The Pipeline and Hazardous Materials Safety Administration (PHMSA) has issued Spectra Energy Corp. an amended corrective action order detailing a slate of work that must be completed before Texas Eastern Transmission's (Tetco) Penn-Jersey system can return to full-service after an April blast that damaged it.
A portion of the system, which runs from Delmont, PA, to Lambertville, NJ, exploded and caught fire in April in Westmoreland County, PA (see Shale Daily, April 29). The system consists of four parallel pipes, one of which, the 30-inch Line 27, ruptured in the blast. While another, Line 19, was returned to partial service in May, Lines 28 and 12 have been offline awaiting the green light from PHMSA to restart.
In the amended order issued to Spectra on Tuesday, PHMSA's Acting Associate Administrator for Pipeline Safety, Alan Mayberry, said Lines 19, 28 and 12 were likely affected by the blast and could not be returned to full service until the company fulfills the requirements included in the amended order and another issued in May.
"Continued operation of the affected segment...without corrective measures is or would be hazardous to life, property, or the environment," Mayberry wrote in the order. "In addition to the failed Line 27, subsequent investigation by respondent and PHMSA has demonstrated that lines 12, 19 and 28 could potentially have been damaged or adversely affected by the explosion and fire at the failure site and pose a serious risk to life, property or the environment if returned to normal operation unless respondent takes certain corrective actions in addition to those required under the original [corrective action order]."
The amended order contains new and changed preliminary findings that require Tetco take more action in the wake of the blast, which toppled trees, razed one house, damaged others and sent one resident to the hospital with severe burns that covered three-quarters of his body. The explosion also knocked out about 1 Bcf/d and cut flows east of the Delmont compressor station to zero for 10 days after the incident before partial capacity was restored.
In the amended order, PHMSA said the failure resulted in the release of 208.4 MMcf of natural gas, "which ignited, producing a crater approximately 30 feet wide, 50 feet in length and 12 feet deep." The explosion ejected 24.5 feet of 30-inch pipe from the site, the agency added.
In its first corrective action order, PHMSA said a preliminary investigation had shown evidence of corrosion along two of the affected pipe's circumferential welds (see Shale Daily, May 4). A failed tape coating on the pipe at the site has also been installed at hundreds of points along the system. PHMSA said in its latest order that the cause of the accident remains unknown and said an investigation is ongoing.
Line 27 was constructed in 1981. It was last inspected in 2012, at which time Spectra said there was nothing wrong with the pipe. PHMSA said a review of previous operating history and remediation records for a segment of Line 12 showed a pattern of external corrosion with "characteristics similar to the condition that caused the failure on Line 27."
Last month, Spectra said it would voluntarily conduct a "thorough and conservative assessment" along the Penn-Jersey system's entire 263-mile stretch, saying full-service might not be restored on the system until November (see Shale Daily, June 28).
PHMSA's amended order requires Tetco to submit assessment, remediation and restart plans. It also requires a testing and failure analysis. The order requires the restart of Line 27 to be done in increments, stipulating that pressure on the system be stepped-up from 25% to 50% and then to 80% before Tetco can request written approval to run at pre-failure pressure.
Among other things, the new order also requires a root cause failure analysis be completed within 90 days of the order's receipt; an emergency response plan and training review, and a public awareness program review.
Spectra said in a statement released Thursday that the order's requirements are "well-aligned with the work plan we developed as part of our thorough assessment of the entire Penn-Jersey system, including anomaly investigations, in-line inspections and hydrostatic testing." The company said it has already started or completed much of the work, adding that it expects to have the root cause analysis completed by late summer or early fall.