Leveling Out Demand Was the Key to Putting This Florida Water Plant and Distribution System on Track

Leveling Out Demand Was the Key to Putting This Florida Water Plant and Distribution System on Track

The team at the Plantation Water Treatment Plant includes, from left, Christopher Surgener, plant technician; Helga Bundy, lead operator; Al Purvis, chief plant operator; Bradley Leachman, apprentice operator; and Daniel Myklejord and Adam Hamblin, operators.

When the City of Leesburg in Florida took over a water plant serving a large subdivision, it inherited a facility that did not meet customers’ demands.

A homeowner association had owned the plant, and customers were plagued by low water pressure, made worse by limited system storage and heavy demand for irrigation. But the Leesburg team overcame the problem. It took a few years, many changes and some public education that is still going on, but demand is now spread out and the pressure problems are under control.

Cycling pumps

The Plantation Water Treatment Plant draws from three of the 17 wells the city has in the aquifer. Raw water comes in through a 12-inch pipe and flows into a 800,000-gallon aboveground storage tank and through a 3,500 gpm aerator (Precon). Sodium hypochlorite is mixed at the same time. A baffle wall in the tank ensures sufficient chlorine contact time.

High-service pumps (Pentair - Fairbanks Nijhuis) pull water out and send it to customers. In 2015-16, the utility added an 800,000-gallon tank, pump room and chemical storage. A new raw waterline was laid to the site of the new tank, about a mile from the existing plant and a new building for pumps and chemical storage. This became the new water plant.

The homeowner association gave the city land for the project; in return, the city gave the association the land where a wastewater treatment plant for the subdivision used to be. That plant was replaced with a lift station to move wastewater to the city’s central plant.

The Plantation plant is not interconnected with the other five water plants operated by Leesburg, says Al Purvis, chief operator. Because the Plantation plant operates under a separate state permit, it cannot be interconnected at the moment, but stub-outs are in place so that in an emergency a crew could make a connection in about an hour. When the current permit expires, the city can consider combining all its plants on the same permit.

Reducing pressure

Pressure problems began from the day the city took over the water plant. The original plant for the subdivision drew from wells and pumped water directly into the distribution pipes. A series of upgrades followed as the subdivision grew. The association had a private firm running the facility, but the plant wasn’t well designed from the start, Purvis says.

The original storage was a 54,000-gallon tank. Four pumps with capacities of 1,000 to 4,000 gpm pushed water into the distribution pipes. “But, really, you could run only three of them because cavitation was so bad that the pipe would heat up on the fourth one and make the pump nonfunctional,” Purvis says.

Producing 2.5 mgd with so little storage was almost impossible. Most of the demand occurred between 2 and 9 a.m., about 90% of it for irrigation. Purvis knows that because of the difference between what the water plant produced and the wastewater plant treated.

“I would produce 2.5 million gallons, and they would only get back 300,000 to 400,000 gallons, so you know where the rest of it went,” Purvis says. “We have a lot of sandy soils, so it just soaks up the water, and it’s gone.”

Boosting efficiency

During those early-morning peak hours, an operator on site ran the plant manually to keep the storage tank as full as possible and maintain system pressure. After taking over the plant in 2006, one of the city’s first actions was to upgrade the pumps with variable-frequency drives (Danfoss VLT Drives) in 2008.

Previous operators had tried to run the system with pressure switches. The pumps came on every 30 seconds to charge the system. “It was on off, on off all day long,” Purvis says. Power bills were high because of the electricity needed to start pumps so often. The VFDs reduced the on-off cycles.

The terrain is hilly: On high ground is a newer section of the subdivision built in the 2000s, and on lower ground is a section built in the 1950s. “So if we increased the pressure to get water uphill, we were blowing pipes on the older section,” Purvis says. “When we took over, we increased the pressure to help with demand, and some of the pipes just couldn’t handle it.”

