PALMETTO – Stormwater collected over several months in a pond on top of a phosphogypsum waste stack at Piney Point is being released this week into Tampa Bay at Port Manatee, according to the Florida Department of Environmental Protection (FDEP).
The “dewatering,” another step toward the final closure of the idled phosphate plant, began on Aug. 12 and will amount to about 4.5 million gallons, spokesperson Alexandra Kuhta said.
“This is the first pond to be closed and contains strictly rainwater,” she said. “Ultimately all (ponds) will be closed on the site.”
The stormwater is separate from the 262 million gallons of phosphate process wastewater still on site, which is contained in separate lined compartments and is managed separately, according to an FDEP press release.
A leak in one of the gypsum stacks in March 2021 resulted in FDEP approving the dumping of 215 million gallons of contaminated process water into Tampa Bay to prevent flooding of homes and businesses in the event of the stack’s collapse. The discharged water spread throughout Tampa Bay and Sarasota Bay, transporting nitrogen and phosphorus that worsened a bloom of the toxic algae red tide that lasted from April to November, causing fish kills and respiratory irritation.
The stormwater is less problematic, according to FDEP.
“DEP and the court-appointed receiver have independently tested the water, and current water sampling results indicate the concentrations of total nitrogen range from 2.3 to 3.5 mg/L.
At this level, the nutrient loading to the bay is expected to be less than 0.1%
of the federally adopted annual Total Maximum Daily Load for Lower Tampa Bay,” according to the press release.
The stormwater pond will be modified so that it will no longer accumulate rainwater, eliminating the need for future stormwater releases, according to the agency.
Court-appointed receiver and Tampa-based attorney Herb Donica recommended a phased approach to closing the ponds, which are less than two miles from Tampa Bay, near two state aquatic preserves.
The Piney Point site will be closed by December 2024, according to a plan approved by the FDEP on March 30.
