Anybody who’s lived in the Bay Area for any amount of time need not look at the numbers provided by the Florida Phosphate Council to understand how important the industry is to Central Florida.
Last year alone, according to the Florida Phosphate Council, 33.8 million metric tons of phosphate rock were extracted from 6,355 acres of land by 8,256 Floridians directly employed by the industry, earning a payroll, with benefits, of $404.3 million.
The industry — with a multibillion-dollar capital investment in Florida — owns or has rights to nearly 500,000 acres in the Sunshine State. About three-quarters of the nation’s phosphate supply and about one-fourth of world production comes from Florida. Ninety-three percent of the outbound cargo at the Port of Tampa is phosphate.
Yet while phosphate is important to the area and helps feed the world’s burgeoning population — about 90 percent of the mined rock is used to make fertilizer, 5 percent is used in animal feed, and the remainder is used in products as diverse as vitamins, soft drinks and toothpaste — it doesn’t come without a price.
That price? Air, water and land quality, all of which may be adversely affected from the byproducts of phosphate mining and production.
A main concern over the years, and a major challenge to the phosphate industry, are the gypsum stacks, most commonly seen dotting stretches of State Road 60 from the Bay Area east into the phosphate belt in the middle of the state.
Looking like giant loaves of bread, the stacks’ bases can cover more than a square mile and rise a couple hundred feet into the air. These stacks contain a byproduct of phosphate manufacturing called phosphogypsum, with ponds at the top of the stacks where the phosphogypsum has been pumped as a slurry after the phosphate has been extracted.
While gypsum itself is a harmless material used extensively in products such as wallboard, the phosphogypsum stacks contain an acidic element that may cause concern when located near a drinking source. Also, phosphogypsum itself contains low-level radiation, which can be a source of radon gas.
The state has been responding to the threat.
“We have a program in place designed to close unlined gypsum stacks that have seepage,” said Robert Vanderslice, head of phosphate management for the state Department of Environmental Protection.
Under that program, phosphate companies are required to construct a two-ply polyethylene lining under any new gypsum stacks in order to prevent the seepage of acidic water into the ground. However, there are older stacks that don’t have this protection. Those stacks must be “closed” by March 2001.
The process is already under way at some phosphate mining companies.
“We were the first company to commit to closing gypsum stacks,” said Gray Gordon, a representative for Tampa-based Cargill Fertilizer Inc. “We spent about $5 million to close and cap a gypsum stack over 100 acres in area with a vinyl liner, dirt and grass. We wanted to be sure that the water problem wouldn’t become an issue.”
Not everyone views the phosphate byproduct as a problem.
For example, in Europe and Japan, it is mixed with soil, or is used as a base for new roads.
Some domestic interests support similar applications.
“The Environmental Protection Agency has banned any further use of phosphogypsum. But their risk analysis is based on incorrect data,” said Christopher Earl, president of KEMworks Technology in Mulberry.
“There have been hundreds of tests done and there’s been no indication of the uptake of phosphogypsum into plants when it’s been used as a soil amendment,” Earl said.
But while Earl said the byproduct has been used abroad for years as a soil additive and an additive to cements, it wouldn’t be economical for U.S. companies to export.
Vanderslice, of the state environmental regulatory agency, said some phosphogypsum is indeed used at this time, but there’s only one North Florida company that meets the regulations for radioactivity limits. “The phosphate rock in some North Florida locations doesn’t have as high a radioactivity level as the rock in Central Florida, so it may be used in some cases.”
Vanderslice added that phosphogypsum is still being actively looked at as a viable source for a road base material. “It’s a good material to replace lime rock in roads. Lime rock will run out at some time, and we’re still building a lot of roads. Building roads with phosphogypsum would consume quite a bit of gypsum.”
Besides the effort toward closing and eventually reducing the stacks of phosphogypsum, the phosphate industry is actively working toward other methods of helping the environment while cutting down on costs.
“While the industry is continually looking for ways to take care of current problems, we’re also looking ahead to see what can be done in the future,” said the phosphate research institute’s Richardson.
That organization was formed in 1978 by the state Legislature with a portion of the severance tax on phosphate rock. In 1990, the institute started an in-house project to look at developing effective, low-cost techniques for establishing vegetation on the 700 million tons of gypsum stacks on 5,000 acres in Florida. “Without compromising the effectiveness of safe, environmentally sound practices, we’re looking at a number of ways of reducing the cost of the environmental issues,” said Richardson.
Studies have shown that vegetation such as Bermuda grass or switchgrass could be grown directly on the stacks provided the correct pH level existed and the necessary plant nutrients were added. This approach decreased both radon emissions and improved the quality of runoff.
“With the size of the stacks, you can imagine the cost of adding a foot or two of material to the tops and sides of the stacks,” (now necessary in closing gypsum stacks), said Richardson. “Then you have an impact to take into consideration of the borrow area. It can become a very expensive proposition.”
Richardson points out that growing plants directly on the gypsum stacks not only saves money, but comparisons have shown the ecological effects were more beneficial than other methods used. “The dead plant matter builds up a thick layer, and water runs off the stack without ever touching the gypsum.”
Another, formerly unwanted byproduct of phosphate manufacturing is fluorine gas, which is contained in phosphate rock. Today, however, the industry is capitalizing on an increasing demand for the gas, which is used in a great many products, including plastics and Teflon, as well as stannous fluoride.
“In our overall waste minimization program, we feel technological advances make the recovery of fluorine a viable proposition,” said KEMwork’s Earl. “You don’t want it discharged into the atmosphere, and a lot of it is being produced. It’s one of the ways we can help keep the environment clean and minimize our waste while producing a useful product.”
Cargill Fertilizer is among those companies that extract flourine and sell it to municipalities.
Brenda Menendez, a spokeswoman for Cargill, said the company also keeps its emissions clean by burning off the ammonia “before it leaves the stack.” She added that the company has a computerized system that reduces the possibility of exceeding environmental limits on emissions by automatically shutting down the plant, even if an operator doesn’t recognize the problem in time.
Reclaiming land mined for phosphate rock is also a problem faced by the industry.
During the phosphate mining process, about 50 feet of the earth’s crust is removed and flipped in order to get to the ore. Florida requires that miners replace water bodies, the topography and animal habitats. Since 1975, the law has required that the property be restored acre by acre. Today, reclamation must be accomplished within a two-year period after mining has been completed. Reclamation includes considerations of aesthetic qualities, animal and bird habitat requirements, and restoration of the land surface to productive use.
“We research a number of ways reclaimed land can be put to productive use,” said the phosphate research institute’s Richardson. “For instance, we’re looking at the economic feasibility of planting agricultural crops in clay settling areas (produced when the subsurface clay is washed from the phosphate ore). Currently we’re looking at growing sugar cane and other tall grasses in these areas.”
He said the institute also is investigating how other lands forms such as sand palings — which occur as sand is washed from the phosphate ore — can be put to use.
“A lot of people think of reclamation as turning the land into forests or citrus groves, but we can also use it for things such as power plants, which nobody else wants in their backyards. We’ve done that in Polk County, and it’s worked out well.”
Richardson said that where once it was only important to get productive use out of restored land, be it agriculture or development, now there is also a public desire to return land to a natural state where Florida grasses, trees and native animals once again thrive after years or decades of development.