MARATHON PIPE LINE LLC

Incident Narrative

ON APRIL 30, 2022, AT 10:21 MT, MPL'S PIPELINE OPERATIONS CENTER (POC) WAS NOTIFIED BY A TENANT FARMER THAT THERE WAS A SUSPECTED RELEASE ON THE SALT LAKE CITY TO BOISE #2 GAS LINE SEGMENT OF THE NORTHWEST PRODUCTS SYSTEM (NWPS), APPROXIMATELY 1.25 MILES DOWNSTREAM OF MURTAUGH STATION. THIS SEGMENT OF THE PIPELINE WAS NOT OPERATING AT THE TIME DUE TO AN ONGOING DELIVERY OCCURRING UPSTREAM OF THE INCIDENT LOCATION. AS A PRECAUTION, MPL SHUT DOWN AND ISOLATED THE #1 OIL LINE SEGMENT, WHICH RUNS PARALLEL TO THE #2 GAS LINE. WHEN MPL PERSONNEL ARRIVED ON-SCENE, THEY OBSERVED PRODUCT MISTING FROM THE PIPELINE AT THE 12 O'CLOCK POSITION. THE PIPELINE WAS REPAIRED WITH A BOLT-ON SPLIT SLEEVE CLAMP AND RETURNED TO SERVICE ON MAY 1ST AT 01:29 MT. AN INVESTIGATION REVEALED THAT THE FARMER WAS EXAMINING A WET SOIL THAT WAS ASSUMED TO BE AN IRRIGATION LINE LEAK. AN EXCAVATION OCCURRED TO EXPOSE THE SUSPECT LINE WITHOUT A ONE-CALL TICKET. ONCE THE FARMER EXPOSED WHAT WAS THOUGHT TO BE THE IRRIGATION LINE, THE FARMER ADMITTED TO CUTTING AND BREACHING THE GASOLINE PIPELINE WITH A BATTERY-OPERATED ANGLE GRINDER. BASED ON THE INFORMATION AVAILABLE AT THE TIME, AN INITIAL ASSESSMENT OF THE CONTAMINATED SOIL DETERMINED THAT THE TOTAL REPAIR AND CLEAN-UP COSTS WOULD LIKELY BE BELOW $50,000. HOWEVER, AFTER FURTHER DELINEATING THE FULL EXTENT OF THE SOIL CONTAMINATION, IT WAS REASONABLY DETERMINED THAT A REPORTABLE EVENT HAD LIKELY OCCURRED (I.E. WITH COSTS EXCEEDING $50,000) ON MAY 2, 2022 AT 16:05 MT (CONFIRMED DISCOVERY). NOTIFICATION TO THE NRC (#1334977) WAS MADE AT 16:15 MT ON MAY 2, 2022. THE SUPPLEMENTAL/FINAL REPORT WAS SUBMITTED WITH MINOR UPDATES TO TIMES AND NARRATIVE DUE TO THE COMPLETION OF MPLS INTERNAL INVESTIGATION.