I write in response to Jeff Stidham’s March 28 commentary, “Making Something Of Florida’s `Mountains,’ ” an article about phosphogypsum stacks.

Central Florida phosphogypsum is an acidic, radioactive industrial waste – a public health and environmental hazard that should continue to be prohibited by state and federal agencies for use in roadbeds and agricultural uses. Environmental regulations properly require Central Florida phosphogypsum to be disposed in lined phosphogypsum stacks that are capped and closed when they become inactive.

A quick overview of facts about phosphogypsum clearly demonstrates the appropriateness of current regulations. The Central Florida phosphate rock mined by the phosphate industry contains large quantities of radionuclides. Until the price of uranium declined, the phosphate industry operated two uranium extraction facilities in Central Florida. At phosphoric acid plant facilities, the phosphate rock is treated with sulfuric acid, creating phosphoric acid and phosphogypsum waste. The uranium goes primarily with the phosphoric acid, which becomes fertilizer and additives to products such as Coca- Cola. The radium 226 and 228 primarily go with the phosphogypsum waste.

The phosphogypsum waste that results from treating Central Florida phosphate rock with sulfuric acid contains an average of 21 to 27 picocuries per gram of radium 226, plus various heavy metals such as arsenic, barium, cadmium and lead. Unlike natural gypsum, phosphogypsum is approximately 75 percent sulfur, resulting in phosphogypsum being very acidic, with pH levels as low as 2.15. The acidity of phosphogypsum mobilizes contaminants in both the phosphogypsum and in the groundwater environment. Because of these characteristics, both the Florida Department of Environmental Protection and the U.S. Environmental Protection Agency regulate Central Florida phosphogypsum as solid waste that must be disposed in lined landfills with leachate collection systems, with the stack having to be closed and capped when it becomes inactive.

Federal Regulations Enacted

After years of detailed examination, public hearing notices and agency responses to public comment concerning Central Florida phosphogypsum under the Clean Air Act, the Resource Conservation and Recovery Act and the Toxic Substance Control Act, the EPA correctly adopted regulations in the Federal Register that prohibit the reuse of phosphogypsum that has radium 226 levels greater than 10 pCi/g. Contrary to Stidham’s assertion, this EPA action was a “formal decision” after very much “public input” and comment.

EPA’s formal rule-making decision was proper because the average radium 226 level of 21 to 27 pCi/g is very radioactive – more than 40 to 50 times higher than the background radium 226 level of soil in Polk County, 0.5 pCi/g,. Because north Florida phosphate rock is less radioactive, north Florida phosphogypsum has radium 226 levels less than 10 pCi/g. Stidham’s assertion that radium 226 levels of 21 to 27 pCi/g are “slightly radioactive” is as incorrect as asserting that a woman who is seven months pregnant is only slightly pregnant.

Stidham’s proposed use of phosphogypsum in roadbeds and road material and on agricultural lands would significantly harm the public health and the environment. Roadbed and road material use of Central Florida phosphogypsum would unnecessarily expose workers and the general public to otherwise avoidable radon and gamma radiation exposure. Increased worker exposure would occur through the additional handling of the phosphogypsum. Roadway resurfacing work would grind the phosphogypsum into fine dust, resulting in the ultimate deposition and fate of these fine phosphogypsum particles being unknown. Tests of road use of phosphogypsum have documented violations of groundwater standards for fluoride, iron, lead, manganese, radium 226 and 228, total dissolved solids, sulfate and cadmium. These tests have also resulted in rain washing phosphogypsum into public waterways.

What’s The Real Motive?

Use of Central Florida phosphogypsum with radium 226 levels greater than 10 pCi/g is unnecessary since a sufficient source of north Florida phosphogypsum with a radium 226 level less than 10 pCi/g is available. The real motive behind the push to repeal environmental prohibitions on the use of phosphogypsum with radium 226 levels higher than 10 pCi/g is to once again have the residents of the state of Florida bail out the phosphate industry from having to properly close phosphogypsum piles as required by state and federal law.

Having dug up the phosphate rock and chemically processed it, the phosphate industry has a duty to Floridians to safely and properly dispose of its acidic radioactive phosphogypsum in lined stacks. The phosphate industry has no right to spread its mountains of acidic radioactive waste across Florida.

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