The U.S. Pipeline and Hazardous Materials Safety Administration ordered an Enbridge Inc. subsidiary to take more than a dozen corrective actions on several lines along its Texas Eastern Transmission LP system following a deadly explosion in Lincoln County, Ky.
PHMSA ordered Texas Eastern to keep 19 miles of the pipeline near the Danville Compressor Station out of operation and shut down two adjacent lines. The agency also ordered Texas Eastern to reduce pressure along the remainder of the 775-mile-long line between Kosciusko, Miss., and Uniontown, Pa., by 20% until PHMSA gives the company written approval to restore pressure to higher levels.
The order covered Line 15 on the Texas Eastern system, which transports gas from the U.S. Gulf Coast to the mid-Atlantic and Northeast along 8,835 miles of pipeline. On Aug. 1, the explosion on Line 15 in Moreland, Ky., killed one person, injured six others and damaged several homes.
"After evaluating the foregoing preliminary findings of fact, I find that continued operation of the affected segment and the two other adjacent [Texas Eastern Transmission LP] TETLP pipelines, Line 10 and Line 25, without corrective measures is or would be hazardous to life, property or the environment," Alan Mayberry, PHMSA's associate administrator for pipeline safety, said in the report.
"The adjacent lines could potentially have been affected by the failure and that, accordingly, should not be restarted without further investigation. At this time, the risk of concussive force or thermal damage to the adjacent lines cannot be ruled out," Mayberry warned.
The explosion blew a 50-foot-long, 35-foot-wide and 13-foot-deep crater into the ground and resulted in the release of an estimated 66 million cubic feet of natural gas, according to PHMSA's order. The resulting fire also scorched or burned approximately 30 acres of land, PHMSA said. An NTSB spokesperson earlier said the blast ejected approximately 30 feet of pipe into the air.
Mayberry also ordered Texas Eastern to submit a plan to restore operations along the impacted segment for approval and mandated that Texas Eastern conduct several reviews, including a gas leakage survey, mechanical and metallurgical testing, and a root cause failure analysis.
Enbridge acknowledged receipt of the corrective action order on Friday and said it was "working diligently" to meet the requirements laid out in the order. The company confirmed that it had taken Lines 10 and 25 out of service as a precautionary safety measure.
"Enbridge takes these issues very seriously. We will address all the site-specific concerns identified by PHMSA and will be undertaking rigorous inspections on the pipelines in compliance with the CAO before returning the two pipelines to service. These pipelines will not be returned to service until we satisfy regulatory requirements and it is safe to do so," the company said in a statement.
There is currently no timeline for returning the lines to service, Enbridge said. The National Transportation Safety Board, which took control of the site after the incident, returned control to Enbridge on Aug. 9, and the company was deploying crews to the area to begin assessment work.
Construction on Line 15 began in 1942, according to the PHMSA order. The wall thickness along the portion at the heart of the blast site is 0.375 inch. The line is coated with tar enamel, is cathodically protected and was constructed using flash welding.