Dakota Access pipeline owners want to pump more oil through Illinois. Critics worry the move will increase the risk of leaks or a devastating spill.

Oil has been flowing through the Dakota Access pipeline across Illinois since the summer of 2017, traveling underground from the Mississippi River to a hub in a tiny central Illinois town.

Every day, an average of 560,000 barrels of oil flows through the pipeline.

Now the company that owns the pipeline, which begins in North Dakota, wants to nearly double the volume, pumping up to 1.1 million barrels from the oil-rich Bakken region through South Dakota and Iowa into Illinois.

To increase the flow, the company wants to build a series of new pump stations along the 1,172-mile route, including in western Illinois, and upgrade its facilities where Dakota Access links up with other Midwestern pipelines.