PACIFIC GAS & ELECTRIC CO

Incident Narrative

ON JULY 16TH 2016 AT 1320 HRS, GSR RESPONDED TO ODOR CALL AT 333 JOHNSON ROAD, LOS BANOS (ADJACENT TO KAGOME FOODS). PG&E SHUT-IN THE FLOW OF GAS AT 1400 HOURS BY SHUTTING THE INLET & OUTLET VALVES AT THE PRIMARY REG STATION. IT WAS DETERMINED THAT AN OVER-PRESSURE EVENT OCCURRED AT 1045 HOURS, RESULTING IN A 4-INCH PLASTIC LINE FAILURE AND AN UNINTENTIONAL RELEASE OF GAS. AFTER THE PIPE RUPTURE, AN INSPECTION OF THE PRIMARY REGULATOR SET REVEALED THE REGULATOR BOOT HAD FAILED. BASED ON THE EVENT REVIEW, THERE IS A POSSIBILITY THAT THE MONITOR FAILED TO CONTROL OR DID NOT LOCK UP WITH CAUSED THE OVERPRESSURE EVENT. AN ANALYSIS OF THE 4 INCH PLASTIC SERVICE PIPE REVEALED A DUCTILE FAILURE ON THE PIPE. THE MAOP OF THE PLASTIC LINE IS 60 PSI, AND THE SYSTEM WAS OVERPRESSURED TO 370 PSIG. THE SERVICE SUPPLIED A SINGLE CUSTOMER (KAGOME FOODS) AND THE CUSTOMER WAS SUPPLIED WITH CNG BY 2100 HOURS WHILE PG&E CREWS REPAIRED THE LINE. REPLACEMENT OF THE 4-INCH PLASTIC LINE, LARGE METER SET, BOTH REGULATOR AND MONITOR WERE COMPLETED ON 7/18/16 AT 2000 HOURS; CNG WAS REMOVED AND THE SERVICE WAS RESTORED BY 2100 HOURS. THERE WERE NO INJURIES, NO FATALITIES, NO IGNITION ASSOCIATED WITH THIS INCIDENT. FIRE DEPARTMENT AND POLICE DEPARTMENT WERE REPORTED ON-SITE. THIS INCIDENT IS BEING REPORTED TO CPUC AND DOT DUE TO THE UNINTENTIONAL RELEASE OF GAS AND ESTIMATED DAMAGES EXCEEDING $50,000. PLEASE NOTE THAT AFTER FURTHER REVIEW, THIS INCIDENT SHOULD BE CLASSIFIED AS A TRANSMISSION BECAUSE THE LINE IS SERVING A TRANSMISSION LARGE VOLUME CUSTOMER (NOT DOWNSTREAM OF A DISTRIBUTION CENTER).