Marshall pipeline that exploded remains at risk
MOUNDSVILLE — The federal agency in charge of investigating a recent pipeline explosion has notified its owner that six other areas on the same pipeline have issues that could cause another catastrophic event if they are not repaired.
The Pipeline and Hazardous Materials Safety Administration issued on July 9 a 13-step notice of proposed safety order to lower the risk of future explosions like the one that occurred June 7 on Nixon Ridge. The notice gives companies an opportunity to respond to a proposed correction plan before finalizing an order, which then makes the steps involved mandatory.
PHMSA Eastern Region Director Robert Burrough sent the notice to TransCanada Corp. and its subsidiary, Columbia Gas Transmission LLC, which owns the 130-mile Leach Express pipeline. Burrough said in the notice that completing the steps outlined in the notice is necessary for the safety of the people and property near the 36-inch gas transmission line.
“It appears that the continued operation of the Affected Segment, without corrective measures, poses a pipeline integrity risk to public safety, property and the environment,” Burrough wrote.
TransCanada did not return a call seeking comment.
Several people who live or own property near the site of the June explosion declined to comment.
Tom Hart, Marshall County Director of Emergency Management, said he had not had time to review documents submitted by TransCanada and the PHMSA.
“We’re still reviewing the documents, both from (TransCanada) and the feds,” Hart said.
TransCanada filed an incident report on June 27 with the PHMSA regarding the June 7 explosion. In it, the company said it had sent the damaged pipeline to a metallurgy lab, but it had not determined the cause of the pipeline’s failure as of the time of the report.
PHMSA said its preliminary findings suggest the failure was the result of land subsidence that caused stress on a girth weld. However, it also said the investigation is ongoing and the cause of the failure remains unknown.
Meanwhile, land and soil issues are what concern the administration about the other six areas TransCanada discovered in the wake of the June 7 event. The issues include the existence of large soil piles, steep slopes or indications of slips.
To correct these problems and prevent another explosion, Burrough said the PHMSA is proposing a safety order that would require the company to take certain steps within the next 30-90 days, and some of the steps would be ongoing after that. They include reviewing the isolated segment; enhancing surveillance and monitoring; installing strain gauges; performing hydrostatic testing; creating a weather contingency plan; performing an instrumented leakage survey; verifying the records of the operating pressure where the previous explosion occurred; reviewing the prior inline inspection results; arranging for mechanical and metallurgic testing; completing a root cause failure analysis; submitting a remedial work plan; submitting monthly reports; and finalizing a safety order documentation report.
PMHSA’s preliminary findings indicated that the Leach Express pipeline was operating at approximately 86 percent to 89 percent of its maximum capacity of gas when the failure was reported around 4:55 a.m. on June 7. That’s when a drop in pressure was discovered by a gas controller. The section of the pipeline was manually closed down by 5:20 a.m.