By David Madden and Al Novack

PAULSBORO, N.J. (CBS) – A major spill at a South Jersey oil refinery was being confined to the site today, and officials say there is no threat to local health or the environment.

Neighbors around the Paulsboro Refining Company started smelling the oil Thursday afternoon.  The problem turned out to be centered around a 12-million-gallon tank.

New Jersey lieutenant governor Kim Guadagno toured the site today, dressed in a protective suit.

“We have an unexpected leak that’s being handled just like any other unexpected leak would be,” she told reporters. “They’ve done all of the proper protocols and following all the proper precautions, and they have everybody on site from the federal government to the state government to the county and the locals, and they’re handling it.  And it’ll be cleaned up in the next three days.”

Estimates are that four to six million gallons of crude leaked into a containment area.  The cause of the leak remained under investigation.  Operators planned to drain the tank completely into another one on site.  Crews will remain through the process to make sure the oil gets no further.

As of 9am today, a Gloucester County 911 dispatcher says they were still getting complaints about the odor from people in both Gloucester and Salem counties.