A pipeline operated by Calgary-based Enbridge has spilled over three million litres of oil into a creek near Lake Michigan.

Critics say the incident proves that plans to ship oil across B.C. aren’t safe.

Birds and other wildlife are now at risk from a leak that started Monday morning. The pipeline carries crude oil from Griffith, Indiana to Sarnia, Ontario.

Enbridge crews are using booms, skimmers and vacuum trucks to contain the spill, which occurred at a pumping station near Battle Creek.

"We know that leak has had a major impact on people in that community and on the environment and on wildlife," Enbridge spokeswoman Gina Jordan told the CBC.

The company is proposing to build a highly contentious pipeline from Alberta’s oil sands to Kitimat, B.C. Crude oil would be shipped on supertankers to China, a naval route opponents fear is hazardous.

At least one green group is using Monday’s spill to bolster arguments against the project.

“Spills happen, the risks are real, and the consequences are potentially devastating for British Columbia’s rivers, coast and communities,” said the Dogwood Initiative's Eric Swanson in a statement.

Enbridge still does not know what caused the spill.

Geoff Dembicki reports for the Tyee.