Oil company Phillips 66 has been federally indicted in connection with alleged violations of the Clean Water Act in California, authorities said Thursday.

The Texas-based company is accused of discharging hundreds of thousands of gallons of industrial wastewater containing excessive amounts of oil and grease, the U.S. Department of Justice said.

The company allegedly dumped the wastewater from its Carson oil refinery into the Los Angeles County sewer system in 2020 and 2021 and did not report the violations, prosecutors said.