Officials say city plant released sulfur dioxide into air

DELAWARE CITY, Del. -- The Delaware Department of Natural Resources and Environment Control says 40 pounds of sulfur dioxide has been released into the air from the Delaware City Refinery.

The department says the release happened at the plant in Delaware City early Monday. Officials told area residents on Tuesday.

Officials say that the substance is considered hazardous by the Environmental Protection Agency.

The release of the chemical is under investigation.