COLUMBIA GAS TRANSMISSION, LLC

Incident Narrative

ON MAY 28, 2019, AT APPROXIMATELY 10:55 P.M., COLUMBIA GAS TRANSMISSION, LLC (COLUMBIA) RECEIVED NOTICE OF A POTENTIAL INCIDENT AT 2464 PINE RUN ROAD NEAR MAYPORT, PENNSYLVANIA. THE INCIDENT LOCATION WAS ADJACENT TO A COLUMBIA PIPELINE, LINE 4010, WHICH IS PART OF A 13.88-MILE GATHERING SYSTEM THAT TRANSPORTS GAS FROM PRODUCTION FACILITIES IN JEFFERSON AND CLARION COUNTIES, PENNSYLVANIA, TO A COMPRESSOR STATION IN RIMERSBURG, PENNSYLVANIA. THE FEDERAL POWER COMMISSION ORIGINALLY APPROVED COLUMBIA'S ACQUISITION OF LINE 4010 IN 1971, AND THE PIPELINE REMAINS SUBJECT TO THE JURISDICTION OF THE FEDERAL ENERGY REGULATORY COMMISSION UNDER THE NATURAL GAS ACT. COLUMBIA'S RECORDS INDICATE THAT THE SECTION ADJACENT TO THE INCIDENT LOCATION WAS REPLACED IN 1982 USING 0.156-INCH WALL THICKNESS, 6-INCH NPS CARBON STEEL PIPE WITH AN EXTRUDED POLYETHYLENE COATING. COLUMBIA'S RECORDS ALSO INDICATE THAT AT THE TIME OF THE INCIDENT THE MAXIMUM ALLOWABLE OPERATING PRESSURE OF LINE 4010 WAS 50 PSIG, PRODUCING A HOOP STRESS THAT IS LESS THAN 20 PERCENT OF SPECIFIED MINIMUM YIELD STRENGTH OF THE LINE PIPE, AND THAT THE OPERATING PRESSURE WAS 32 PSIG. COLUMBIA'S RECORDS FURTHER INDICATE THAT THE SECTION ADJACENT TO THE INCIDENT LOCATION WAS NOT PART OF A REGULATED GATHERING LINE, ALTHOUGH PHMSA AND COLUMBIA ARE CURRENTLY REVIEWING THAT DETERMINATION. COLUMBIA OPERATIONS PERSONNEL ARRIVED AT THE INCIDENT LOCATION AT APPROXIMATELY 11:10 P.M. A RESIDENCE AT THE LOCATION SUSTAINED FIRE-RELATED DAMAGE, AND AN OCCUPANT SUSTAINED INJURIES NECESSITATING IN-PATIENT HOSPITALIZATION. ANOTHER SINGLE-FAMILY DWELLING IN THE VICINITY WAS EVACUATED AS A PRECAUTIONARY MEASURE. AS PART OF ITS INITIAL RESPONSE TO THE INCIDENT, COLUMBIA SURVEYED THE AREA TO IDENTIFY POTENTIAL LEAK SOURCES, ISOLATED THE AFFECTED SECTION, AND TOOK OTHER REMEDIAL ACTIONS IN COOPERATION WITH STATE AND LOCAL AUTHORITIES. COLUMBIA ALSO SUBMITTED INCIDENT REPORTS TO THE NATIONAL RESPONSE CENTER (NRC) ON MAY 29, 2019 (NRC REPORT NO. 1247157), AND MAY 31, 2019 (NRC. REPORT NO. 1247379). A THIRD PARTY, ECHELON- APPLIED GEOSCIENCES CONSULTING, CONDUCTED A STRAY GAS ORIGIN STUDY AS PART OF COLUMBIA'S INCIDENT INVESTIGATION. THE STUDY REVEALED THAT THE STRAY GAS IN THE SOILS IN THE VICINITY OF THE INCIDENT LOCATION WAS OF THE SAME GENETIC ORIGIN AS THE GAS IN LINE 4010, AND THAT THERE WAS A FEASIBLE PATHWAY FOR LEAKING GAS TO MIGRATE FROM LINE 4010 TO THE RESIDENCE. HOWEVER, THE STUDY ALSO INDICATED THAT STRAY GAS DETECTED IN THE SOILS WAS OF THE SAME GENETIC ORIGIN AS GAS FROM A NEARBY WELL (API # 37-031-00978), WHICH IS THE SUBJECT OF AN ONGOING INVESTIGATION BY THE PENNSYLVANIA DEPARTMENT OF ENVIRONMENTAL PROTECTION (PADEP). ANOTHER THIRD PARTY, KIEFNER AND ASSOCIATES (KIEFNER), PREPARED A ROOT CAUSE FAILURE ANALYSIS (RFCA) FOR COLUMBIA. IN THE RCFA, KIEFNER CONCLUDED THAT A LEAK IN LINE 4010 BENEATH PINE RUN ROAD WAS THE SIGNIFICANT CONTRIBUTOR OF FUEL TO THE FIRE AT THE RESIDENCE, AND THAT THE LEAK WAS CAUSED BY EXTERNAL CORROSION. HOWEVER, KIEFNER ALSO NOTED THAT TWO OTHER POTENTIAL COMBUSTIBLE GAS SOURCES WERE PRESENT IN THE AREA: (1) A THIRD-PARTY METER STATION LOCATED TO THE SOUTH OF THE RESIDENCE, WHICH WAS LEAKING AT THE TIME OF THE INCIDENT, AND (2) A THIRD-PARTY WELL LOCATED ON A NEIGHBORING PROPERTY WITH GAS GEOCHEMISTRY THAT WAS INDISTINGUISHABLE FROM THE GAS IN LINE 4010. KIEFNER COULD NOT OFFER A CONCLUSIVE DETERMINATION ABOUT THE POSSIBLE INFLUENCE OF THESE OTHER GAS SOURCES ON THE INCIDENT. COLUMBIA IS IN THE PROCESS OF IMPLEMENTING THE RECOMMENDATIONS THAT KIEFNER INCLUDED IN THE RCFA TO PREVENT THE POTENTIAL RECURRENCE OF A SIMILAR INCIDENT. COLUMBIA HAS COOPERATED WITH THE VARIOUS AUTHORITIES INVOLVED IN THE INCIDENT INVESTIGATION AND WILL UPDATE THE INFORMATION PROVIDED IN THIS REPORT IF ADDITIONAL RELEVANT MATERIAL BECOMES AVAILABLE.