NUSTAR PIPELINE OPERATING PARTNERSHIP L.P.

Incident Narrative

"AT APPROXIMATELY 20:00 ON 08MAY25, SUNOCO / NUSTAR LOCAL PERSONNEL RECEIVED A CALL FROM A LANDOWNER THAT THEY SMELLED AMMONIA ANHYDROUS. LOCAL PERSONNEL DISPATCHED TO THE SITE, ARRIVING AT APPROXIMATELY 21:05 TO BEGIN WALKING THE LINE AND LOOKING FOR A LEAK. THE LEAK WAS CONFIRMED AT 21:32 WITH A CALL TO AMMONIA SYSTEM LEADERSHIP. SUNOCO / NUSTAR PIPELINE SAFETY PERSONNEL WERE NOTIFIED OF THE RELEASE AT 22:01 TO BEGIN THE NOTIFICATION PROCESS WITH THE NATIONAL RESPONSE CENTER (NRC). A CALL WAS PLACED AND RECEIVED BY THE NRC AT 22:19. MR. DAVIS TOOK THE CALL AND PROVIDED INCIDENT NUMBER 1430608. A FOLLOW-UP CALL WAS RECEIVED BY REGION 6 EPA AT 23:06 REQUESTING AN UPDATE ON THE INCIDENT AND AN OFFER TO PROVIDE ASSISTANCE, IF NEEDED. A SMALL VAPOR STREAM WAS IDENTIFIED COMING FROM THE UPSTREAM SIDE OF VALVE 3-27. CONTROL CENTER PERSONNEL WERE NOTIFIED OF THE RELEASE AND ASKED TO SHUT DOWN THE PIPELINE (22:15). LOCAL PERSONNEL WERE DISPATCHED TO CLOSE THE UPSTREAM VALVE (3-25) AND THE DOWNSTREAM VALVE (3-27). LOCAL PERSONNEL PROVIDED OVERNIGHT AIR MONITORING OF THE SITE. VISQUEEN WAS USED TO COVER THE LEAK AND KEEP THE VAPORS DOWN. THERE WAS NO DANGER TO LOCAL RESIDENTS AND NO NOTIFICATIONS WERE MADE TO LOCAL AUTHORITIES. SUNOCO / NUSTAR MAINTENANCE PERSONNEL WERE CALLED AND DISPATCHED TO THE SITE FOR REPAIRS. UPON EXCAVATION OF THE VALVE SITE, A SMALL CRACK WAS DISCOVERED ON THE SIDE SEAM WELD OF A STOPPLE TEE. REPAIRS WERE COMPLETED AND THE LINE WAS RETURNED TO SERVICE AT 18:45 ON 09MAY25."