January 11, 2011 > PG&E gas line
PG&E gas line
By Abraham Cruz
On October 3, 2010, Milpitas City Council requested an on-going report regarding the state of the city's PG& E gas lines in the wake of last September's San Bruno explosion. The report, presented to Council on January 4, 2011, was spearheaded by Milpitas Fire Chief Brian Sturdivant, Milpitas Public Works Director Greg Alemndariz and Emergency Operations Center Manager Sean Simonson. PG&E's Government Liaison Officer Tamon Narimoto and Gas Superintendent Bill Wallace were also present.
The report includes the following points related to San Bruno gas line accident - causes of the explosion, present state of Milpitas' gas lines, emergency response plans, information on high-pressure gas lines, public outreach on home gas line valve-shutoff procedures and periodic scheduled reports on all items mentioned above as information becomes available.
At about 6.11 p.m. on September 9, 2010, a natural gas transmission pipe (line 132) ruptured in a residential area in San Bruno. Approximately 47.6 million standard cubic feet of natural gas was released and somehow ignited, resulting in an explosion that destroyed 37 homes, damaged 18 residences, killed eight people and injured many others.
The National Transportation Safety Board (NTSB) is responsible for regulating pipeline safety and is leading the investigation. To date, the NTSB has released two preliminary reports. The first states that line 132 may have ruptured because gas pressure increased; the second details the NTSB's investigative efforts and notes no evidence of external corrosion or evidence of a pre-existing leak.
However, the second report notes a discrepancy in PG&E's records of the type of pipe installed at the San Bruno location (30-inch diameter steel pipe with 0.375-inch thick wall, installed circa 1956). The records state the pipe was seamless (one-piece) but what was discovered was a welded, seamed pipe which the NTSB deems weaker than seamless pipes. Although the investigation is on-going, the reports give no definite conclusion as to what caused the leak and subsequent explosion.
As a result of the accident, PG&E has implemented a program titled "PG&E Pipeline 2020" whose objectives are to modernize the existing pipeline infrastructure, expand the use of automatic or remotely activated shutoff valves, develop better inspection technology, improve industry-leading practices and enhance public safety partnerships through community involvement and safety awareness.
Fire Chief Sturdivant outlined the Milpitas Fire Department's "Underground Pipeline Emergencies" and "Hazardous Materials Incidents" policies, which were updated in November 2010, in coordination with PG&E with further revisions and/or development in the following areas - PG&E Emergency Contingency Plan, PG&E Pipeline Valve Maps, Communication Plan with PG&E and a PG&E Security Plan. Additional emergency response training will include first-response familiarization with PG&E facilities, exercises of mock emergencies and drills or emergency scenarios.
Wallace and Narimoto informed Council the Milpitas PG&E station is staffed and monitored 24 hours a day. Councilmember Debbie Giordano asked whether PG&E is assuming any financial responsibility for the cost of the city's improved training and communication updates; PG&E does not currently have a shared cost model for such training with other cities. Recent leak surveys concluded the Milpitas gas pipes are currently sound with further testing techniques to be used, as necessary, when the final NTSB report and the PG&E pipe installation records have been completed.
There are other high pressure hazardous pipelines in the city. Kinder.Morgan has an 864-mile pipeline system transporting petroleum products from refineries in Richmond and Concord to Brisbane, Sacramento, Chico, Fresno, Stockton and San Jose. The 10-inch diameter line conveys regular gasoline, diesel and jet fuel products through Milpitas following the Union Pacific Rail Road right-of-way. A nitrogen gas line is operated by Air Products and passes through Milpitas from the East Bay to San Jose; although inflammable, nitrogen is still hazardous.
The report is considered a "living document" and further updates will occur at subsequent Council meetings. Vice-Mayor Pete McHugh motioned inclusion of completion dates in future reports to retain momentum on these issues.
For more information, visit www.ci.milpitas.ca.gov