Plant City has produced and sold high-quality reclaimed water for 30 years. But events ultimately called for more reliable outlets for that resource — and a secure drinking water supply for the future.

That set the city on a path toward an Advanced Treatment Water Facility, now in design and planned for completion by 2032. It’s an ambitious project that combines a thorough assessment and pilot testing of technologies with extensive public outreach.

The new facility will receive output from the 10 mgd Plant City Water Reclamation Facility and treat it with membrane technologies and UV for delivery to the drinking water distribution system.

“In the end, we will have a variety of ways to beneficially use our recycled water,” says Lynn Spivey, director of utilities for Plant City, in central Florida about 30 miles east of Tampa. “We already have tertiary treatment and the best-quality reclaimed water in the state, for which we have won awards time and time again. It just made sense to take the next step to ensure a reliable potable water supply.”

A WATER INNOVATOR 

Even before the potable reuse project, Plant City, which calls itself the Winter Strawberry Capital of the World, stood as a pioneer in water recycling. “Our reclaim strategy started out as purple pipe,” Spivey observes. “We also had a surface discharge that took a year-long study to receive.

“Approval came after a water quality effluent limit study showed that the discharge would positively contribute to the stream system. The plant had been upgraded to an advanced water reclamation facility with tertiary treatment.”

But a few years ago, a fertilizer plant and a sausage processor that had taken a combined 3 mgd of reclaimed water closed down, leaving the city with a surplus.

In response, leadership turned to a 370-acre property left in trust to the city. The parcel contains uplands and wetlands next to a highway and railroad tracks. Plans are in place to rehabilitate that ecosystem by developing more stormwater retention cells and recharging it with 1 mgd to 5 mgd of reclaimed water. The project is being co-funded with the Southwest Florida Water Management District and will include cells in which the wetland vegetation will help polish stormwater, absorbing nutrients.

“We will be able to use our reclaimed water beneficially at the wetland, and serve some public-access reuse customers to offset potable water irrigation with our purple pipe in our large neighborhoods,” Spivey says. Direct potable reuse will be the final step in a holistic water management initiative.

TREATMENT TODAY 

The Plant City Water Reclamation Facility uses an advanced aeration activated sludge process. Influent passes through a bar screen (Parkson Corporation) and a PISTA Grit Sand Removal System (Smith & Loveless). 

The flow is then split into two trains of biological treatment with anoxic and aerated zones for nutrient removal. After biological treatment, the flow passes to secondary clarifiers, followed by tertiary treatment with sand filters. “We are looking to replace our sand filters, probably with membrane bioreactors,” Spivey says. “That will give us greater log removal of viruses before the water enters our future advanced water treatment process.”

The final effluent is disinfected with chlorine before discharge to Itchepackesassa Creek, which feeds into Blackwater Creek, a Hillsborough River tributary. Biosolids are anaerobically digested, dewatered to about 14% solids on belt presses and removed by T. Wayne Hill Trucking for composting.

THE NEXT LEVEL 

With potable reuse, Plant City will have more diverse and reliable out- lets for its reclaimed water as well as a secure drinking water supply. In planning the project, the city first explored the relative merits of indirect and direct potable reuse.

“We looked at the potential to treat the water to a potable level and then inject it into the Floridan Aquifer,” says Spivey. “We found there would be a positive impact on aquifer levels in Hillsborough County as well as our neighboring Polk County.”

However, getting an underground injection control permit was extremely difficult, and the city would not be allowed to use all of the water injected. “We would be able to take out only 80% of what we put in,” says Spivey. “Additionally, injection wells are costly, and we would have to treat the water again after withdrawal. So we looked at direct potable reuse instead.” 

That decision led to a 15-month pilot study on site with membrane systems leased from Xylem and UV treatment from WEDECO - a Xylem Brand. “Working with consultant Hazen and Sawyer, we did a complete study, treating our reclaimed water for the entire study period,” Spivey says. Water samples were tested for more than 400 constituents.

“We had our operators trained on the system, and we took thousands of lab analyses. The treatment results were fantastic. We were able to remove everything from emerging contaminants to PFAS.”

