An oil spill in Montana's Yellowstone River surged toward North Dakota on Sunday as outraged residents demanded more government oversight of Exxon Mobil's cleanup.
An estimated 750 to 1,000 barrels, or up to 42,000 gallons, spilled through a damaged pipeline in the riverbed, Exxon spokesman Alan Jeffers said. The break near Billings could be related to the river's high water level, officials said.
More than 120 people were working on the cleanup late Sunday, Jeffers said. But local officials said because of the raging floodwaters, only a handful of crews were laying absorbent pads and booms to trap the oil along short stretches of the river between Billings and Laurel. In some areas, residents said, oil may be flowing underneath the booms and continuing downstream in the murky water.
Jeffers said most of the oil was believed to be within 10 miles of the spill site, and Exxon crews were flying over the area late Sunday to assess how far it had spread since the Friday night spill.
But Montana's governor disputed the 10-mile estimate.
"Nobody can say definitively," Gov. Brian Schweitzer said. "It's too early. We need boats on the water," not just flyovers. Because of the high water, however, boats were potentially unsafe.
There were reports of oil as far as 100 miles away near the town of Hysham, Yellowstone County Commissioner Bill Kennedy said.
Although the spill is downstream from Yellowstone National Park and the fertile Yellowstone fly-fishing grounds, some officials worried it could harm the tourism industry, which draws 11 million visitors a year to a state with a population of just 980,000.
"We take our rivers very seriously here in Montana," said Schweitzer, a soil scientist who planned to visit the spill site Tuesday. "We will not allow this catastrophe to affect the $400-million trout industry in Montana."
Schweitzer, a Democrat, said the U.S. Environmental Protection Agency had been working with state agencies to investigate the cause of the spill and would test air, water and soil samples. Exxon will be expected to pay for the cleanup so that "everybody along that river is made whole," he said.
But residents were worried.
"We can't really tell what it's going to do for our fisheries downstream," Eric Beebee, 37, said as he worked Sunday at Bighorn Fly and Tackle Shop in Billings. "If it was going to affect anybody, it's going to be the farmers and the ranchers because the water is pushed up so high, when it recedes [the oil is] going to be left on their land."
Goat rancher Alexis Bonogofsky pulled on waders and slogged through the oily residue at the bottom of her pasture, snapping photographs of oily grass and water.
"Places where the water has gone down the soil is shiny, there's residue oil and you can see where the grass is already dying. I'm really concerned about the wildlife," said Bonogofsky, 30, who also works for the National Wildlife Federation. "I've seen Canada geese try to take off and they can't get lift because of oil on their wings."
An Exxon crew arrived at her ranch south of Billings late Sunday to lay absorbent pads on oil patches.
Bonogofsky and husband Mike Scott, 31, who works for the Sierra Club, were trying to organize landowners to demand more transparency and accountability from Exxon. She faulted local public health officials for failing to conduct their own reports and relying instead on Exxon.
"Exxon says they are monitoring it, but we don't have access to that data," Bonogofsky said.
"We're sort of in limbo here," Scott said. "We have been spending a lot of time in the soil, and our livestock has. Nobody is telling us what we could have been exposed to."
Jeffers said he met with some residents Sunday and assured them that company tests, including air quality monitoring, showed no cause for alarm.
"There's no effort to withhold important information from the public," he said. "We have not seen anything that causes public health concern."
Exxon pipeline workers became aware of a problem shortly before midnight Friday when pressure readings in the pipeline dropped, Exxon Mobil Pipeline Co. President Gary Pruessing said Sunday. Workers turned off the pumps within six minutes, he said.
Jeffers said Exxon had temporarily turned off the foot-wide pipeline in May out of concern that seasonal flooding could damage it. The company reopened it a day later after reviewing the 20-year-old pipeline's safety record.
"We did a safety analysis and concluded the line was safe to operate," Jeffers said.
The pipeline was last inspected in 2009 using a robotic device designed to detect corrosion and other flaws, Jeffers said.
The most recent depth tests, in December, showed the pipe was 5 to 8 feet below the riverbed, he said. But that was before record rains and melting snowpack flooded the river in May, which Exxon and government officials have said may have exposed the pipe to damage from debris.
"That's just speculation at this point," Jeffers said. "We don't know at this point what caused it."
Some officials feared the oil would reach the Missouri River, just across the border in North Dakota.
"The water is fast and furious," said Kennedy, the Yellowstone County official. "I'm hoping that we get it cleaned up and stopped before it even approaches there."