A brief history
Phosphate is a non-renewable natural resource obtained from the extraction of phosphate-containing minerals. Florida’s phosphate rock deposits are believed to have originated when seawater conditions caused dissolved phosphorus to solidify and form the sediment that is mined today (1). Marine life also played an important role in the formation of the sediment deposits.
Pebble River Phosphate was first discovered along the Peace River, Florida, in the late 1800s by a captain in the Army Corps of Engineers (5). Phosphate extraction began shortly thereafter. Florida miners did not have mechanized digging equipment. That means early mining was done by hand using wheelbarrows, wagons, picks, and shovels. The mining task was slow and laborious, but the phosphate pebble showed promise. Interest in this pebble increases and the phosphate industry is born. The 20th century brought mechanized excavation equipment like power shovels to Florida’s phosphate mines, but hydraulic shovels didn’t last long.
Draglines were first introduced in the 1920s, and their use has increased since then. Dragline technology continued to advance, leading miners to switch from river pebble phosphates to overland cobble and hard rock, and then to mine the finer grained “phosphate matrix”.
Phosphate matrix deposits (4) occur in a broad area of west-central Florida known as “Bone Valley”. In 1900, it took 3-4 years to mine 15 acres with picks and shovels. In the early days of small draglines, about 5 acres were mined in a year. As the draglines grew in size, they could pull 500 to 600 acres a year. Conservatively, today’s draglines can completely destroy 50 acres per month.
Phosphate Mining Process Florida’s phosphate ore (matrix) is located approximately 40 feet below the earth’s surface. The matrix is intertwined with one of Florida’s true treasures, the aquifer systems. Phosphate rock is mined and then manufactured through the fertilizer manufacturing process. A typical Florida phosphate mine gets about 9,000 tons of phosphate rock per acre of land. Huge draglines are brought in that can remove Florida soil from the surface down 100 feet to remove all of the “field” from the matrix.
The phosphate industry refers to the land mined as “overburden.” The rest of us call it orange groves, meadows, old spas, springs, aquifer systems, rivers, springs, etc.
Once the overburden is removed, the draglines can “stripped” the matrix, which consists of equal parts phosphate rock, clay, and sand. The matrix (2) is then dumped into huge mud pits where literally untold volumes of fresh, clean water from the aquifer are used.
The water comes from the freshly crushed aquifers under the powerful dragline. Billions of gallons of Florida fresh water are released and used in high-pressure water cannons to create a slurry that can then be pumped to the beneficiation plant, which can be up to 10 miles away.
In the beneficiation plant, the phosphate is separated from the sand and clay. The toxic sludge is then stored in huge clay settling ponds until untold amounts of water evaporate from the aquifer.
One byproduct, called phosphogypsum, is slightly radioactive, so it can’t be easily disposed of. The only thing miners can do with it is pile it up in mountainous piles next to processing plants. Florida is such a flat state that 150-foot-tall “plaster piles” are often the highest point on the landscape for miles around. They contain large pools that can be as large as a square mile of highly acidic sewage.
Not surprisingly, mining and mineral processing facilities generate more toxic and hazardous waste than any other industry sector. (4) Reducing the environmental impacts of the operations of large fertilizer manufacturers is a national priority for EPA.
The United States produces the most phosphate (2) in the world, while Morocco and China rank second and third, respectively. Phosphate reserves are found in Central Florida, North Carolina, Utah, and Idaho. Florida currently provides about 75 percent of the nation’s supply of phosphate fertilizers and about 25 percent of the world’s supply. Follow the Money Florida’s phosphate deposits today are the foundation of an $85 billion industry that supplies most of the phosphate consumed in the United States. Of the industry’s $85 billion worth, only a few million dollars are spent in the local communities where the mines are located. Some have called this a boon for local communities. However, the phosphate industry seems to be a bad neighbor. This is because they are “allowed” to put their environmental catastrophes behind them so that local citizens pay for them. Interestingly, the Central Florida phosphate mines are now known as “Bone Valley”.
This $85 billion phosphate producing area is located in the middle of one of Florida’s greatest natural treasures called aquifer systems or “water tables.” These aquifer systems can be compared to bee hives, where the aquifer system is the hive and water replaces honey.
Aquifer systems are considered the foundation of Florida’s entire supply of clean fresh water. Today, this Central Florida phosphate region (3) consists of Hillsborough, Polk, Hardee, DeSoto, and Manatee counties. These same counties also contain huge watersheds including the Alafia River Watershed, Peace River Watershed, Manatee River Watershed, Little Manatee River Watershed, and Myakka River Watershed.
As of this article, the phosphate industry continues to purchase more land intended to mine the valuable phosphate in the aforementioned basins. Florida’s phosphate dilemma continues to escalate, causing more extensive irreparable environmental damage on a daily basis.
Resource Information
1. Florida Institute for Phosphate Research (FIPR)
2. Florida DEP Mining and Minerals Regulations
3. Watershed data
4. Peace River Cumulative Impact Study
5. US Army Corps of Engineers—Jacksonville District