A highly corrosive acid that leaked from a storage facility at a Braithwaite chemical plant on Monday could have eaten through adjacent storage tanks to cause a “catastrophic” mix of toxic chemicals, a state Department of Environmental Quality official said Tuesday.
The disaster was averted by pumping the spilled material into the Mississippi River, where it quickly diluted to a safe level, said DEQ’s Jeff Dauzat.
At 9:24 a.m. Monday, workers at Stolthaven New Orleans LLC’s transfer facility discovered that as much as 50 gallons a minute of fluorosilicic acid was leaking through a 16-inch-long crack in a welded seam in the storage tank.
While the material was being held in a concrete containment area, the acid was eating through the concrete, Dauzat said, and threatened the other tanks within that area.
“If we allowed that material to stay in the containment, it could have eaten through the other tanks, releasing other incompatible chemicals,” he said. He didn’t have a list of the other chemicals.
The 23 percent solution of fluorosilicic acid being held at the Stolthaven transfer facility is mixed into drinking water at a parts per billion level, Dauzat said.
Material safety data sheets providing hazard information about the acid indicate the dangerously corrosive material can irritate or burn the skin, eyes, lungs and other mucous membranes.
Plant officials and emergency personnel responding to the leak wore respirators and protective clothing.
While residential areas are just north of the plant and to the west, across the Mississippi, Dauzat said air sampling outside the plant “showed no cause for alarm. There were no hits for toxicity.”
Workers pumped 468,740 gallons of fluorosilicic acid into the Mississippi River on Monday after the leak was discovered, leaving 129,882 gallons in the tank below the level of the cracked seam, he said.
Plaquemines Parish water officials were notified of the release, and testing at their water intake facilities showed only background levels of fluoride, Dauzat said.
Chemical monitoring of the river by a clean-up contractor hired by Stolthaven found the acid had diluted to parts per million levels within a few miles, he said.
“The river is able to handle a lot of the abuse we give it because of its flow and the amount of water it has,” said Dauzat. “It’s unfortunate it had to happen, but it saved us a potentially catastrophic loss.”
The Mississippi is at springtime high levels, and moving at about 4 knots per hour, which speeded the mixing process, he said.
After the release, the Coast Guard also established a security zone from 7 p.m. to 12 a.m. Monday, barring any vessels from navigating on waters in the contaminated area
The Coast Guard also is reviewing the circumstances of the chemical spill and said that it “could lead to enforcement actions.”
“We can’t discuss the details of any legal action until the case is closed,” said Petty Officer Tom Atkeson, a spokesman for the Coast Guard.
Dauzat said state officials will look into whether the acid was being held in an incompatible tank, and whether it should have been held within the same containment area as tanks holding the other, incompatible chemicals.
That investigation “will take several days to a couple of weeks, depending on the cooperation of the industry,” he said.
Dauzat said a DEQ team had just inspected the facility for compliance with water disposal permits a few weeks ago and found no problems.
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