A fracture in a buckle probably caused a 140,000-gallon leak in a Southern Maryland oil pipeline two years ago that fouled the shoreline of a Patuxent River tributary, according to a National Transportation Safety Board accident report released yesterday.
Contributing to the problem were inaccurate readings of equipment data, and inadequate operating procedures and practices for monitoring the flow of fuel oil through the pipeline. As a result, the leak wasn't detected for several hours, according to the NTSB report.
The April 7, 2000, spill from the pipeline, owned then by Potomac Electric Power Co., cost about $71 million for environmental response and cleanup operations.
Yesterday, the NTSB recommended that nationally recognized engineering criteria be developed to evaluate pipeline wrinkles - bends or kinks in the steel conduit - to determine whether they should remain. The board also recommended that pipeline owners and operators provide telephone updates to the National Response Center to ensure a timely response to accidents.
"We believe that what Mirant did in order to get the pipeline back in operation [is] consistent with NTSB's recommendations," said Steven Arabia, spokesman for Atlanta-based Mirant Corp., which paid Pepco $2.65 billion to take over the pipeline in December 2000.
"We have taken a very conservative approach," Arabia said. "We performed pipeline internal, in-line inspections and then had another party check that work. To give us a further comfort level, we did a second type of in-line inspection. We took both [sets of] data and cross-checked the information and then had it checked by a third party. We went the extra mile ... and as a result, the safety of this pipeline is exponentially greater now than prior to the spill."
At the time of the spill, the pipeline - which carried oil from a terminal in Piney Point in St. Mary's County to Chalk Point in Prince George's County - had not been inspected by federal regulators for three years. A storm the day after the spill pushed large quantities of oil over containment booms, fouling about 20 miles of shoreline. Hundreds of turtles, fish, muskrats and other wildlife were killed.
According to a report that two state legislators issued in May, Mirant's 52-mile pipeline has 51 wrinkles and corrosion that continues to weaken its outer shell.
State officials await an official inspection report from the Maryland Public Service Commission's Pipeline Safety Group, which assumed jurisdiction of the line last year.