Environment

Miami-Dade County wants closer study of FPL cooling canals

Worried that rising temperatures and a festering algae bloom in Turkey Point’s cooling canals may hint at bigger problems for Florida Power & Light, Miami-Dade County officials said Tuesday they plan to assert the county's regulatory power to find out what’s ailing the aging canals.

“Clearly the cooling canal water is migrating outside the boundaries of their system,” Lee Hefty, director of the Division of Environmental Resources Management, told county commissioners before suggesting the county take action.

Since June, FPL has been struggling to control the hot canals and an algae bloom that has spread throughout the 168-mile loop. The canals were dug in the 1970s and act like a radiator to help keep the nuclear power plant from overheating.

The utility has twice asked the South Florida Water Management District for more water to freshen the canals. Earlier this summer, the agency signed off on up to 14 million gallons a day from the Floridan aquifer and last week agreed to a temporary permit for up to 100 million gallons of freshwater a day from a nearby canal.

The utility needed the county’s permission to lay pipes across endangered wetlands, a request that could have been granted by staff. But environmental groups asked for a public hearing, warning that a spreading underground saltwater plume potentially worsened by the hot canals posed a bigger risk to Biscayne National Park and area water quality.

“We have the distinction of being the only national park adjacent to a nuclear power plant,” park superintendent Brian Carlstrom told county commissioners. “We really need to understand why this unprecedented event is happening.”

The utility has blamed below-normal rainfall on the rising temperatures and increased salinity. In July and August, temperatures exceeded 102 degrees and twice threatened to shut down the plant. Because of the spike, the Nuclear Regulatory Commission raised temperature limits to 104 degrees to keep the plant operating.

“The water quality varies with the season,” Steve Scroggs, an FPL senior director, told commissioners. This summer’s rainfall over the canals is off by as much as 50 inches, he said.

“That is the precipitating event that results in higher salinity and high temperatures,” he said.

But Hefty argued the temperatures began rising and algae blooming after FPL temporarily shut down canal pumps when it expanded the plant to increase capacity by 15 percent. At the time, Hefty said, FPL worried temperatures would increase.

“And now all of a sudden you’re going to say it’s the weather?” he asked after the meeting. “I don’t necessarily agree.”

Hotter water can lead to saltier canals. This summer, salt levels have been about 50 percent higher than normal and twice the salinity of the nearby bay. Salinity is potentially more worrisome since the area’s salt front has already crept farther inland than in other parts of the county, threatening area drinking wells.

The state is currently revising its regulations on how the canals operate. Part of the revisions eliminate strict monitoring imposed when the plant was expanded. But county commissioners agreed Tuesday that the canal problems point to the need for even more monitoring.

“There is not consensus on why this problem has gotten worse,” Christopher McVoy, a hydrologist and soil physicist, told commissioners. “All the data FPL has collected needs to be included and accessible to somebody who can put it together so you’re not voting for a temporary solution that becomes a permanent one and gets us into problems.”

Commissioners unanimously agreed to grant permission to lay the pipe, which must be removed when the water permit expires Oct. 14. The commissioners also agreed to include recommendations from the Everglades Law Center, Tropical Audubon and the National Parks Conservation Association to conduct an independent study of the problem.

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