GREAT BASIN GAS TRANSMISSION COMPANY

Incident Narrative

ON WEDNESDAY, OCTOBER 9, 2024, ASPEN DEVELOPERS CORPORATION (ASPEN DEVELOPERS) WAS OPERATING A TRACK HOE TO COMPLETE ROAD WORK (GRADING AND DRAINAGE) IN PREPARATION FOR A WATER LINE INSTALLATION IN THE SIERRA NEVADA MOUNTAINS, APPROXIMATELY 3.5 MILES EAST OF THE WASHOE COUNTY CENSUS-DESIGNATED PLACE OF INCLINE VILLAGE, NEVADA. WHILE PERFORMING WORK ON THE EXISTING DIRT ROAD, THE TRACK HOE OPERATOR PUNCTURED THE TOP OF GREAT BASIN GAS TRANSMISSION COMPANY'S (GREAT BASIN) 8-INCH DIAMETER NORTH TAHOE LATERAL GAS PIPELINE WITH A TOOTH OF THE TRACK HOE BUCKET. THE DAMAGE OCCURRED AT THE APPROXIMATE MILEPOST LOCATION OF NT-13.56 AND RESULTED IN THE UNINTENTIONAL RELEASE OF GAS FROM THE STEEL TRANSMISSION FACILITY. GREAT BASIN RECEIVED NOTIFICATION OF THE DAMAGE AT APPROXIMATELY 16:00 PDT ON OCTOBER 9, 2024, BY TRUCKEE MEADOWS FIRE AND RESCUE, AND PROMPTLY DISPATCHED EMERGENCY RESPONSE PERSONNEL TO THE SCENE FOR ADDITIONAL INVESTIGATION AND REMEDIATION. THE PIPELINE AND HAZARDOUS MATERIAL SAFETY ADMINISTRATION (PHMSA) NOTIFICATION WAS MADE TO THE NATIONAL RESPONSE CENTER (NRC) ON OCTOBER 9, 2024, AT 20:14 PDT AND ASSIGNED INCIDENT #1413294 DUE TO THE NATURAL GAS RELEASE ANTICIPATED TO EXCEED THREE MILLION CUBIC FEET. GREAT BASIN DID NOT SHUTDOWN THE FACILITY TO AVOID SERVICE INTERRUPTION TO A DOWNSTREAM SHIPPER (LOCAL DISTRIBUTION COMPANY). A REPAIR CLAMP WAS USED TO CONTROL THE FLOW OF GAS ON OCTOBER 10, 2024, AT 20:49 PDT. A SUPPLEMENTAL NOTIFICATION WAS MADE TO THE NRC ON OCTOBER 14, 2024, AT 09:08 PDT AND ASSIGNED INCIDENT #1413672. GREAT BASIN CALCULATED THE TOTAL RELEASE OF GAS TO TOTAL 7,304 MCF . GREAT BASIN PERFORMED A PRELIMINARY INTERNAL INVESTIGATION TO DETERMINE CONTRIBUTING FACTORS ASSOCIATED WITH THE INCIDENT ON OCTOBER 16, 2024, AND DETERMINED THAT THE FACILITY LOCATE MARKS, ESTABLISHED ON AUGUST 28, 2024, DEVIATED FROM THE ACTUAL FACILITY LOCATION BY 19 FEET AND THE LOCATOR INCORRECTLY MARKED THE FACILITY DUE TO BLEED OFF ONTO A NEARBY, UNMARKED STEEL WATER LINE. GREAT BASIN ALSO DETERMINED THAT THE FACILITY LOCATE TICKET (2024081500260) USED BY ASPEN DEVELOPERS WAS EXPIRED AS OF SEPTEMBER 12, 2024. IN ADDITION, AND AS REQUIRED BY GREAT BASIN THROUGH DOCUMENTATION AND VERBAL COMMUNICATIONS WITH THE EXCAVATOR, ASPEN DEVELOPERS DID NOT NOTIFY GREAT BASIN IN ADVANCE OF EXCAVATION TO REQUEST A HIGH PRESSURE STANDBY, NOR DID ASPEN DEVELOPERS POTHOLE GREAT BASIN FACILITIES TO VERIFY LOCATION AND DEPTH. THE REPAIR CLAMP GREAT BASIN INSTALLED ON OCTOBER 10, 2024 TO CONTROL THE FLOW OF GAS WAS WELDED ONTO THE IMPACTED AREA AS A PERMANENT REPAIR ON OCTOBER 25, 2024.