Florida Phosphate Operations
- News & Videos
This series will further explain some of the technical terms used in our remediation posts.
This post defines the term: gypstack, which we often use when referring to Mosaic Fertilizer’s manufacturing operations.
Phosphogypsum (primarily calcium sulfate) is a byproduct of the fertilizer manufacturing process that is created when the phosphate rock we mine is combined with sulfuric acid to form phosphoric acid and phosphogypsum. The term gypstack refers to a stack where phosphogypsum is stored.
Gypstacks are engineered features and are highly regulated. Federal regulations require phosphogypsum to be stored in stacks because of naturally occurring radionuclides in the mined phosphate rock. The Florida Department of Environmental Protection has developed stringent standards regarding the design, operation, maintenance, closure and long-term care of gypstacks.
Central Florida Geology Fact Sheet (originally posted 9/30/2016)
The State of Florida has unique subsurface geology, with much of the underground rock layers made up of limestone, a highly porous rock. The Floridan Aquifer flows through these limestone layers and is known to be one of the most productive aquifers in the world. Due to the porous nature of these limestone layers, deep cavities have naturally formed over time in the rock layers below the surface. Sometimes, the surface layer of rock comprising the upper Floridan Aquifer above those underground cavities contain imperfections like small vertical gaps. Over many years, the surface layer can slowly erode downward, resulting in the formation of a sinkhole. Although scientists cannot accurately predict precisely where and when a sinkhole may occur, they do know that sinkholes are naturally occurring geological phenomena throughout much of Florida, where thousands of sinkholes are found.
Once the sinkhole at the New Wales site developed, Mosaic began evaluations to learn as much as possible about it. Because there was a water loss event associated with this sinkhole, Mosaic’s experts, third-party scientists and engineers have been closely studying what effects the sinkhole, and water lost to the sinkhole, could have on the underlying Floridan aquifer.
Through extensive well monitoring that collects data from 79 monitor wells tapping the shallow, intermediate and Floridan aquifers beneath the facility, as well as site-specific modeling of the direction and speed of water movement within the aquifer, hydrogeologists have accurately determined groundwater flow directions and movement characteristics in the particular part of the aquifer directly underneath the New Wales site.
In this part of the Floridan Aquifer, groundwater flows slowly in a westward direction. In general, the speed of water movement in an aquifer depends on many factors. In this case, it has been determined that, even without any influence from operating Mosaic’s recovery well, this part of the aquifer moves at only about 500 feet per month. This means that without any pumping, it would take more than 2 years for the water to move just to the western edge of the New Wales property boundary. However, Mosaic is taking action, by drawing the water from the affected portion of the aquifer directly up to the surface through a recovery well. This well acts essentially like a straw in the aquifer, recovering all of the slow-moving impacted water back up to the surface.
To keep additional water from entering the aquifer, the company will plug the sinkhole. Mosaic has retained a geotechnical firm that has extensive experience in remediating sinkholes. Remediation is expected to include a process of injecting a concrete mixture into the neck of the sinkhole to fill the cavity and stabilize the formation.
It is important to note that, as gypsum on surface layers surrounding the sinkhole’s opening begins to dry out over the next few weeks, it will shrink and some localized cracking and breaking around the hole can be expected. As this occurs, it may appear that the sinkhole is enlarging – though the underlying cavity remains the same size.
To further ensure the integrity of drinking water wells in the communities around the New Wales facility, the company is relying on elements of its extensive network of monitoring wells surrounding the facility that have been both reviewed and approved by regulators. The company is adding several more monitoring wells, to confirm that, as expected and as verified by models, the lost water is not moving past the recovery well.
Mosaic will continue to monitor the water for as long as it takes to demonstrate that all water lost to the aquifer has been safely recovered and that there are no impacts beyond our property boundaries.
Information about Well Testing (originally posted 9/22/2016)
Recently, some of our neighbors have been asking questions related to the water tests that are being provided to those requesting them. The water tests are being offered free of charge. The company coordinating these water tests, Environmental Consulting & Technology, Inc. (ECT), is a Gainesville-based environmental consulting firm that has provided water testing and other environmental services in Florida and nationally for nearly 30 years. ECT has deep experience in providing those services, to both the private and public sectors.
