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US sinkhole causes contaminated wastewater leak

NCE stock health and safety

More than 757M litres of contaminated wastewater from a phosphate mine in Florida has leaked into the underground system that feeds the state’s drinking water supplies.

On 27 August water level monitoring at its New Wales facility showed a decline in levels for one of the two cells of its phosphogypsum stacks, according to fertiliser company Mosaic. 

Mosaic – the world’s largest combined producer of potash and phosphates – said it reported the decline to authorities, the Florida Department of Environmental Protection (FDEP) and US Environmental Protection Agency (EPA), as well as Polk County.

According to the company, an approximately 13.7m diameter sinkhole formed under the west cell and damaged the system at the stack’s base. As a result of the damage, a contaminated wastewater pond that was situated on top of the stack drained and some seepage continues.

It is believed that the sinkhole has reached the Floridian aquifer, the porous rocks which supply some of the state’s drinking water, although Mosaic said groundwater monitoring and sampling have shown “no offsite impacts”.

A pumping water recovery operation has been implemented, which involves Mosaic trying to reclaim the water from the aquifer and sending water to an alternative holding area.

The company said: “We have also called in top experts in the field to advise us on this issue. Enhanced water quality monitoring continues, and we are developing a comprehensive corrective action plan to address and rectify the cause of the water loss.”

Environmental group Earthjustice’s managing attorney in Florida Tania Galloni said: “I wish we could say that watching an environmental tragedy unfolding at a Florida phosphate mining site was a new occurrence, but sadly it’s happened repeatedly.

“These phosphate companies are playing roulette with our public waters.”

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