Public Works & Utilities

Water System Fluoridation Implementation Study

The City of Spokane operates the third largest water system in the state of Washington. The Water Department's priority is to deliver safe, high-quality drinking water to its residents with efficient operations, while keeping rates affordable for our community. To inform future decisions, the City is completing a feasibility study to better understand the costs and implementation steps associated with providing fluoridated water to the community. The study will take about a year and a half to complete and is fully paid for with grant funds. City of Spokane's elected leaders are committed to a full and transparent public process throughout, including a public engagement period once the study is complete.

Non-Project SEPA Comment Period

Public comment to the Non-Project State Environmental Policy Act (SEPA) process closed at midnight on June 5, 2023. Once the study is complete, the information will be presented to the City's elected officials. These City Leaders will determine next steps and have committed to an open public discussion about this matter.

Fluoridation Implementation Study Frequently Asked Questions (PDF 246 KB)

Project Timeline

The study will be completed in three key phases of work described below.

Study Underway

February 2022

PHASE 1:

Collect Data & Develop Alternative

Completed Spring 2022

PHASE 2:

Evaluate Alternatives & Select Preferred Alternative

Completed Summer 2022

PHASE 3:

Prepare Conceptual Design of Selected Alternative

Completed Summer 2023

SEPA Comments, Draft Study, Final Study

Completed Summer 2023

Study Underway

START

In February 2022, City Council approved the contract to study the feasibility of delivering fluoridated water to Spokane’s customers, using its existing infrastructure. The City is working with a team of engineers, environmental scientists, and communications specialists to complete the study.

PHASE 1: Collect Data and Develop Alternatives

Completed Spring 2022

PHASE 1

The project team:

Assessed the condition of existing drinking water well stations to identify what, if any, upgrades are needed to incorporate fluoridation into water delivery operations.
Developed criteria for the proposed fluoridation implementation alternatives.
Interviewed 20 stakeholders representing a cross-section of community views to inform outreach efforts for the study.
Completed cultural resource survey to support the future State Environmental Policy Act (SEPA) filing. The survey includes pre-field research and review of known archaeological resources within a one-mile radius of the area of potential effect as inventoried at the Washington State Department of Archaeology and Historic Preservation.

PHASE 2: Evaluate Alternatives and Select Preferred Alternative

Completed Fall 2022

PHASE 2

The project team:

Worked to identify up to three preferred alternatives based on a review of technical standards, visited peer cities with different fluoridation implementation options, analyzed environmental requirements, and consideration of operations and maintenance needs.
Appliedn criteria developed in Phase 1 to evaluate the alternatives and select the best fluoridation implementation approach for the City.
Completed technical review of factors associated with the potential implementation of providing fluoridated water to the community. Impacts on water quality, specifically corrosion potential, considerations of downstream impacts to the City’s Riverside Park Water Reclamation Facility wastewater treatment plant, and considerations for non-fluoridated fill stations were evaluated.
Used a Multi-Objective Decision Analysis to assist the City in determining a preferred alternative. Both liquid and dry fluoridation options were analyzed, considering the impacts of each on the environment, service reliability, maintenance, and operations. A life cycle cost analysis was also completed, which was used to inform an analysis of the total cost of operations and maintenance for each alternative.

Related Documents:

Fluoridation System Alternatives (PDF 15.3 MB)
Fluoridation Ancillary Technical Review (PDF 222 KB)
Fluoridation Implementation Multi-Objective Decision Analysis report (PDF 2.5 MB)

PHASE 3: Prepare Conceptual Design of Selected Alternative

Completed Spring 2023

PHASE 3

The project team:

Developed preliminary designs for the selected implementation alternative.
Completed State Environmental Policy Act (SEPA) review.
Prepared project capital and lifecycle cost estimates to include in the final study.

FINAL

Finishing Up

In Summer 2023, the study was finalized and shared with the City of Spokane's elected leaders who will determine next steps.

Community Water Fluoridation Letter from Council President & Pro-Tem - October 16, 2023

NOTE: The June 2023 study document was revised in August 2023 to reflect comments received following the Study’s public comment period. Updates include a recalculation of the estimated cost of fluoridation chemicals using a less conservative demand basis, which modified the previously defined operational costs. They are noted as “August 2023 Update” in the document below.

Final Fluoridation System Study

(PDF 63.9 MB)