A breach in a dike at a phosphate company in Tampa lets loose 18,000 gallons of wastewater.
By JANET ZINK, JONI JAMES and BILL VARIAN
Published September 6, 2004
[Times photo: Thomas M. Goethe]
Wastewater flows through a breach at the top of the Cargill Crop Nutrition gypsum stack Sunday off U.S. 41 in Riverview. Strong winds created high waves that weakened the dike's southwest corner, a DEP official said.
TAMPA - A dike holding millions of gallons of acidic phosphate water breached Sunday during hurricane rains, releasing at least 18,000 gallons of wastewater into Hillsborough Bay.
Cargill Crop Nutrition, a phosphate company with a factory along the bay in Riverview, tried to protect against environmental damage by mixing a lime product with the acidic fluid to neutralize it.
But state officials said they feared Sunday night that the wildlife in the bay might suffer because containment efforts had failed.
At some point, the company ran out of the neutralizing agent, and a pump being used in the process stopped working, said Russell Schweiss, a spokesman for the state Department of Environmental Protection.
State officials did not expect the release to harm residential areas or threaten public safety.
"We feel terrible that this has happened. We're sick about it," said Cargill vice president Gray Gordon, who was protected from the driving rain by a long yellow rain coat as he spent Sunday afternoon monitoring the breach at the sprawling plant off U.S. 41.
The 6-foot deep break at the top of a 100-foot-tall gypsum stack occurred when heavy winds created high waves that bashed the dike's southwest corner, said DEP secretary Colleen Castille.
Although Cargill representatives said only 18,000 gallons of wastewater had been released, DEP officials say the potential remains for as much as 120 million gallons to escape from the retention pond through the breach.
In the midst of the severe weather, communications between Cargill and the DEP apparently was spotty.
DEP, which was not on site Sunday, said it believed caustic soda, not lime was being used to treat the discharge.
The polluted water, Gordon said, is flowing from an opening at the top of the gypsum stack down its side and into a stormwater ditch that runs around its 400-acre base. Cargill decided to open a valve and release water from the ditch into Archie Creek, which flows into Hillsborough Bay, after consulting with the DEP.
Releasing the water, he said, should prevent a break or overflow of the ditch, a situation that could have caused an uncontrollable flood of water.
"Our goal is to limit the amount of water we're discharging," Gordon said.
The treatment with lime and, perhaps, steady rainfall, should neutralize the discharge, Gordon said. Once the weather clears, crews will repair the break and test the creek and bay water to see how much damage has been done, he said. The repair should take less than a day.
The wastewater, left untreated, would be toxic to fish, wildlife and humans.
"It would give you burns if you walk through it ... like a sunburn," Castille said.
Cargill alerted the state at 12:45 p.m. about the leak, immediately after it happened, Castille said.
Hillsborough County Administrator Pat Bean said the county's Environmental Protection Commission also has been notified, along with the U.S. Coast Guard.
"It's distressing. Gypsum stacks near the bay just don't work. They're a ticking time bomb," said Jan Platt, Hillsborough County commissioner and chairwoman of the Hillsborough County Environmental Protection Commission.
The wastewater contains gypsum, or calcium sulfate, with a pH level of 1.8. Low pH levels indicate high levels of acid. By comparison, the pH number for orange juice is 2.5; for cola soft drinks, 2; drinking water, 7 to 8; lime, 12, a DEP spokesman said.
The fluid is also radioactive, about two to three times the water quality standard, according to the DEP.
Adding lime or caustic soda to the discharge would lower the acidity. It would also reduce some, but not all, of its radioactivity, Castille said.
By early Sunday night, the company had gone through 5,000 pounds of neutralizer and the DEP had helped locate additional supplies that were in transit late Sunday, Schweiss said.
Cargill makes fertilizer at the plant using phosphate mined from the central part of the state. Gypsum is a radioactive waste product of the process.
Several ponds dot the Cargill property in Riverview. That water is constantly recycled and used to either make fertilizer or pump gypsum to the top of the stack.
During the rainy season, Cargill keeps the ponds level by taking excess water to a huge retention pond at the top of the gypsum stack. Under normal circumstances, the water evaporates, Gordon said.
But the abundant rains in recent months have made it difficult for Cargill to keep water levels under control.
"We have been like everybody else. We've had a lot of excessive rain over the last several months," Gordon said.
More than 2 feet of rain fell at Cargill in July and August, he said.
To accommodate the water glut, crews over the past two weeks have been working to reinforce the dike.
"Mother Nature just beat us," Gordon said, noting that the spill could have been worse.
