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Inspection of On-site Sewage System (OSS)

All sellers of properties with onsite sewage systems must have their system inspected by a certified On-Site System Maintainer (OSM) before the transfer of title. OSS Property Transfer Inspection Reports are valid for six months from the inspection date.

Maintainers use the King County reporting system to submit inspection reports to Public Health. Public Health staff will review the report within 10 business days. To view OSS Property Transfer Inspection Reports, access www.onlinerme.com. Search for the property of interest, then look in the "Application History."

Contact a Maintainer to schedule an inspection

Resources: Sample Operation/ Performance Monitoring Report form (official copy of this form is made available only to licensed OSM)


Notice of On-site System Maintenance Requirements (OSSM)

Before closing, the seller must record a Notice of On-site Sewage System Operation and Maintenance Requirements (OSSM) at the King County Recorder's Office. This is also known as the Northwest Multiple Listing Service form #22U. If the Notice is already recorded on title, this requirement has been met – the seller does not need to record the Notice again. The seller must give a copy of the recorded OSSM to the buyer prior to closing.

Resources:

At the time of property transfer, the buyer must submit the required Operation and Maintenance Program fee and a copy of the first page of the recorded On-site Sewage System Operation and Maintenance Requirements to Public Health. The buyer will receive information regarding good practices for maintaining septic systems.

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