Central Florida Drinking Water Could Run Out in Five Years

by Donald Sutherland

Kirby Green, director of the St. Johns Water Management District, says as populations and their demands increase it will become more and more difficult to supply water to people without harming lakes, rivers, streams, springs and marshes.

District hydrologists had relied on population projections provided by utilities to predict that water demand would not exceed supply until 2020. Green now says those levels will be reached by 2006.

In a state where Governor Jeb Bush has declared a drinking water supply crisis and 93 percent of Florida's 16 million residents rely on groundwater for their drinking water, desalination membrane utility plants are providing desperately needed drinking water from deep brackish aquifers.

The desalination plants use either electricity in the form of electrodialysis or a reverse osmosis filtration process incorporating semi-permeable membranes to remove salts, calcium, and other undesirable dissolved substances from the brackish water to produce potable drinking water.

Most of the 127 membrane plants listed by the Florida Department of Environmental Protection (FDEP) use reverse osmosis desalination and are concentrated in south Florida.

"Florida is the leading source of desalination membrane plants in the world," says Dr. Steven Duranceau, director of water quality and treatment for Boyle Engineering Corporation, a designer of desalination plants in Florida.

"This is a huge market for membrane use being driven by stringent disinfection regulations, coastal saltwater intrusion, and stressed shallow underground sources of drinking water supplies," says Dr. Duranceau.

As Florida's population has grown, so has its reliance on desalination plant treatment of saline ground water for potable drinking water. Sources of drinking water are at record low levels stressed by population growth and a four year drought.

Throughout south Florida, overuse of aquifer water supplies by expanding communities has aggravated saltwater intrusion into drinking water aquifers, requiring expensive well relocations and the use of desalination plants.

"If you look at the use of desalination in Florida it is a strong push for an alternate source of water," says Richard Marella, spokesman for the U.S. Geological Survey, Florida District.

"Desalination growth is also responding to the environment which is now a real player in water management policy making with such issues as water demands for the Everglades," he says.

The City of Cape Coral on the Gulf Coast, where the population has grwon from 12,000 to 85,000 in the past 25 years, is almost entirely dependent on desalinated water for drinking. The city has one of the biggest desalination plants in the state with a capacity of 15 million gallons per day.

In Sarasota County, the largest municipal water treatment facility of its type in the world using Ionics Electrodialysis Reversal (EDR) was commissioned in 1995 to demineralize brackish well water to meet drinking water standards. It produces over 12 million gallons per day.

Rapidly growing coastal communities of Jupiter, Melbourne, Hollywood, Cape Coral, Naples, Fort Myers, Carlton, Dunedin, Marco Island, Sanibel, Palm Coast, and Pine Island have constructed water treatment plants in the last 10 years with a total capacity of 145.6 million gallons per day.

Sarasota, Collier, Palm Beach, and Indian River Counties are also expanding their reverse osmosis and desalination plants.

"The big issue is finding alternatives and enacting stricter conservation measures, a politically tough act," says Marella. Caught in the political squeeze are state government district water officials, county commissions, and water utilities.

"There is a lot of pressure being put on growth management with water resources," says Bart Weiss, senior project manager for the Resource Conservation and Development Department of the Southwest Florida Water Management District.

Increasing existing inland wellfield use to supply booming coastal communities is hotly contested under Florida's Local Sources First legislation which governs the movement of water across county lines.

"Removal of water from existing inland wellfields is conditional. The withdrawal can't cause saltwater intrusion, harm the environment and hurt others ability to withdraw water," says Michael Molligan, communications and community affairs manager for the Southwest Florida Water Management District.

In the Southwest Florida Water Management District, part of the reform process has been the establishment of a funding arrangement that will give $188 million over 10 years to develop new water sources. They include desalination plants, reduction of inland wellfield pumping with emergency orders, and water rate conservation structures.

Based on an agreement between the Southwest Florida Water Management District agreement and three counties in the Tampa Bay area, the largest desalination plant in the western hemisphere is planned for Tampa. Scheduled to be operating by December 2002, it will cost an estimated $100 million dollars.

Covanta Energy Corporation of Fairfield, New Jersey received the green light in June from Poseidon Resources Corporation to build and operate the 25 million gallon per day reverse osmosis desalination potable water drinking facility for Tampa Bay Water, a government agency. Poseidon, a developer of water projects, entered into a Water Purchase Agreement with Tampa Bay Water in 1999.

Tampa Bay Water officials say 25 million gallons per day will meet roughly one tenth of the drinking water needs of the city and the surrounding counties.

In a study commissioned this year by Tampa Bay Water, 90 percent of Tampa Bay residents support the need for alternative water sources to groundwater to meet future water needs. This includes support for pumping water from outside the region. Of the respondents, 74 percent also believe that alternative water sources are good for the environment. In addition, 81 percent of respondents agree that water belongs to the people of Florida, regardless of city or county designation; and 70 percent believe the water should be pumped in from other areas.

State government and industry officials claim they have not financially assessed the projected costs of existing and projected desalination membrane plants needed to meet Florida's drinking water carrying capacity projections

"Estimating desalination plant costs is difficult with smaller plant operations costing more per gallon then large plants but Florida's desal treated water capacity is currently about 230 million gallons per day with costs ranging from $2 to $3 per gallon," says Dr. Duranceau.

The costs aside, the big question is whether desalination plant growth is going to put a dent in south Florida's increasing demand for water from shrinking sources.

"Desalination plants have capacity limits, and they will process only a small percentage of the needed potable drinking water in the state," says Morella.

State officials claim they cannot stop the booming migration and building in a state reliant on its shrinking underground sources of drinking water supplies, but a building moratorium has been mentioned.

Governor Bush said earlier this year that "de facto building moratoriums" could be imposed by utilities if they cannot provide minimum drinking water supplies.

"We can only advise on desalination growth, emergency and conservation measures," says Molligan. "It's going to be up to the local governments to make water use decisions on density and new growth levels in this crisis."