DENBURY GULF COAST PIPELINES, LLC

Incident Narrative

ON 2/22/2020 AT 19:07, THE DENBURY CONTROL CENTER (DCC) OBSERVED A LOW-PRESSURE ALARM AT THE SATARTIA MOTOR OPERATED VALVE (MOV) LOCATION ON THE DELHI SEGMENT. THE CONTROL CENTER SUPERVISOR WAS NOTIFIED AND AT 19:15 THE UPSTREAM MOV, DOWNSTREAM MOV, AND THE SATARTIA MOV WERE CLOSED BY THE DCC. DENBURY OPERATIONS PERSONNEL WERE IMMEDIATELY NOTIFIED BY THE DCC OF LOW-PRESSURE ALARMS AND VALVE CLOSURES AND WERE MOBILIZED TO THE AREA IN ADDITION TO EMERGENCY RESPONSE CONTRACTORS. WHILE MOBILIZATION OF PERSONNEL OCCURRED, THE DCC CLOSED ALL CO2 SOURCES TO DELHI SEGMENT BETWEEN 19:26 AND 19:28. AT 19:54, A DENBURY REPRESENTATIVE CONTACTED THE TRI-COMMUNITY FIRE CHIEF, WHO WAS ON-SITE AND IDENTIFIED HIMSELF AS THE INCIDENT COMMANDER ON LOCATION ACKNOWLEDGING THE INCIDENT WAS BEING MANAGED IN THE UNIFIED COMMAND. DENBURY PERSONNEL ARRIVED ON-SITE AT 20:20 TO CONFIRM THE DELHI SEGMENT HAD EXPERIENCED A PIPELINE FAILURE UPSTREAM OF THE HWY 433 ROAD CROSSING. AT 20:21, A DENBURY REPRESENTATIVE CONTACTED THE YAZOO COUNTY EMA, WHO WAS DIRECTING THE YAZOO COUNTY SHERIFFS DEPARTMENT, MS HIGHWAY PATROL, AND MDOT. THE YAZOO COUNTY EMA CONFIRMED THAT THEY BEGAN FACILITATING THE EVACUATION OF RESIDENCE NEAR SATARTIA, MS AT APPROXIMATELY 19:20. MSDEQ WAS NOTIFIED AT 19:58. BOTH MSDEQ AND MEMA WERE ON-SCENE AND PERFORMING SUPPORTING AGENCY ROLES DURING THE EMERGENCY PHASE OF THE RESPONSE (4 HOURS). AT 20:51, THE NRC WAS NOTIFIED, AND THE CO2 LEAK WAS REPORTED (NRC #1271847). AT 21:36 EMERGENCY RESPONSE CONTRACTORS ARRIVED ON-SITE AND BEGAN CONDUCTING PRELIMINARY AIR-MONITORING FOR RESPONSE PERSONNEL. AT 21:55 ADDITIONAL EMERGENCY RESPONSE CONTRACTORS ARRIVED ON-SITE AND BEGAN CONDUCTING COMMUNITY AIR MONITORING AND ATMOSPHERIC TESTING IN AND AROUND THE FAILURE SITE AND THE CITY OF SATARTIA AND THE SURROUNDING AREA. AIR MONITORING AND ATMOSPHERIC TESTING CONTINUED THROUGHOUT THE NIGHT. AT 23:06, DENBURY PERSONNEL OBSERVED NO PRODUCT COMING FROM THE FAILURE LOCATION. AT 0:00 ON 2/23/2020, AN OPERATION PERIOD BRIEFING WAS CONDUCTED BY THE UNIFIED COMMAND. DURING THE BRIEFING, THE INCIDENT COMMAND TEAM INSTRUCTED RESPONDERS TO CONTINUE AIR MONITORING, CONDUCT RECONNAISSANCE WITHIN THE EVACUATED AREAS TO ENSURE NO PEOPLE WERE LEFT BEHIND, CLEAR THE DEBRIS AND SOIL OFF OF HWY 433, AND BEGIN DEVELOPING A PLAN TO LIFT THE EVACUATION. AT 06:00 A PLANNING MEETING WAS CONDUCTED BY THE UNIFIED COMMAND. THE RECON TEAM CONFIRMED ALL PERSONNEL HAD BEEN EVACUATED AND REPORTED SEEING LIVE COWS, DOGS, AND CATS THROUGHOUT THE EVACUATED AREA. THE AIR MONITORING TEAM ALSO REPORTED THAT CO2 LEVELS WERE DOWN TO AMBIENT LEVELS AND THE EVACUATION COULD BE LIFTED. AT 08:00 THE UNIFIED COMMAND GAVE THE ALL CLEAR, AND THE ROADS WERE OPENED AND RESIDENTS IN THE SURROUNDING AREA WERE ALLOWED TO RETURN TO THEIR HOMES. PERSONNEL AND A TOXICOLOGIST FROM CTEH WERE MADE AVAILABLE TO INSPECT HOMES PRIOR TO THE RESIDENCE RE-ENTRY. AT 18:39 ON 2/24/2020, THE NRC WAS CONTACTED AND GIVEN A 48-HOUR UPDATE REPORT (NRC #1272001). A TOTAL OF 200 RESIDENTS WERE EVACUATED AND 45 RESIDENTS WERE TAKEN TO THE HOSPITAL. TO DENBURYS KNOWLEDGE, ONE INDIVIDUAL WAS ADMITTED TO THE HOSPITAL FOR REASONS UNRELATED TO THE PIPELINE FAILURE. ON 3/9/2020 PIPELINE SAMPLES OF THE FAILURE LOCATION WERE REMOVED, PREPARED FOR SHIPMENT, AND SENT TO A TESTING LABORATORY ON 3/11/2020. THE RESULTS FROM THE LABORATORY TESTING WERE RECEIVED AND SHARED WITH PHMSA ON 6/26/2020. BASED ON THE FINDINGS OF METALLURGICAL AND STRESS EVALUATIONS AND THE EVIDENCE OF A CODE COMPLIANT PIPELINE, IT IS CONCLUDED THAT SOIL MOVEMENT UPSTREAM OF THE FAILURE LOCATION INDUCED AXIAL STRESSES SUFFICIENT TO CAUSE AN OVERLOAD CONDITION AND RESULTED IN THE PIPELINE RUPTURE. SOIL MOVEMENT WAS PROMOTED BY UNUSUALLY HIGH RAINFALL AVERAGES AND NOT A SINGULAR RAINFALL EVENT. THE PIPELINE SEGMENT WAS REPAIRED AND ON 10/26/2020 AT 12:30 THE PIPELINE WAS RESTARTED WITH NO ISSUES.