Stories you shouldn’t miss:
1. The federal investigation of PG&E’s pipeline explosion in San Bruno has revealed that the utility was operating the line at dangerously high pressure levels for an old pipe — and at a higher pressure than PG&E had previously disclosed, the Mercury News reported. PG&E was operating the line at up to 386 pounds per square inch — not 375 as the utility had said publicly. Too much pressure has caused other pipelines to explode, and experts said that the San Bruno line might have been too old and worn out to handle that much pressure.
2. At the same time, industry experts told the Chronicle that PG&E has been using outdated tests to examine its natural gas pipelines, including the San Bruno line. In fact, the utility’s claim that the line recently passed inspection was based on one of those out-of-date tests. The inferior testing method doesn’t adequately check for pipeline corrosion — another possible reason for why the San Bruno line blew up. PG&E says newer, more effective testing methods are too expensive.
