The slick of oil from a ruptured Enbridge pipeline in Michigan has been contained to a local lake and river and should not present a threat to the Great Lakes, say both U.S. officials and the Calgary-based company.

The U.S. Environmental Protection Agency said the spill has been halted at Morrow Lake, just east of Kalamazoo, about 120 kilometres inland from Lake Michigan.

Ralph Dollhopf, the on-scene coordinator for the EPA told reporters Thursday that agency does not "anticipate" that the oil poses a threat to the lake.

An estimated 3.9 million litres of oil has spilled from the Enbridge pipeline, which carries about 30 million litres of oil daily from Griffith, Ind., to Sarnia, Ont., a significant leak but nothing like the 800 million litres of oil that has spilled into the Gulf of Mexico.

Residents in about 100 homes along the Kalamazoo River near Battle Creek have been warned to stop using their tap water because of fears of contamination from oil seeping into their wells.

The U.S. Fish & Wildlife Service said the slick has killed a number of fish and coated other wildlife in oil, with about 20 injured animals being treated at a local wildlife rehabilitation centre.

Enbridge president and chief executive Patrick Daniel has said the company is "committing to cleaning up anything and everything" that the oil touches outside the pipeline.

While he stopped short of providing information on how long it will take to clean up the mess, the EPA has said cleanup will take several weeks.

Daniel apologized to the residents of Calhoun County "for the mess that we have made" to the river and nearby properties.

"We are responsible for the cleanup and we will be here until you are happy in this community... that we have completed our responsibilities."

Daniel added: "We have a huge job in front of us. There is no doubt about that."

Hundreds of workers are now working on scooping away the oil. About 3,600 metres of containment and absorption boom are being laid with the help of 14 skimmers vessels.

Giant vacuums will then suck up the contained oil and place it in a tanker truck for disposal.

John Green travelled to the area to see if his Ottawa-based company, International Rescue, could assist with the cleanup effort.

"People here see it as a Canadian problem, and they're actually very happy to see that Canadians are here to clean up 'our mess' as they call it," he said.

Even with the cleanup underway, the PR nightmare for Enbridge is just starting. U.S. officials claim Enbridge was warned about corrosion in the 41-year-old pipeline back in January.

The Pipeline and Hazardous Materials Safety Administration at the U.S. Department of Transportation informed Enbridge that its monitoring of the corrosion in Line 6B was out of line with U.S. regulations.

An Enbridge spokesperson contacted by The Associated Press on Thursday declined to comment on the letter.

It wasn't the first time the company has caught the attention of a government agency in the United States. Since 2002, Enbridge and its affiliates have been cited 30 times by the Department of Transportation's regulatory branch.

The company detected the oil leak in its pipeline on Monday in Michigan's Talmadge Creek. Before the leak could be repaired, the oil flowed into the Kalamazoo River and Morrow Lake.

With files from The Associated Press and CTV's Omar Sachedina