UPDATE 5 p.m.: Some 250 personnel have now been deployed to help clean up the oil spill that hit the Yellowstone River on Friday night, according to Sonya Pennock, spokeswoman for the Environmental Protection Agency.
In an afternoon news release, Pennock said the river has now been divided into three divisions for planning and operational purposes. Initial cleanup activities are concentrated in the first two divisions — from Dove Creek to Coulson Park where responders have identified the most oil-impacted areas. The third river segment runs from Coulson Park to Miles City. Reconnaissance and cleanup of that area is planned.
Workers are walking the shores and deploying absorbent boom to soak up oil that has collected in slow moving water, Pennock said.
Responders continue to assess where the oil has traveled and what impact it may be having. On Sunday, EPA and U.S. Fish and Wildlife Service officials conducted an aerial assessment of the area beginning where the pipeline apparently broke, near Laurel, to a point 30 miles downstream of Billings.
They reported seeing bank deposits and small pooling of oil in backwaters and slow water at intermittent points along both the north and south banks of the river.
Pennock said the EPA is coordinating its response actions with the Department of the Interior, Fish and Wildlife Service and state and local agencies and "will take whatever steps are necessary to ensure ExxonMobil, as the responsible party, addresses any and all potential impacts of this spill."
UPDATE 12:30 p.m.: ExxonMobil spokesman Alan Jeffers says that not all 70 calls made to a hotline set up for property owners suffering from the spill were reports of oil.
Jeffers said 125 workers were on the ground Monday cleaning up scattered sections of riverbank that received crude. But he added that there was no longer a defined slick of oil moving down the river and the impacts were unlikely to grow.
"It's unlikely there's any oil in the water at this point," Jeffers told The Associated Press. "That doesn't mean we know where it all is."
Officials in Yellowstone County were working with the company to connect cleanup personnel with affected property owners, Commissioner John Ostlund said.
Montana's Disaster and Emergency Services Division was unable early Monday to give an update on the spill, including whether the oil had in fact dissipated. Environmental Protection Agency officials also could not immediately provide any new information, the Associated Press reported.
UPDATE 9:30 a.m.: ExxonMobil says it is making daily flights over the Yellowstone River to direct the oil-spill cleanup and locate oil deposits.
In a news release, the oil company said it has received more than 70 calls to its community claims line, 888-382-0043.
Another 80 people involved in the cleanup effort were expected to arrive Monday, bringing the total to about 200.
ExxonMobil said the cleanup area has been organized into four zones. Cleanup activities are focused in the first two zones, Laurel to Duck Creek Bridge, a distance of seven miles from the spill location, and the 12 miles from Duck Creek Bridge to Johnson Lane. The second two zones go from Johnson Lane to Miles City, 144 miles, and Miles City to Glendive, 78 miles.
UPDATE 7 a.m.: Gov. Brian Schweitzer says statements from ExxonMobil officials that no injured wildlife had been found were premature.
"For somebody to say at this early stage that there's no damage to wildlife, that's pretty silly," Schweitzer told the Associated Press on Saturday. "The Yellowstone River is important to us. We've got to have a physical inspection of that river in small boats — and soon."
The Billings Gazette has published photos of soiled pelicans and turtles. The Environmental Protection Agency said it can't confirm any damage to wildlife or fish kills, but investigators were checking and the federal agency expected to know more Monday.
The U.S. Department of Transportation, which oversees pipelines, last year issued a warning letter to ExxonMobil that cited seven safety violations along the ruptured Silvertip pipeline. Two of the warnings faulted the company for its emergency response and pipeline corrosion training.
Transportation department spokeswoman Patricia Klinger told the Associated Press that the company has since responded to the warnings and the case was closed.
The Associated Press reported that the company was also cited for "probable violations" in a letter in February. The problems included inadequate pipeline markers in a housing development, a section of pipeline over a ditch covered with potentially damaging material and debris, vegetation in housing area covering a portion of line that prevented aerial inspections, and a line over a canal not properly protected against corrosion. The company responded in a March letter that it had corrected all of the problems, most of them within a few weeks of being notified.
UPDATE 6 a.m.: The federal Environmental Protection Agency has sent 50 members of its emergency response team to Billings to assist in cleanup efforts, according to EPA spokeswoman Sonya Pennock.
Members of the U.S. Coast Guard's Pacific Strike Team were also scheduled to arrive Sunday night. ExxonMobil has 120 personnel on the ground, Pennock said in a news release from the EPA, which is directing cleanup activities.
The EPA is working with the Department of the Interior, U.S. Fish and Wildlife Service and state and local agencies. She said the EPA will take "whatever steps are necessary to ensure ExxonMobil, as the responsible party, addresses any and all potential impacts of this spill."
The U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration is responsible for determining the cause of the pipeline failure. Agency officials arrived Saturday to begin their work, Pennock said.
The Yellowstone River has been divided into four areas for the cleanup, Pennock said. The first two areas include the first 15-20 miles downstream of the spill, just east of Laurel. The next two areas run from Billings to Glendive, an 180-mile stretch of river.
MORNING REPORT: Flying over a stretch of the Yellowstone River on Sunday morning, ExxonMobil officials saw evidence of the pipeline break east of Laurel.
Most of the soil contamination was within five to 10 miles downstream of the pipeline break, with pockets of oil beyond Billings, said Gary Pruessing, the Houston-based president of ExxonMobil Pipeline Co. Pruessing spoke at a midmorning press briefing Sunday at the Crowne Plaza hotel in Billings.
An estimated 750 to 1,000 barrels of oil spilled late Friday, before the flow of oil from the damaged, 12-inch pipeline could be stopped.
