"FLINT HILLS RESOURCES, LC"

Incident Narrative

"UPDATE FOR FINAL REVISED REPORT: PART A4.-LOCAL TIME (24-HR CLOCK) AND DATE OF ACCIDENT UPDATED FROM 03/03/205 18:54 TO 02/27/2025 04:37 PART A7.-ESTIMATED VOLUME OF COMMODITY RELEASED UNINTENTIONALLY UPDATED FROM 148 BBLS TO 5 BBLS. PART D8.-ESTIMATED COST OF COMMODITY LOST UPDATED FROM $4,958 TO $168. PART H-NARRATIVE ALTHOUGH THE ORIGINAL REPORT WAS BELIEVED TO BE CORRECT BASED ON KNOWLEDGE AVAILABLE WHEN REPORTED, FURTHER CALCULATIONS FOLLOWING AN EVENT ON THE SAME LINE WHICH WAS DISCOVERED ON MARCH 19, 2025 RESULTED IN THE NEED TO UPDATE THE ORIGINALLY REPORTED INFORMATION AS FOLLOWS: A LEAK DETECTION WARNING ALARM ON MARCH 3, 2025 RESULTED IN A FIELD INVESTIGATION AND DISCOVERY OF A VALVE LEAK IN THE THREADED FITTING. THE RELEASE ESTIMATE OF 148 BARRELS WAS BASED ON A CALCULATED IMBALANCE IN THE LEAK DETECTION MODEL THAT BEGAN ON FEBRUARY 27, 2025. THE FIELD OBSERVATION, BASED ON THE SIZE OF THE FROST BALL AND THE SIZE OF THE DEFECT ON THE THREADED FITTING, DID NOT ALIGN WITH THE CALCULATED IMBALANCE FROM THE LEAK DETECTION MODEL. AT THE TIME, THE THREADED FITTING WAS THE ONLY KNOWN RELEASE POINT AND SO THE 148 BARRELS TOTAL WAS REPORTED FOR THIS EVENT. HOWEVER, FOLLOWING AN EVENT UPSTREAM ON THE SAME LINE WHICH WAS DISCOVERED ON MARCH 19, 2025, THE DATA AND CALCULATIONS FOR THIS EVENT WERE REEVALUATED. THE UPDATED CALCULATIONS IN LIGHT OF THE UPSTREAM EVENT REVEALED THAT THE REQUIRED DEFECT SIZE FOR THE THREADED FITTING TO RELEASE 148 BARRELS IS SUBSTANTIALLY LARGER THAN THE MEASURED DEFECT SIZE IN THE THREADED FITTING. THIS, COUPLED WITH MINIMAL LEL DETECTIONS AND FIELD OBSERVATION OF THE SIZE OF THIS FROST BALL AS COMPARED TO THE ONE AT THE UPSTREAM FAILURE, LEADS US TO BELIEVE THE VOLUME RELEASED REACHED THE 5 BARREL REPORTING THRESHOLD WITH THE MAJORITY OF THE RELEASE BEGINNING ON FEBRUARY 27, 2025 OCCURRING AT THE UPSTREAM RELEASE LOCATION IDENTIFIED ON MARCH 19, 2025. AS A RESULT, THE RELEASE VOLUME FOR THIS EVENT IS BEING REDUCED TO 5 BARRELS. AT APPROXIMATELY 14:00 ON MARCH 3, 2025, FLINT HILLS RESOURCES' (FHR) PIPELINE CONTROL CENTER (PCC) RECEIVED A PROVER METER ALARM ON THE WISCONSIN 6-INCH PROPANE PIPELINE SYSTEM AND SHUT DOWN THE LINE. AFTER PERFORMING A LEAK TEST ON THE LINE, THE TEAM DISPATCHED FHR PERSONNEL TO THE SITE TO FURTHER INVESTIGATE. AT APPROXIMATELY 18:45, FHR PERSONNEL ARRIVED AND DETECTED A HISSING SOUND FROM AN UNDERGROUND MAINLINE VALVE, INDICATING A LEAK. FHR PERSONNEL MONITORED LEL LEVELS AND DETECTED READINGS NEAR THE VALVE EXTENSION AND BLEEDER LINE AT GROUND LEVEL, CONFIRMING A RELEASE. THE UPSTREAM AND DOWNSTREAM VALVES WERE ISOLATED BY 19:20. THE SITE WAS OBSERVED OVERNIGHT, WITH CONTINUOUS AIR MONITORING AT THE VALVE LOCATION. ON TUESDAY, MARCH 4, 2025, FHR DISPATCHED A GROUND THAW UNIT DUE TO WEATHER CONDITIONS. THE GROUND THAW UNIT WAS SET OUT OVERNIGHT TO PREPARE THE SITE FOR EXCAVATION. FHR FIELD STAFF PERFORMED CONTINUOUS AIR MONITORING. ON WEDNESDAY, MARCH 5, 2025, THE SITE WAS EXCAVATED, AND THE VALVE WAS EXPOSED. FHR PERSONNEL IDENTIFIED DAMAGE TO THREADS ON THE BODY BLEED 1/2-INCH THREADED LINE ON THE GATE VALVE. THE DAMAGED CONNECTION FITTINGS WERE REMOVED AND REPLACED WITH A 1/2-INCH STEEL PLUG. THERE WAS APPROXIMATELY 148 BARRELS OF PROPANE PRODUCT RELEASED FROM THE LINE BEFORE REPAIR WAS MADE. PRESSURE WAS REAPPLIED TO THE VALVE AFTER REPAIRS, WITH NO LEAKS OR LELS DETECTED. FHR PERSONNEL MONITORED THE SITE OVERNIGHT AND FOUND NO ACTIVE RELEASE. ON THURSDAY, MARCH 6, 2025, AT 12:00, THE LINE WAS RESTARTED AND RETURNED TO NORMAL OPERATIONS."