Until plans to excavate and investigate the area around the crude oil pipeline that dumped several thousands of barrels of oil in Mayflower are approved by the US Department of Transportation, the cause of the rupture will remain unknown, an ExxonMobil spokesman said Monday.
"We've not yet gotten authority to excavate around the pipeline…We're pulling together a plan to get it approved," said Alan Jeffers, ExxonMobil media relations manager.
The plan will be submitted to the US Department of Transportation Pipeline and Hazardous Materials Safety Administration, which enforces regulations on the 2.6 million miles of pipes in the United States, according to the group's website.
Jeffers said ExxonMobil officials have confirmed they've observed several thousands of barrels of oil above ground in Mayflower, but an exact amount is not known.
One barrel is equivalent to 42 gallons of oil.
"What we know is there was a breach in the pipeline, a rupture, and the oil which is under pressure came out. We shut down valves on either side to keep the oil from flowing. Somehow there was a failure in the pipeline. We do not know the cause of it," Jeffers said.
Three days after the line ruptured in the front yard of a home in the Northwoods subdivision off of Main Street in Mayflower, 12,000 barrels of an oil and water mixture had been recovered from pools and small water surfaces.
Fifteen vacuum trucks have been pumping the mixture into tanks, Jeffers said.
Jeffers and Faulkner County Judge Allen Dodson said again at a press conference Monday no oil had made its way into Lake Conway.
Dodson said shortly after the leak was discovered Friday, crews worked "feverishly" in several locations to stop the flow to the lake.
The rupture is about nine-tenths of a mile from Lake Conway.
According to Dodson, the oil flowed down North Starlight Road in the subdivision and into a culvert, passed under Main Street, the railroad, US Highway 365 and under Interstate 40 to a lowland area.
The lowland area Dodson described is just north of the Bell Slough State Wildlife Management Area.
Dodson said crews installed wooden flood gates at culverts near Lake Conway and dumped gravel as "our last line of defense" before oil could reach the lake.
A pond on the south side of US Highway 89 South that feeds to Lake Conway was being monitored Monday, and floating barricades are seen just on the other side where the culvert empties into the lake.
Jeffers said the barricades are a precaution, and if oil gets to the lake, it will be a "sheen" on top of the water.
"This (barricade) will keep it in one area so it can be recovered," he said.
Oil is present in drainage ditches and low, wet areas near Bell Slough along Dam Road.
Several ducks covered in oil have been recovered from the area and are being treated at a wildlife rehabilitation center in Pope County.
All recovery efforts are being paid for by ExxonMobil.
"We'll cover all costs. We are the responsible party here," Jeffers said.
More than 50 Mayflower residents had filed claims since Friday, he said.
He encouraged others with questions or claims to call the claims line at 1-800-876-9291.
"This isn't fast, so we'll be around for a while. But we're committed to staying here until it is cleaned up," he said.
The 20-inch line that ruptured Friday is part of a 850-mile crude oil pipeline that stretches from Patoka, Illin. to Nederland, Tex.
Jeffers said the oil is not "tar sand," but crude oil produced from a conventional drill well in Alberta, Canada.
The crude oil makes its way to Texas through the pipeline at a rate of 95,000 barrels a day, where it is then piped to refineries in the Gulf area.
The line is 24 inches under the ground and was installed in the late 1940s, according to Jeffers.
The line's age does not determine its integrity, he said, and the lines should have a "long life."
Residents have returned to the neighborhood, but not to homes on North Starlight Road, where oil is still present in yards and on the street.