"It's bound to have some impact. Every landowner along the river from Laurel to Coulson will have some issues," said Yellowstone County Commissioner John Ostlund.
"Between Billings and Laurel, any place there's backwater, that oil floats on the top, so it's migrating to the sides and it's stuck on any land where the water level is dropping," Ostlund said.
Reports of the oil moving along the Yellowstone came in from as far away as Hysham, about 75 miles east of Billings.
The Yellowstone's turbulent floodwaters dispersed some of the crude oil as it flowed downstream, Pruessing said. But while the fast-flowing water may reduce damage to wildlife, crops and vegetation along the river, it makes the spilled oil difficult to recover.
About 100 cleanup workers and specialists were due to arrive in Billings by Sunday night, joining about 25 local refinery workers trained in cleanup who were already at work along the river. ExxonMobil's North American regional response team will be joined by Clean Harbors, a large hazardous-waste-disposal company, and an oil spill response team from International Bird Rescue, a group specializing in wildlife recovery.
"We will stay with the cleanup until it is complete, and we sincerely apologize to the people of Montana for any inconvenience the incident is creating," Pruessing said.
Gov. Brian Schweitzer has also directed state agencies to do all they can to monitor and assist with the cleanup. Disaster and Emergency Services, Department of Environmental Quality and other state agencies will monitor the situation until the spill and its impacts are taken care of, Schweitzer said.
"The parties responsible will restore the Yellowstone River," he said.
While the pipeline was shut down within six minutes of the time pipeline sensors detected a loss of pressure, it took longer to pinpoint the location of the problem.
"A large amount of oil entered the water very quickly," Pruessing said.
Normally, 40,000 barrels of crude oil flows through the pipeline each day.
As of late Saturday night, 41 people had called the information and complaint line set up by ExxonMobil, 888-382-0043.
Operations at the ExxonMobil refinery in Billings have slowed, said Jon R. Wetmore, the Billings refinery manager for ExxonMobil. He did not anticipate any disruption to the refinery's overall operation.
No explanation for what may have caused the spill beneath the Yellowstone River has been identified, Pruessing said.
The pipeline under the Yellowstone was built in 1991 and was last inspected in 2009, when it met all regulatory requirements, Pruessing said. Soundings done in December 2010 determined that the pipeline was buried 5 to 8 feet below the riverbed. In June, a field audit of the pipeline's integrity management program was done by the U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration.
In late May, when heavy rains drenched the area and the Yellowstone River flooded some low-lying areas near Laurel, the pipeline was shut down for a day while the pipeline company evaluated potential risks. There were no indications of danger, Pruessing said.
The river hit a peak of 13.9 feet on Friday night, said Brian Tesar, a meteorologist with the Billings office of the National Weather Service. Flood stage is 13 feet.
By Sunday, the river dropped to 12.5 feet, Tesar said.
"We're expecting it to stay below flood stage, but we might see a bump up by Tuesday to near flood stage from the hot temperatures we're seeing in the high country," he said. "But right now it's expected to be relatively mild."
Air quality readings in the area indicate no danger to public health, Pruessing said. Devices worn by cleanup crew members are also monitoring air quality.
Crude oil contains benzene, a carcinogen that is also found in tobacco smoke, motor vehicle exhaust and other sources. Benzene levels are specifically being monitored, Pruessing said.
"We know of no safety issues to the public," he said.
No impact has been reported on any city water systems, he said. The Billings water plant was not affected by the spill, and water plant officials in Miles City said they saw no evidence of the Friday night oil spill. Dave Harris, the water plant supervisor in Miles City, said the plant has been monitoring water quality every 30 minutes and that no concerns have been raised.
Crews from the Billings refinery on Saturday and Sunday used booms and absorbent pads to sop up oil. Floodwaters began to recede Sunday, but because of the Yellowstone's turbulence, boats cannot be used in the response effort.
"We are presenting a detailed plan this morning which outlines how we clean up oil already located and continue to search for additional oil," Pruessing said.
Residents in Laurel who were temporarily removed from their homes early Saturday morning as a precaution returned later in the morning.
"All the ditches were shut off as soon as they were notified," Pruessing said.
Carl Peters, manager of the Lockwood Irrigation District, said because the river was running high Friday night, he shut the pumps down at 9:30 as a precaution so water wouldn't enter the pump house. He got a series of calls after midnight warning him of the spill.
"When I got down there Saturday morning, I noticed we did have oil slicks in our intake canal and we had concern about pumping that to our customers," Peters said.
He called ExxonMobil, and a cleanup response team responded by 3 p.m. Saturday and put down two absorbent booms, which soaked up the oil on the surface of the water. Soon after 3:30, Peters said, he was able to restart the pumps.
On Sunday, Duane Winslow, Yellowstone County director of disaster and emergency services, challenged published statements from officials in towns downstream from Billings who said they were not contacted immediately about the oil spill.
The DES did contact downstream communications centers through teletype messages sent to county sheriffs' departments at about 3 a.m. Saturday, Winslow said.
He also asked for cooperation from members of the public who might be tempted to gawk at cleanup efforts along the river.
"Just stay away from the river right now and let the workers do their jobs," he said.
Winslow also advised people to stay out the river east of Laurel because of the contamination and the dangers posed by the receding floodwaters. The Duck Creek fishing access site has been closed.
Bill DeMeyer, president of the Yellowstone Valley Audubon Society, said his organization plans to work with the International Bird Rescue group to help with the birds and other animals affected by the oil spill. For now, he said, people should report any oil-covered birds they find to the Billings office of the Montana Fish, Wildlife and Parks, at 247-2940, or call the Exxon information and complaint line.
"Our concern is birds and all the animals," DeMeyer said. "We're volunteering to help them any way we can."