| Metropolitan Sewer Service | Seattle | (206) 542-5466 | 4.0 (42) |
| Sonny Seattle Plumber | Seattle | (206) 410-7873 | — |
| Warden Construction | Seattle | (206) 778-8384 | 4.6 (11) |
| Wu Construction | Seattle | (206) 361-8886 | 4.3 (81) |
| Zone 8 Plumbing And Sewer | Seattle | (206) 580-3360 | — |
| United Site Services (Emerald Sanitary Service | Seattle | (801) 573-6554 | — |
The as-built drawing, the permit file, recent pumping receipts and a full inspection report. Check the permitted design flow against the bedroom count in the listing.
The records. An inspector who has the as-built knows where the tank and field are and can inspect the whole system rather than the parts he can locate.
Requirements and disclosure duties are set by state law and by the county, and they vary. This page does not restate them; check the state regulations page and the county.
From the Census ZCTA-to-place relationship file, with the share of Seattle’s land area that falls in each. A ZIP is not a place boundary and the two only ever partly agree, which is exactly why both pages exist.
Straight-line distance from the Census internal point of Seattle.
Parcel Perfect generates a code-shaped septic design and as-built style drawing for a parcel from the records and site data we hold, and shows every parcel we have classified as septic or sewer on one map. Both are open to use for any parcel in King County, Washington.