Environmental Health
Septic Systems
  Certified Septic System Professionals  

Environmental Health maintains a current list of septic system professionals that are certified to perform services in Thurston County. Although we strive to keep these lists current, we recommend you check with your contractor to make sure they are still certified.

To be certified, contractors must pass a test and have their equipment (i.e. pump trucks) inspected every three years (for specific requirements, see Article IV [PDF], Section 23).


Thurston County does not regulate the business practices of certified contractors.
Get several estimates, check references, and be clear what services are requested
before hiring a contractor.

The following contractors are certified to perform services in Thurston County.

Designers / Professional Engineers

Can evaluate soil suitability and subsequently design an appropriate septic system. For a list of designers, see WA State Licensed Sewage System Designers [PDF]. NOTE: Designers are licensed by Washington State Department of Licensing, not by Thurston County.


Can install new systems, make repairs, and modifications; also can replace pumps, septic tanks, pump chambers, and holding tanks. For a list of installers, see Certified Sewage System Installers [PDF].


Can inspect and pump septic tanks, make minor repairs (such are sealing cracks and replacing baffles), pump and dispose of septage. For a list of pumpers, see Certified Sewage System Pumpers [PDF].

Monitoring Specialists

Can monitor Aerobic Treatment Units (ATUs) and other septic systems. For a list of monitoring specialists, see Certified Monitoring Specialists [PDF].

Information for Septic System Professionals

Forms, manuals, and other information for septic system professionals doing business in Thurston County. ...more

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This page last updated: 10/02/15