A little over a year ago a 24-inch natural gas transmission pipeline in Lycoming County, PA failed.  It didn’t explode, but people were evacuated for safety.

The investigation has determined that external corrosion was was to blame.

Interestingly, the pipeline had no history of internal corrosion.

It’s important to point out that these pipelines are failing after decades of use.  It seems that as the pipelines get older, they would be more subject to corrosion.  To counter that, pipeline companies could increase their inspections.  But pipeline companies aren’t increasing inspection frequency.