HOUSTON (Reuters) - The U.S. Environmental Protection Agency is investigating possible criminal violations by Chevron Corp (CVX.N) at its SanFrancisco Bay-area refinery in Richmond, California, according to a report by the San Francisco Chronicle.
The investigation is unrelated to state and federal probes of an August 6 explosion and fire that shut the central crude oil refining unit at the 245,000 barrel-per-day (bpd) Richmond refinery, according to the Chronicle report.
Chevron told the newspaper that it was cooperating with the investigation, which began early this year, prior to the fire.
California pollution investigators have also been investigating the use of the 3-inch (7.6-centimeter) pipe, which allowed emissions from a hydrocracking complex to bypass the refinery's pollution control equipment on the way to the refinery's safety flare system, at the discretion of the complex's operator.
Chevron told the Chronicle the use of the pipe was inadvertent.
A Chevron representative was not immediately available on Sunday to discuss operations at the Richmond refinery.
Reporting By Erwin Seba; Editing by Maureen Bavdek