Pre-strip-mining, clay ponds were smaller and gypstacks were fewer and smaller. There were many clay spills anecdotally referred to in the histories, but few documented disasters until about 1980.
• 1945: Peace River/Polk County spill.
• 1963: Brandon slime dam failure (slime was a miner’s term for the clays retained after ore separation in clay settling areas (CSAs), as they are now known.
• 1967: Mobil Oil retention dam failure (probably a toxic clays spill). Several oil companies were players in the phosphate rush, including Mobil, Occidental and Texaco.
• 1971: Fort Meade waste spill.
• 1980: Agrico dumps 12,000,000 gallons of toxic process fluids into the Peace River. • 1988: Gardinier phosphoric acid spill into the mouth of the Alafia River. • 1989: Big Four Mine clay spill.
• 1990: Gardinier 250,000 gallons of toxic clays into Peace River.
• 1993: Cargill fertilizer plant in Gibsonton (Riverview) spills acid into Archie Creek. • 1994: IMC/Agrico gypstack “drops through a sinkhole”
• 1994: IMC Payne Creek Mine unspecified spill.
• 1994: 500 million gallons acidic process water spills from stack breach and floods parts of Keysville, FL.
• 1994: IMC/Agrico Hopewell Mine toxic clay pond breach.
• 1995: Sinkhole at New Wales north stack (IMC) creates a “15-story sinkhole.”
• 1997: Mulberry Corp. 55,000,000 gallons acidic process water spills into Alafia River, killing millions of fish and leaving thirty miles of river “dead as a sewer pipe.”
• 2003: Owners of Piney Point chemical plant and stack (Manatee County) declare bankruptcy, leaving FDEP and taxpayers with responsibility.
• 2004: Cargill Riverview stack spills 65,000,000 gallons acidic process water during Hurricane Frances.
• 2004: Sinkhole at New Wales south stack.
• 2011: Piney Point/FDEP 170,000,000 gallons of contaminated sea water from port dredging, stored in the process water lake, spills into Bishop’s Harbor.
• 2013: IMC/Mosaic invisible sinkhole spills for four years beneath New Wales north stack. Over 40,000,000 gallons probably released into Floridan Aquifer before detection.
• 2015: USEPA demands consent decree with Mosaic over illegally mixed contaminants sent to the gypstacks for an unspecified length of time, rendering west-central Florida the largest repository of toxic and hazardous waste in the United States, and possibly the world.
• August, 2016: Mosaic New Wales sinkhole in south stack, sends 215,000,000 gallons of contaminated, acidic process water into Floridan Aquifer.
• September, 2016: Mosaic 97,000 gallon spill (unspecified) at Bartow.
• October, 2016: Mosaic 50,000 gallon pure phosphoric acid spilled at Plant City.
• 2018: Bartow gypstack crack, shifting, movement.