The U.S. Supreme Court this week denied a petition by ExxonMobil appealing a loss that requires the company to pay millions for air pollution in Texas.

A lawsuit by Environment Texas, the Sierra Club, and other groups filed in 2010 resulted in a $14.25 million civil penalty against Exxon – the largest ever imposed by a court in a citizen-initiated lawsuit to enforce the Clean Air Act.

The groups cited repeated violations at the company’s Baytown, Texas, oil refinery and chemical plant complex east of Houston.

“Our members in Baytown knew Exxon might fight this case all the way to the Supreme Court, but we matched Exxon’s persistence so the company could not escape responsibility for its years of illegal air pollution,” said Neil Carman, Clean Air director of the Sierra Club’s Lone Star chapter.

The case went to trial in federal district court in Houston in 2014 on behalf of neighbors harmed by Exxon’s 10 million pounds of illegal pollution, which included toxic, carcinogenic and ozone-forming chemicals. Exxon lost four prior appeals at the Fifth Circuit Court of Appeals prior to this Supreme Court rejection.

“At trial, Exxon’s neighbors bravely testified to the harms they suffered from the company’s illegal pollution, painting an ugly picture of what it’s like to live in Exxon’s shadow,” said Josh Kratka, managing attorney at the National Environmental Law Center and one of the plaintiffs’ lead attorneys.