TRANSCONTINENTAL GAS PIPE LINE COMPANY

Incident Narrative

AT 2:40AM ON 2/25/2016, WILLIAMS PIPELINE CONTROL RECEIVED A CALL FROM WYATT BENTON WHO WAS HUNTING IN THE AREA OF OUR PIPELINE RIGHT OF WAY. MR BENTON STATED THAT HE WANTED TO REPORT A POSSIBLE LEAK AROUND THE WILLIAMS PIPELINE. PIPELINE CONTROL IMMEDIATELY CALLED THE STATION 60 ON CALL PERSON TO REPORT THE POSSIBLE LEAK. PERSON ON CALL CALLED A SECOND EMPLOYEE TO ASSIST WITH INVESTIGATION, DROVE TO STATION TO PICK UP A GAS DETECTOR AND SECOND EMPLOYEE, AND DROVE OVER TO THE SITE IN QUESTION. AFTER ARRIVING THE TWO EMPLOYEES BEGAN SCANNING THE RIGHT OF WAY AND DISCOVERED BUBBLES WITHIN THE RIGHT OF WAY LIMITS. AT THIS TIME THE LEAD RIGHT OF WAY EMPLOYEE ARRIVED ON SITE AND BEGAN THE PROCESS OF ELIMINATING POTENTIAL FOREIGN LINE CROSSINGS BEING THE SOURCE OF THE LEAK. RIGHT OF WAY LEAD CALLED DISTRICT MANAGER AND REPORTED HIS FINDINGS OF NO KNOWN FOREIGN LINE CROSSINGS AND HE WAS PICKING UP A SMALL GAS LEAK LOCATED ABOVE THE MAIN LINE C PIPE. DISTRICT MANAGER BEGAN MAKING CALLS TO PIPELINE CONTROL, CYPRESS DIVISION DIRECTOR, AND THE CYPRESS DIVISION MANAGER ENGINEERING WHO ASSISTED BY PIPELINE SAFETY. PIPELINE CONTROL CALLED AND REPORTED THE POSSIBLE LEAK TO THE NRC AND THE LOUISIANA STATE POLICE. DISTRICT MANAGER INSTRUCTED RIGHT OF WAY LEAD TO ISOLATE THE C LINE PIPING SECTION BETWEEN THE 50C50 AND 50C60 AS A PRECAUTIONARY MEASURE AND TO CONTINUE TO VERIFY IF THE LEAK WAS IN FACT COMING FROM OUR LINE. AFTER ISOLATION THE STATION CREW MEMBERS INSTALLED GAUGES AT THE 50C50 AND 50C60 AND BEGAN TO MONITOR FOR ANY LOSS IN PRESSURE ON THE C LINE SECTION. OTHER CREW MEMBERS CONTINUED TO INVESTIGATE RECORDS FOR ANY FOREIGN LINE CROSSINGS AND CONTINUED UPDATING PIPELINE CONTROL AND CYPRESS DIVISION. AFTER MONITORING PRESSURES FOR A PERIOD OF TIME SHOWED NO DROP IN PRESSURE THE DISTRICT MANAGER DISCUSSED WITH THE DIVISION DIRECTOR THE NEED TO BLOW DOWN THE C LINE SECTION TO VERIFY THAT THE LEAK WAS EMANATING FROM THIS SECTION OF LINE. DIRECTOR AGREED, SAFE BLOW DOWN PROCEDURES WERE DISCUSSED WITH THE STATION CREW, AND THE 50C50 TO 50C60 LINE SECTION WAS BLOWN DOWN. DISTRICT MANAGER AND DIVISION SAFETY EMPLOYEE ARRIVED AT LEAK SITE WITH APPROX. 100 PSI REMAINING ON THE LINE SECTION. AT THIS TIME THE BUBBLES WERE VERIFIED TO HAVE STOPPED. STATION EMPLOYEES CONTINUED BLOW DOWN TO 0 PSI, SECURED ALL VALVES AND SITES, AND BEGAN SCHEDULING FOR INVESTIGATORY DIGS TO DETERMINE THE SOURCE OF THE LEAK. ***UPDATE PER SUPPLEMENTAL REPORT 5/16/2016*** METALLURGICAL ANALYSIS HAS CONCLUDED THAT THE LEAKING SECTION OF PIPE WAS MANUFACTURED WITH AN AREA OF VARYING HARDNESS. RCA INDICATES THAT THIS AREA OF PARTICULARLY HARDER STEEL WAS THE MAIN CAUSE OF THE CRACK FORMATION. THE INSPECTION OF AFFECTED PIPE SAMPLE WAS COMPLETED BY ANDERSON AND ASSOCIATES IN HOUSTON ON 4/15/16. INSPECTIONS INDICATED ONLY THIS LOCALIZED AREA BECAME SUSCEPTIBLE TO EITHER HYDROGEN EMBRITTLEMENT OR HIGH PH SCC MECHANISMS; WITHOUT THE HARD SPOT, THE LAB SAID THERE IS NO EVIDENCE CRACKING WOULD HAVE OCCURRED. UPON REVIEW OF THE 2013 ILI, TWO ADDITIONAL INVESTIGATION DIGS WILL BE CONDUCTED IN 2016 TO SEARCH FOR ADDITIONAL AREAS OF ELEVATED HARDNESS. ONCE THESE TWO DIGS ARE EITHER REPAIRED OR CLEARED WITH REGARD TO HARD SPOTS, MAIN LINE 'C' FROM 50C41 TO 50C60 CAN BE CONSIDERED AT VERY LOW RISK FOR CRACKING SUSCEPTIBILITY DUE TO HARD SPOTS. ***UPDATE PER SUPPLEMENTAL REPORT 12/1/2016*** THE TWO ADDITIONAL INVESTIGATION DIGS REFERENCED ABOVE CAME BACK NEGATIVE FOR INDICATIONS OF THE SAME DEFECT THAT APPARENTLY CAUSED THIS INCIDENT. THE INVESTIGATION HAS BEEN CONCLUDED WITH NO FURTHER ACTION DEEMED NECESSARY.