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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.

Statewide OSS rule revision process

The Washington State Board of Health is revising the statewide OSS rules. You can learn more about this process, including how to comment, on the state Department of Health’s website: On-site Sewage System Rule Revision.

Search for your septic records using this new 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.

Record search tool

You can search for on-site sewage/septic system records using a parcel number or address.

Use the parcel number

  1. Enter the parcel number (use only numbers – 2925001011 not 292500-1011) in the "Parcel Number/APN" box below.
  2. Click on the “Search” button.

A list of available records will display. A search resulting in "0 rows" means no electronic septic system records are available for this parcel number.

If you don't know your parcel number, use King County's Parcel Viewer to find it. Enter your address in the search bar, click on the “Search” button, and your parcel number will be shown to the left of the map.

Use the address

  1. Enter the house number and street name or number. Do not use your full address.
  2. Click on the “Search” button

A list of available records with that house number will be displayed. It may take a few seconds for results to appear after clicking the search button.

Do not search for the parcel number and house number at the same time.

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.