ExxonMobil will be sued by two environmental groups over the release of large amounts of air pollutants from its Baytown oil refinery, the nation's largest, according the Center for Public Integrity, a nonprofit investigative journalism group based in Washington.

According to the report, the refinery released at least 5.9 million tons of "dangerous air pollutants" over five years, above permitted levels, according to the center's analysis of records from the Texas Commission on Environmental Quality. During that time the refinery, plus two chemical plants also in the complex, incurred only about $1.2 million in fines, the center found.

Environment Texas and the Sierra Club plan to file a lawsuit in a federal district court later this summer. The lawsuits come as tensions between federal and state air-pollution regulators remain high. TCEQ records showed that about 85 percent of the incidents at the three plants were “avoidable” or “preventable,” according to the center's analysis.

ExxonMobil declined comment to the group on the lawsuit but said that since 2001 it had spent $700 million on environmental improvements to the refinery, which began operating in 1920.

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The full story is here, along with an interactive timeline of toxic emissions the company reported to regulators.

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