CASCADE NATURAL GAS CORP

Incident Narrative

THE CASCADE NATURAL GAS CORPORATION (CNGC) PIPELINE AFFECTED WAS A 2"" STEEL MAIN THAT WAS INSTALLED IN 1967. THE PIPELINE SEPARATED AT A GIRTH WELD CAUSING THE UNINTENTIONAL RELEASE OF MORE THAN 3 MILLION CUBIC FEET OF GAS, TOTAL GAS LOSS WAS ESTIMATED TO BE 3,875 MCF. THE AREA IN WHICH THE RELEASE OCCURRED WAS EXPERIENCING EXTREME COLD WEATHER AND SUBSTANTIAL UNDERGROUND FROST. THE DAMAGE TO THE PIPELINE OBSERVED WAS CONSISTENT WITH DAMAGE CAUSED BY FROST HEAVE. FROST HEAVE IS THOUGHT TO BE A CONTRIBUTING FACTOR TO THE RELEASE. THE SEPARATED GIRTH WELD WAS RETAINED BY CNGC AND UNDERWENT AN EXAMINATION BY QUALIFIED STAFF. THE EXAMINATION CONCLUDED THAT THE WELD HAD FAILED AND CNGC CLASSIFIED THE LEAK AS A ""PIPE, WELD OR JOINT FAILURE"" AS A RESULT. THE SUB CAUSE WAS DETERMINED TO BE A CONSTRUCTION DEFECT CAUSED BY POOR WORKMANSHIP. CNGC WORKED CLOSELY WITH EMERGENCY RESPONDERS AND QUICKLY MOBILIZED RESOURCES AND EQUIPMENT TO ENSURE PUBLIC SAFETY. NO INJURIES, DAMAGE TO PROPERTY (OTHER THAN CNGC PIPELINE) OR IGNITION OCCURRED.