Water Desalination Overview
 

Use of Brackish Water and Desalination

Compared to using groundwater from the Floridan or the Biscayne Aquifer systems as a source of potable water, very little seawater sources have been used in South Florida Water Management District's (SFWMD) jurisdiction of sixteen counties. Nine of these counties have coastal boundaries and access to limitless sea water. The reason is mostly because the cost of seawater desalination is still significantly higher than traditional treatment of less saline groundwater.  Seawater has much higher chlorides and total disolved solids range from 20,000 to 35,000 mg/l. However, seawater desalination costs are declining due to improvements in membrane technologies and energy recovery research.

In an effort to develop conservation methods, the District is in the process of developing a program that will track the development and treatment of brackish water and its uses. The purpose of this effort is to develop a better understanding of this valuable resource, develop water conservation initiatives and use these data to assist in updating the District's four Regional Water Supply plans.

Investments in desalination by utilities within the South Florida Water Management District assisted by grants from the District's Alternative Water Supply Program have resulted in doubling the amount of desalinated water and number of plants built in the past 10 years. Currently, there are 24 brackish and 2 seawater desalination plants within the District. Fourteen brackish water plants are under construction. The total capacity will reach 260 million gallons of potable water per day by 2010.

Advances in Seawater Desalination
Significant advances have been made nationally in seawater desalination over the last decade, but it began in South Florida since 1860. As a leader in USA, Florida accounts for about 40 percent of desalination from both groundwater and seawater. The technology exists today for treating seawater, as it is done in the Middle East and the Caribbean. Florida has the oldest and the biggest seawater desalination plants in the nation. There are currently three seawater desalination plants in Florida: two small plants in the Florida Keys that combine for 3 million gallons per day and the 25 million gallons per day plant in Tampa, completed in December 2007.  Tampa's success will definitely encourage the construction of more seawater plants.

Implementing Desalination Technologies

• The District Completed studies in 2002 and 2006 to assess technical and economic feasibilities of co-locating desalination facilities with power plants in South Florida. Another study in 2007 provided planning-level cost estimates for a range of capacities, sources of water and treatment modules. The studies showed that seawater desalination could cost $3 to $5 per 1,000 gallons, depending on source water quality and several other site-specific factors, compared to $1 to $2.5 per 1,000 gallons for treating less saline groundwater or surface water.
• Despite the technological advances made to reduce costs, desalination is still expensive due to the increasing cost of energy and steel used in making membranes.

Desalination Funding Opportunities

• The State of Florida's SB444 of 2005 or Water Protection & Sustainability Trust Fund provides annually recurring grants for qualified construction projects
• Private - public partnerships
• State appropriations through legislative mandates
• Federal grants

Contact Information:

Ashie Akpoji 
561-682-2571