NEMAHA, Neb. - Magellan Midstream Partners LP returned its products pipeline system to service in Nebraska late on Dec. 12.
Repairs to the pipeline that spilled an estimated 2,834 barrels of refined oil products have been completed, Bruce Heine, a company spokesman, said in an e-mail.
Two separate lines carrying diesel and gasoline were shut Dec. 10 after they were struck by a bulldozer. The pipelines were damaged when a bulldozer operator - the son of a landowner - was tearing out trees with a "rock ripper," Heine said. The plow-like piece of equipment is attached to the rear of a bulldozer and is used to break up hard soils, or remove tree stumps and boulders.
The landowner's son was clearing brush with the bulldozer when he hit the pipelines at a site 2 1/2 miles southwest of Nemaha.
Some of the site was saturated with fuel to a depth of up to 15 feet, DEQ said, and the agency expected to drill wells to see if the fuel reached groundwater.
Magellan said the spill could have been prevented if the bulldozer operator would have called the Nebraska One-Call Center at 811 before excavating in the area near the pipelines.
Crews installed four underflow dams on a tributary of Jarvis Creek that flows to the Little Nemaha River in an attempt to keep the fuel from flowing to the river. An underflow dam draws water from the bottom of a stream through a tube and allows it to continue downstream. Because petroleum floats, the dam holds the fuels back so they can be removed. Such structures are preferred over holding back the entire stream flow, which would cause the contaminated water to flood surrounding property. However, some components of refined petroleum products dissolve into water and would flow downstream regardless.
The company also has built berms on the site to contain runoff from rain, which is forecast for Dec. 13-14.
State officials have set up monitoring sites downstream from the spill to measure for contamination. They also will drill deep into the soil to determine how far the fuel has penetrated. Contaminated soil will have to be removed.
"There have been no dead fish reported," said Jim Bunstock, spokesman for the Nebraska Department of Environmental Quality, on Dec. 12. "There's a lot of monitoring going on."
The company spokesman declined to say how deeply the pipelines were buried. He indicated there had been no call to the digger's hotline, as required by state law before any underground work is done.
The incident was the biggest pipeline spill in Nebraska since 2001. The Pipeline and Hazardous Materials Safety Administration (PHMSA) said the next worst spill happened in 2007, when 72,450 gallons spilled. However, the PHMSA figure ignores 5,000 barrels that spilled from the Platte Pipeline in 1996 near Lawrence, said Bunstock. Bunstock added that 6,300 barrels of petroleum products were spilled by Williams Pipeline in Omaha in 1989.