Delaware regulators are citing the PBF refinery for new pollution violations.
The Department of Natural Resources and Environmental Control also reported the unplanned release of nearly 1.5 tons of sulfur dioxide. The News Journal reports that the refinery's open-air incinerator stack burned for more than six hours Sunday into Monday after a loss of water in a tank used to control flows of volatile gases and remove liquids before flaring.
The incident comes weeks before a planned restart for one of the larger and harder-working units at the plant.
Officials say about 2,750 pounds of sulfur dioxide escaped as a result of the burn-off. A PBF spokeswoman declined to comment.
Last week, officials separately notified PBF that it was reviewing potential sanctions for a much larger release in June.