Building the new plant near the middle of the distribution system helped reduce the need for higher pressures. There are now two 12-inch taps into the distribution pipes, one directly in front of the plant and the other about three-quarters of a mile away and downhill. Those also helped balance pressure across the system. Pressure is now adequate to satisfy demand but not high enough to break older pipes.

Green as grass

Because most of the subdivision’s demand was for lawns, addressing irrigation was key. Using rules from the area water management district and a list of connections in the subdivision, the team divided the development into sections and set a schedule specifying which sections could irrigate on which days of the week. That spread out demand and helped ease pressure problems.

By far, the largest challenge was educating homeowners about water use, Purvis says. Homeowners favor St. Augustine grass, a native tropical grass, but maintaining a dense, green, weed-free piece of turf in inland areas requires supplemental water. Leesburg is inland, about 45 miles northwest of Orlando.

“We started bringing in contractors to have little town meetings about conservation and the different things we could do — rock landscaping and things like that,” Purvis says. Educators included Purvis, the city’s utility director, University of Florida experts and some private contractors who specialized in water conservation.

“That was a battle, too, because the homeowner association had its rules, which weren’t conservation friendly,” Purvis says. “It slowly came around as well.” Homeowners still must obtain association approval for alternative landscaping, but the group has loosened its regulations to allow other options.

No single incident or meeting changed minds. The slow, continuous process of providing information made a difference. “I think over time people realized that other landscaping would still look nice and conserve water at the same time,” Purvis says.

“Also, some residents jumped on board and helped us. One gentleman did his entire front yard in rock. He tracked his water use, and he saved enough to basically repay himself. We now have a full-time conservation officer on staff. We still go out to all the communities and have meetings and discussions.”

Rotating experience

Operators at the Plantation plant don’t work there all the time. They rotate among the city’s six plants. The team includes Helga Bundy, lead operator; Matthew Turner and Daniel Myklejord, Class C operators; Christopher Surgener, plant mechanic; and Adam Hamblin, Jonvier Christian, Bradley Leachman and David Brown, apprentices.

This group’s performance earned the facility a 2018 Most Improved Water Treatment Plant award in Class C from the Florida Section of the American Water Works Association. Its accomplishments included managing pressure problems, adding new pumps, adding an emergency generator (Caterpillar Inc., Electric Power Division), promoting water conservation, building the new plant and replacing chlorine gas with sodium hypochlorite for disinfection.

“When we started out, we were pumping 2.8 mgd, and now we average about 1.5 mgd,” Purvis says.

No longer does an operator have to run the plant manually in the early morning during peak irrigation demand. There is just one day shift at the plant — one hour per day, six days a week, plus a visit on Sundays to look at the equipment and take daily readings. At all others times, the plant is monitored through the utility’s SCADA system.

When the new storage tank and plant were finished in 2016, the plant team held an open house. Many people were surprised at what is needed to provide their water. “What I tell my team is, if the public doesn’t know we exist, then we’re doing our jobs the best we can, because that means every time they turn their faucet on, they have water. It’s good quality, at the lowest price possible, and everything is fine.”

Licensed operators wanted

Al Purvis, chief operator, has a good team working at the Plantation Water Treatment Plant in Florida. There’s one thing he wishes he had more of.

“The biggest problem I’m having is getting licensed operators,” he says. “We get people as apprentices. We spend the dollars to get them trained and get them certified, and they move to a neighboring city making more.” They sometimes move to smaller cities, sometimes larger cities, sometimes to upper or lower Florida. And he says they can’t be blamed, because they have families to care for.

A person hired without training is given two years to become licensed. Once the state license is granted, team members typically stay for another year before moving on. “That’s not every case,” Purvis says. “We’re fully staffed right now, and I hope I keep it that way.” 

Occasional job fairs and regular open houses keep the plant team in touch with the public and provide forums to explain water careers to potential operators. His team now is very young. “That’s good for us if we can get them to stay, because their knowledge of our system would be fantastic as they grow,” he says. “Right now we’ve got a great bunch of operators and apprentices.”


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