O&M Inspections are important to maintain the health of your system. Routine inspections can catch potential issues before they become problems and cost you more money in the long run.

Maintainer Duties:

There are different inspections that occur depending on the type of system. Some examples of the things that we monitor for are below.

The first inspection must occur between 45 days to 6 months (depending on the type of system) after occupancy and annually thereafter. The homeowner is to notify Columbia Land Services to the date of occupancy. The primary purpose of the monitoring visit is to evaluate the performance of the onsite system. Important basic maintenance of the system is also performed at the time of monitoring such as:

Obtain preventative maintenance and comply with county and state regulations through a monitoring and maintenance agreement. With this agreement, we will inspect your system yearly and provide a detailed report.

Monitoring and Maintenance FAQ

What does Operation And Maintenance Consist of?

A traditional onsite sewage system or “standard gravity” onsite sewage system may only need limited amounts of maintenance. The maintenance of a standard gravity onsite sewage system may be limited to pumping of the septic tank as needed.


In comparison to the standard gravity onsite sewage system the modern day next generation or “alternative” on-site sewage systems may require:

-Septic tank inspections, pumping if necessary of the septic tank.

-Inspection of the pump tank (if present) which may include checking floats, cleaning screens and pumping if necessary.

-Inspection of an aerobic treatment unit (if present).

-Cleaning the filter within the aerobic treatment unit (if present); cleaning and inspecting the aeration device.

-Inspection of the lateral drain field lines for levels of effluent (ponding); flushing lateral pressure distribution lines (if present).

-Inspection of the sand filter pretreatment device and flushing of the lateral pressure lines within the sand filter.

-Inspecting mound systems noting effluent seepage, and ponding (if present).

-Inspecting and cleaning any disinfection unit components and replacing parts as necessary.

Why Should I Maintain My Septic?

The first reason is to protect the health of your family, your neighborhood, and the environment. When sewage systems fail, inadequately treated household wastewater is released into the environment. Any contact with sewage can pose significant health risks. Untreated wastewater from failing sewage systems can also contaminate nearby wells, groundwater, streams, marine water and shellfish.

The second reason is cost. Failing sewage systems are expensive to repair or replace. It typically costs between $9,000 to $18,000 or more to replace a failing sewage system with a new, onsite sewage system.

Lastly, proper maintenance of your sewage system protects the financial investment you have in your home and your neighborhood. Failed sewage systems can cause property values to decline. Often, building permits cannot be issued, or real estate sales delayed, until systems are repaired or replaced.

Who Can Perform Monitoring and Maintenance?

In King County Monitoring and Maintenance must be conducted by a certified maintenance specialist. Maintenance specialists certified by the health department must maintain the following:

-Certificate of competency

-Two years of relevant OSS experience

-Yearly evidence of continuing education

-Current business license and bonding

-Pay all applicable fees and be in good standing with the Health District

-Passed the certification exam

Septic System Maintenance Agreements

Septic system service contracts are a great way to achieve peace of mind while complying with county regulations. If you are a King County, Washington aerobic system homeowner we would like to become your maintenance service provider.

County Requirements

OSS Notice on Title

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Obtain your As-Built

King County As-Builts

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To learn more about our services or speak to a team member, please reach out to us via the contact form below.