POLK COUNTY, Fla.- A Mosaic pond has leaked about 215 million gallons of “slightly radioactive” water into the Florida aquifer since August 27 when a sinkhole opened up under a retention pond, says Mosaic.
The drainage is happening at Mosaic’s New Wales plant off of Highway 640 in Polk County. The plant sits on top of a huge gypsum stack and stores wastewater in ponds.
On August 27 a representative told Fox 13 News that they noticed the water level in one of the ponds dropping. About a week later a sinkhole was confirmed to have opened up under the gypsum stack. The sinkhole is 40 feet across and it’s depth is unknown.
Gypsum comes out of the plant after Mosaic produces phosphate fertilizers and animal feed ingredients. Gypsum is a soft white or gray mineral consisting of hydrated calcium sulfate.
David Jellerson, Mosaic’s director of environment and phosphate projects, told WFLA, “when it was first noticed (the drop in water level), we installed pumping systems to move water out of that compartment on the gypsum stack, to recover the water.”
The water, which was leaking into the Florida aquifer, is contaminated with phosphoric acid and is slightly radioactive. It is water you wouldn’t want to drink. Sodium and sulfate are the contaminants of concern, along with the phosphoric acid.
“We also have quite a number of monitoring wells and have increased the monitoring schedule to confirm nothing has left the perimeter of the site,” said Jellerson.
Mosaic said they immediately notified the state Department of Environmental Protection and the EPA. They also said the groundwater has been routinely tested since the sinkhole was confirmed.
As of now Mosaic doesn’t believe the contaminated water has made its way to any private wells since it hasn’t shown up in the monitoring wells around the plant.
The plant assistant general manager, Chris Hagemo, said Mosaic will continue to monitor the stack to insure there is no safety concerns. Mosaic will also continue to remediate groundwater beneath the sinkhole until DEP gives the all-clear.