In This Florida County, Wastewater Effluent Goes on to Become Irrigation Water for a Variety of Green Spaces

A team in Collier County takes pride in consistent treatment excellence and delivery of 8 mgd of reclaimed water to a growing customer base.

In This Florida County, Wastewater Effluent Goes on to Become Irrigation Water for a Variety of Green Spaces

The Collier County Water Reclamation Plant

Team members at the South County Water Reclamation Facility IN Collier County, Florida, have been scrambling to keep up with growth since 1980. They’re doing a stellar job.

The county’s population, which includes the popular destination city of Naples, has more than quadrupled to some 365,000 in the 38 years since the first plant was built. Water reuse has become a required practice. Smaller independently owned utilities continue to be added to county’s wastewater division. The need for new operators never stops.

But through it all, Robert Edge, plant manager, and his professional team constantly provide the community with excellent and efficient wastewater treatment, providing about 8 mgd of reclaimed water to irrigate golf courses, parks, roadways and environmental areas.

For exemplary performance, the plant won a 2017 Operations Excellence Award from the Florida Department of Environmental Protection, and the Earl B. Phelps Award from the Florida Water Environment Association. In 2018, the plant received the Florida Water Environment Association’s David W. York Water Reuse System of the Year award for plants in its size range.

“It’s the team of people inside our facility who make this plant unique, in my opinion,” Edge says. “We have a plethora of professionals who work day and night, as a team, to ensure that we maintain an environmentally healthy wastewater treatment plant.”

Continuous growth

The South County facility started out as a small oxidation ditch plant. To keep pace with the mushrooming population, it was expanded to 2.0 mgd in 1983, to 6.0 mgd in 1987, and to 8.5 mgd in 1991. In 1997, the plant was converted to a modified Ludzack-Ettinger (MLE) process and capacity was increased to 13.7 mgd. In 2005, capacity was boosted to 16 mgd.

Today, influent wastewater flows to a pair of 1.25-million-gallon equalization tanks. Influent screening (JWC Environmental) removes rags and debris; that is followed by a Grit King system (Hydro International). 

The biological treatment process consists of 14 anoxic and aerobic zones. Average daily flow is 7 mgd. Two variable-speed ABS-Sulzer turbocompressors and six multistage centrifugal blowers provide process air. After treatment, the water flows through a splitter structure and then to four circular center-feed clarifiers. Effluent is polished in eight traveling bridge sand filters (Aqua-Aerobic Systems), each with 960 square feet of surface area.

Four chlorine contact tanks follow before the effluent is discharged to the reclaimed water storage system. The plant uses sodium hypochlorite for advanced disinfection required by Florida reclaimed water regulations. In wet-weather months, the effluent is deep-well injected or can be discharged to a holding pond or to wetlands.

The recent addition of the pair of variable-speed turbocompressors has produced twin benefits. “They have reduced our energy costs by 29 percent,” says Chris Farris, chief operator. “Plus, they’ve reduced noise. You can hardly hear them when they’re running. Ear protection is not necessary.”

Edge adds, “After installing the compressors, we noticed that we could optimize the airflow throughout the plant by reducing cubic feet per minute during low-flow periods and by adjusting the variable-frequency drive speeds as needed.” Additional compressors are being installed, and there are plans to upgrade all blowers to that style of air system.

Flexible operations

Solids are aerated in two 300,000-gallon storage tanks, then thickened and dewatered to about 16 solids percent on four belt filter presses (Komline-Sanderson). Two of the presses operate at a time. The resulting cake is hauled to a landfill.

Edge observes, “The facility can be operated in the MLE mode where return sludge and nitrate-rich mixed liquor from the aeration tanks are mixed in the anoxic zone. The nitrate serves as the oxygen source for the facultative bacteria. Or we can operate as a conventional activated sludge system since we have diffusers in the anoxic basins.”

That decision is based on the nitrate limits of the effluent discharge option: “We can only meet the nitrate limits for alternative discharge methods if we operate in the MLE mode.”

