Where is my septic system?
If your system is permitted, you can probably find an “as-built” drawing, showing its location, online. The permit itself will include the size and type of system and the maximum number of bedrooms it will support.
The first place to look for your as-built is online at:
King County’s Onsite Septic Records page.
The first picture shows how to navigate the page. The one below is an example of an individual septic record.
Not every property has an as-built on file, especially older homes. For homes built before 1965, there are probably no records on file. If your records don’t include an as-built, send a request via email to:
Include the parcel number and street address. Your parcel number is at the very top left of your septic records page (see image above). If you don't get a reply within 5 business days, check your spam folder for a message from PAEGAT25. If you still need help, call the Environmental Health Services Division at 206-477-8050.
Also, a company that has pumped your tank in the past will likely have a record of the tank location.
Can I find my septic by looking in my yard?
Yes! The location of your septic and drainfield may be be obvious. Take a walk around, looking for:
Patchy spots and sparse plant growth may mark where dirt barely covers the septic tank.
Round (often green) septic tank lids on risers –they can be exposed or cleverly hidden with pots or stepping stones and gravel. The tank lids may be buried; use rebar to bang on the ground until you find something hard. Most tanks are within 10-25 feet of the house.
Lots of extra-green grass where you mow more often might indicate a drainfield.
A company that has pumped your tank in the past will likely have a record of the tank location. You can also hire a septic professional to find your tanks.