Bone Valley: Phosphate Beneath the Bay
Near Tampa Bay, Florida
Florida's most economically consequential landscape is not the beach. It is a region the phosphate industry calls Bone Valley.
Bone Valley encompasses portions of Hillsborough, Polk, Hardee, and Manatee counties, the inland territory stretching east of Tampa. The name comes from what miners find in the phosphate matrix: the fossil bones of ancient marine mammals, sharks, mastodons, and giant ground sloths that lived when this region was a shallow sea, buried alongside the phosphate rock that their decomposition helped create over millions of years. Florida contains the largest known phosphate deposits in the United States. Much of the food the world eats grows in soil fertilized by what is extracted from this ground.
Phosphate was discovered along the Peace River in eighteen eighty-one, and commercial mining followed by the late eighteen eighties. The industry connected almost immediately to Tampa Bay. The ore was processed into fertilizer at facilities along the bay's shores and loaded onto ships at Port Tampa Bay, which for much of the twentieth century was the busiest phosphate port in the world. In recent years Tampa Bay has shipped as much as eight million tons of phosphate in a single year.
The environmental record is complicated. Early mining operated with minimal regulation and left behind a landscape of open pits and clay settling ponds. Processing phosphate produces a radioactive byproduct called phosphogypsum, and the stacks that accumulate it at Tampa Bay area plants represent some of Florida's most serious long-term environmental liabilities. In nineteen seventy-one, a dam failure at a phosphate operation sent an estimated one to two billion gallons of waste slime into the Peace River and killed millions of fish.
Regulations tightened after nineteen seventy-five. Reclamation is now required. Former mining pits have been converted to lakes, parks, and golf courses.
The bones in Bone Valley, the fossils that give the region its name, are still there, underneath the phosphate that the industry took, in the ground that the agriculture made, in the food that arrives at grocery stores without any indication of where it came from or what was disturbed to grow it.