As with many treatment facilities, the community has grown up around the South County plant, and odor control is important. The biological process is enclosed, and the plant employs five chemical scrubbing systems (Evoqua Water Technologies).

“One is on our EQ tanks,” Edge says. “Two others are on the biological system, another on pretreatment, and another on the sludge holding tanks. We have a full-time staff person who calibrates the probes and adjusts the chemical feed rates to maintain proper operations. We want to be a good neighbor.”

Water reclamation

Visit Collier County and you’re bound to come across the purple pipes that carry recycled water. Except in the rainy season, all effluent from the South County facility is used for irrigation. “Our water joins the effluent from the North County plant in our reclaimed water storage facilities,” Edge says. “If our supply is lower than normal, the flow from the North County plant compensates. We’re interconnected.”

The county supplies reclaimed water to 50,000 end users, including 21 golf courses, six county parks, 60 miles of roadway median strips, residential communities, and environmental ponds and mitigation areas. The water is pumped through 130 miles of purple pipe and fills seven storage tanks and 29 storage ponds. The bulk user rate is 43 cents per 1,000 gallons. In 2015 the South County plant supplied 4.83 billion gallons of reclaimed water, accounting for 36 percent of the total water demand in the county. 

Rob Kaine, the wastewater division’s irrigation quality manager, says Collier County has been recycling wastewater since the early 1990s. First, the motivation was compliance with state requirements that call for consideration of water reuse instead of other discharge methods. Since then, reclaimed water has evolved into a valuable resource: “It’s very accepted at this point.” 

In fact, the biggest challenge is finding enough water to reuse. “We have a long list of customers,” Kaine says. “We don’t have the resources to provide reclaimed water to all of them. We need to find additional sources, either through new wells or increases in treated wastewater from our plants as the county continues to grow.” Another potential source is aquifer storage and recovery, where reclaimed water, or any excess water, is injected into the ground and later recovered for use.

Residential and commercial users are closely monitored for cross connections, and end users are informed about the nitrogen and phosphorus content of the reclaimed water. A Friendly Fertilizer Ordinance helps customers avoid overuse of these nutrients. “We provide information to customers quarterly so they can adjust their fertilizer practices,” Kaine says.

Control sophistication

Operators can monitor and control all wastewater treatment and recycling processes using a state-of-the-art iFIX system from GE Digital. The system provides real-time operational information, allowing operators to make critical decisions.

“This benefits plant operations and maintenance of equipment, and enables monitoring of electrical usage, amperage, and run time,” Edge notes. “Total influent flows from the county pump stations can be compared to effluent flows from the plants so that all are accounted for. When issues arise in the field, appropriate teams can be directed immediately to solve them. That saves time.” Operators also have access to all compliance data via pop-up screens.

The plant recently added a web-based Cityworks asset management program (Azteca Systems). “It’s pretty cool,” Edge says. “We’ve had it for about two years. It has taken off in a huge way since I’ve been here, and it has been interesting to watch it grow and evolve.”

The program is GIS-centric; all assets and all attributes related to each asset are stored in the GIS database. Staff members can add or remove information layers graphically, enabling them to see and analyze patterns and relationships among assets. “We’ve identified nearly 900 individual assets within the facility,” Edge says. “We can document all available attributes, including manufacturer, model, serial number, date of installation, status and condition, criticality and performance rating, as well as probability of failure and reliability ratings.”

The software assists managers in decision-making. Using life-cycle costs, they can improve performance and extend asset life. It also helps with budgeting, capital improvement project timelines and preventive maintenance processes. All staff members attended extensive training on the Cityworks software, and some were identified as subject matter experts, helping to train new staff members on the program.

