State environmental regulators are investigating an unscheduled chemical release Monday evening at the NOVA Chemicals Olefins plant in Ascension Parish, officials said.

Louisiana Department of Environmental Quality officials and Ascension sheriff's deputies reported on Tuesday that they had received calls from the public Monday night about a possible plant fire somewhere in the parish's east bank industrial belt along the Mississippi River.

But DEQ officials said there was no fire but that NOVA Chemicals was routing the released chemicals to a ground flare. Those kinds of flares can create a large, low-level flame that lights up the nighttime horizon and low-hanging clouds.

NOVA Chemicals is located along La. 3115 near the Iberville Parish line. It is the former Williams Olefins plant, which caught fire in 2013, injuring 167 people and killing two.

NOVA Chemicals, a Canadian company, bought the complex in 2017. The plant produces about 1.95 billion pounds of ethylene each year.

Company officials said in a statement Tuesday evening that "a production upset" led to "visible flaring in the community and subsequently led to the discovery of an environmental release."

"The release did not result in emergency conditions, and no employees were injured," the company statement adds.

Greg Langley, spokesman for DEQ, said that NOVA Chemicals had no shelter-in-place orders during the chemical release. Facilities typically call for a shelter-in-place when workers or the surrounding public may face a risk from the chemicals in the air.

The amounts and kinds of chemical released, however, were not immediately available.

Langley said a compressor tripped, leading to the chemical release being sent to the flare. He couldn't say whether all the chemicals were combusted in the flare.

"That's under investigation," he said.

NOVA Chemicals officials said safety is their top priority and regretted the flaring. They said they were also conducting their own extensive investigation about what led to the release and how a similar incident could be prevented.

If any of the released chemicals exceeds a minimum reporting limit in state and federal regulations, the incident will be sent to DEQ's enforcement division, Langley said.

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