For the first time, Mosaic gave reporters a ground tour of the gigantic sinkhole near the company's phosphate plant in Mulberry.
- Ground on top stabilized
- Work continues to seal bottom of sinkhole
- Project on schedule; sinkhole should be filled by mid-June
"Originally the sinkhole was 220 feet below surface,” said Project Manager Jeff Golwitzer. “We’ve added 45 feet of concrete to the base of that stack. We’re at about 180 feet down right now.”
Golwitzer said the ground on top is stabilized. The company is currently working to seal the bottom of the sinkhole with concrete grout. Once its filled, workers will then fill the part above ground with gypsum.
"We have some of the best scientists working on this to help us understand exactly why these happen in the first place," said Herschel Morris, Vice President of Phosphate Operations.
More than 80 workers from a variety of contracting companies are involved.
"We've estimated the cost of this is about $70 million,” Golwitzer said. “That’s between water treatment, water recovery, as well as gyp stack remediation. We’ve built an entire water treatment facility and two recovery wells as part of this project so it’s a pretty sizable operation.”
Mosaic said the project is on schedule and the sinkhole should be filled by mid-June.
"We believe we are going to seal this hole. It has been done in the past,” Morris said.
Morris said the goal is to also learn from the incident so the company can prevent it from happening in the future.
"We’re doing an exhaustive study of what causes sinkholes, of what can be done to determine the likelihood of sinkholes in areas where we might put a gyp stack in the future," said Morris. "We’re assessing all of our other gyp stacks to the degree that we can."
The company has also had more than 1,300 private wells tested. Morris said he believes the recovery well is working because results show that none of the private drinking water wells have been contaminated by the sinkhole.
" I would have no concerns whatsoever drinking the water, once my well was tested," said Morris. "Not tested for our issue but tested for all well water like they should in Florida."
The Department of Environmental Protection reports that 84 homeowners’ wells showed no impacts from the contaminated water from Mosaic’s sinkhole, but did show results above drinking water standards.
In 2017, Mosaic plans to test private wells within four miles every quarter. It also has more than 80 monitoring wells on-site. It plans to test those indefinitely.