NOBLE MIDSTREAM SERVICES, LLC

Incident Narrative

NOBLE MIDSTREAM OPERATIONS PERSONNEL WERE MADE AWARE OF A SUSPECTED LEAK AT 10:17 AM MDT ON AUGUST 16TH, 2021, AS REPORTED BY A LANDOWNER. FIELD PERSONNEL WERE DISPATCHED, AND THEY CONFIRMED THE REPORT. THE COMPROMISED SEGMENT OF THE BURIED 12"" GATHERING LINE WAS SHUT DOWN BY THE OPERATIONS CONTROL CENTER AND THE NEAREST ISOLATION VALVE WAS MANUALLY CLOSED AT 11:09 AM MDT ON AUGUST 16TH, 2020. EMERGENCY RESPONSE CREWS REACHED THE SITE AND DEPLOYED BOOM TO PROTECT A NEARBY IRRIGATION CANAL AT 11:45 AM MDT ON AUGUST 16TH, 2020. RECOVERY CREWS BEGAN TO EXCAVATE A CONTAINMENT SYSTEM AND RECOVER LIQUIDS WITH VACUUM TRUCKS AT 02:17 PM MDT ON AUGUST 16TH, 2021. A PIPE CLAMP WAS INSTALLED TO STOP THE RELEASE AT 02:11 PM MDT ON AUGUST 20TH, 2021. THE AFFECT PIPELINE SEGMENT REMAINS OUT-OF-SERVICE AT THE TIME OF THIS REPORT. THE ESTIMATED RELEASE VOLUME IS BASED ON ENGINEERING CALCULATIONS AND THE VOLUME OF LIQUID RECOVERED. 13,946 TONS OF CONTAMINATED SOIL IN THE AREA SURROUNDING THE RELEASE WAS REMOVED AND PROPERLY DISPOSED. SAMPLING CONDUCTED BY AN ENVIRONMENTAL SERVICES VENDOR CONFIRMED THAT GROUNDWATER IN THE IMMEDIATE AREA SURROUNDING THE RELEASE WAS IMPACTED. EFFORTS TO REMEDIATE CONTAMINATED GROUNDWATER AND ESTIMATE THE VOLUME OF PRODUCT RECOVERED ARE STILL IN PROGRESS AT THE TIME OF THIS REPORT. A REPRESENTATIVE FROM THE COLORADO OIL & GAS CONSERVATION COMMITTEE WITNESSED INCIDENT RESPONSE AND SOIL REMEDIATION EFFORTS AT THE RELEASE LOCATION ON AUGUST 16TH, 2021 AND AUGUST 26TH, 2021. NOBLE MIDSTREAM ENGAGED THE CHEVRON TECHNICAL CENTER LABORATORY IN HOUSTON, TX FOR FURTHER ANALYSIS OF THE FAILED PIPING. THE LABORATORY CONCLUDED THE HARPER-KONA PIPELINE FAILED FROM MICROBIALLY INDUCED CORROSION (MIC). THE LABORATORY ALSO RULED OUT THAT CONSTRUCTION AND MANUFACTURING QUALITY OF THE PIPING WAS A FACTOR IN INTERNAL CORROSION. THE FOLLOWING ANALYSES WERE PERFORMED BY THE LABORATORY TO SUPPORT THIS CONCLUSION: VISUAL INSPECTION SECTIONING AND METALLURGICAL INSPECTION TO EVALUATE MICROSTRUCTURE MICROBIAL ASSESSMENT USING ATP PHOTOMETRY AND QPCR QUANTITATIVE X-RAY DIFFRACTION (QXRD) ENERGY DISPERSIVE X-RAY SPECTROSCOPY (EDS) THE FOLLOWING REMEDIAL ACTIONS HAVE BEEN IDENTIFIED TO MITIGATE THE INTERNAL CORROSION: 1. CONDUCT AN ENGINEERING STUDY ON THE WELLS RANCH GATHERING SYSTEM TO IDENTIFY AREAS WITH SLOW MOVING FLUIDS AND THE POTENTIAL FOR MIC. DUE 2Q2022. 2. REEVALUATE PIPELINE INTEGRITY RISK ASSESSMENT WITH A FOCUS ON LEARNINGS FROM THIS EVENT. DUE 2Q2022 3. IMPROVE THE CHEMICAL PROGRAM IN THE WELLS RANCH GATHERING SYSTEM. DUE 4Q2021. 4. REPLACE THE FAILED SECTIONS OF HARPER-KONA PIPING. COMPLETED SEPTEMBER 2022