Building talent

Training extends to all phases of the operation at the South County facility, and the wastewater division encourages growth for all employees. Besides Edge, Farris, and Kaine, the South County team includes:

  • Donnie McDowell, Robert McKinley, Joe Bierly, Mark Gedvillas, Anthony Gracia, Jeffrey Smith, Richard Stefanko, Stephen Titmas, Elio Cassanova, Frank Gawlinski, Bernard Frerick, Peter Moser, Chris McKellar, and Jordi Aviles-Lopez, plant operators.
  • Sam Jinkins, pretreatment coordinator; Roy Hendry and Greg Yanda, inspectors.
  • Mauro Altamirano, belt press operator.
  • Robert Dennison, plant mechanic; Werner Hacker, Tim Moore, and Charles Robichaud, maintenance specialists.
  • Gary Angelus and Mario Garcia, instrumentation and electrical technicians.
  • Scott Cooper, quality assurance/quality control specialist.
  • Diane DiPascale, environmental compliance manager; Tyler Horst, Russell Longworth, and Andy Riccio, lab technicians; Jon Flomerfelt and Carlos Villegas, chemists.
  • Judy Johnson, administrative assistant.

“Besides helping trainees obtain their licenses through correspondence courses or classrooms, facility-related craft training programs are offered that expand the knowledge of wastewater personnel in areas related to their job functions,” Edge says.

Safety courses are emailed to all employees. They can earn certification in CPR, forklift operation, safe driving and portable generator hookup through classes offered by the utility.

All wastewater division employees have completed all Federal Emergency Management Agency National Incident Management System required courses.

These measures are designed to improve operations and to help prepare the county’s wastewater infrastructure for growth. The U.S. Census Bureau predicts that the county’s population will surpass 500,000 by 2040. In line with that, the utility envisions larger regional treatment facilities.

Skilled operators will be the most critical asset. “As we grow and acquire more of the smaller utilities, we will be challenged to find certified operators,” Edge says. “We need to accommodate growth and continue to give everybody good quality service.

“We’re reaching out to the big pool of operators all over the country — first within Florida, and then those who might want to move to Florida. Or, we can promote existing staff, such as maintenance people who want to become certified operators. We’re trying everything we can to grow from within and pull from the outside. Sure, we have some state-of-the-art equipment, but it’s the team that really makes it all work!”

Lab on board

When operators at the South County Water Reclamation Facility in Collier County, Florida, take a sample, they get the analytical results back that same day. That’s because the wastewater division maintains a fully staffed and equipped National Environmental Laboratory Accreditation Conference-certified laboratory on the treatment facility grounds, operating seven days a week.

The laboratory, housed in a separate building, serves four county wastewater facilities. Under the direction of Diane DiPascale, also the utility’s environmental compliance manager, the staff includes three lab technicians, two chemists, and a quality assurance/ quality control specialist. Together, they provided some 46,000 analyses in 2017, ensuring permit compliance and timely and accurate data reporting. The utility’s pretreatment director coordinator and field personnel are also on DiPascale’s staff.

It’s a lot better than having to send samples to an outside contract laboratory, DiPascale says: “I’ve seen situations where we might not get results back for as long as three weeks. Here, we get same-day reporting, which enables our operators to make operational decisions quicker, and with more accurate data.”

Robert Edge, South County plant manager, likes having the lab on the plant property: “If I have a question, I can just walk across the yard.”

DiPascale agrees that communications are vital. “We work hard to have a good relationship and to be able to assist in sampling, compliance, and reporting. We’re constantly on the phone with our North County plant, and we can walk over and talk with the operators at the South County plant. We try to work really closely together.” DiPascale also points out that a central lab saves money by consolidating expensive equipment and certifications.

Even with its own building, the laboratory faces space issues as the utility grows. “We now serve four plants, as the county just added a small wastewater utility in Golden Gate,” DiPascale says. Lab staff members also collect samples at groundwater monitoring wells, deep injection wells, aquifer storage and recovery wells, supplemental irrigation wells, and pretreatment facilities.

That, and the need to stay abreast of and adapt to changing regulations, are the lab’s main challenges.


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