By Jay Landers

The city of Fort Lauderdale, Florida, relies on two drinking water facilities to serve approximately 270,000 customers in the city and several neighboring communities. One of the facilities, the 12 mgd Peele Dixie Water Treatment Plant, was renovated in 2008 to include the use of nanofiltration membranes. By contrast, the 70 mgd Fiveash WTP, which uses lime softening as its primary treatment method, has been operating since the early 1950s and is in dire need of replacement.

Under the terms of a recently finalized public-private partnership, the city will receive a new 50 mgd drinking water treatment facility in only 3 1/2 years. As part of the unique arrangement, Fort Lauderdale will finance three-fourths of the upfront capital needed for the $485 million facility, while the private entities that will deliver and operate the treatment plant for 30 years assume the construction risk and some risks associated with long-term operations and maintenance.

Replace rather than refurbish

In 2017, Fort Lauderdale completed a utility strategic master plan that assessed the entirety of the city’s drinking water and wastewater systems, says Alan Dodd, P.E., M.ASCE, the director of the city’s public works department. “The analysis showed that the Fiveash Water Treatment Plant was 70 years old and the majority of its components were at the end of their life cycle,” Dodd says. Simply repairing the facility was estimated to cost approximately $200 million.

This steep price tag, along with two other key factors, persuaded the city to replace the Fiveash facility entirely, rather than repair it, Dodd says. Given its age, the plant does not “meet current standards for hurricane resilience and is at real risk during extreme weather events,” he notes.

At the same time, the lime-softening treatment process used at the facility has difficulty removing the yellow color that results from the high levels of organic material in the groundwater that is the source of the city’s drinking water. Although not a safety hazard, the yellow color of the finished water often raises concerns among residents and the city’s many visitors. “We have a lot of tourists who come to South Florida, and they wonder if the water is safe to drink,” Dodd says.

Unsolicited solution

A 2019 study conducted by the consulting engineering firm Carollo Engineers Inc. recommended that the city replace the Fiveash WTP and suggested the location and treatment options for the new facility. “That really was the basis for the project that came afterwards,” Dodd says.

In December 2020, the water treatment solution provider IDE Technologies and the infrastructure investment firm Ridgewood Infrastructure submitted to the city an unsolicited proposal to design, construct, operate, and maintain a new drinking water facility, using the findings of the Carollo report as a basis for their offer.

To be designed and constructed within 3 1/2 years, Fort Lauderdale’s new 50 mgd Prospect Lake Clean Water Center will replace the city’s Fiveash Water Treatment Plant, which has been in operation for approximately 70 years. (Image courtesy of city of Fort Lauderdale)
To be designed and constructed within 3 1/2 years, Fort Lauderdale’s new 50 mgd Prospect Lake Clean Water Center will replace the city’s Fiveash Water Treatment Plant, which has been in operation for approximately 70 years. (Image courtesy of IDE Technologies)

Under Florida law, the city was obligated to request additional proposals from other interested parties. After receiving three other proposals, the city reviewed the submissions and ultimately selected the proposal from IDE and Ridgewood. Under the terms of its proposed P3, the project team — which includes the Kiewit Corp. as its design-build contractor — pledged to design and construct a new 50 mgd drinking water facility within 42 months and then operate and maintain it for 30 years.

To be constructed at the site of the city’s groundwater wellfield, the new facility, which is known as the Prospect Lake Clean Water Center, features a combination of nanofiltration membranes and ion exchange technologies. Additional project components include connections to the existing raw groundwater wellhead network pipe and the finished water delivery pipe, chemical storage tanks, a deep injection well, backup generators, a control room, laboratory, and administrative and warehouse space.

Cost and timing concerns

For its part, the city of Fort Lauderdale opted to deliver the project by means of the P3 mainly because of concerns regarding cost and timing, Dodd says. The project’s fixed cost of $485 million essentially shields the city from the “uncertainty of cost escalations,” he notes, a key factor in light of the price inflation that has roiled the construction market during the past two years.

Given the age of the Fiveash WTP, the city also had a “lot of concerns” about the need to bring a replacement facility online as quickly as possible, Dodd says. “Time to production was a very important consideration,” he says.

Because of how the P3 is structured, Fort Lauderdale is relieved of certain risks associated with the project, including cost overruns or delays, says Lior Croll, the vice president of assets and developments for IDE Water Assets, a project development company within IDE Technologies.

“The city benefits from optimal risk sharing allocation, where the project company is taking risks such as construction time and budget and long-term performance as well as operation and maintenance risk,” Croll says. “This provides the city with long-term clear and clean water for 30 years as well as a steady, pre-known budget. It is truly a partnership. The city also benefits from IDE's technological expertise and its global (operation and maintenance) experience to allow constant improvements and efficiency.”

