Seawater Desalination

Seawater Desalination Feasibility Study

Brooksville, FL

WAT-SWFWMD2WRA was engaged as the prime contractor by the Southwest Florida Water Management District (SWFWMD) to conduct an investigation to identify and evaluate the feasibility of additional of large scale (>15 mgd) seawater desalination facilities along the Gulf Coast of Florida.  Mark Farrell, P.E. served as the project manager and principal investigator.  The WRA team utilized their combined experience in water supply planning and desalination facilities to conduct the study.

Specific elements of the project included identification of evaluation methods, data collection, environmental assessments, economic evaluations, public opinion surveys and permitting feasibility evaluations.  The scope of work also called for the assessment of current and future water users to determine the amounts and quality of water that would be required from the desalination facility. The location evaluations included existing power plant sites, wastewater and industrial discharges, as well as ‘greenfield’ sites.

The SWFWMD provided detailed evaluation criteria that were to be applied to water resource development projects being reviewed by the SWFWMD in addition to the desalination projects.  Rating criteria included:

  • Environmental compliance/ease in permitting
  • Engineering/technology risk and uncertainty
  • Number of years from design to startup
  • Net environmental benefits
  • Seasonal water supply
  • Impact of drought on daily expected water yields
  • Ability to assist in meeting the water needs of user groups with limited options during drought years
  • Present value per 1000 gallons of water produced
  • Capital cost per mgd of capacity and project acceptability.

Economic analysis also included capital cost, operating cost, price elasticity of consumers and funding alternatives.  All capital and O&M costs were expressed in $/1000 gallons based upon a 20 year life cycle.  Cost varied based on the ability to co-locate with an exiting power supply source.  The feasibility study did not yield any other co-location opportunities.

Finally, the feasibility study included an analysis of potential funding sources for implementation of the desalination projects.  Funding sources included VA-HUD, Independent Agencies Funding; Capitalization Grants for Clean Water, State Revolving Funds, and SWFWMD New Water Initiative Funds.  Examples where funds had been provided for similar projects were provided for each funding source.

WRA proposed siting criteria that was reviewed and accepted by the SWFWMD.   The application of these criteria led to the identification of five possible locations for further evaluation.  Following a Phase I analysis, the locations were reduced to four sites that were subjected to detailed evaluation.  These sites included the Anclote River Power Station- Pasco County, Big Bend Power Station – HillsboroughCounty, Port Manatee – ManateeCounty and the City of Venice – SarasotaCounty.

The project was completed on schedule in July 2000. Since production of the final report, there has been significant interest in developing addition desalination facilities at all of the four selected sites.  The City of Venice is attempting to raise funding for a facility at the City of Venice location, a private independent power company is evaluating the Port Manatee site and Tampa Bay Water is investigating the Anclote site for the Desal II project.  SarasotaCounty has also contracted a consulting company to evaluate desalination feasibility.