Chemical maker Clariant Corp. says a spill from its Mount Holly West plant might have killed thousands of fish in the Catawba River in late May.
The kill, which claimed 2,000 to 10,000 fish, had stumped investigators. Water samples in the kill area, south of N.C. 27 and north of Wilkinson Boulevard, found nothing toxic.
Clariant said a recently discovered spill at its plant in Gaston County took place about the same time.
“We don't know if we've caused this, but we wanted to make it right,” said Mike Teague, Clariant's vice president for environment, safety and health. “I think people are going to conclude that we did it whether we did or not.”
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The spill was discovered as state officials, looking for the cause, toured the plant a few days after the kill. They and plant officials found chemical residues in a storm drain that leads to the lake.
A pump and alarm apparently failed due to a lightning strike or power surge, the company said, sending an unknown amount of ingredients for soaps, detergents and cosmetics into the storm drain.
A couple of chemicals in the ingredients are toxic to fish, Teague said. But the substances would have degraded in the water and eluded investigators. “It's all circumstantial that this led to the kill. It could very well have been the cause.”
The pump has been repaired, the drain cleaned and fixes made to keep future overflows from reaching the drain, Teague said. He said Clariant will talk to the state wildlife agency about restocking fish in the lake.
Rob Krebs, a state water-quality official based in Mooresville, said the company had made needed fixes. He wouldn't speculate on whether fines are likely.
“I would almost commend them for acting so rapidly to make sure this doesn't happen again,” said Catawba Riverkeeper David Merryman.