A California Public Utilities Commission (CPUC) initiated investigation of Pacific Gas and Electric Co.'s (PG&E) recordkeeping in its natural gas distribution system has turned up repeated violations contributing to explosions over the past two years. The report is part of proceedings on pipeline safety and possible penalties for recordkeeping violations.
A PG&E spokesperson did not respond to individual allegations in the report, saying the utility is "working aggressively every day to maintain the safe operation of our gas system and to keep our customers and employees safe." PG&E is slated to offer its responses Nov. 12.
A safety consulting firm, P Wood Associates (PWA), has prepared a report for the CPUC that found "factors contributing to accidents, incidents and third-party damage," including lack of records, maps not being updated in accordance with mapping procedures, and the San Francisco-based combination utility "not maintaining control and updating historical records of gas distribution mains and service pipelines."
"PG&E's maps and records have suffered from years of neglect, leading to a situation in which maps are inaccurate and records are incomplete, [and] the inaccuracy and incompleteness has contributed to numerous incidents, some serious," co-authors David Berger, John Gawronski and Paul Wood wrote in the report.
They concluded that the utility's handling of an incident in July 2013 in the Silicon Valley suburb of Mountain View, CA, was "a clear precursor" of a home gas pipeline explosion in Carmel, CA, in March 2014 (see Daily GPI, March 17, 2014). In fact, an earlier third-party investigation commissioned by PG&E called the home explosion an instance of the utility having "inadequate verification of system status and configuration when performing work on a live [pipe]line (see Daily GPI, May 6, 2014)." At that time, the report recommended a number changes in the utility's procedures to assure "positive verification" of a pipeline's real-time status.
The PWA report, a redacted version of which the CPUC released Sept. 30, found that PG&E lacks the necessary records to comply with code requirements, primarily as a result of not maintaining its maps and records up to date.
These shortcomings are alleged in the report to manifest themselves as:
Failure to follow written procedures to ensure operating maps/data are updated and accurate;
Failure to mark out and inspect gas lines in the area of excavations;
Failure to carry out data gathering to evaluate the causes and implications of incidents; and
Failure to meet operating pressure restrictions.
PWA found that PG&E was in violation of basic 1970 requirements for establishing the maximum allowable operating pressure for 243 hydraulically independent distribution systems. "It is probable that this violation resulted because of the absence of the distribution system pressure records/charts associated with the five years (1965-1970) needed to comply," the PWA report said.
Pointing to what PG&E has done to its transmission pipeline system in the five years since the deadly high-pressure gas pipeline failure and explosion in San Bruno, CA, south of San Francisco, the utility spokesperson said that PG&E has applied "key learnings" from the transmission improvements to "enhance, digitize and modernize" its distribution system records.
"As the first major step, we recently completed a multi-year effort to consolidate and digitize multiple sources of gas distribution records into a centralized electronic system,” the spokesperson said.
Among the facts that PWA uncovered is that PG&E's recordkeeping problems were not caused by "defective procedures," but rather they resulted from a "failure to follow the procedures, including failure to keep the records secure."