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Prince George’s Co. and MD / Don’t Let the San Bruno natural gas explosion happen here

September 9, 2011

San Bruno neighborhood before explosion

The same San Bruno neighborhood following the explosion and fire; click photo to enlarge

The San Bruno Gas Explosion: One Year Later

 On September 9, 2010, a 30-inch-diameter segment of an intrastate natural gas transmission pipeline [1] owned and operated by the Pacific Gas and Electric Company (PG&E), ruptured in residential San Bruno,

A massive fire is roars through a mostly residential neighborhood in San Bruno, Calif., Sept. 9, 2010. Photo/Paul Sakuma)

California – located adjacent to San Francisco International Airport. The gas under high pressure and escaped in huge quantities causing an  explosion and fire that killed 8. injured many, and forced numerous families to evacuate their homes. Thirty-eight homes were destroyed, dozens damaged. The immediate cause of the accident was the rupture of a 28 foot section of the 54 year-old pipeline due to the failure of a welded seam. Click here to see an incredible video of the San Bruno inferno with aerial photos showing the neighborhood before and after the explosion More information on the accident are available on previous posts. [2] 

The National Transportation Safety Board Report: NTSB just published its the findings of its year-long investigation on the causes of the accident and on adequacy

Chris Johns, President PG&E

of the responses to the accident. The report, holds no punches, and faults Pacific Gas & Electric (PG&E) for a myriad of preventive steps and non-compliance with important regulations. It also  contains a series of recommendations for the PG&E the utility company that owns and operates the transmission line and for regulatory agencies responsible for pipeline safety. You can see the full report on the Board’s Website.[3]  The main findings are summarized below:

  • The fracture originated in a partially welded seam along an aging line progressively weakened due to cracking.
  • PG&E failed to to meet industry quality control and welding standards in place when the line was installed in 1956.
  • The 95 minutes that PG&E took to stop the flow of gas was excessive.
  • Use of automatic shutoff valves would have significantly reduced the amount of time taken to stop the release of gas into the air. Had operators been able to use automatic shutoffs, the gas-fed fire could have been put out in minutes according to safety experts.[4]
  •  PG&E lacked detailed, comprehensive procedures needed to respond to a large-scale emergency such as a transmission line break.
  • The California Public Utilities Commission (PUC) and the U.S. Department of Transportation grandfather clauses that allowed older (pre-1970) pipelines to escape pressure tests were not justified. Pressure testing would have exposed the defective pipe that caused the accident.
  • Weak enforcement by the the PUC permitted PG&E’s deficiencies to continue over many years. The Pipeline and Hazardous Materials Safety Administration’s (PHMSA) enforcement program and its monitoring of state oversight programs have also been weak.
  • Finally, the board gave high marks to local emergency workers for a well coordinated and effectively managed response.

Firemen battled to control the San Bruno inferno; emergency responders -- don't cut public employee budgets, we need these men and women!

 NTSB Recommendations: The NTSB made numerous recommendations to PG&E and state and federal regulatory authorities. The NTSB recommended that PUC conduct a comprehensive audit of Pacific Gas and Electric Company operations and correct all deficiencies identified. The Board also recommended that PHMSA amend its regulations to require: (1) automatic shutoff valves control valves for lines in populated area (2) that all natural gas transmission pipelines be configured to accommodate in-line inspection tools, with priority given to older pipelines (3) that all gas transmission pipelines constructed before 1970 receive hydrostatic pressure testing.

Aging pipelines, a national problem: The following graph shows that nearly 60 percent of the nation’s 300,000 miles of natural gas transmission lines are at least 40 years old, lack modern safety equipment and are subject to corrosion and cracking.

Transmission line mileage as a function of age. Click to enlarge

Chillum Road: One area with more than its share of aging high pressure gas transmission lines is the densely populated Chillum Road area of Hyattsville, Maryland. This predominantly African-American community includes 3000 people, a large nursing and rehabilitation center, and a Metro station – all located in close proximity to a major natural gas handling facility owned and operated by Washington Gas & Light (WG&L). Four high pressure transmission lines run through the area.[5] In the past the site housed two large storage tanks for natural gas which were removed in 1999.

WG&L has been trying for the past 6 1/2 years to locate a Liquefied Natural Gas (LNG) plant at its Chillum facility – a proposal that’s been held at bay by a number of area community organizations and by Prince George’s County. It is unfathomable that the Maryland Public Service Commission would approve an LNG facility in so highly a populated area, especially given that WG&L has not promise to replace the area’s aging pipelines before the project is approved. Residents in the area report that some segments of the transmission lines may be 80-years old and many have experienced numerous odors. This past August 15, there was a gas line leak with sufficient pressure to carry dust some 30 feet into the air according to Imani Kazana, a resident and community leader. “The smell was incredible.”

San Bruno: Ruptured natural gas transmission line and burnt out car:

 The Blunt warning: Deborah Hersman, the NTSB Chair issued a blunt statement saying, “It was not a question of if this pipeline would burst but a question of when…The aging pipelines, our oldest pipelines really are without a safety net.”[6]  This statement applies to all transmission lines located in populated areas and not just San Bruno. A rash of gas accidents occurred over the past year including two fatal explosions in Philadelphia and Allentown, PA.

Maryland: Heed the warning! The NTSB findings and recommendations provide a template for the kind of action that is needed to prevent serious accidents in Hyattsville. Based on NTSB report, we urge the Maryland legislature to hold a series of hearings on the safety of Maryland’s natural gas transmission lines. The hearings should:

  • Identify the age, composition, condition of all natural gas transmission lines in populated areas.
  • The adequacy of monitoring and shutoff equipment needed to prevent and mitigate accidents
  • The adequacy of the Maryland Public Service Commission’s regulations and enforcement; for example, does the PSC have a sufficient number of inspectors
  • The adequacy of emergency response plans and responses to citizen reports of odors

The law makers should immediately pass legislation that would require  require gas utilities to (a) replace the oldest transmission lines (b) ensure that transmission lines have automatic shutoff valves and (c) ensure that transmission lines are monitored and tested frequency.

Added Benefit: Replacement and modernization of age-weakened natural gas pipelines can provide large numbers of jobs to construction workers, pipe workers, engineers, electricians and others that are currently idle or underemployed. Click here for a complete discussion. 

[1] Transmission lines are high pressure pipelines that deliver natural gas great distances, e.g. from the source to a local distribution station. Distribution lines are the low pressure pipes that deliver gas from the local station to homes.

[3] Pipeline Accident Report: Pacific Gas & Electric Co. Natural Gas Transmission Pipeline Rupture and Fire,San Bruno,CA, September 9, 2010, August 2011,

[4]Huffington Post San Francisco, “San Bruno Explosion: National Transportation Safety Board Blames PG&E’s ‘Litany Of Failures’”

 [5] Testimony of Kevin Murphy, P.E., June 6, 2009 before the MD PSC, Case No. 9180.


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