COLUMBIA GAS TRANSMISSION, LLC

Incident Narrative

PIPELINE 18039 IS A TRANSMISSION PIPELINE THAT IS OPERATED AND MAINTAINED BY COLUMBIA GAS TRANSMISSION, LLC (OPID 2616). COLUMBIA HAS EXPERIENCED A LEAK ON THIS PIPELINE IN THE NORTH BRANCH OF THE POTOMAC RIVER NEAR THE TOWN OF MCCOOLE, ALLEGANY COUNTY, MD. PIPELINE 18039 IS A 6-INCH CARBON STEEL, 0.219-INCH WALL THICKNESS, ERW, GRADE B PIPE COATED IN THE AREA OF THE REPORTED LEAK. LINE 18039 MAXIMUM ALLOWABLE OPERATING PRESSURE IS 273 PSIG AND ITS OPERATING PRESSURE AT THE TIME OF DISCOVERY WAS APPROXIMATELY 250 PSIG. LOCAL OPERATIONS WERE NOTIFIED OF A LEAK IN THE POTOMAC RIVER, THE LEAK WAS EVALUATED AND DETERMINED NOT TO BE A HAZARD TO LIFE OR PROPERTY. THE PIPELINE IS A SINGLE FEED TO THE KEYSER INDUSTRIAL PARK LOCATED ACROSS THE POTOMAC RIVER IN KEYSER, WEST VIRGINIA, THEREFORE; FROM AN OPERATIONAL-PERSPECTIVE, IT IS NOT FEASIBLE TO DISCONTINUE THE FLOW OR SHUT DOWN THE PIPELINE. IN ORDER TO REDUCE THE GAS LOSS, PRESSURE REGULATING EQUIPMENT WAS INSTALLED TO REDUCE PRESSURE TO APPROXIMATELY 60 PSIG. A QUALIFIED DIVE COMPANY WAS CONTRACTED TO EVALUATE THE PIPELINE CONDITION AND NATURE OF THE LEAK. INTEGRITY ENGINEERS EVALUATED THIS INFORMATION AND DEVELOPED A REPAIR PLAN WHICH WAS PROVIDED TO THE MARYLAND DEPARTMENT OF THE ENVIRONMENT FOR APPROVAL. UPON APPROVAL, OUR CONTRACTOR INSTALLED TWO LEAK CLAMPS, WRAPPED THE PIPELINE WITH AN APPROVED COATING AND INSTALLED A PROTECTIVE OUTER WRAP. THE PIPELINE WAS THEN PRESSURED UP TO THE PRESSURE AT THE TIME OF THE INCIDENT, 285 PSIG, HELD FOR ONE HOUR, INSPECTED FOR LEAKS AND RETURNED TO SERVICE.