By Vickie Buchanan
The National Transportation Safety Board (NTSB) investigates
transportation accidents, determines the probable cause of
the accident, and often issues recommendations to prevent
similar accidents from occurring. Recently, the NTSB has been
investigating the Pacific Gas and Electric Company’s (PG&E)
pipeline rupture and explosion in San Bruno, California. Its
investigation has revealed that emergency response procedures
established by pipeline operators may rob emergency responders
of the opportunity to act in the critical first minutes after a rupture
or a leak of a pipeline has occurred.
On September 9, 2010, a PG&E 30-inch- diameter underground
natural gas transmission pipeline ruptured in a residential area in
San Bruno and released 47.6 million standard cubic feet of natural
gas. The released gas ignited and caused an explosion which
resulted in a crater about 72 feet long and 26 feet wide. Eight
people were killed, dozens more injured, 38 homes were destroyed,
and 70 more homes suffered damage.
During the NTSB’s investigation, it discovered that PG&E
received first notice of the rupture four minutes after it occurred
but then PG&E technicians spent the next several minutes
trying to interpret alarms and the low-pressure indications on
the pipeline. Consequently, local emergency response agencies
were not notified of the pipeline rupture for 16 minutes after it
had occurred. The NTSB believes that the catastrophic nature of
the rupture could have been communicated to PG&E if 
prompt
notice of the suspected rupture had been provided to emergency
first responders. In turn, PG&E could have then taken aggressive
measures to isolate the rupture and prevent the release while
emergency first responders could have formulated an evacuation
plan and a plan to minimize harm to the environment and request
such assistance as necessary from other emergency agencies.
As a result, the NTSB has recommended that the Pipeline
and Hazardous Materials Safety Administration (PHMSA) issue
guidance to pipeline operators (1) to retain specific information
regarding the components of their pipeline system (2) to ensure
system specific information (including pipe diameter, operating
pressure, product transported and potential impact radius) is
shared with emergency response agencies in communities where
the pipelines are located and (3) regarding the importance of
control room operators to immediately and directly notify 911
emergency call centers in the communities where the pipelines are
located when a possible rupture of any pipeline is suspected.