Tampa moves forward with innovative ion exchange system to boost water quality
The Tampa City Council has approved funding to design a large-scale Suspended Ion Exchange (SIX) system at the David L. Tippin Water Treatment Facility, positioning the project as both the largest SIX installation globally and the first full-scale deployment in the United States.
The system will be designed to treat up to 140 million gallons per day (MGD) and is intended to improve finished water quality while reducing long-term operating costs. The decision follows several years of pilot testing and independent technical review evaluating the technology’s effectiveness.
“Council’s support of this investment shows a clear commitment to doing what is right for Tampa’s future,” said Tampa Water Department Director Rory Jones in a press release. “After years of testing and data driven evaluation, our team selected Suspended Ion Exchange as the right fit for our system, one that improves water quality, reduces long term costs, and builds on the legacy of the David L. Tippin Water Treatment Facility.”
The project will be delivered through a design-build partnership led by Garney and Wharton-Smith, with Carollo Engineers serving as lead designer.
"We are honored to lead the design of the world's largest SIX system," said Carollo Project Manager and Executive Vice President Vinnie Hart in a press release. "Tampa's vision to pioneer this technology and desire for improved water quality, combined with rigorous pilot testing and the collaborative efforts of the entire project team, will establish new standards that water utilities across the country and beyond can follow. This technology is truly a game changer for the high organics waters that we see in Florida."
The David L. Tippin facility currently produces an average of 80 MGD of drinking water for more than 733,000 residents and visitors. However, variability in the Hillsborough River—its primary source—has created seasonal challenges, particularly elevated total organic carbon (TOC) levels that contribute to disinfection byproduct formation and increased chemical demand.
SIX technology, developed by PWNT, removes dissolved organic matter through a resin-based ion exchange process, serving as an alternative or supplement to conventional coagulation. The process can also improve downstream treatment efficiency, including for PFAS removal, by reducing organic interference.
A 10-month pilot study demonstrated significant performance improvements, including up to 79% reductions in chemical usage, projected annual savings of $1.7 million to $1.9 million, and increased filter efficiency. Results were validated by an independent third-party review.
With design funding secured, the project will now move into detailed engineering, permitting and construction planning. Once operational, the facility is expected to serve as a national demonstration site for SIX technology, providing operational data and guidance for utilities considering similar treatment approaches.