PACIFIC GAS & ELECTRIC CO

Incident Narrative

ON JANUARY 25, 2017 AT 0922 HOURS, PG&E DETECTED AN OVERPRESSURE EVENT WITH THE SCADA SYSTEM NEAR 1717 DORNIE CIRCLE, FOLSOM. THE REGULATOR AND MONITOR VALVES AT PG&E'S REGULATOR STATION A-55 NEAR THE INTERSECTION OF EAST BIDWELL STREET AND OAK AVENUE PARKWAY IN FOLSOM FAILED TO ACHIEVE LOCK-UP, RESULTING IN AN OVERPRESSURE EVENT. THE MAOP PLUS ALLOWABLE WAS EXCEEDED AT 0941 HOURS. PG&E CREWS ARRIVED ON-SITE AT 1020 HOURS. WHEN PG&E CREWS ARRIVED ON-SITE, THE PRESSURE WAS READING AT 114 PSIG. THE CREW SHUT IN TWO REG STATIONS TO REDUCE PRESSURE AND THE PRESSURE RETURNED TO NORMAL AT 1107 HOURS. GAS SERVICE REPRESENTATIVES (GSRS), GPOM CREWS, M&C CREWS, AND LEAK SURVEY PERSONNEL WERE DISPATCHED AND STAGED TO PERFORM LEAK SURVEY, INSPECT FILTERS AND REG STATIONS, AND PERFORM ANY NECESSARY REPAIRS. M&C COMPLETED REPAIRS ON ALL GRADE 1 LEAKS IDENTIFIED FROM THE POST-INCIDENT LEAK SURVEY AND THE REMAINING LEAKS ARE SCHEDULED FOR RECHECK/REPAIRS IN ACCORDANCE WITH PG&E PROCEDURES. THE CAUSE OF THE INCIDENT IS EQUIPMENT FAILURE DUE TO PIPELINE DEBRIS FROM PIGGING OPERATIONS. THERE WERE NO REPORTED INJURIES, FATALITIES OR IGNITION. CNG WAS MOBILIZED TO SUPPORT PEAK CONDITIONS. THERE WAS NO CUSTOMER IMPACT. THIS INCIDENT IS BEING REPORTED TO THE CPUC DUE TO AN UNPLANNED EVENT RESULTING IN AN OVERPRESSURE EVENT MAOP PLUS ALLOWABLE BUILDUP. AT 1500 HOURS, IT WAS DETERMINED THAT COSTS ASSOCIATED WITH THE INCIDENT WOULD EXCEED $50,000. AT 1520 HOURS, THE DOT WAS NOTIFIED DUE TO ESTIMATED COSTS EXCEEDING $50,000.