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Search on-site sewage/septic system records

An online search tool to look up records for on-site sewage/septic systems. Records include site designs, historic inspection reports, and as-built record drawings.

OSS rule revision process

Recently, the Washington State Board of health approved changes to statewide OSS rules. Now, King County is updating our local codes to make sure they comply with the state’s changes.

Stay informed by signing up for our code revision newsletter. You can also read our June edition.

Search for your septic records using this tool:

What records are available?

Records are available for both new construction and repairs to failing systems. Approved on-site sewage/septic system site design applications submitted online since May 2019 are also available.

Why can't I find my record?

Online records are not available if:

  • The home was built before the early 1970s.
  • The on-site sewage/septic system was installed without a permit.
  • The on-site sewage/septic system designer did not submit final construction documents to Public Health.
  • The property address or parcel number has changed. Some addresses have changed, especially within areas incorporated into cities recently. Some parcels have been re-platted since the original documents were submitted. In these cases, it is helpful to search with the original house address. 
  • Record drawings may be in our microfiche files but not yet scanned into the electronic database. You may wish to contact the septic system designer or engineer for a copy.
  • Many pre-1998 records are available but may not be as accurate, legible, or as detailed as recent record drawings. 

More resources

OnlineRME - Find operation and maintenance records by address or parcel number. Make sure to choose "King County" before searching. Updated record drawings/site sketches may be found attached to the Time of Sale Inspection Reports under Application History.

Search King County recordsSearch our free online database of King County's official records.

King County Parcel Viewer - A search utility to find King County parcel information. You can search by address, parcel number, or by zooming in on the map and selecting a parcel.

King County iMap - View King County spatial information (GIS data and images) in an interactive map display.