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from a feld technician near the accident location. Around the same time that the Columbia Gas control center was notifed of the rupture, a Columbia Gas operations manager was called by a Columbia Gas feld operator and informed of the release and fre. The operations manager sent a crew to the isolation valves ~3.2 miles (5 km) downstream of the rupture, which were closed by feld technicians at about 1:19 p.m. to prevent the backfow of gas. The operations manager also notifed personnel at the Lanham compressor station to shut the six upstream valves, which required a technician for closure. The operations manager was notifed at 1:40 p.m. that the valves were fully closed, stopping the gas fow to the rupture nearly one hour after the rupture occurred. "Although it is premature for the NTSB to determine the cause of the Sissonville accident, issue fndings, or draw conclusions, there are a number of recur- NACE International, Vol. 52, No. 5 ring safety issues we have identifed in previous pipeline accidents we have investigated that merit highlighting today," Hersman said at the hearing. "In particular, these safety issues include automatic and/or remote control shut-off valve installation, use of in-line inspection (ILI) tools, integrity management program, and SCADA training." A Corrective Action Order (CAO) was issued to Columbia Gas Transmission by PHMSA regarding the failure of Line SM-80. The CAO calls for, among other things, verification that all CP equipment and test stations are operating properly on all three pipelines, three miles up- and downstream of the incident location, to return the line to restricted operation. As part of the pipeline's longterm assessment and remediation phase, corrective actions include conducting an ILI for high-resolution deformation and metal loss; performing a close-interval survey (CIS)—a series of structure-toelectrolyte direct current (DC) potential measurements performed at regular intervals to assess the level of CP on a pipeline—within 30 days of returning to restricted operation; and assessing the integrity of the coating using a direct current voltage gradient (DCVG) or alternating current voltage gradient (ACVG) survey (methods used to locate and size pipe coating defects) within 30 days of completing the CIS. At the feld hearing in Charleston, Jimmy D. Staton, executive vice president and group CEO of Columbia Pipeline Group, summarized the company's integrity assurance plan, which addresses the CAO for safely returning Line SM-80 to limited service. Repair work includes replacing mainline valves along a 30-mile (48-km) stretch of the line; installing launcher and receiver facilities at points along the line to enable the passage of ILI tools; verifying that the CP system is operating properly on all three of Continued on page 18 May 2013 MATERIALS PERFORMANCE 17