A massive sinkhole opened at a Florida fertilizer plant and crews are urgently working to stop the flow of contaminated waste water into an aquifer.
The incident occurred at the Mosaic Company's New Wells plant in Mulberry, Florida, located about 45 minutes east of Tampa.
The sinkhole was first discovered on Aug. 27 when water loss was detected from one of Mosaic's phosphogypsum stacks. The water level decline was soon reported to the Environmental Protection Agency and the Florida Department of Environmental Protection (FDEP). Mosaic said the sinkhole is approximately 45 feet in diameter and reaches the Floridan aquifer. The depth of the sinkhole is unknown.
Mosaic is one of the world's leading producers of concentrated phosphate. Phosphogympsum is a byproduct of the fertilizer manufacturing process.
Officials told WPTV in West Palm Beach that over 215 million gallons of contaminated water has drained into the sinkhole. The company said extensive groundwater monitoring has found no offsite impacts thus far.
"While to date there is no evidence of offsite movement or threat to offsite groundwater supplies, in an abundance of caution, FDEP is coordinating with Mosaic to reach out to the nearest adjacent homeowners who may want testing for their drinking water wells," FDEP spokesperson Dee Ann Miller told AccuWeather.
While the process water is being successfully contained, goundwater monitoring will continue to ensure that there are no offsite or long-term effects, Miller added.
The process of water recovery is being done by pumping through onsite production wells.
The Florida aquifer system is one of the most productive aquifers in the world and supplies 100,000 square miles across the Southeast, including portions of Alabama, Georgia, South Carolina and all of Florida, according to the United States Geological Survey.
For residents who want to have their drinking wells tested, Mosaic will place contact information on its website.
Mosaic said it is working closely with regulators and has been in daily contact with the FDEP. The plant remains in operation and continues to manufacture fertilizer.
A call to Mosaic seeking additional comment went unreturned.
Sinkholes are a type of karst landform and are common across all of Florida. Karst refers to the characteristic terrain produced by erosional processes associated with chemical weathering and dissolution of limestone, one of the most common carbonate rocks in Florida, according to the FDEP.
"The weather and geographic environment in the Florida Peninsula is conducive for sinkholes. The Tampa area averages between 6 and 8 inches of rain each month during the summer," said AccuWeather Senior Meteorologist Alex Sosnowski. Rainfall from June 1 up to the time of discovery of the sinkhole was approximately 24 inches, which is 122 percent of normal."
"While it is impossible to say precisely which rainfall was the trigger for the sinkhole, heavy rainfall events in the Tampa area and the Florida Peninsula in general are common during the summer," Sosnowski said. "This rainfall combined with the limestone bedrock is favorable for the formation of sinkholes."