The Canadian company in charge of a ruptured oil pipeline in southern Michigan says a spill into the Kalamazoo River has been contained.
Cleaning up the site may take many more months.
Estimates are in conflict, but at least 800,000 gallons of crude spilled into the waterway earlier this week when the pipe broke, fouling waters about 80 miles away from Lake Michigan.
Officials of Enbridge, Inc., say the oil is mostly contained now. A snow fence has been installed around affected areas to keep wildlife away from the site.
The oil is contained by boom and other devices that can keep it in place until vacuum equipment can suck it up, company spokesman Alan Roth said.
"It's been captured, it's not going anywhere," Roth said.
Environmental Protection Agency officials estimate the amount of oil that went into the river exceeded 1 million gallons. But they agree the spill does not seem likely to reach Lake Michigan
But federal safety regulators say they warned the company in January it was not properly monitoring corrosion in the pipeline. And some members of Congress are demanding hearings on the cause of the leakage.
Hundreds of workers and contractors were working on cleanup. Enbridge said it had recovered 100,800 gallons of oil so far and estimated that 420,000 gallons are in a holding area and will be pumped into tanks.
"No one is sugarcoating it," Roth said. "There's still a tremendous amount of work to do but good progress is being made."
Scientists fear the worse may be yet to come for fish in the river. Jay Wesley, a biologist with the state of Michigan, said the oil spill had killed fish in "very limited numbers" along the affected stretch of the river from Marshall westward into Battle Creek.
The bigger problems for fish may come within a week or so, if the oil spill results in decreased water oxygen levels. Wesley said insects, algae, frogs and turtles along the river have been killed in high numbers — which could hurt the fish food supply.
"The effects are probably going to be more long-term," Wesley said. "We probably won't know the full effects for weeks or months or years."
A wildlife rehabilitation center staffed and managed by a Enbridge contractor near Marshall had received about 50 injured animals — mostly geese — by midday Friday. During a tour, two white-suited workers were trying to clean up an oil-soaked turtle, one holding and rotating the reptile while the other dabbed it with what appeared to be a cloth.
With reporting from Quinn Klinefelter of member station WDET and The Associated Press.