That said, Fort Lauderdale will bear some risk when it comes to the operations and maintenance of the Prospect Lake Clean Water Center. In particular, the city will be responsible for costs associated with all electricity and chemicals used at the facility as well as labor costs.

Close monitoring by the city

Although the city will retain ownership of the facility, the project team will be responsible for its operation and maintenance. For example, “they will decide when media needs to be switched out and when regular maintenance needs to be conducted,” Dodd says.

However, 40 city employees will work at the new facility “under the overall guidance and direction of the project company,” Dodd says. The public works department will specify the water production requirements to be met by the facility, and the project team will ensure that the requirements are met. “We'll be working very closely with them in the overall operation of the plant,” he says. In this way, “we will be closely monitoring their operations and ensure that everything they're doing is fully in compliance with our state and federal requirements,” Dodd says.

Initially, the proposal called for the private entities to finance the entire $485 million project.  However, “we realized that we could save some costs if we provided some of the funding,” Dodd says, because the city’s bonding capacity enabled it to obtain funding at a lower rate than could the private companies. Ultimately, the city agreed to finance 75% of the initial capital expenditures for the project and the private partners would provide the remaining 25%.

“We think that may be a good model for others to follow,” Dodd says, “where they have the ability to provide some funding to help offset the cost of a large project like this.”

Following the completion and acceptance of the Prospect Lake Clean Water Center, the city will begin making monthly availability payments of nearly $2.5 million to the project team, Dodd says. The payment total “will go up by 5% per year for the first five years, and then 2.5% per year for the remainder of the operations period, which is a 30-year contract,” he says.

2 treatment trains

As for the main treatment processes to be used at the new facility, the nanofiltration membranes and ion exchange media will achieve the color reduction that the city desires, Croll says. “These treatments have several supporting treatment systems such as stripping towers, multimedia filters, deep-well injection wells, and many other chemical dosage systems,” he says. “In combination, this allows the plant to reach a highly challenging water quality that the city of Fort Lauderdale has requested and requires great precision in terms of operation.”

The nanofiltration membranes will treat 70% of the water at the facility, while the ion exchange media will treat the remaining 30%. The two streams will be blended before entering the distribution system.

The combination of the two treatment systems is needed to help Fort Lauderdale remain within its permitted limits for how much groundwater it may withdraw from the Biscayne Aquifer, Dodd says. “With nanofiltration, you lose about 15% of the water as part of the process,” he says. “The ion exchange helped us to reduce that quantity while still producing water that meets our specifications.”

Unlike the existing Fiveash facility, the new Prospect Lake Clean Water Center will be designed and constructed with such threats as hurricanes and flooding in mind. (The need for this was evident this month as Fort Lauderdale endured serious flooding. And hurricanes persistently threaten the region.)

“A lot of the components are going to be hardened against wind damage and rain damage,” Dodd says. Meanwhile, the facility will have “redundancy in every system and every component,” he says. “If we have a failure in one part, we'll be able to quickly switch over and continue to produce water and meet the demands.”

To protect against flooding, the entire site will be elevated to raise it above the minimum base flood elevation, and the site’s drainage system will ensure that runoff from even heavy rains will leave the property efficiently. Redundant power supplies and diesel-powered backup generators will enable the facility to continue to operate even in the event of a power outage. “We'll have enough fuel on hand to operate them for more than a week,” Dodd says.

Enabling the project

Because the P3 entails the design and construction of the treatment facility only, Fort Lauderdale will have to conduct multiple “enabling projects” for the new plant to take its place within the city’s water system, Dodd says.

For example, the city must construct approximately 4 mi of 54 in. diameter pipe to convey treated water from the new plant to the existing distribution system. Other improvements will include modifications to the existing wellfield raw water supply pipelines, upgrades to the Fiveash distribution pumps, a 13.2 kV electrical power feed and transformer building, water and wastewater utility connections, and a communication system to allow plant operators to synchronize wellfield raw water withdrawals and finished water distribution, according to a Jan. 4 memo from Greg Chavarria, the city manager of Fort Lauderdale, to the city’s mayor, vice mayor, and commissioners.

All told, the city expects to spend approximately $181 million on the enabling projects, Dodd says. Although the project company will construct some of the components, the city will be responsible for the others. Acting as the city’s owner representative, the engineering consulting firm Hazen and Sawyer will “develop design criteria packages for those projects and will go through a standard solicitation for design and construction,” Dodd says.

Fort Lauderdale and the project team finalized the P3 agreement in mid-February. Permitting work is ongoing, and a groundbreaking could occur by early summer, Dodd says. “That should have us producing water in mid-September 2026.”

This article first appeared in Civil Engineering Online.