Personalize your online experienceSign Into My Dashboard

Go To Search
Click to Home
Your GovernmentOur ResidentsFor VisitorsDoing BusinessHow Do I
Water Fluoridation


To ensure reliable and safe drinking water for decades to come, Issaquah is now planning for a new water treatment plant.

As part of this planning, the City Council is currently considering whether the new plant would provide fluoride to all City water customers.

Current Service
A large portion of the City’s existing service area (generally Squak Mountain, Olde Town and Issaquah Valley) receives unfluoridated water from a complex system of groundwater wells.

Meanwhile, other areas of the City (Issaquah Highlands, Talus, Lakemont, Montreux and South Cove) receive fluoridated water, as at least some of their supply comes from a regional supply.

See Issaquah’s fluoridation map for further details (please note some Issaquah residents are not City water customers, but instead are served by other systems).

Why Now?
Issaquah’s population is estimated to grow from 37,000 in 2017 to approximately 50,000 by 2027, with much of that growth focused in the Central Issaquah Area along Interstate 90. 

Due to that projected growth, the City’s existing groundwater rights and pumping capacities will not meet the demand as soon as 2021, and regional (fluoridated) water will be needed to serve currently non-fluoridated portions of the City. Learn more in the City’s 2018 Water System Plan Update.

A centralized treatment plant would enable the City to modernize its water treatment system; meet future water demands more efficiently; and be more responsive to emerging water quality regulations. 

As a future treatment plant would most likely blend both regional and well water, now is the time to plan for how fluoride is addressed.

Fluoride Information
Learn more about fluoride, and its history in this area, via Seattle Public Utilities.

Get Involved
  • Email the City Council.
  • An open house was held on Aug. 7, 2019. In total, eight people attended.       
    • Here's what we heard:
      • Five people were anti-fluoride in the water, and preferred to have it removed. 
      • Two of the attendees were OK with having fluoride remain in the water — one lived in a fluoridated area, the other lived in an area that currently is not fluoridated. 
      • Some of the questions that were asked were: - Why now? - Where would the plant be located? - How much fluoride would be in the water once Issaquah’s water mixed with Cascade Water Alliance? - How much is this going to cost me?
  • Provide feedback to the City Council during public testimony:

Issaquah Contacts

Staff Liaison

Robert York
Utilities Engineering Manager