HELENA, Montana Governor Brian Schweitzer vowed on Tuesday to cling to Exxon Mobil like "the smell on a skunk" for as long as it takes to get the company to clean up a weekend oil spill that fouled an otherwise pristine stretch of the Yellowstone River in Montana.
A 12-inch Exxon pipeline ruptured on Friday night about 150 miles downstream from Yellowstone National Park near the town of Laurel, Montana, southwest of Billings, dumping up to 1,000 barrels, or 42,000 gallons, of crude oil into the flood-swollen river.
Toxic fumes from the oil overcame a number of people who reported breathing problems and dizziness and were taken to local hospitals. But state and federal officials on Tuesday said they lacked a tally of health problems or the number of riverside homes that were evacuated after the accident.
The U.S. Department of Transportation on Tuesday ordered Exxon to re-bury the pipeline underneath the Yellowstone river bed to protect it and conduct a risk assessment on the 69-mile long pipeline where it crosses any waterway. It must then submit a restart plan before operations can resume.
"The investigation into this incident is ongoing," said Transportation Secretary Ray LaHood. "When companies are not living up to our safety standards, we will take action. We will continue to work with the EPA, while ensuring that those responsible are held accountable."
Exxon officials said shoreline oil contamination extended at least 25 miles downstream but appeared to be confined mostly to scattered pockets along the river.
The company said water pipes for municipal drinking supplies to the city of Billings and suburban Lockwood were reopened after a precautionary shutdown for a few hours just after the spill.
But Schweitzer said dozens of landowners have been affected so far and that a "great deal of oil" had washed into low-lying areas along the banks of the Yellowstone.
"These riparian, lowland areas, these wetlands are the health of these rivers," he said, adding that the full extent and scope of contamination remains to be seen. He said trace amounts of oil already had been swept hundreds of miles downstream into the Missouri River and beyond.
About 350 cleanup personnel were working along the Yellowstone on Tuesday, using oil-absorbent materials to blot up as much crude as possible, according to Exxon and the U.S. Environmental Protection Agency, which is overseeing the operation.
The spill wreaked immediate havoc on ranching and farming operations along the Yellowstone, the longest river without a dam in the United States.
Cathy Williams, who raises livestock, wheat, alfalfa and hay with her husband Jerry on some 800 acres of land around Laurel, said high water from the river has washed oil across much of their property.
"It was the night the river peaked, so the river water was flooded all over the place, and that brought oil all over both ranches," she said. "All of our grasslands ... have just thick, black crude stuck to all the grass, trees, low lands."
Williams said their spring wheat crop and alfalfa are both in need of irrigation, but farmers in the area were advised not to take water from the river for the time being. Drinking supplies also are in limbo, she said.
"We get all our drinking water from our wells and for our animals," Williams said. "All the groundwater, I assume, is probably contaminated. We just don't know."
The cause of the rupture was under investigation. But possible damage from erosion caused by unusually heavy river flows following a spring of heavy rains, and runoff from record mountain snows, are likely to be examined as factors.
Exxon briefly shut down the pipeline in May after the city of Laurel raised concerns due to rising river levels, but the company said it reopened the line after a safety review.
The Silvertip pipeline normally carries about 40,000 barrels of crude per day from the Montana-Wyoming border north to Billings, connecting to two of the state's three major refineries. Exxon said it was forced to cut back operations at its Billings refinery.
Schweitzer said he has told Exxon and federal agencies overseeing the spill response that the state alone will decide when the cleanup is done.
"The state of Montana is going to stay on this like the smell on a skunk," he told Reuters by telephone as he toured areas hit by the spill.
The EPA began water-quality sampling on Sunday, but those results have yet to be released. Environmental experts said it will likely take months, even years, for the ecosystem to rebound from the influx of crude.
"It will be unclear even next spring as to what kind of recovery has taken place," said Ronald Kendall, chairman of the department of environmental toxicology at Texas Tech University and head of its Institute of Environmental and Human Health.
"It's a very significant amount of oil moving downstream right now, and oil is a toxic substance in itself," he said. "A whole suite of organisms, from mink to herons to sturgeon to dragonflies, are going to be affected as waves of oil come through."
Schweitzer said local public health authorities would have to determine the safety of groundwater well supplies, adding, "I'm not going to make a blanket statement about all wells that are adjacent to the Yellowstone River.
Some Montana residents have reported symptoms ranging from shortness of breath to fainting spells linked to exposure to petroleum-based chemicals.
Stacy Anderson said on Tuesday her parents, Bob and Patty Castleberry, are still living in a hotel after their home was evacuated Saturday along the Yellowstone less than a mile from the site of the ruptured pipeline. She said her mother, who suffers from a respiratory condition, passed out several times even after the couple left the house.
"All their clothes, the suitcase -- everything smelled like solid crude oil; when my mom got away from it, her symptoms disappeared," Anderson said.
She said Exxon is paying her parents' hotel bill as well as covering the cost of feed for the couple's 10 goats that have been steered away from oil-soaked grasslands.
Shares of Exxon Mobil closed down slightly on Tuesday on the New York Stock Exchange as investors worried about the bad publicity from the oil spill.
The Montana oil spill is far smaller than the BP oil spill in the Gulf of Mexico last year and the Exxon Valdez spill in Alaska in 1989. The BP spill spewed 168 million gallons of oil and the Exxon Valdez spilled 11 million gallons of crude oil.