Septic Maintenance

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:

  • Complete additional routine maintenance that is required for some system types
  • Monitor what goes into your system
  • Protect the system from surface water and drainage, soil compaction, and other activities that might use it to fail, such as flooding
  • Schedule regular pumping for your septic tank. See our list of certified pumpers

Monitoring your system

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 failure

  • 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


If you think you need a septic system repair, follow these steps to comply with the Snohomish Health District and Washington State regulations. See our Septic Contractors page for a list of certified professionals.

  1. Contact a certified installer, who will be able to look at the multiple elements of your system and possibly determine the cause of the septic failure
  2. If recommended by the installer, contact a licensed designer to design a repair and apply for a permit from the Snohomish Health District
  3. Once the repair is approved, you will receive a letter in the mail
  4. Hire a certified installer to request the permit be issued for installation and complete the work
  5. Once the installer notifies your designer that the repair is complete, the designer will ensure that the repair was installed correctly and then submit an as-built to the Snohomish Health District
  6. A sanitarian from the Snohomish Health District will complete a final inspection to make sure the installation is correct and the as-built is an accurate depiction of your repaired septic system


Snohomish County now offers a new program with financing options, incentives, and education to help you maintain a healthy septic system. Visit the Savvy Septic website to learn more.


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.


Please reference this guidance document for septic system abandonment.