Maintaining Your Septic System

State law (Chapter 246-272A-0270) requires that homeowners inspect and maintain their septic systems to ensure it is functioning properly. The longevity of your on-site septic system relies heavily on the way that you care for it. Be sure to:

  • Complete additional routine maintenance that is required for some system types.
    • Gravity systems typically need maintenance every 3 years.
    • Low Pressure Distribution systems need maintenance annually unless otherwise specified by manufacturer requirements. 
    • Alternative systems need maintenance annually unless otherwise specified by manufacturer requirements.
  • Monitor what goes into your system
  • Protect the system from surface water and drainage, soil compaction, and other activities that might cause it to fail, or lead to early failure.
  • Schedule regular pumping for your septic tank. See our list of certified pumpers.

Monitoring Frequencies

Information on monitoring frequencies for common septic systems installed in Snohomish County is available in our On-Site Sewage System Monitoring Frequencies document.

Signs of Septic System FailureSlow draining

  • Fixtures are draining slowly
  • The ground above the drain field is soggy and has unusually lush vegetation
  • Sewage is backing up into the house
  • Sewage is surfacing on the ground over the drain field or septic tank
  • There is a strong sewage odor

Find a Certified Pumper

See our list of certified pumpers.

Helpful Septic Care and Maintenance Videos

Maintenance Records 

Some properties have septic maintenance records included with their septic as-built record. Septic as-builts and maintenance records are available through OnlineRME database of septic records. You will need the street address or Property Tax Account Number (PTA), to look up the records.

Cleaning Indoor Sewage Spills

In the event of an indoor sewage spill, thorough cleaning is necessary so that people, especially small children, are not exposed to potentially harmful bacteria and viruses. The amount of cleanup work depends on the extent of the problem, but general guidelines are available to help. Read more in our document on Guidelines for Cleaning Indoor Sewage Spills.

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Septic Tank Abandonment 

The Washington Administrative Code (WAC) contains regulatory requirements for septic tank abandonment. The Snohomish County Health Department does not have additional regulations. Please reference this guidance document.