Phosphate giant Mosaic pumps from Florida's aquifer to dilute its pollution

A Mosaic mine operates in 2010 in Hillsborough County, where a permit allows Mosaic to withdraw water from wells for mining and production facilities. Mosaic also uses freshwater to dilute pollution from plants, a process the industry calls “blending.”
A Mosaic mine operates in 2010 in Hillsborough County, where a permit allows Mosaic to withdraw water from wells for mining and production facilities. Mosaic also uses freshwater to dilute pollution from plants, a process the industry calls “blending.”
Published July 21, 2013

Last year, a state water agency granted the world's largest phosphate mining company a permit to pump up to 70 million gallons of water a day out of the ground for the next 20 years.

Some of those millions of gallons of water — no one can say how much — is being used by the phosphate giant known as Mosaic to dilute polluted waste so it can be dumped into creeks without violating state regulations.

The permit allows Mosaic to withdraw water from more than 250 wells in Hillsborough, Manatee, Polk, Hardee and De Soto counties, an area that since 1992 has been under tight restrictions for any new residential and commercial water use.

"The water use is crazy," said John Thomas, a St. Petersburg attorney who challenged the Mosaic permit on behalf of a client who ended up settling. "They're pulling an awful lot of water out to discharge with their waste."

Odd though it may sound, that's a standard practice for the phosphate industry, according to Santino Provenzano, Mosaic's environmental superintendent.

It's allowed under the state Department of Environmental Protection's rules, said Brian Starford of the Southwest Florida Water Management District, the agency commonly known as Swiftmud. Without that freshwater to dilute it, what Mosaic is discharging would violate the DEP's limits on a type of pollution called "conductivity," he explained. That term refers to the solids that are left in the waste after it's processed.

"If they were exceeding the standards, the DEP would not allow the discharge," explained Starford, whose agency issued the Mosaic permit.

DEP press secretary Patrick Gillespie said using freshwater to dilute a phosphate plant's discharge "is permissible and used only in closure activities or in storm-related activities in order to meet department water quality standards."

Mosaic spokesman David Townsend said the company is only using freshwater for dilution with waste from inactive processing plants, which he said complies with DEP rules. He could not provide a list of where those were located or how many there were.

The diluted waste is discharged "usually into a creek or smaller water body that feeds into a larger one at some point," he said.

The issue of how much water Mosaic pumps out of the ground was explored by a recent environmental impact study on phosphate mining that was commissioned by the U.S. Army Corps of Engineers. The report found that the miners' water use in some areas could lower the aquifer by up to 10 feet, but contended the aquifer would eventually recover when the pumping stopped.

The same agency that issued Mosaic's water permit, Swiftmud, declared a 5,100-square-mile area covering all or part of eight counties south of Interstate 4 to be the Southern Water Use Caution Area in 1992. The reason: so much water had been pumped out of the aquifer in that region that the water table had fallen 50 feet.

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Mosaic previously had a permit that allowed it to take up to 99 million gallons a day from underground, so the permit issued last year is a reduction. As of last month, the mining giant was pulling only 30 of its allotted 70 million gallons a day out of the ground, Provenzano said.

Half of that was being used in the mining process and the other half was being used at production facilities, he said. He said he could not specify how much was being used to dilute the pollution from some plants, a process the industry prefers to call "blending."

In approving the Mosaic permit, Swiftmud officials had to rule that the company had offered "reasonable assurances" that its use of the water isn't wasteful and won't adversely affect downstream users and the environment.

But Thomas questioned whether Swiftmud or Mosaic have ever considered coming up with a different way to deal with the pollution. By repeatedly pumping millions of gallons of water from underground just for blending, he said, the company will leave behind "a swiss cheese aquifer with pools of groundwater contamination and cascades of diluted gyp stack waste for decades."

Craig Pittman can be reached at