Update 12 p.m.: FPL has responded to the study, saying it needs more time to review the specific data but defending its efforts to protect Biscayne Bay. "Our top priority is the health and safety of the public, and there is no threat to the health and safety of the public," says Bianca Cruz, an FPL spokeswoman.

As Florida Power & Light finalized plans to expand its nuclear reactors at Turkey Point three years ago, critics were aghast. The nuclear plant already stands on environmentally fragile land, and upping the power production would seriously threaten the ecosystem, they argued.

Turns out they may have been right. This morning, the county released the results of a study into whether Turkey Point has been leaking dangerous wastewater into Biscayne Bay. County water monitors found more than 200 times the normal levels of tritium, a radioactive isotope linked to nuclear power production, in the bay water, a finding environmentalists say justifies their concerns.

"This is one of several things we were very worried about," says South Miami Mayor Philip Stoddard, who is also a biological sciences professor at Florida International University. "You would have to work hard to find a worse place to put a nuclear plant, right between two national parks and subject to hurricanes and storm surge."

The study is just the latest blow to FPL, which lost a state court ruling last month when a judge found the utility had failed to prevent hundreds of thousands of gallons of wastewater from seeping into the bay.

County commissioners and other local politicians are scrambling this morning to get answers about how threatened Biscayne Bay is by the leakage.

"I was shocked to read this," says Commissioner Xavier Suarez, who in a letter demanded answers from FPL "by the end of the day." County Mayor Carlos Gimenez, meanwhile, says the county has "aggressively enforced its regulations" and would demand that the state force FPL to fix the problem.

Adds State Rep. Jose Javier Rodriguez: “For years our state regulators have failed to take seriously the threat to our public safety, to our drinking water and to our environment posed by FP&L’s actions at Turkey Point. Evidence revealed this week of radioactive material in Biscayne Bay is the last straw and I join those calling on the US EPA to step in and do what our state regulators have so far refused to do - protect the public.”

At the heart of the troubling issue revealed in the new report is a system of canals surrounding the nuclear plant in southeast Miami-Dade. Nuclear cores must be constantly cooled to avoid meltdowns. The canals circulate water through the plant to leach heat off the reactors.

As FPL prepared to expand the plant's reactors in 2013, critics such as Stoddard warned that relying on the canals was a mistake. For one thing, environmentalists argued, the hot, salty canal water would inevitably leak back into Biscayne Bay and the Everglades.

"They argued the canals were a closed system, but that's not how water works in South Florida," Stoddard says.

In the two years since, environmentalists have pointed to a growing litany of concerns, including spiking heat levels in the canals and saltwater plumes exploding from the power plant into nearby groundwater systems. Stoddard says salty water has intruded as far as four miles inland through groundwater.

But FPL resisted new monitoring, Stoddard says, and deflected blame. "FPL has argued and argued and denied and denied there was any connection to their canals," he says. "They've tried to prevent monitoring. They were successful until the county commission finally demanded this study."

FPL hasn't returned New Times' phone calls for comment on the study. The county's numbers are cited in another report released today, which was conducted by University of Miami scientist Dr. David Chin, who analyzed how an influx of new water could affect the cooling canals.

As for those elevated tritium levels, it's not clear whether the isotope itself is dangerous to people or wildlife at that concentration; that's one topic on which the commission will demand answers from FPL, Suarez says.

But the hot, salty water is certainly a problem for the delicate ecosystems in Biscayne National Park and the Everglades. Stoddard — who argues the new study might point to violations of the federal Clean Water Act — says he believes only two solutions are viable: building new cooling towers to replace the canals, or shutting down the plant.

"There's a certain validation to critics in seeing this result in the study," he says. "But more important, it's now crossed the threshold of federal law here."

Update 12 p.m.: While FPL says it needs to review the new county data on tritium levels in Biscayne Bay, the utility strongly defended its work to protect Biscayne Bay. Cruz, the FPL spokeswoman, points out the agency reached an accord with the county last October. In the agreement, FPL promises to clean up its act by pumping wastewater into a deep aquifer, among other steps.

"We'll continue to comply with regulatory agreement we reached with the county in October," Cruz says.

Cruz also emphasized that FPL has collected its own data on impacts to Biscayne Bay and has seen no indication of a larger pollution problem.

"We've collected this data for many years, and this data has reviewed by independent scientists," Cruz says. "We're going to continue to work closely with regulatory agencies."

Cruz also criticized Stoddard for slamming the agency over the latest report. "He's selecting portions of the data to further his anti-FPL campaign," she says.

