Officials in Pennsylvania and Delaware say they are getting calls Thursday morning about an odor in the air.
Covanta is apologizing to the community around its Plymouth Township, Montgomery County plant following several recent problems with its waste energy incinerator.
Investigators said as a precaution they evacuated the Autumn Woods complex in Woodbury as the Hazmat team and the Camden County Bomb Squad investigated.
Residents in a Philadelphia neighborhood were told to shelter in place Thursday morning as authorities investigated a strong smell of gas.