A federal judge ordered Citgo Petroleum to pay more than $2 million for Clean Air Act violations over toxic emissions at its refinery in Corpus Christi, Texas, from 1994 to 2003.

A jury convicted Citgo of illegally operating two tanks at its Corpus Christi refinery in 2007 following a three-week trial.

The refinery’s tanks emitted benzene and other chemicals, polluting the air and causing health and respiratory problems for nearby residents, according to the Department of Justice. The Justice Department also accused the company of violating the Migratory Bird Treaty Act.

In a statement, Citgo said that it corrected the problem at the tanks a decade ago.