Canada-held energy company Enbridge has begun digging up a leaking pipeline which stopped almost a third of Canada's crude oil exports to the US when it spewed product on 9 September.
Removal of the damaged pipe is complicated by utility lines and sewer pipes near its line, forcing workers to dig by hand or use high-pressure water to expose the oil conduit.
Excavation has begun, but it's a busy corridor, Gina Jordan, Enbridge spokeswoman says. There is still no estimate on when we can restart.
The leak was discovered at a stretch of pipeline in Romeoville, Illinois, about 30 miles southwest of Chicago. Enbridge quickly shut down its Line 6A, the largest of its three major lines that take Canadian crude to refineries in the US Midwest and on to the Cushing, Oklahoma, oil storage hub.
The line can handle 670,000 barrels per day but was transporting about 459,000 bpd before the leak.
The U.S. Environmental Protection Agency is supervising Enbridge's clean-up at the spill site. It said on 11 September that the oil had been contained and the company was removing spilled oil in a retention pond near the site of the leak.
Some oil spilled into storm sewers, forcing the temporary closure of a waste-water treatment plant. However, that oil has also been isolated in the plant's lagoons and is beginning to be removed.
The EPA is still unable to estimate the size of the leak and said it was unsure whether oil continued to drain out of the damaged line.