In addition to working with Mosaic, ECT has worked with the following federal and state governmental agencies:
- U.S. Environmental Protection Agency (EPA)
- U.S. Fish & Wildlife Service
- U.S. Forest Service
- U.S. Army Corps of Engineers
- U.S. Department of Agriculture
- U.S. Department of Energy
- U.S. Department of Interior
- Alabama Department of Environmental Management
- Florida Department of Agriculture and Consumer Services
- Florida Department of Environmental Protection (FDEP)
- Florida Fish and Wildlife Conservation
- Indiana Department of Environmental Management
- Michigan Department of Environmental Quality
- Michigan Department of Natural Resources
- Mississippi Department of Environmental Quality
- South Carolina Department of Health and Environmental Control
So far, ECT has taken samples from 52 wells and has scheduled 210 testing appointments.
The well water samples are being analyzed for constituents and parameters that are indicative of the type of water that was released as a result of the sinkhole. ECT is collecting these samples in accordance with the Florida Department of Environmental Protection’s (FDEP) Standard Operating Procedures.
These parameters and constituents are:
- Total Dissolved Solids, or TDS
- Gross Alpha
According to ECT, results will be released in two phases because some laboratory analyses take longer than others. The first phase will report on results for pH, conductivity, turbidity, sodium, sulfate, TDS, and fluoride. The second phase will cover results for Gross Alpha.
Neighbors who have requested alternative means of testing are encouraged to receive a water test at no cost from FDEP. You can contact the department online by visiting http://www.dep.state.fl.us/secretary/ps/default.htm.
Recovery of Water from the Floridan Aquifer (originally posted 9/21/2016)
Our monitoring indicates that water released from the gyp stack remains onsite.
Water within the Floridan aquifer in the vicinity of the New Wales facility generally moves to the west, and at a slow pace – around 500 feet per month. Please note: In our original update, we cited that the flow of water within the aquifer was approximately 1,000 feet per month. But, based on further evaluation, the pace of groundwater movement is even slower than initially estimated. That pace allows us to recover water from the gyp stack in the aquifer by pumping it through our well as shown on the graphic below. That well is located west of the gyp stack and taps into the Floridan Aquifer.
Walt Precourt, Senior Vice President of Phosphates Addresses Polk County Board of Commissioners (originally posted 9/20/2016)
This morning, Walt Precourt, Senior Vice President of Phosphates for Mosaic addressed the Polk County Board of County Commissioners providing them with an update related to the sinkhole as well as the details of our recovery and remediation efforts. Walt was joined by Herschel Morris, Vice President of Phosphate Operations. The meeting which was streamed live can also be seen here.
Here are excerpts from Walt Precourt’s remarks as prepared:
“On behalf of Mosaic and our nearly 4,000 employees in Florida, we’d like to express our sincere regret that the sinkhole and water recovery operations on our property have caused concerns for the community.
“At Mosaic, the health and safety of our employees and our local communities is paramount. We live, work and raise our families here too, so we take our responsibility to protect the public and the environment very seriously.
“The day we confirmed a change in water level in the process water pond at the New Wales facility in Mulberry, we promptly notified the Florida Department of Environmental Protection, the U.S. Environmental Protection Agency and Polk County.
“We immediately took steps to remove as much water from the leaking process pond as possible, and are now operating a recovery well to remove the rest of the water from the aquifer. Based on extensive monitoring data, no water from the stack has migrated off our property.
“Using test wells surrounding our facility, we immediately increased the frequency of water quality monitoring. The water samples from all of these test wells continue to test normal, indicating that there has been no offsite impact.
“Understandably some of our neighbors who live near the New Wales facility are concerned about water coming from their wells. We don’t want our operations to cause concern or worry among our neighbors, so to allay any concern, we’re reaching out to our neighbors and offering to pay for the cost of testing their wells. Some neighbors have requested bottled water, and to allay their concerns, we are providing that too until their well tests are complete. We want our neighbors to not just be safe, but to have peace of mind.
“Since August 28, when we realized we had major water loss at the gypsum stack, we have been working closely and constructively with state environmental regulators. We update the Florida Department of Environmental Protection daily and its representatives have been on site regularly, providing us with diligent oversight and assistance in rectifying this situation.
“Our Mosaic team continues to work around the clock to review the situation, and our response to it. We continue to analyze the situation, and our response to it, and we realize we could have done a better job in providing timely information to our neighbors and the broader community.
“I regret and apologize for not providing information sooner, and am committed to providing regular updates to the public as we move forward. As new information is available, we will be posting it on our website, and providing continued updates to regulators, the press, our local community, and most importantly our neighbors.
“Mosaic has a long history of working closely with our neighbors and the communities where we operate, and we will work hard to honor our commitment to them now and in the future.”