Environmental Health
Drinking Water & Wells
Public Water Systems
  Group b wATER systems  

Group B water systems have 3 to 14 service connections and less than 25 people per day or serves 25 or more people per day during fewer than 60 days per year. The WA State Department of Health (DOH) and local health jurisdictions share administrative responsibilities for these systems. All Group B systems in Thurston County are regulated by the Environmental Health Division.

Water System Approval Process

Find out the steps to getting a Group B system approved by the County. ...more


Group B systems have many requirements, including system maintenance and operation, and sampling, reporting and recordkeeping requirements. ...more

Water Testing

Group B systems should test for coliform bacteria every 12 months and nitrate every 36 months. For information on the Thurston County lab, see Water Quality Lab. To view a list of other certified testing facilities in Washington, see the Dept of Ecology Accredited Lab Search.

Rules and Regulations

Applications, Forms, and Resources (all forms and applications are in PDF format)

The following are frequently used Group B water system forms:

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This page last updated: 05/18/22