TAMPA – Fertilizer companies scour and blast crusty, radioactive deposits from filtering equipment, then pile the waste on gypsum stacks.

Contaminated with radium, it is among the most concentrated radioactive waste that comes from natural materials. Yet the federal government has no rules for its disposal.

That’s because the government considers it “naturally occurring radioactive material,” called NORM waste, even though it comes out of the belly of a fertilizer plant.

The U.S. Nuclear Regulatory Commission leaves regulation of such industrial waste products up to the states. Only one, Louisiana, has adopted regulations. Louisiana’s oil industry, like the phosphate industry, produces large amounts of radium-containing residue called scale.

The Florida Department of Health and Rehabilitative Services (HRS) has no formal guidelines for discarding the water. But it has licensed phosphate companies to bury it in their mounds of another waste, gypsum.

That’s a bone of contention for one citizen’s group that wants the state to ban the dumping of radium scale in gypsum piles across Central Florida.

The US Environmental Protection Agency is considering making federal rules for disposal of natural wastes.

“That scale can be pretty hot,” said Craig Conklin, a health physicist for the EPA’s radiation program.

Louisiana banned indiscriminate dumping of radium scale in 1989 after finding widespread contamination in marshes near oil fields and radium-contaminated piping in scrap yards.

The EPA says radium scale has polluted the soil in New Jersey. It has been found in used oil pipes that made their way into Mississippi schoolyards as parts of playground equipment.

Radium can cause cancer if inhaled or ingested over a long period. One of the first radioactive elements discovered, it was used in luminous paint for watch dials and instrument panels until the 1960s. Studies showed increased rates of cancer among workers who painted the dials.

The radium waste from the fertilizer plants is among the most radioactive kinds of NORM waste – so concentrated it can’t be dumped at the one landfill in the country licensed to take only NORM waste.

That landfill is owned by Envirocare of Utah Inc. It’s president, Khosrow Semnani, said he can accept only wastes with an average of no more than 2,000 picocuries of radium per gram of waste. A picocurie is about one-trillionth of a gram. Federal and Florida laws allow up to 5 picocuries of radium in a liter of drinking water. Radium scale from phosphate plants contains up to 100,000 picocuries per gram of waste.

“We could call this an orphan waste because there is no direction on how you deal with it,” Semnani said.

An environmental activist asked about the radium waste disposal said it should be regulated like other low-level radioactive wastes.

“I would question, logically, the designation of it as a naturally occurring material,” said Suzi Ruhl, executive director of the Legal Environmental Assistance Foundation in Tallahassee. The non-profit environmental law firm specializes in water pollution issues.

Regulations, she said, should be based on whether the waste is dangerous, not on how it’s produced.

“It’s probably been a political decision to make this something that doesn’t have to comply with hazardous waste rules,” Ruhl said.