Hundreds of thousands of miles of natural gas lines run beneath the nation’s homes and cities, some welded and buried decades ago. The potential for failure and causing harm was underscored in September, when a gas line in San Bruno, Calif., exploded, destroying homes and killing eight people.
Now Pacific Gas & Electric Co., which installed the pipeline in 1956, is acknowledging that it can’t find 8 percent of key safety records required for high-pressure lines running through the state’s most densely populated areas. The company told the Associated Press that a search for documents is continuing.
The AP is reporting that California regulators now want Pacific Gas & Electric Co. to provide detailed safety updates, including information about whether the utility was prioritizing work on high-risk lines during the next three years.
The California Public Utilities Commission also is expected to decide whether PG&E should be forced to conduct expensive, time-consuming tests on lines for which records could not be found.
"While we have made good progress on our records validation, we are not satisfied with the results to date and will continue to search for and review our files for additional pressure test records and provide regular updates on our efforts," said Chris Johns, PG&E’s president.
Company engineers, estimators, mappers, information technology specialists and managers — as well as a number of outside contractors — have been scouring more than 1.25 million individual gas transmission records. The company said Wednesday it plans to test and potential replace some 150 miles of aging pipelines.
The National Transportation Safety Board has not ruled out the age of the pipelines beneath San Bruno, or their welds, as potential factors. The NTSB has warned companies for two decades about the vulnerabilities of pipelines assembled before 1970. Many were put together with lower-quality welding techniques.