ML19179A320

Mandatory Disclosure Document 2 - Future Impacts on Biscayne Bay of Extended Operation of Turkey Point Cooling Canals

ML19179A320
Person / Time
Site:	Turkey Point
Issue date:	06/28/2019
From:	Friends of the Earth, Miami Waterkeeper, Natural Resources Defense Council
To:	Atomic Safety and Licensing Board Panel
SECY RAS
Shared Package
ML19179A317	List: ML19179A318 ML19179A320 ML19179A322
References
50-250-SLR, 50-251-SLR, ASLBP 18-957-01-SLR-BD01, RAS 55067
Download: ML19179A320 (1)

Text

FUTURE IMPACTS ON BISCAYNE BAY OF EXTENDED OPERATION OF TURKEY POINT COOLING CANALS Laura Reynolds1, James Fourquean2 and William Nuttle3 1Conservation Concepts LLC, 360 Hunter Street, West Palm Beach FL, 33405 USA, 2 Florida International University, 11200 SW 8th Street, Miami, FL 33199 USA, 311 Craig Street, Ottawa, Ontario, Canada K1S 4 B6 Florida Power and Light (FPL) has applied to extend operations of its Turkey Point power plants until the early 2050s. Currently, FPL is under orders from regulators to correct problems stemming from the canals that cool the water used to run the steam turbines. Among these, the cooling canals discharge nutrient-rich, hypersaline water into Biscayne Bay and the Biscayne aquifer. The Interceptor Ditch has failed its intended function to prevent contamination of the aquifer, and its continued operation comes at the cost of extracting around 3 mgd of freshwater from the wetlands in the Model Lands area. What are the consequences for the health of the bay and success of the C-111 and Biscayne Bay Coastal Wetlands Restoration projects if the cooling canals operate for another 30 years?

Results from an expanded monitoring program, initiated in 2009, reveal how the cooling canals interact with Biscayne Bay and the regional groundwater system through an active exchange of water between the canals and the aquifer. The cooling canals were constructed in the 1970s to prevent damaging discharge of heated water directly into the bay from the Turkey Point power plants. Until about 2009 it was widely assumed that the canals had little impact on the bay and adjacent wetlands. However, by 2012, investigations demonstrated the canals were the source of a plume of hypersaline groundwater extending several miles west, and nutrient-rich water from the canals was found in the bay.

Water in the canals is hypersaline as a consequence of high rates of evaporation. Evaporation is one of the primary mechanisms that cools the heated water as it circulates through the canals from the point of discharge on the west side of the power plants, returning to the water intake on the east side of the plant. For the first 40 years of operation, an inflow of saline water from Biscayne Bay made up the difference between losses from evaporation and water added by rainfall, pumping from the Interceptor Ditch and other minor sources. As a result, salt accumulated in the canals. Since 2010, the salinity of water in the canals has averaged around 60 psu. Seepage out of the canals provides a steady supply of hypersaline water to feed the growth of the groundwater plume.

In 2016, FPL initiated actions to remediate the discharge of hypersaline water into the aquifer. In particular, fresher water is being added to the canals from the Upper Floridan aquifer to decrease the average salinity to 34 psu. And, water is being withdrawn from the groundwater plume through a series of recovery wells and pumped into a deep injection well. These actions address the factors involved in the formation and westward migration of the saline groundwater plume. However, these measures do little to mitigate the discharge of water into Biscayne Bay. Monitoring results indicate that adding water to lower salinity has had the effect of increasing discharge toward Biscayne Bay. Discharge to the bay occurs intermittently in response to changes in plant operations, heavy rainfall, and fluctuations in bay water levels, the last two being also affected by climate change and accelerated sea level rise.

BIO (50-word maximum): Laura Reynolds is a biologist with over 20 years experience working in and protecting Floridas ecosystems. With Conservation Concepts LLC she helps nonprofits bring environmental issues into the public eye and bridge the gap between science and policy to better protect Floridas ecosystems and resources.

Contact Information: Laura Reynolds, Conservation Concepts LLC, 360 Hunter Street, West Palm Beach FL, 33405 Phone: (786) 543-1926 Email: lreynolds@conservationconceptsllc.org