PEOPLES NATURAL GAS COMPANY LLC

Incident Narrative

ON 03/09/2019 AT APPROXIMATELY 07:27, THE INLET PIPE TO THE WESTERN AVENUE METERING SITE EXPERIENCED A SEPARATION OF THE 6 INCH INLET PIPING. DUE TO LONG TERM, HEAVY RAINS THAT OCCURRED OVER A PERIOD OF SEVERAL DAYS PRIOR TO THIS INCIDENT, THE SATURATED SOIL CREATED A HEAVY OVERBURDEN ON THE INLET PIPING, AND THAT STRAIN CAUSED THE STEEL PORTION OF THAT PIPING TO SEPARATE AT THE COUPLER. THE FIRST RESPONDERS ON SITE DETERMINED TO SHUT THE SYSTEM DOWN FOR SAFETY, MAKE REPAIRS AND RESTORE SERVICE. PERMANENT REPAIRS RENEWED THAT COUPLED PIPE, REPLACING IT WITH ALL WELDED STEEL PIPING. NRC FOLLOW UP QUESTIONS: GIVEN THAT THIS WAS A RELATIVELY NEW INSTALLATION (2018), IS IT POSSIBLE THERE WERE SOME WORKMANSHIP ISSUES THAT MAY HAVE CONTRIBUTED TO THE FAILURE? WAS THE PIPING INSTALLED IN A BIND? HOW FAR DID IT SEPARATE WHEN IT PULLED APART? WERE THE CONSTRUCTION SPECIFICATIONS ADHERED TO? PEOPLES FOLLOW UP ANSWERS: AN INTERNAL INVESTIGATION WAS CONDUCTED AFTER THIS INCIDENT OCCURRED AND NO POOR WORKMANSHIP ISSUES WERE FOUND THAT CONTRIBUTED TO THIS INCIDENT, WITH ALL CONSTRUCTION SPECIFICATIONS BEING ADHERED TO. AT THE TIME THAT THIS INCIDENT OCCURRED, THE PIPING HAD SEPARATED APPROXIMATELY 3 INCHES AND SHOWED NO SIGNS OF MISALIGNMENT AND WAS STILL IN LINE WITH THE INLET RISER IT HAD SEPARATED FROM, INDICATING THAT THE PIPE WAS NOT INSTALLED IN A BIND. THE NUTS ON THE COUPLING BOLTS WERE FOUND IN THE POSITION OF HAVING BEEN TIGHTENED WELL INTO THE FINAL TORQUED TIGHTENED PHASE. ALL INDICATIONS POINT TO THE FACT THAT SEVERAL DAYS OF HEAVY RAINS WAS THE PRIMARY FACTOR THAT INITIATED THIS INCIDENT.