Mosaic Co. believes that the 45-feet sinkhole, which opened at its New Wales phosphate fertilizer facility in Florida in late August, has reached the Floridian aquifer, a source of drinking water for the locals, Bloomberg News reported Sept. 27.

The leak, which was not publicly disclosed until Sept. 15, is now the basis of a lawsuit filed by three locals who are claiming that the company failed to store the radioactive and chemical waste properly.

The residents are asking for class-action status and are asking for the company to pay for property damage and to test the water wells in the area.

According to the report, there are about 1,500 private wells in the area affected by the leak, with about 5,000 people living within five miles of ground zero.

Mosaic said Sept. 23 that it is working to remove the water from the Floridian aquifer, and ongoing tests have revealed no contamination of the local water supply.

The company noted that as of midnight Sept. 27, it had received a total of 603 requests for testing water wells. The tests, which are being conducted by a third party, Environmental Consulting & Technology Inc., are being prioritized on the basis of proximity to the New Wales facility.

According to Jonas Oxgaard, a New York-based analyst at Sanford C. Bernstein & Co., the spill could hamper the company's expansion plans in Florida, where it has mining permit applications for the Wingate mine, and plans to develop the DeSoto and Ona mines.

Mosaic has estimated the cost of fixing the sinkhole fertilizer facility at between US$20 million to US$50 million.