Project: Desalination plant

Agency: Tampa Bay Water

Contractor: American Water - Pridesa (a partnership between Voorhees, N.J.-based American Water and Madrid, Spain-based Acciona Agua)

Date completed: Spring 2007

Cost: $110 million for initial cost and $48 million for remediation

After a history of turbulence, the Tampa Bay Seawater Desalination Plant is up and running as the largest desalination plant in North America, providing 10 percent of Tampa Bay Water's supply. The new water supply is a welcome relief for the fast-growing area, which previously relied on groundwater for its drinking water.

Because of design and financial problems with the original contractor, the facility never fully went online. Tampa Bay Water shut down the plant in June 2005 and hired a new contractor to correct the processes.

With an expected lifespan of 30 to 50 years, the facility supplies 25 million gallons per day (mgd) and can expand to 35 mgd. The average unit cost of the water produced is less than a penny per gallon. The water is distributed to Tampa Bay Water's six member governments, which supply the water for more than 2.5 million residents in the region.

The plant removes salt from seawater through reverse osmosis, which uses high pressure to force pretreated water through semi-permeable membranes that trap salt and other minerals. The treated water is combined with water from other sources at Tampa Bay Water's facilities. The salty water residue created by the process is diluted with water used at a local power plant and re-enters Tampa Bay at near-normal salinity.

Read the main story, "At the breaking point," to learn more aboout the sorry state of the country's water infrastructure and what it means if we don't fix it.