Final Pipeline Report Out Monday

The final report on what caused the Sept. 9, 2010, pipeline explosion is expected to be released Monday, the National Transportation Safety Board said today.

Investigators have already determined that the in the Crestmoor neighborhood was PG&E's inadequate handling of Line 132 in which a poorly welded section of pipe expanded over time and ruptured into a fireball when the gas pressure suddenly spiked on that tragic Thursday night. The fire left eight people dead, dozens of people injured and 38 homesdestroyed.

The NTSB also determined that PG&E's flawed integrity management program, which was supposed to detect problems in its pipeline system, led to the explosion.

It isn't clear whether the final report will contain any new information. The agency's six-member board held a hearing Aug. 30 in Washington, D.C., to discuss the report's findings and to ask questions to get further feedback about the findings. Afterward, Deborah Hersman, chairwoman of the NTSB, at PG&E and that pipeline safety will only become better when lasting improvements are made.

The Aug. 30 report also included 29 recommendations urging PG&E, the California Public Utilities Commission and federal pipeline regulators to take immediate action to ensure the safety of pipelines throughout the country.

If the agency's last report on the , which killed one person and injured five others, is any indication, Monday's report will contain more detailed graphs and diagrams that explain how the pipe failed.

Bob Bea, a UC Berkeley engineering professor who has been following the NTSB's investigation, said the agency's several preliminary reports released during the investigation should be key signals for what the final report will conclude.

Those reports revealed multiple deficiencies in PG&E's operations, including , an to the disaster and ineffective federal and state oversight.

Whatever the final conclusions, Bea said, the NTSB will be looking to address some very crucial risks associated with an at-risk pipeline system.

"What they're trying to do is frame how to effectively close a gap that has taken years to develop," Bea said. "PG&E and the CPUC have been frozen in time, and they have largely been using a process for those earlier days (when cities weren't as developed)....Catching up with that distance isn't easy or free."

The final report is expected to be posted at 7 a.m. Monday on the NTSB website.