Public water supplies are divided into three main categories based on the number of people who have access to the water.
Group A Systems
Washington Administrative Code for Group A systems: WAC 246-290.
These are systems that regularly serve 15 or more residential connections or 25 or more people per day for 60 or more days per year. They are regulated by the Washington State Department of Health (DOH). If you are interested in developing a new Group A system or replacing an existing source, contact DOH at (360) 236-3030. Then, when you’re ready to request a well site inspection, fill out and submit a Critical Area and Resource Land Review (CARL) form and Well Site Inspection form to the county Permit Center, along with the applicable fees.
Group B Systems
Washington Administrative Code for Group B systems: WAC 246-291.
These are systems that serve less than 15 residential connections and less than 25 people per day or 25 or more people per day fewer than 60 days per year. Lewis County regulates Group B systems through an agreement with DOH.
New or expanding Group B systems must go through the full approval process before permits can be issued.
Some Group B systems may be allowed to complete a less stringent process to be determined "Provisionally Adequate." This would only apply to existing, unapproved, non-expanding systems. For example, Provisional Adequacy would be appropriate if someone wished to replace an existing mobile home with a newer one of similar size, and their water was obtained by a well that served three other homes. For a checklist with related documents necessary for Provisional Adequacy, click here.
Two-Party Group B systems (Shared Wells)
Group B systems with only two residential connections are governed by Lewis County’s Shared Well Policy.