PACIFIC GAS & ELECTRIC CO

Incident Narrative

AT APPROXIMATELY 0320 HOURS ON AUGUST 24, 2014, A MAGNITUDE 6.0 EARTHQUAKE STRUCK THE NAPA COUNTY REGION. PG&E CONDUCTED SPECIAL AERIAL PATROLS ON OVER 150 MILES OF TRANSMISSION PIPELINE. OVER 250 MILES OF TRANSMISSION PIPELINE UNDERWENT LEAK SURVEYS. PG&E IDENTIFIED FOUR LEAKS (ONE HAZARDOUS; THREE NON-HAZARDOUS) ON ITS GAS TRANSMISSION SYSTEM THROUGHOUT THE COUNTIES OF NAPA, SOLANO, AND SONOMA. THE FOUR LEAKS WERE FOUND ON VALVES (INSTALLED IN 1968, 1981, 1992, & 2004) AND WERE REPAIRED ON OR BEFORE SEPT. 5, 2014. SEVENTY-SIX REGULATOR STATIONS UNDERWENT SPECIAL LEAK SURVEYS AND NO LEAKS WERE DETECTED. FOLLOWING THE NAPA EARTHQUAKE, SURFACE CRACKS WERE DISCOVERED IN THE GROUND AT AN APPROXIMATE 74 DEGREE ANGLE ABOVE TRANSMISSION LINE L-21A, AND AS A PRECAUTION, THE PRESSURE IN L-21A WAS LOWERED FROM 325 PSIG TO 300 PSIG. LEAK SURVEYS AND AERIAL PATROLS HAVE INDICATED NO ANOMALIES WITH THIS LINE OTHER THAN THE GROUND DISPLACEMENT OVER IT. PG&E HAS REPLACED APPROXIMATELY 210 FEET OF 26-INCH PIPE ACROSS THE FAULT CROSSING. L-21A WAS PLACED BACK INTO SERVICE ON SEPTEMBER 13, 2014 AT THE TEMPORARILY REDUCED PRESSURE OF 300 PSIG. PENDING FINAL APPROVAL OF ITS FITNESS FOR SERVICE EVALUATION, L-21A WILL RETURN TO NORMAL OPERATING PRESSURE. L-21B WILL BE ISOLATED BETWEEN MLV 2.31 (NAPA RIVER CROSSING) AND MLV 6.05 AND TAKEN OUT OF SERVICE SO AN INSPECTION CAN BE PERFORMED. RESULTS OF INVESTIGATION WILL DETERMINE THE EXTENT OF L-21B PIPELINE REPLACEMENT AT THE FAULT CROSSING. L-21H PRESSURE WAS REDUCED FROM 250 PSIG TO 140 PSIG AS A PRECAUTIONARY MEASURE. THE FITNESS FOR SERVICE EVALUATION HAS BEEN COMPLETED AND L-21H WILL TO BE RETURNED TO NORMAL OPERATING PRESSURE SHORTLY. SAFETY-RELATED CONDITION REPORTS WERE SUBMITTED FOR L-21A AND L-21H. A SAFETY-RELATED CONDITION REPORT WILL BE SUBMITTED FOR L-21B IF REQUIRED. THERE ARE NO KNOWN INJURIES OR DEATHS RELATING TO PG&E'S GAS FACILITIES. PG&E REPORTED THIS INCIDENT TO THE DOT AND THE CPUC BASED ON OPERATOR JUDGMENT OF THE SIGNIFICANCE OF THIS EVENT. PLEASE NOTE THAT PG&E'S RESPONSES TO PARTICULAR SECTIONS OF THIS REPORT MAY NOT APPLY AS OUR REPORTING IS ON THE REPAIR AND RESPONSE WORK PERFORMED ON PG&E'S GAS TRANSMISSION SYSTEM AND NOT A SPECIFIC LOCATION. (NOTE: THE EARTHQUAKE MAGNITUDE HAS BEEN CORRECTED FROM 6.1 TO 6.0 IN THIS PHMSA 7100 SUPPLEMENTAL REPORT.) PLEASE NOTE THAT FOR PART A, QUESTION 11, ""ESTIMATED VOLUME OF INTENTIONAL AND CONTROLLED RELEASE/BLOWDOWN."" IS 1,099,000 MCF. PLEASE NOTE THAT FOR PART C, QUESTION 4, ""YEAR ITEM INVOLVED IN ACCIDENT WAS INSTALLED,"" THERE ARE FOUR ITEMS TOTAL AND THAT THE EARLIEST YEAR WAS INPUTTED WITHIN THE BOX (1968).