EXXONMOBIL PIPELINE COMPANY LLC

Incident Narrative

"INCIDENT SUMMARY: ON MONDAY, MARCH 24, 2025, THE STATION OPERATOR ARRIVED ON SITE AT 06:15 AND IDENTIFIED THE LEAK. THE FIRST NOTIFICATION CALL WAS MADE AT 06:31. THE STATION WAS PUT ON BYPASS AT 06:52, ISOLATING THE STATION FROM TANK HEADERS AND SHUTTING DOWN FACILITY BOOSTER PUMPS. VACUUM TRUCKS ARRIVED ONSITE MID-MORNING AND BEGAN REMOVING POOLING OIL. HYDRO EXCAVATION TO IDENTIFY LEAK SOURCE BEGAN AT 13:34. ON TUESDAY, MARCH 25, 2025, AT 04:15, THE SOURCE OF THE LEAK WAS IDENTIFIED (PINHOLE IN 4"" TEE ON DRAIN LINE SYSTEM) THROUGH HYDRO EXCAVATION AND SECONDARY CONTAINMENT WAS PLACED UNDER THE LEAKING 4-INCH TEE. EXACT IDENTIFICATION OF LEAK SOURCE LED TO DISCOVERY OF A VALVE LEAKING BY INTO THE DRAIN SYSTEM. ISOLATION UPSTREAM FROM THIS VALVE STOPPED THE ACTIVE LEAK MIDDAY ON MARCH 25TH. INVESTIGATION ROOT CAUSE: THE RELEASE RESULTED FROM UNDER-DEPOSIT CORROSION IN UNDERGROUND PIPING DUE TO CHLORIDE SETTLEMENT FROM WATER DROPOUT, WHICH CREATED A LOCALIZED CORROSIVE ENVIRONMENT. A CONTRIBUTING FACTOR WAS LEAKAGE THROUGH A DRAIN VALVE, DUE TO PIG BRUSHES FOUND LODGED IN THE VALVE BODY WHICH ALLOWED ABNORMAL FLOW INTO THE DRAIN SYSTEM. (UPDATED 2/19/25) PREVENTING RE-OCCURRENCE: A FAILED 4"" SCRAPER TRAP DRAIN VALVE HAS BEEN REPLACED TO ELIMINATE THE SOURCE OF THE LEAK. THE ASSOCIATED DRAIN SYSTEM UNDERWENT INTEGRITY TESTING. THESE MEASURES ARE EXPECTED TO FULLY ADDRESS THE EQUIPMENT FAILURE AND RESTORE RELIABLE CONTAINMENT."