Environmentalists and national park managers plan to fight FPL's push for rock mining approval at a county hearing, saying Turkey Point plans will put supplies of fresh water at risk.

The 168-mile-long loop of canals that cool the twin nuclear reactors at Turkey Point was dug in the 1970s to avoid pumping billions of gallons of damaging hot water into Biscayne Bay.

More than 30 years later, the solution to one environmental problem has emerged as a prime suspect in another -- an underground saltwater wedge that has pushed miles inland from Florida Power & Light's bayside
plant.

Regulators don't yet know the size of the salty plume, but preliminary studies suggest a leading edge has marched far enough east, just past the Homestead Miami Speedway, to pose risks to drinking-water wells for Keys and Homestead residents and Everglades restoration projects intended to revive historic freshwater flows to the bay.

"This is a significant issue, and there is a real concern about the pace of the movement of the salt front," said Carlos Espinosa, director of Miami-Dade County's Department of Environmental Resource Management.

Potential Roadbloack

The salt front -- and the role of the cooling canals in fueling it -- has popped up as a high-stakes hurdle to FPL's plans to both coax more power out of its existing reactors and build two more 25 miles south of Miami.

Environmental groups, backed by Biscayne National Park, will ask Miami-Dade's Planning Advisory Board on Monday to reject a request key to its Turkey Point plan. The land-use change would clear the way for FPL to dig rock pits in up to 880 acres of nearby farmland as a source of limestone fill for future construction.

FPL officials declined interviews. Spokesman Tom Veenstra, in an e-mail response to questions, said the utility did not believe its cooling system had caused any "adverse environmental impacts" but was working with water managers and state and county agencies on a monitoring plan.

"FPL takes its commitment to the environment very seriously and always seeks to make decisions that are both responsible and based on scientific fact," he wrote.

Critics are skeptical, accusing FPL of pushing approval of quarries likely to worsen salt intrusion before agencies gauge ongoing impacts from the massive cooling system. The nine-square-mile grid of canals, hidden from view by mangroves, resembles a radiator in satellite photos.

Dawn Shirreffs, South Florida organizer for Clean Water Action, noted FPL's land-use amendment touts the quarries as "water management projects" that could be used for Everglades restoration, though no plans call for reservoirs so close to the bay.

"Mining for Everglades restoration is like starting a smoking habit for your health," she said.