Types of water systems

While most parts of incorporated King County get water from Group A water systems, many areas of unincorporated king county get their water from a Group B or private individual well. According to KCC Title 13, 13.24.138, new development in rural areas must be served by Group A, Group B, or private individual well in the following priority order:

• By an existing Group A water system with the proposed development inside its approved service area.
• By a new Group A or Group B public water system when the proposed development is in the approved service area of a Group A but direct service cannot be provided in a timely or reasonable manner.
• By an existing Group A or Group B water system willing and able to provide water with reasonable economy and efficiency when the proposed development is outside of their approved service area.
• By a new Group A or Group B water system that has been approved by the state Office of Drinking Water and meets relevant land use and public health requirements.
• By a private water source such as a well or spring that meets relevant land use and public health requirements. However, if the proposed development is in the approved or future planned services area of a Group A water system, approval of a private water source comes with the condition that the property must connect to the Group A when water service becomes available.