The Louisiana Department of Environmental Quality is asking state Attorney General Jeff Landry for permission to sue Denka Performance Elastomer, saying the chemical company that for years has been embroiled in controversy over its emissions of chloroprene has violated the Clean Air Act.

A letter obtained by The New Orleans Advocate shows that the state agency is requesting to file a civil petition in federal court over the alleged environmental violations.

Sent to Ryan Seidemann, the section chief of land and natural resources in Landry's office, the letter also states the department's intent to sue E. I. du Pont de Nemours, which owned the plant before Denka bought it in 2015.

Presently, thousands of plaintiffs are seeking damages against Denka in several suits scattered throughout state and federal courts.

If granted, the suit would be a rare move by state regulators to rein in a polluter, according to Wilma Subra, an environmental activist with the Louisiana Environmental Action Network.

“We may be at a major turning point here,” said Subra, who has been a vocal critic of the department. 

LDEQ spokesman Gregory Langley said he couldn't comment on the letter because it was a legal matter.

Denka spokesman Jim Harris also said his company doesn't comment on pending lawsuits.

The request to sue comes three years after the U.S. Environmental Protection Agency sent investigators into the Denka plant for five days to find out why it was discharging concerning amounts of chloroprene, which the agency determined to be a likely carcinogen in 2010.

An air toxics assessment released in 2015 showed that St. John Parish had the highest cancer risk from airborne pollutants of any place in the nation — largely because of the high levels of chloroprene.

In 2017, it was revealed that an EPA inspection of the LaPlace plant done the year before found about 50 potential violations of the Clean Air Act.

The report was the result of a compliance investigation ordered by the federal agency in 2015 to determine whether the plant had violated environmental laws. As is typical in federal and state enforcement cases, the probe has continued for years while regulators get feedback from the company, which they consider when deciding whether or not to take action.

Denka has contested some of the findings.

The company uses chloroprene to produce neoprene, a synthetic used to make wetsuits, orthopedic braces, electric insulation and other products. It's the only plant in the country that produces that chemical.

Before Denka took ownership, DuPont had produced chloroprene in St. John for about 50 years.

While DuPont had been cited by the EPA during previous routine investigations, the air toxics assessment gave federal and state agencies new impetus to better understand how the plant controlled its pollution, and it served as a catalyst for a new series of actions agreed upon by the EPA, LDEQ and the plant's new owner, Denka.

Around that time, residents also began protesting the plant, citing an EPA report that said the chemical may potentially cause cancer in addition to less dangerous conditions like headaches, dizziness and skin rashes.

The agencies began working together to monitor air quality around the plant and, after data came back showing high levels of chloroprene, Denka voluntarily entered a consent decree with the state, agreeing to retrofit the plant with new technology and reduce emissions by 85 percent.

The company spent most of 2017 working to abide by the order, retrofitting the plant with more than $35 million worth of equipment that officials said would significantly reduce the discharge of toxic chemicals.

However, in May, LDEQ said the LaPlace plant had not met the reduction target and had 30 more days to come into compliance with the 2017 consent order, and could face stricter enforcement, including fines, if it didn't further reduce emissions in the near future.

According to the letter sent May 16, the company has only a few more days to fully comply.

Harris said at the time that the company's emissions rate for the second half of 2018 and preliminary numbers for 2019 both show it will meet its reduction goal.

Denka "is a responsible operator and will continue to reduce its environmental footprint where possible," he said.

However, those reassurances have done little to assuage community members who have been breathing chloroprene for years.

Follow Della Hasselle on Twitter, @dellahasselle.