The U.S. Environmental Protection Agency is monitoring the cleanup of an oil leak from an underground pipe near in the Chicago area.

Officials with the Lockport Township Fire Protection District discovered the leak in an industrial area around 7 a.m. Tuesday after a complaint about petroleum odors.

The EPA says the pipeline has been shut down. And fire district spokesman Rich Berndt says the leak has stopped. Federal officials say early estimates show 21,000 gallons of oil may have been released.

The pipeline is owned by West Shore Pipe Line Co. Spokeswoman Colleen Kester says temporary repairs have been made and the company is working on a plan to restart the pipeline.

The underground pipeline feeds into tanks in Lockport, about 35 miles southwest of Chicago.