Phosphogypsum is a byproduct of the fertilizer manufacturing process. It is produced when the phosphate rock we mine is combined with sulfuric acid to form phosphoric acid and phosphogypsum. The phosphogypsum must be filtered and removed so the remaining phosphoric acid can be used to make fertilizer. The phosophogypsum is subsequently deposited on a gypstack under strict standards established by the Florida Department of Environmental Protection (FDEP) and the U.S Environmental Protection Agency (EPA).