January 26, 2022
Advanced Monitoring Provides Important Insights into Gypstack Operations
Phosphate helps America’s farmers put food on everyone’s table. Before farmers can use phosphate, we’ve got to make it. One of the byproducts of phosphate manufacturing is called phosphogypsum.
Over 30 years ago, the Environmental Protection Agency (EPA) required phosphogypsum, a byproduct of phosphate production, be stored in gypstacks. Gypstacks look like flattened pyramids, with a “layered” style of construction. Today, gypstacks are equipped with the latest technology and geotechnical monitoring devices that allow for a stack to be constantly studied inside and out.
Over time, gypstacks experience settling that may require periodic maintenance and inspection. Advanced technology including piezometers and vibrating wires are embedded in the structure and provide engineers with important data that helps properly manage stacks. Piezometers measure the pressure of a liquid or gas underground and are placed in deep boreholes to support stack analysis. Similar to guitar strings, vibrating wires measure environmental and geologic changes around a gypstack and provide data about a stack’s structural integrity.
Drones, operated by certified pilots and equipped with high-definition cameras, routinely inspect gypstacks from the air, providing engineers with a bird-eye view of stack operations. Ground-penetrating radar, a tool used to gather images of gypstacks beneath the surface, is regularly deployed to detect the subtlest movement.
So, gypstacks are highly regulated, closely monitored and carefully constructed. However, continually expanding the size of existing gypstacks and building new ones is becoming an outdated solution. When we embrace innovative approaches like recycling phosphogypsum, we will decrease our reliance on gypstacks, reduce their size and make more land available for conservation and wildlife habitat.
Check out this short video that explores gypstacks and beneficial use opportunities for phosphogypsum: Gypstacks 101