NUSTAR PIPELINE OPERATING PARTNERSHIP L.P.

Incident Narrative

NUSTAR PIPELINE WAS CLEARLY MARKED WITH PIPELINE MARKERS LOCATED ON ARKANSAS GRAVEL COMPANY PROPERTY AND NUSTAR RIGHT-OF-WAY. WITHOUT MAKING AN ARKANSAS ONE CALL, AT APPROXIMATELY 7 P.M. THURSDAY, SEPTEMBER 23, 2021, AN ARKANSAS GRAVEL COMPANY EMPLOYEE WAS DIGGING IN THEIR QUARRY NEAR HAMPTON, ARKANSAS, WHEN THEY PUNCTURED NUSTAR'S AMMONIA LINE. THIS INCIDENT CAUSED THE RELEASE OF ANHYDROUS AMMONIA VAPOR INTO THE AIR. LOCAL EMERGENCY PERSONNEL ISSUED A VOLUNTARY EVACUATION ORDER FOR THE COMMUNITY IN PROXIMITY TO AND DOWNWIND FROM THE SITE. ROADS NEARBY WERE CLOSED, ALONG WITH HIGHWAY 167. FEDERAL AND STATE AGENCY NOTIFICATIONS WERE TIMELY MADE. AS OF 11:15 A.M. ON SEPTEMBER 24, 2021, THE PRESSURE OF THE AMMONIA RELEASING FROM THE PUNCTURED PIPELINE REDUCED SIGNIFICANTLY DUE TO THE RESPONSE BY NUSTAR MAINTENANCE CREWS, AND THE LOCAL AUTHORITIES LIFTED THE EVACUATION ORDER AND OPENED THE HIGHWAY. ON SEPTEMBER 26, 2021, NUSTAR MAINTENANCE PERSONNEL INSTALLED STOPPLE TEES, AND THE PORTION OF THE PIPELINE BETWEEN THE TWO STOPPLE TEES WAS EVACUATED OF CONTENTS. A REPLACEMENT SECTION WAS INSTALLED INTO THE DAMAGED PIPELINE. REPAIRS WERE COMPLETED ON SEPTEMBER 27, 2021. THE SECTION OF PIPE CUT OUT WILL BE SENT FOR METALLURGICAL REVIEW. THE PIPELINE WAS RESTARTED WITHOUT ISSUE ON THE AFTERNOON OF SEPTEMBER 27, 2021. ARKANSAS GRAVEL COMPANY IS LISTED IN NUSTAR'S PUBLIC AWARENESS PROGRAM AS A RECIPIENT OF THE ANNUAL AFFECTED PUBLIC AND EXCAVATOR BROCHURE, WHICH IS MAILED FROM AUGUST TO OCTOBER FOR THIS AREA. THIS PIPELINE BROCHURE DESCRIBES THE NATIONAL PIPELINE MAPPING SYSTEM, WHICH NUSTAR UPDATES ANNUALLY, THE ONE CALL PROGRAM, WHICH IS MONITORED DAILY AND UPDATED, RECOGNITION OF A PIPELINE VIA VARIOUS TYPES OF MARKERS, AND WHAT TO DO IF YOU SUSPECT A LEAK. NUSTAR ALSO PARTICIPATES IN ARKANSAS 811, WHERE ANYONE CAN CALL FOR ANY OPERATOR TO MARK THEIR LINES. THROUGH ARKANSAS 811, NUSTAR HOSTS COLLABORATIVE MEETINGS IN THE COUNTIES THAT NUSTAR OPERATES. *UPDATE* METALLURGY CONCLUSION - NO DEFECTS OR DEFICIENCIES WERE FOUND ASSOCIATED WITH THE MANUFACTURE OF THE PIPE OR CONDITION OF THE PIPE PRE-DAMAGE. ALL DAMAGE DOCUMENTED (EXTERNAL GOUGES AND DENTS, THROUGH WALL PENETRATION AND INTERNAL CRACK) WAS CAUSED BY FORCES APPLIED TO THE TOP SURFACE OF THE PIPE AS MARKED, APPROXIMATELY PERPENDICULAR TO THE PIPE OD AND IN THE DOWNSTREAM DIRECTION VARYING DIRECTIONALLY APPROXIMATELY 5 TO 15 DEGREES CLOCKWISE FROM THE LONGITUDINAL AXIS.