The process consists of microfiltration, ultrafiltration and reverse osmosis membranes that remove progressively smaller particles, pathogens and molecules, followed by a UV advanced oxidation process. “The water is so pure that it would leach compounds out of your body,” says Spivey. “We will have to add minerals back into it.”

WINNING THE PUBLIC 

Meanwhile, recognizing that direct potable reuse could raise concerns among the public, the city conducted extensive outreach to the community. “We let everybody around us know what was going on,” says Spivey. “We had several tours of the pilot process for kids, business groups, school and scouting groups, and others.” More than 300 people toured the pilot, called the One Water Demonstration Facility.

“In one chamber of commerce group, there was a farm-to-table restaurant owner who saw the quality of the water and said, ‘Wow, I could make a really good beer with this.’ He took 500 gallons of our water and brewed beer with it, and we had a Hoppy Hour party with city leaders and representatives from other municipalities, the Florida DEP and Southwest Florida Water Management District.

“So people got to experience how pure this water was by hearing it from a fellow resident and master brewer. When utilities people talk, not everybody believes it. Having local people talk about the quality of the water really helped us. We’ve done a good job every step of the way working with our residents and our city leadership to show how safe this is and that we’re taking every precaution to do it the right way.”

Now the city is moving ahead with preliminary design to determine the actual cost of treatment, while researching loan and grant sources that would help limit rate increases.

LEADING THROUGH CHANGE 

Spivey, winner of the 2024 President’s Award from the WateReuse Association, is leading through the transition to DPR.

A native of upstate New York, she served eight years in U.S. Air Force, working in the intercontinental ballistic missile program and related satellite-based control systems. Along the way she earned a bachelor’s degree in chemical engineering at the University of South Florida.

After leaving the service she joined an ion-exchange water treatment company ultimately acquired by Calgon Carbon. “The opening they had was in the water group, and I loved it,” she recalls. “I was doing positive things for the environment. I got to work all over the world.” After that she did water-related consulting with engineering firms for 24 years.

She was consulting for Plant City when, nine years ago, the city manager asked her to come on board as director of utilities. “I am extremely glad of my military experience,” Spivey says. “It’s a very tough career field. It teaches you fortitude and work ethic.”

SUCCEEDING TOGETHER 

As a leader, Spivey fervently believes in teamwork: “You don’t oversee billions of moving parts without a team. I learned in the military how strong a unit can be when there is a good team. I approach my role by team building, making sure that everybody is happy in what they do and that we have the right skill sets.

“How can we do our work effectively? How many people does it take? How can we be innovative? How do we grow our organization chart? I take a really integrated approach to this utility, making sure that I have everybody’s input. We meet frequently. We’re constantly looking for new and innovative tools that can help us work smarter.”

That includes leaders having active roles in organizations like WEF, AWWA, the Florida Water Environment Association, the WateReuse Association, and the Florida Water & Pollution Control Operators Association. Team members attend conferences and training sessions. Equipment vendors are invited in to showcase their latest technologies.

One key priority is asset management: “We put a great amount of effort into making sure that we have a very robust work order system that we can use to trend and track our work.” A robust GIS (Esri) ensures that field crews have accurate, up-to-date information accessible on tablets. They can easily access instruction manuals, notes on previous maintenance and repairs, and a great deal more.

The city is transitioning to a cloud-based GIS so that all field people have GPS and the ArcGIS Survey 123 data-gathering software on their tablets. “Every time they go out to an asset, they can collect more information about it,” Spivey says. “So we’re continuously updating and providing accurate information.”

Plant City is also incorporating Microsoft Power BI data visualization dashboards to give team members at-a-glance views of system operations appropriate to their roles. That includes a dashboard tailored to city leadership. “Having a dashboard for our city manager, so he can see the moving parts and what we’re up against, helps me when I say to him, ‘I need to hire these people, and here’s why,’” says Spivey.

BRIGHT FUTURE 

All in all, Spivey sees Plant City utilities as squarely on the right path: “We’re the right size, we’re the right people. We’re very forward-thinking, and our city leadership is very concerned about our water supply.

 “They understand that we’re securing our water for generations. While some cities are built out, we’re still annexing large portions of unincorporated Hillsborough County. Having this water will help ensure that we can grow responsibly. We’ve seen the development moratoriums going on around our state. We don’t want that to be our story.”