A preliminary investigative report from the National Transportation Safety Board says Columbia Gas received 16 pressure drop alerts before it learned one of its natural gas pipelines had exploded in Kanawha County.
The NTSB report, issued Wednesday, contains a lot of the same information investigators released to the public in the days following last month’s blast and fire near Sissonville.
About 20-feet of the 21-inch in diameter pipe was separated and ejected in the blast landing 40-feet from its original location. The fire destroyed three homes, damaged several others and melted a section of pavement along Interstate 77.
A link to the full preliminary report can be found at: http://go.usa.gov/4grH
The report, also repeated previously released information that the pipeline, installed in 1967, had thinned from corrosion.
Columbia Gas did not have an alarm in its control room notifying it of the blast but a call came in from Cabot Gas which had a worker near the explosion site.
Between the explosion and that call the NTSB report says there were ”16 pressure drop alerts on the Supervisory Control and Data Acquisition (SCADA) system from Lanham Compressor Station (Lanham) 4.7 miles upstream of the rupture. The alerts indicated discharge pressure dropping on all three pipelines in SM80 system (Line SM-80, Line SM-86, and Line SM-86Loop).”
Columbia released a response Wednesday afternoon:
The NTSB is continuing its investigation. No official cause has been determined.
Earlier this week the parent of Columbia Gas, NiSource, sent a check to the Kanawha County Commission paying more than $231,000 in local and state expenses in connection with the explosion. The company has also been working with residents who were impacted.
Columbia has not yet reenergized the line that ruptured. It’s been working with federal and state agencies on a corrective order that was previously issued. Kanawha County officials say they want to make sure the entire pipeline is safe before its used again.