By Emilie Ritter
HELENA, Montana (Reuters) - Environmental officials scrambled on Tuesday to assess the extent of contamination from a weekend oil spill that has fouled water supplies and ranch lands along a scenic and otherwise pristine stretch of the Yellowstone River in Montana.
An Exxon Mobil pipeline ruptured on Friday night about 150 miles downstream from Yellowstone National Park near the town of Laurel, Montana, just 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 spill also has wreaked havoc on ranching and farming operations along the Yellowstone, the longest river without a dam in the United States, which provides irrigation and drinking water for communities along its banks.
Jerry Williams, who raises livestock, wheat, alfalfa and hay on some 800 acres of land around Laurel, said high water from the river has washed oil across much of his 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," he told Reuters. "All of our grasslands ... have just thick, black crude stuck to all the grass, trees, low lands."
Williams said his 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, he said.
"We get all our drinking water from our wells and for our animals," Williams said. "We don't know if we'll be able to use them since the river was high. All the groundwater, I assume, is probably contaminated. We just don't know."
Montana Governor Brian Schweitzer said on Tuesday 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.
State and federal authorities had few answers to questions about the extent of oil pollution or the potential impacts on human health.
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."
Concerns about petroleum contamination prompted downstream communities that rely on the river for drinking water to shut off their intake valves, but it was unclear whether residents who depend on well water had been urged to avoid drinking it.
Many state health and emergency workers had been told to direct inquiries about environmental contamination and health concerns to the U.S. Environmental Protection Agency. EPA officials said on Tuesday that readings were not yet available from air and water monitors mostly downstream of the spill.
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.
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 a factor.
Exxon shut down the pipeline in May after the city of Laurel raised safety concerns due to rising river levels, but the company said it restarted the line after conducting an inspection.
Shares of Exxon Mobil fell slightly on Tuesday on the New York Stock Exchange as investors worried about the bad publicity from the oil spill. Exxon said its Billings, Montana oil refinery cut back production over the weekend as a result of the spill but other refineries in the area were operating normally.
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. By contrast, Exxon estimates the Montana pipeline has leaked only 42,000 gallons of crude into the Yellowstone River.
(Additional reporting by Laura Zuckerman; Writing by Steve Gorman; Editing by Greg McCune)