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Potable Reuse in Florida: How City of Plant City is Making it Happen
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Carlyn Higgins, Paul Biscardi, Stephanie Ishii, and Andre Dieffenthaller
he City of Plant City (city) is a small, agricultural-based community on the eastern outskirts of the greater Tampa Bay area faced with both water supply limitations and effluent management challenges. The city launched an integrated water management plan, which includes increased water supply through potable reuse as part of its recommendations. To evaluate the feasibility of using treated wastewater effluent as a potential alternative source for drinking water, the city is conducting a potable reuse pilot study consisting of membrane filtration (MF), reverse osmosis (RO), and an ultraviolet/advanced oxidation process (UV/ AOP). The year-long pilot study demonstrated that the purified water quality met current and anticipated pending regulations. The pilot study also identified several key design parameters for the full-scale potable reuse design. The city’s comprehensive public outreach program, aimed at educating and receiving feedback from the community, was successful in gaining support in favor of the city utilizing potable reuse as an alternative drinking water supply.
Background The city is known for abundant berry production and the annual Strawberry
Festival, which brings thousands to the area to engage in rodeo-like activities, listen to music from national headliners, and enjoy strawberry shortcake. The city also owns and operates an integrated water, sewer, and reclaimed utility. Plant City is projected to have significant population growth within the next 20 years, prompting increased water demand that will eventually surpass the existing water supply. The city has limited expansion opportunity with its current groundwater potable supply due to the location within the Dover Plant City Water Use Caution Area and is faced with identifying alternative drinking water sources to satisfy increasing demand. Plant City intends to remain water secure, while also acknowledging the potential for mutually shared resources. As a unified water management approach, the city developed a holistic project that incorporates stormwater treatment, mitigation of localized flooding, rehabilitation of a natural habitat park, and increased water supply through potable reuse. The overall program objectives are to increase water supply while providing restoration of hydrologically impacted wetlands and enhancing the beneficial reuse of high-quality reclaimed water.
Carlyn Higgins, Ph.D., P.E., is an engineer; Paul Biscardi, Ph.D., P.E., is an associate; Stephanie Ishii, Ph.D., P.E., is an associate; and Andre Dieffenthaller, P.E., is a vice president, at Hazen and Sawyer in Tampa.
As a part of the feasibility phase, the city evaluated potable reuse by investigating the effectiveness of technologies to further treat reclaimed water, with the goal of augmenting its drinking water supply. Current regulations in Florida require a pilot to demonstrate performance for intended potable reuse. Florida has been a “hot spot” for testing of potable reuse, with more than a dozen Florida utilities having conducted pilots or demonstrations in the last decade. The city is unique, as it’s one of the few in Florida to pilot while still adhering to a set of draft Florida Department of Environmental Protection (FDEP) statewide potable reuse regulations. Continued discussions with FDEP have confirmed that the city is collecting the appropriate data for future permitted full-scale implementation. These discussions with FDEP will continue to help shape and finalize the statewide potable reuse rules. Although the city has a smaller utility that may not have been originally thought of as being in the forefront of implementing a full-scale potable reuse process, it’s paving the way for potable reuse in Florida and providing an example of a small community’s holistic water management strategy for the future.
Potable Reuse Considerations
Figure 1. City wastewater effluent historical conductivity.
48 April 2023 • Florida Water Resources Journal
The pilot- and subsequent full-scale potable reuse facility is designed to treat reclaimed water to meet all regulated chemical and pathogen concentrations for drinking water, while also providing monitoring for unregulated contaminants. The city considered both membraneand nonmembrane-based potable reuse treatment types. Both treatment approaches have been studied and utilized at other pilotand full-scale facilities in Florida and the United States. Criteria in the potable reuse