High-Stakes Case: Oil Companies Face Billions in Louisiana Coastal Damage Disputes

The U.S. Supreme Court will hear oral arguments on Jan. 12 in Chevron U.S.A. Inc. v. Plaquemines Parish, a case that could determine whether dozens of Louisiana coastal lawsuits are heard in federal or state court, impacting billions in damages and environmental justice efforts.

By Alex Lubben

Source The Times-Picayune | The New Orleans Advocate (TNS)

Nov. 24, 2025

5 min read

map of wetlands damage to Louisiana Gulf Coast

The U.S. Supreme Court will hear oral arguments on Jan. 12 in a high-stakes legal dispute that could have wider implications on dozens of lawsuits pitting Louisiana coastal parishes against oil companies over historic damage to the state's wetlands.

At stake is a $745 million verdict, handed down in April by a jury in Plaquemines Parish. But the ruling could ultimately affect a range of cases involving billions in damages.

The Supreme Court agreed in June to hear the case, but the date for arguments was only recently announced.

The case, Chevron U.S.A. Inc. v. Plaquemines Parish, concerns dozens of lawsuits accusing major oil companies of violating coastal use laws and destroying wetlands. The issue the Supreme Court is taking up, however, does not have to do with land loss or pollution, but rather where the case should be heard.

The lawsuits were originally filed in state court. Chevron, Exxon and other major oil companies have long argued that they belong in federal court, a jurisdiction that is seen as friendlier to the companies.

Chevron has argued that it was acting under federal contracts during World War II, when the oil and gas it extracted from Louisiana lands was used to produce aviation fuel for warplanes, and so the lawsuits belong in federal court. Lower courts have repeatedly rejected that argument.

The April trial was the first of 42 similar lawsuits, all led by Baton Rouge-based law firm Talbot, Carmouche & Marcello, on behalf of coastal parishes. The lawsuits all claim that oil companies damaged wetlands and left behind pollution after drilling operations, in violation of state coastal regulations that went into effect in 1980.

"The obligation couldn't be clearer," attorney John Carmouche said during opening statements in the Plaquemines trial. "You have to restore the property back to its original condition. ... That's the law. That's what the marsh deserves."

The companies say the lawsuits will unnecessarily hurt employment and energy production. They also argue that some of the operations in question occurred before a law they are accused of violating took effect in 1980.

'This isn't about the merits'

The parishes' lawyers have said the decision will directly affect a subset of 11 "refinery cases" — suits where a single company both produced and refined oil — but could indirectly influence all 42 coastal lawsuits brought by six parishes and the state.

Vic Marcello, a co-founder of Talbot, Carmouche & Marcello and one of the lead lawyers for the parishes, has emphasized that the high court will not be deciding whether the oil companies caused environmental harm. Instead, he has described the forthcoming ruling as "procedural" — focused entirely on jurisdiction and the reach of the federal officer removal statute.

"This isn't about the merits of our claim," he said in an earlier interview.

Still, even a procedural decision from the high court will be consequential. If the justices side with the companies and finds that the Plaquemines case belonged in federal court all along, a federal judge could be asked to revisit the $745 million state court verdict. If they rule for the parish, the decision would effectively green‑light more coastal trials in Louisiana state courts, potentially exposing oil and gas companies to billions of dollars in additional damages.

The legal battle has stretched over more than a decade. Carmouche and his firm filed the first of their coastal lawsuits in 2013. Since then, both sides have repeatedly sparred over the proper venue for the cases, and Carmouche's firm has also pursued settlement negotiations with several oil companies.

Freeport-McMoRan settled for $100 million. Cameron Parish settled with oil companies for an undisclosed sum. Carmouche said that Shell had also settled for an undisclosed amount.

'Make a Decision Then'

And though the Supreme Court hearing looms over the cases, Carmouche said that settlement discussions were ongoing.

"We're discussing with a couple of majors," he said. "In my opinion, I think we'll get a ruling from the U.S. Supreme Court sometime in March, April. I think they're going to have to make a decision then."

The case also pits local Louisiana Republicans against the Trump administration — one of the only instances in which the state has clashed openly with the White House. Louisiana has intervened in the cases, siding with the parishes and Carmouche; the Trump administration — along with former U.S. Attorneys General William Barr and Michael Mukasey — are backing the oil companies.

Finding money to salvage as much of Louisiana's eroding coast as possible will increasingly become a challenge in the years ahead, with proceeds linked to the 2010 BP Deepwater Horizon oil spill set to expire by 2032. The state has lost roughly 2,000 square miles over the last century, and sea level rise linked to climate change is projected to worsen the crisis.

Confining the Mississippi River in place with levees set the crisis in motion, but oil and gas production has greatly contributed to the problem.

Louisiana Attorney General Liz Murrill has vocally backed the lawsuits.

"Quite simply, Chevron chose profits over people and the law — and it continues to do so every day it refuses accountability for its actions," she wrote in a guest opinion column for The Times-Picayune. "This is not controversial."