Coquina Coast Seawater Desalination Project Cost
Coquina Coast Seawater Desalination Project Cost
Cost
project overview > costs

Overall Costs
Desalinated seawater has become more affordable over the past decade, but it still costs more than traditional groundwater due to the extensive treatment required to remove the salt and meet drinking water standards.

Based on the engineer’s opinion of probable construction costs and associated assumptions, the capital cost of a 10-15 million gallon per day plant would be between $190 million and $260 million (net present value).  The estimated initial unit cost for water supplied from the facility is between $6.27 and $7.74 per 1000 gallons for treatment, including intake and concentrate discharge. The unit cost includes capital costs as well as operations and maintenance costs, which vary as costs for power and chemicals vary.
 
Future expansion of the plant would result is costs as low as $4.72 per 1000 gallons of treated water.

The engineer’s opinion of probable construction costs for the transmission pipelines is approximately $1.29 per 1000 gallons net present value.

The unit cost of water from a desalination facility would be blended with the project participants’ other water supplies to lessen the rate impact to customers.

Engineer’s opinions of probable construction costs are based on a number of assumptions, including intake pipeline length, finished water quality, transmission system length, pipe diameter and so on. These estimates are expected to be refined as the project is better defined in Phase 2B.

Cost Comparison
The costs for a desalination project are site-specific and depend on several variables, including source water quality, location, plant capacity, regulatory requirements and more. According to a 2011 analysis by the WateReuse Association, desalinated water costs vary from approximately $2.00 to $11.00 per 1000 gallons. The average cost is $4.00 per 1000 gallons.

The Coquina Coast Plant engineer’s estimates for the expanded facility are comparable to other operating facilities of similar size, including the 32 mgd Perth, Australia plant that produces water at about $4.00 per 1,000 gallons. 

Customer Rate Impacts
It’s too early to know exactly how the proposed Coquina Coast desalination plant might affect customers at home because the water rate impact depends largely on five factors:

  • How much you currently pay for water,
  • Whether your utility participates in developing seawater desalination facility and the ultimate size of the facility,
  • How far your utility is from the plant,
  • How much of your utility’s total water demand will be met from desalinated seawater, and
  • Whether state or federal grant funding is secured for the project.

Once the project participants determine whether they will proceed with the project, each utility will conduct rate studies to determine the effects on its water rates. Those studies will be refined as the project and its costs are refined over the next three years.

Phase 2A project participants include the cities of Palm Coast, Leesburg and Deland along with St. Johns County and the St. Johns River Water Management District.