Seawater desalination: Is it a viable solution for our area's water woes?
Charlotte Sun
June 16, 2008
By NEIL HUGHES
Staff Writer
In Southwest Florida, drinking water is dependent on the run of the river.
Lately, the river isn’t running so much.
There is, however, plenty of water in the area — in the Gulf of Mexico, that is. But turning it into something drinkable is a costly, difficult process.
Still, the prospect of a seawater desalination plant in Southwest Florida is likely an inevitable reality, albeit in the semidistant future, according to local officials.
But the sense of urgency required — specifically, whether Charlotte, DeSoto and Sarasota counties need to consider building desalination plant in the next 10 years or the next 30 years — is a point of debate. Current members of the Peace River/Manasota Regional Water Supply Authority, which serves water to Charlotte, DeSoto, Sarasota and Manatee counties, have intention to discuss a seawater desalination plant, to turn seawater into drinking water, in their long-term plans. “It will be a viable source in the 20-to-30-year range in this region,” said Pat Lehman, executive director of the water authority. “There are just other options that are environmentally friendly and more economical right now.”
But Charlotte County Commissioner Adam Cummings, who served on the water authority for more than a decade, said the authority previously intended to look at seawater desalination sooner, before it instead opted to pull more freshwater out of Charlotte Harbor.
While he doesn’t see desalination as an immediate solution, Cummings said it should be a more urgent option for the authority. “I think that the desal needs to be given more weight,” he said. “I think it tends to be just dismissed particularly by staff on the water authority, and elected officials tend to follow along with that.”
Twenty-five million gallons per day are currently pulled from the river, but he said future plans from the authority would have that number quadrupled.
“The part of the environment I’m interested in is Charlotte Harbor, and I haven’t figured out how pulling an extra 75 (million gallons per day) of freshwater flows out of it is going to be good for it,” Cummings said. “The more you try to withdraw from the river, the more expensive it becomes, because you have to have more and more infrastructure that sits there idle most of the year, waiting for that one high-flow day that it can take more.”
Communities considering desalination
At least one member of the water authority, the city of North Port, is moving ahead with its own water supply plans separate from the authority, and desalination is a big part of the picture.
In April, North Port Utilities staff and board members toured the Tampa Bay Water desalination plant in Gibsonton. The plant is the largest of its kind in the United States.
At the time, City Utilities Director Cindi Mick said North Port was interested in the plant because, despite the recent economic downturn, the city is still one of the fastestgrowing in the state, and its utilities board has been interested in learning more about other water options.
And to the south in Lee County, a seawater desalination plant is expected perhaps within the next two decades.
Susan Sanders, spokesperson for South Florida Water Management District, said the organization has acted as a sort of matchmaker between Lee County Utilities and Florida Power & Light to encourage the project to become a reality.
“We’re basically the facilitator between Florida Power & Light and Lee County Utilities,” Sanders said.
Through current technology, seawater desalination plants are best when paired with a power plant. Power plants typically use seawater to cool systems, and the warmer water is then taken and purified by the desalination plant. According to Ron Parker, senior operations manager for Tampa Bay Water’s desalination plant, the warmer water from the power plant tends to work better when flowing through a desalination plant’s highpressure system.
For that reason, Lee County Utilities is exploring the possibility of colocating a desalination plant with a FPL power plant.
Patty DiPiero, compliance and public information officer for Lee County Utilities, said a likely location would be the existing plant on State Route 80 in Fort Myers.
Currently, she said, officials are looking at the possibility of three phases costing a total of $60 million, though construction would likely not begin until at least 2020.
But the region realizes with growth, there will be a need for more water that nature alone cannot satisfy.
“We can still expand a few of our facilities and look at our options of what we have now, but we know that there is going to be a time when those options are going to be exhausted,” DiPiero said. “For us, that’s why we also have to have the longrange planning.”
A need — or not?
Whether or not the Peace River/Manasota Regional Water Supply Authority needs a seawater desalination plant in the next 10 years or 30 years, most can agree that a need will arise eventually.
Sarasota County Commissioner Shannon Staub, chair of the water authority, said she feels the current route, which would pull more surface water, is cheaper, safer and more reliable. She doesn’t foresee seawater desalination in the region anytime soon.
“In 50 years I think it would be appropriate to have surface water, groundwater and desal. It’s like having a financial portfolio, you want to diversify,” Staub said. “I don’t discount (desalination), but in my lifetime I’m not sure that we’ll see one in Southwest Florida.”
But Sarasota County has its own water supply sources, unlike Charlotte County, which gets more than 95 percent of its water from the water authority.
Charlotte County is also the owner of Charlotte Harbor, where environmental impacts from pulling water from the Peace River could be felt.
And for those reasons, Commissioner Cummings said he feels now is the time to start thinking about seawater desalination.
“What is your last resort? At what point,” Cummings said, “are you pulling too much fresh water out of Charlotte Harbor? I would say the opinion about how much is too much would vary radically based upon whether you live around Charlotte Harbor.”