FPL agrees to assessment of mysterious saltwater plume near Turkey Point nuclear plant

BY CURTIS MORGAN
cmorgan@MiamiHerald.com
Florida Power & Light will spend millions to assess whether the massive cooling canal system at the Turkey Point nuclear power plant is fueling salt contamination of the aquifer in South Miami-Dade County.
After nearly a year of balking at demands from water managers and county and state environmental regulators, FPL has bowed to expanded monitoring. It's a step the utility agreed to in its quest to complete an ``uprating'' plan intended to coax more power from its two reactors along Biscayne Bay.

The proposed agreement, designed to measure an underground plume of salt water thought to extend inland to at least Homestead-Miami Speedway, will be reviewed Wednesday by the South Florida Water Management District governing board.
It follows new research by federal geologists suggesting that the canals -- dug in the 1970s to avoid pumping billions of gallons of damaging hot water into the bay -- could be driving a salty front that threatens wells in the Keys and Homestead and projects to restore freshwater flows to the bay.
The working theory of the U.S. Geological Survey study, which FPL has dismissed as ``fundamentally flawed,'' is this: The nine-square-mile canal system, off limits to the public and hidden from view by mangroves, creates hot, heavy ``hypersaline'' water that sinks and spreads into the Biscayne Aquifer below.
Some critics argue that enhanced monitoring comes with a trade-off, charging that the district is weakening a 1983 agreement that already gives it authority to order FPL to fix and pay for groundwater problems linked to the canals.
Atlantic Civil, a mining company that contends the advancing salt limits its ability to dig deeper pits, filed papers in Miami-Dade Circuit Court last month threatening to sue the district to force action against FPL now.
Company attorney Stephen Walker said water managers have taken a simple question -- are the canals worsening intrusion? -- and added complication and delay.
``There are multiple layers of modeling and analysis . . . we would view as delay opportunities,'' he said. ``There is not going to be any kind of significant action under the new agreement for a considerable amount of time.''
Terri Bates, a district assistant deputy executive director, said regulators have to determine the scope of any problem before proposing solutions. The plan calls for collecting water quality and other data for two years. Bates called the monitoring plan, ``very comprehensive.''
Over a year of negotiations, records show FPL pressed to limit monitoring to a handful of existing inland wells and tracking water temperature and salt levels, which it had acknowledged will rise slightly as reactors produce more power.
The proposed monitoring plan calls for 14 clusters of wells ringing the site, including in wetlands and Biscayne Bay, and sampling an array of nutrients and chemicals.
Those include a ``tracer suite'' of isotopes, including radioactive tritium, which Bates said should help ``fingerprint'' water moving inland from canals. The tritium is at such low levels that agencies do not consider it a health threat but it has been detected at 10 to 30 times expected background levels in at least one well a mile west of Turkey Point.
``I think everyone agrees there is an issue,'' Bates said. ``If you turned off the plant tomorrow and didn't do anything, those canals are there and still having an influence.''
FPL, however, hasn't agreed that its canals, dug under a plan endorsed by multiple environmental agencies, are causing significant problems. In an e-mail response to questions, spokesman Tom Veenstra said data shows salt intrusion had already reached at least four miles inland before the canals were built.
Veenstra said ``FPL takes its commitment to the environment very seriously'' and will rely on the expanded monitoring plan to establish facts before it decides on any mitigation steps.
Veenstra dismissed Atlantic Civil's claims as ``unfounded allegations'' and argued that the USGS study left out an array of potential contributors to salt water intrusion in South Miami-Dade: rock mines, the Card Sound and other drainage canals, and seasonal canal drawdowns to protect farm fields.
Christian Langevin, a USGS hydrologist who co-authored the peer-reviewed study published online in August in Hydrogeology Journal, acknowledged the relatively simple computer models used to simulate the Turkey Point system didn't analyze every potential influence or provide definitive answers.
But in all four scenarios with varying canal salinity, models showed the aquifer beneath Turkey Point quickly turning salty. With hypersaline water, which reflects existing canal conditions, the plume spread for more than 25 years and over 12 miles inland.
The study, the first of its kind, suggest the canals are fueling intrusion, he said, with the shallow, radiator-like layout likely worsening effects -- creating fingers of denser brine that descend and mix into the surrounding fresher aquifer.
``Think of a lava lamp sort of effect,'' Langevin said. ``Water wants to move from high concentrations into low concentrations.''