State Orders Inspection of All Natural Gas Lines

 The California Public Utilities Commission announced Sunday it's ordered Pacific Gas and Electric to inspect its entire natural gas system. The order is a direct result of the deadly explosion in San Bruno Thursday night that killed at least four people and injured dozens of others.

The ordered inspections came on the same day hundreds of San Bruno residents were allowed back into their homes.  In call, 315 houses were given the green light to be reoccupied following detailed structural inspections.

The order was made to ensure the integrity of PG&E's natural gas pipeline system, according to a press release from the CPUC. The CPUC is a state agency that covers not just the Bay Area, but the entire state.

CPUC President Michael Peevey said in the Sunday afternoon release he wanted to assure residents that immediate action will be taken. "We will direct PG&E to immediately begin an inspection of its natural gas transmission system, as well as to take other immediate actions to ensure safety and to assist in our investigation,” Peevey said.

Other than using the word "immediate" in the release, no timeline of the inspections was given.

Specific directions to PG&E:

  • Conduct leak surveys on all natural gas lines, giving priority to transmission (higher pressure) pipelines, and to Class 3 and Class 4 segments of such lines (i.e., those in areas of highest population density), and keep the affected segment of Line 132 out of service until the CPUC directs otherwise.
  • Preserve all records and accident reports from the San Bruno incident, including work at the Milpitas Terminal during the month of September 2010, and ensure that all PG&E employees and contractors are available for interviews with federal and state investigators, including any requested examinations under oath. PG&E should also retain all records of work performed by PG&E or its contractors on Line 132 in the City of San Bruno.
  • Review and report the classification of their natural gas transmission lines and determine if the classification has changed since the initial designation.
  • Report immediately to the CPUC on procedures for responding to gas leak reports, and provide specific data on all leak reports and PG&E’s response for a recent period, system-wide, and in the affected area.
  • Investigate and report to the CPUC on PG&E’s authorized versus actual levels of spending on pipeline safety and pipeline replacements from 2005 to the present.

Thursday's explosion created a crater 167 feet long and 26 feet  wide, according to NTSB Vice Chairman Christopher Hart.  "This really emphasizes the magnitude of what occurred here," Hart said.

Concern about whether similar pipes are under their homes had Bay Area residents flocking to websites that list such things.

You can check if a pipeline lies beneath your home at this government link.

Here's another link to maps of interstate natural gas pipeline maps.

The pipe that exploded was a "Class 3." Class 3 pipes are in areas with more than 47 homes per linear mile of pipe within 220 yards on  either side of the pipeline.
The gas inside was odorized to make it detectable. People in the area have told reporters they smelled gas in the days and weeks prior to Thursday. But PG&E officials have said so far they haven't been able to find any reports to verify that.

On Friday, the CPUC established a toll-free number and an email address for anyone who has information on a natural gas smell in the San Bruno area in the weeks prior to the explosion and fire. The number is 800-789-0550 and the email address is

The specific section of gas pipeline that ruptured was ranked as high-risk because it ran through a highly populated area.

The Associated Press obtained documents that showed that PG&E submitted paperwork to regulators that said a section of the same gas line, but about two and half miles from the blast site, was within "the top 100 highest risk line sections" in the utility's service territory.
The 30-inch pipe was installed in 1948 and was slated to be swapped for new 24-inch pipe. That project never happened.

Thursday's explosion launched a 28-foot underground pipe about 100 feet into the air and onto the street.

The lead NTSB investigator Ravindra Chhatre has more than 30 years experience with pipelines.

His team is already at work. but we won't know for months what they found. The NTSB said he estimates it would be 14 to 18 months before they issue the final report and recommendations. Chhatre and team will be the only source of information about the  investigation.  The NTSB has instructed PG&E, the Pipeline and Hazardous Materials Safety Management Administration, the California Public Utilities Commission and other organizations to not entertain requests from media.

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