Home Sale Septic System Inspection Services

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Home Sale Septic System Inspection Services

Lilly’s Septic Inspection Services can provide Pumping & Inspection in one convenient appointment!  Most pumping companies do not do the King County Home Sale Inspections therefore 2 or 3 different companies and appointments are needed to complete the inspection process… With Lilly’s everything is done all at once as we are Certified O&M Professionals & Certified Pumping Professionals as well as we hold the King County Master Installers License for repairs needed.

Every property that is serviced by an OnSite Septic System or OSS in King County & Pierce County must be Pumped and Inspected when the property is transferred. The following information and links will help you prepare to sell a home in either King or Pierce County, Washington.

Sales and transfers of properties with septic systems in King County

Public Health- Seattle & King County requires all sellers of properties with onsite sewage systems (Septic Tank System) to have their on-site Septic Tank System inspected by a King County licensed On-Site System Maintainer (OSM). The inspection must be completed and a copy of the report must be given to both the buyer and Public Health before the transfer of title. The OSM must submit the property transfer report to King County environmental health through the Online RME. King Counties new reporting & public record system

King County OSS Septic System Inspection filing fee $198.00 This fee will be included on the service invoice and is collected by your O&M Professional from the homeowner (or whoever is paying) and paid directly to King County – This is not a fee charged by Lilly’s Septic, this is a KC fee…… but we must have the funds prior to submitting  the O & M Sale Inspection Certification paperwork.

Find out more about Sales in King County: King County Real Estate Sale Inspection page

Before closing, the seller must record a Notice of On-site Sewage System Operation and Maintenance Requirements (OSSM)* at the King County Recorders Office. This is a document that acknowledges the property is served by a septic system and describes the owner’s responsibilities for maintaining the system. The seller gives a copy of the recorded OSM to the buyer prior to closing. A declaration of receipt of the recorded OSM should be signed by the seller and buyer for their records (King County does not need a copy of this declaration of receipt).

*OSM – is also known as Form 22U by the Northwest Multiple Listing Service

AS-BUILT DRAWING – An As-Built drawing is a diagram of the septic system and shows where the septic tank, Pump Tank (if there is one), the D-Box and drainfield lines are located as well as any other buildings such as sheds, garages, pools, etc on the property. King County requires that an As-Built is submitted with the OSS Inspection paperwork – If KC does not have an as-built on file that can be submitted, then Lilly’s Master Installer | Professional OSM must draw a Certified scale as-built drawing to be turned into KC with the paperwork. Fee applies and will be quoted (if necessary) at time of booking.

To check if there is an As-Built on file at the KC Health Dept. The As-Built lookup site is: http://www.kingcounty.gov/healthservices/health/ehs/wastewater/owners/AsBuiltDrawings.aspx If nothing is on file then request a copy of your as-built by calling the health department directly at 206-477-8050. OR Lilly’s septic (OSSM) Inspection coordinator will obtain the As-Built via email from KC Health Dept for no charge after booking your Inspection appointment. If there is no as-built available, the county will require us to draw a certified As-Built to submit with the inspection paperwork.

Downloadable Adobe format King County Forms:

Lilly’s Septic Tank Services provides:

Our Certifications & Licensing listed below for your reference:

  • MI 172 – McCullough, Darren
  • KC 106 – McCullough, Darren / Lilly’s Septic Tank Service
  • OSM 64 – McCullough, Darren


Lilly’s Septic System Service can provide your Septic Tank Pumping & Inspection service all in one convenient appointment to sell your home in King County.

(425) 432-3084 * (253) 639-3606 * (360) 825-4809


Serving King & Pierce County including: Maple Valley, Ravensdale, Hobart, Enumclaw, Black Diamond, Covington, Issaquah, Sammamish, Kent, Auburn, Renton, Federal Way, SeaTac, Edgewood, Tukwilla, Seattle, Snoqualmie, North Bend, Fall City, Preston, Carnation, Woodinville, Redmond, Duvall, Kirkland, Bellevue, Clyde Hill, Medina, Mercer Island – Greenwater, Buckley, Bonney Lake, Lake Tapps, Puyallup, Tacoma