King County septic O&M checklist
Quick facts
| Topic | What King County materials say (re-check live) |
|---|---|
| Inspection interval | Depends on system type under Board of Health Title 13. Common pattern: gravity residential ~ every 3 years; pressure / many non-gravity types annually (or more often if required). Proprietary systems: county materials describe a move to annual (from more frequent) in the Apr 2025 code update — confirm for your product. Marine Recovery Areas may require at least annual inspection. |
| Who may inspect | Title 13 Table 13.60-1 (as published on county notice-on-title materials) lists Owner, Licensed Maintainer, or Licensed OSS Pumper for some gravity cases, and Licensed Maintainer for pressure and more complex types. The homeowner manual still steers routine performance inspections to a certified on-site system maintainer. Do not assume DIY is allowed for your parcel — confirm with the OSS program and your system class. |
| Time of sale | Seller must have a monitoring/performance inspection by a licensed OSM before title transfer; report filed via OnlineRME / SkipThePaper with department review. |
| Report portal | Maintainers submit through OnlineRME (and SkipThePaper for sale packets). Owners: use county septic-record tools linked from the OSS hub. |
Homeowner checklist
- Start at kingcounty.gov OSS. Find certified maintainers and your records tools there.
- Identify system type (gravity vs pressure vs proprietary) and whether you are in a Marine Recovery Area — that changes frequency and who may inspect.
- Hire a licensed OSM from the county list for routine monitoring unless the OSS program confirms an owner path for your exact system class.
- Selling? Budget for a licensed OSM time-of-sale inspection and department filing — not a casual DIY report.
- Keep pumping separate: employ an approved pumper when solids/scum indicate need (Title 13 also sets solids-check frequencies).
This page does not reproduce the full Title 13 table. Open the live code / OSS pages for your system row.
Disclosures
Not affiliated with Public Health — Seattle & King County, WA DOH, or OnlineRME. County-gate self-inspect. See about & disclosures.