City of Bloomington Restores Consistent Fluoride to Drinking Water Following Longstanding System Failures

The City of Bloomington Utilities (CBU) has restored fluoride to its drinking water supply following the completion of a new temporary fluoridation system at the Monroe Water Treatment Plant. Fluoride was reintroduced on January 28, 2026, gradually returning fluoride levels to the recommended range after several years during which supplementation was intermittent due to failures in the City’s fluoride delivery infrastructure.

The fluoridation issues began in late 2019, when leaks developed in the bulk chemical storage tank used to deliver fluoride. During the previous administration, the City pursued a temporary workaround while making attempts to repair the system. While intended as a stopgap measure, that approach increased operational costs and introduced additional safety risks for plant staff. While the tank was relined in 2022, leaks persisted.

As a result, City of Bloomington Utilities (CBU) discontinued supplemental fluoride feed. Drinking water continued to contain naturally occurring fluoride, but levels were not consistently supplemented to the recommended range. Throughout this period, Bloomington’s water remained fully safe to drink and compliant with all federal and state drinking water regulations.

After the current administration became aware in mid-2024 of the full scope and duration of the fluoridation disruption—and the limitations of prior temporary fixes—Mayor Kerry Thomson directed CBU to pursue a sustainable and safety-first solution that would restore fluoride delivery and prevent a recurrence of the same failures.

The newly installed temporary system replaces the single bulk storage tank with a more resilient, modular design using multiple smaller tanks. This configuration reduces risk to staff, lowers replacement and operational costs, and allows individual components to be repaired or replaced without shutting down the entire system.  Elements of the temporary system will also be incorporated into a permanent fluoridation system planned as part of CBU’s Capital Improvement Program.

“This solution meaningfully addresses a community concern while strengthening the overall reliability of the fluoride delivery system,” said Utilities Director Katherine Zaiger. “I appreciate the time, expertise, and problem-solving our staff brought to this project. Their approach was guided by past lessons and remained safety-focused throughout.”

The City acknowledges that public reporting on fluoride levels was inconsistent in prior years. During the years 2022 and 2023, the presence or absence of Fluoride was not noted in the Consumer Confidence Report (CCR). While not required, CBU decided in 2024 to include reporting on Fluoride to provide clearer, more comprehensive information about drinking water.  The City recognizes that this lack of information created confusion and that clearer, more proactive communication would have better served the public. In July of 2025, CBU passed Resolution 2025-14, committing CBU to present the CCR annually at a regularly scheduled public meeting of the Utilities Service Board.

While fluoride is not required for water potability, public health officials widely recognize its benefits for dental health, particularly for children and populations with limited access to dental care. With the temporary system now operational, CBU is once again feeding fluoride at recommended levels. 

The temporary fluoridation system will remain in service until a permanent system can be constructed, pending funding and final approvals. Throughout this process, Bloomington’s drinking water will continue to meet or exceed all safety standards.

For updates on this project, customers may contact [email protected].