Desalination Plant Delivering Clean Drinking Water To Tampa Bay Region

The nation's first large-scale seawater desalination plant eases Tampa Bay region's drought worries

Clearwater, FL — As dry conditions are forecasted to continue in the southeastern United States, 2.4 million west-central Florida residents are benefiting from a project pioneered by their regional water utility, Tampa Bay Water. The Tampa Bay Seawater Desalination Plant, now fully operational, is providing millions of gallons of clean drinking water from the sea every day.

At 25 million gallons per day (mgd), the plant provides about 10 percent of the Tampa Bay region's drinking water supply and is operated by American Water and Acciona Agua through their joint venture subsidiary, American Water-Pridesa. The desalination plant will serve as a model that other coastal communities may consider as a practical solution to ease their water troubles.

"We've already had folks from coastal areas in California, Texas and other parts of Florida look at the plant," said Jerry Maxwell, general manager at Tampa Bay Water. "It's good to know that there's a safe and sustainable way to harvest water from the sea."

The plant uses about 44 mgd of seawater from a nearby power plant's cooling system. The seawater is pretreated to remove algae and other particles. Then, reverse osmosis filters separate 25 mgd of freshwater from the seawater.

The unused concentrated seawater is diluted with up to 1.4 billion gallons of cooling water before it is discharged to the bay. That dilution is why environmental studies show no measurable salinity change in Tampa Bay related to plant production. Protecting the environment was a big concern for Tampa Bay Water and its two partners on this project, American Water and Acciona Agua of Spain. The plant was built to meet the stringent U.S. environmental regulations and overcame the challenges they presented.

"We are extremely proud to have partnered with Tampa Bay Water to successfully complete the largest seawater desalination plant in the United States," said American Water President Don Correll. "With rigorous pretreatment, the right technology and proper operation, desalination can be done efficiently and effectively and is a viable solution as a water resource."

Acciona Agua Managing Director Luis Castilla said, "Acciona is pleased to join American Water and Tampa Bay Water in a true public-private partnership bringing together cooperative strengths in technology, design-build implementation and a willingness to overcome significant hurdles."

Because Tampa Bay is a coastal region, seawater desalination was a natural consideration for the area, but originally cost prohibitive. Technological advances brought the cost of desalinated water down significantly and the wholesale cost for desalinated water in the first year of operation is expected to be competitive with other similarly sized desalination plants across the globe.

Tampa Bay Water provides wholesale water to the public utility systems of Hillsborough, Pasco and Pinellas counties, as well as the cities of New Port Richey, St. Petersburg and Tampa, who in turn serve 2.5 million people in the Tampa Bay region. To learn more about Tampa Bay Water, please visit www.tampabaywater.org.

With headquarters in Voorhees, N.J., American Water employs nearly 6,900 dedicated professionals who provide drinking water, wastewater and other related services to approximately 16.2 million people in 32 states and Ontario, Canada. More information can be found by visiting www.amwater.com.

Headquartered in Madrid, Spain, ACCIONA Agua is one of the largest seawater desalination companies in the world. Over the past 30 years, ACCIONA Agua has designed, built and operated more than 70 desalination facilities and 320 water treatment plants around the world. ACCIONA is one of the largest infrastructure companies in Europe with 40,000 employees and a market capitalization over $17 billion (www.acciona-agua.com).

Tampa Bay Seawater Desalination Plant Facts

• The Tampa Bay Seawater Desalination Plant is designed to produce up to 25 million gallons per day (mgd), and can accommodate an expansion to produce up to 35 mgd in the future.
• Plant modifications included overhauling the pretreatment process to correct inadequate screening and filtration, as well as deficiencies in the reverse osmosis and post-treatment processes.
• When operating at full capacity, the Tampa Bay Seawater Desalination Plant provides the Tampa Bay region with nearly 10 percent of its drinking water supply, making it the largest reverse osmosis (RO) seawater desalination facility in North America.
• The cost of water produced at the plant is competitive with other similarly sized plants operating around the world, currently $3.38 per 1,000 gallons.
• The 30,000 square-foot seawater desalination plant is located on 8.5 acres of Tampa Electric's Big Bend Power Station in Apollo Beach on Tampa Bay.
• The concentrated seawater left over from the desalination process will not significantly increase Tampa Bay's salinity because it is diluted with up to 1.4 billion gallons per day of power plant cooling water. Monitoring during the plant's first year of operations showed no measurable changes in salinity, even when the plant was operating at maximum capacity.
• The initial cost to build the reverse osmosis plant and a nearly 15-mile pipeline was approximately $110 million. Significant remediation throughout the plant brought the total capital cost of the project to approximately $158 million, including membrane replacement.
• Under the partnership agreement, the Southwest Florida Water Management District will reimburse Tampa Bay Water $85 million of the plant's eligible capital costs in installments over the next 18 months. The partnership agreement earmarks locally collected ad valorem taxes to offset the cost of alternative water supply development.