Repairs and a search for the cause of Friday morning's rupture and explosion on a natural gas pipeline lateral in northeast Nebraska continued Tuesday, an Omaha-based spokesperson for Northern Natural Gas Pipeline told NGI.

The blast occurred at 8:30 a.m. Friday north of Fremont, NE, on Northern Natural's west leg. There were no injuries reported and no service interruptions from the blast.

The damaged 18-inch diameter pipe was one of three parallel lines. The other two, a 16-inch and a 24-inch line, are continuing to function, but at reduced pressures. The lower operating pressures on the lines have reduced capacity on Northern's West Leg from Fremont (including the Columbus branch line) northwest to Aberdeen, SD, and northeast to the NBPL Welcome interconnect. Northern's preliminary estimate to complete the inspections and repairs on the two lines still operating and return them to full service is March 31. The repair of the damaged pipeline is expected to continue into the summer.

Contracted firm capacity in the impacted area is 581,384 Dth/day in March 2014. At this time, the operational capacity is reduced to approximately 300,000 Dth/day, Northern told its customers. That should be boosted to approximately 400,000 Dth/day once pressure on the two parallel lines is returned to normal. Northern said it does not anticipate any reduction to firm service since historical April flows have been below the reduced operational capacity of 400,000 Dth/day.

The pipeline spokesperson said the company had assigned investigators to determine the cause of the incident on the Northern Natural transmission pipeline system, which is owned by MidAmerican Energy Holdings Co., part of Omaha billionaire Warren Buffett's Berkshire Hathaway companies.

Firefighters from four surrounding communities northwest of Omaha, NE, responded, but had to wait for Northern Natural crews to shut off the gas flow.

"The incident occurred on a short, isolatable segment of Northern's B-line, which runs from Palmyra, NE, to South Sioux City, NE," the spokesperson said. "In that area, there would be multiple local gas distribution utility companies, including Black Hills, Metropolitan Utility District [of Omaha], MidAmerican Energy's LDC and some municipalities. As I noted, there is no anticipated loss of service due to the incident or repairs."