This has not been a good summer for Enbridge pipelines in the United States.

The Calgary-based company has now had to deal with three incidents since July.

Yesterday it's 146-kilometre oil pipeline that runs from Ontario to New York was shut down after a possible leak was discovered near Buffalo.

The line moves 70-thousand-barrels-a-day, and there's no word yet how long it'll be out of commission.

Crews were also working yesterday to remove a four-metre section of an Enbridge pipeline that sprang a leak near Chicago.

Oil from the leak reached a retention pond and the town's wastewater treatment plant -- officials say it could take weeks to clean up the mess.

There's no word when the pipeline will be reopened, and in the meantime the oil supply shortage is driving up regional gasoline prices.

Enbridge also owns a pipeline that ruptured in Marshall, Michigan in July and leaked some three-(m) million litres of oil into a creek.

A congressional hearing is scheduled for Wednesday on that spill.