COLUMBIA GAS TRANSMISSION, LLC

Incident Narrative

ON MAY 4, 2016, A CONTRACTOR PERFORMING A CONSTRUCTION ACTIVITY WITHIN THE RIGHT-OF-WAY OF LINE E-LOOP, DAMAGED A TRANSMISSION PIPELINE THAT WAS CAUSED BY THE RIPPER ON A DOZER PUNCTURING THE PIPELINE. LINE E-LOOP IS A TRANSMISSION PIPELINE THAT IS OWNED, OPERATED AND MAINTAINED BY COLUMBIA GAS TRANSMISSION, LLC (COLUMBIA). THE PIPELINE WAS OPERATING AT APPROXIMATELY 750 PSIG WITH 1,000 PSIG BEING ITS MAOP, PIPELINE DIAMETER IS 20-INCHES WITH 0.375-INCH WALL THICKNESS, AND ITS GRADE IS X45. THERE WERE NO REPORTED FATALITIES, INJURIES OR ANY NEARBY ROADS THAT WERE SHUT DOWN. FURTHERMORE, THE UNINTENDED RELEASE OF NATURAL GAS (MATERIAL) DID NOT IGNITE. INITIAL INFORMATION INDICATED THAT THE LINE WHERE THE INCIDENT TOOK PLACE IS A CLASS 1 LOCATION SOUTH OF EDEN RIDGE ROAD NEAR THE TOWN OF FOSTER IN BRACKEN COUNTY, KY. COLUMBIA OPERATIONS PERSONNEL WHO RESPONDED TO THE INCIDENT AREA WENT TO THE NEAREST CRITICAL VALVES AND OPERATED THEM TO ISOLATE THE AFFECTED SEGMENT OF LINE E-LOOP. THE TWO CRITICAL VALVES WERE FULLY CLOSED AT 12:08 PM AND 12:11 PM RESPECTIVELY PREVENTING ADDITIONAL RELEASE OF MATERIAL INTO ATMOSPHERE. THEREAFTER, THE LINE WAS BLOWN DOWN TO ATMOSPHERIC PRESSURE AND INVESTIGATION INTO THE INCIDENT WAS INITIATED AFTER THE AREA WAS FULLY SECURED. A PRE-TESTED PIPE JOINTS WITH THE FOLLOWING CHARACTERISTICS 20-IN DIAMETER WITH 0.375-IN WT, GRADE X-65, TESTED TO A CLASS 3 LOCATION TEST PRESSURE WAS INSTALLED AND REPLACED THE DAMAGED SECTION. THE TIE-IN WELDS WERE NON-DESTRUCTIVELY EXAMINED (NDE). AFTER CONFIRMING THAT THE NDE RESULTS HAD NO ABNORMAL INDICATIONS AND THAT ALL WELDS WERE WITHIN CODE REQUIREMENTS, THE LINE WAS RETURNED BACK INTO SERVICE. AN INVESTIGATION CONDUCTED BY THE CONTRACTOR, CONCLUDED THAT ADDITIONAL SAFETY MEASURES HAVE TO BE ADDED TO THEIR PRACTICE AND EVALUATED ACTIONS WITH THEIR PERSONNEL TO PREVENT EVENTS SIMILAR FROM OCCURRING ON OTHER WORK LOCATION.