Tampa Bay is tapping bay as a source for drinking water
Published: Monday, January 27, 2003 at 6:01 a.m.
Last Modified: Sunday, January 26, 2003 at 11:01 p.m.
On the Net
Tampa Bay Water:
Southwest Florida Water Management District: http://www.swfwmd.state.fl.us/
Save Our Bays, Air and Canals: http://www.sobac.org/index.cfm
Audubon Society of Florida: http://www.audubonofflorida.org/main/chapters.htm
Sierra Club of Florida: http://florida.sierraclub.org/
The nation's first sea water desalination plant built to serve as a primary source of drinking water is expected to begin providing water by the end of the month to Tampa, St. Petersburg, New Port Richey and surrounding cities.
The initial output will be incremental, only 3 to 4 million gallons a day, but the plant is expected to reach full capacity by early April, generating 25 million gallons a day. That's 10 percent of the area's drinking water.
"We all like to wash our dishes and take long hot showers. As long as we're going to do that we have to find other sources of potable water," said Mark Luther, associate professor of marine science at the University of South Florida.
"No matter where we're getting it, we're depriving our ecosystem of water, whether we take it from our rivers or the desalination process or out of the ground," he said. "The trick is to spread the pain as much as possible to minimize the overall impact. This is as good a way as doing it as any of them."
The basic process of desalination is not new. Salt water is pumped through filters under high pressure, squeezing out minerals.
Israel and Kuwait have relied on desalination for decades, as have military vessels and cruise ships.
Worldwide, 13,600 desalination plants produce 6.8 billion gallons of water daily.
Since the late 1980s, the price of taking salt out of sea water has dropped from nearly $2,000 an acre-foot, or one acre of land covered one foot deep in water, to $800 per acre-foot, said Jessica Rodier, of Poseidon Resources. Poseidon was the original builder of the Tampa Bay project - which is now being completed by another company.
The Tampa Bay Seawater Desalination Plant, run by Tampa Bay Water, is expected to convert sea water efficiently enough to be able to sell it for about $2 per 1,000 gallons, far below the industry standard.
It cost $110 million to build the plant and the 14-mile pipe to transport the water. The Southwest Florida Water Management District gave Tampa Bay Water $85 million to help defray the costs.
In addition, it's located on 8.5 acres at Tampa Electric's Big Bend Power Station, and will use the 44 million gallons a day used by the power station's generators, further lowering costs.
"We continue to add people to the system and we continue to add demand," said Rich Paul, who's responsible for public outreach with Audubon of Florida in Tampa. "We're in a race. Can we find and develop enough water sources to provide for the increasing human demand? Of the alternative sources that I've heard about so far, in my opinion, the desalination plan is the least offensive one."
Concerns over waste The plant will draw the 44 million gallons of water it will use each day from the cooling water used for Tampa Electric's generators. The sea water then undergoes reverse osmosis, where it is pushed through a series of filters before passing through membranes, leaving 25 millions of gallons of fresh water and 19 million gallons of brine.
The pure water is treated with lime and chlorine to ensure proper alkalinity, said Ken Herd, project manager for Tampa Bay Water.
The highly salty byproduct will flow into the Big Bend power plant's cooling water canal, where it will be diluted in the 1.4 billion gallons the canal carries each day.
USF's Luther led a study in 2000 that found the briney waste would not cause any long-term increases in salinity in the bay.
Still, it is this byproduct that has caused the most concern for area residents.
Apollo Beach residents formed Save Our Bays, Air and Canals and fought to have the permits to the plant denied, and eventually sued the Florida Department of Environmental Protection to contest the state permit for the plant. It lost that bid, but group attorney Ralf Brookes said they will monitor the area for any environmental problems.
The group fears the discharge will increase salinity in Tampa Bay and reduce oxygen in the water. "It's going to be devastating for marine life," Brookes said.
But environmental groups, including the Audubon Society and Sierra Club, have said they have not seen any data that shows that to be true, and are waiting to see the results of a $1 million monitoring program.
"We were fairly well-assured by independent groups that looked at this, that this plant alone would probably have very little affect on the salinity of the water because it's just such a drop in the bucket when you compare it to the total quantity of water in the bay," said Lynn McGarvey, with the Sierra Club Tampa Bay Group.
The state permit requires that the plant conduct several types of monitoring on a daily, weekly and quarterly basis. Tampa Bay Water also must submit monthly reports detailing the data they've collected over the previous month, said Vince Seibold, spokesman for the state DEP.
Also, DEP officials will do annual inspections at the minimum.
The plant's permit is good for five years, but can be revoked earlier, Seibold said.
Key West has had a desalination plant for years, and one was built in Santa Barbara, Calif., in 1992. Both are much smaller, and are used only for emergency supplies.
Last month, the prime minister of Singapore visited with a delegation to study the plant going up on the edge of Tampa Bay. Communities from Mexico, Iceland, Texas, California and Florida's east coast have also shown interest, officials said.
"People are starting to really understand the value of water and the importance of having a drought-proof supply that you can rely on year round under any weather condition to deliver drinking water for their area," Herd said. "We're not alone here in the Tampa Bay area as we struggle to find new sources of supply. That problem is experienced around the world."
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