The Delaware City Refinery has been hit with a reprimand from the Delaware Department of Natural Resources.
It results from the release last summer of air pollutants after a sudden shutdown of key equipment.
The Wilmington News Journal reports that this is the 12th time that the refinery has violated one of its permits since the beginning of last year.
The paper notes that is the most violations by any one company during the same period.
The company’s permit requires that state officials be notified of any planned shutdown at least 24 hours before hand.
But regulators say that they were not informed until 26 hours after the incident.
The August incident began with the discovery of a hole in the fluid coking unit where petroleum products are fed into the equipment.
The News Journal reports that the company said that the discovery did not result in an emergency shutdown but was planned beforehand.
