COLONIAL PIPELINE CO

Incident Narrative

ON JUNE 9, 2023, AT APPROXIMATELY 13:00 CST, DURING A SCHEDULED OUT OF SERVICE INSPECTION OF TANK 1479, HYDROCARBON VAPORS WERE DETECTED AND FREE-STANDING PRODUCT WAS FOUND BENEATH THE TANK FLOOR. DURING THE TIME OF DISCOVERY, THE TANK WAS EMPTY OF ALL PRODUCT. TANK 1479 WAS CONSTRUCTED IN 1965 AND HAS HISTORICALLY BEEN USED FOR THE STORAGE OF GASOLINE PRODUCT. UPON DISCOVERY OF THE CONTAMINATION, THE PROCESS OF REMOVING THE TANK FLOOR TO FURTHER INVESTIGATE THE CONTAMINATION BEGAN. FOLLOWING DISCOVERY OF THE CONTAMINATION, REPRESENTATIVE SOIL SAMPLES WERE COLLECTED FOR LABORATORY ANALYSIS TO DETERMINE THE HISTORICAL ORIGIN OF THE PRODUCT. AT THIS TIME, MEDIA SAMPLE RESULTS HAVE NOT BEEN RECEIVED FROM THE LABORATORY AND INVESTIGATION EFFORTS REMAIN ONGOING. A SOIL ANALYSIS REPORT IS EXPECTED TO BE COMPLETED BY THE END OF JULY 2023. BASED ON INVESTIGATIONS CONDUCTED TO DATE, ALL RELATED CONTAMINATION IS LIMITED TO, AND CONTAINED WITHIN, THE CPC PROPERTY. ENVIRONMENTAL REMEDIATION ACTIVITIES ARE ON-GOING. ON JUNE 13, 2023, AT APPROXIMATELY 17:30 CST, IN ACCORDANCE WITH SPILL REPORTING PROCESSES AND DUE TO THE FACT THAT THE TIME FRAME FOR WHICH THE CONTAMINATION ACTUALLY OCCURRED BENEATH THE EMPTIED TANK WAS UNKNOWN, A NRC NOTIFICATION WAS MADE (NRC NO. 1369982) BASED ON A DETERMINATION THAT PROPERTY DAMAGE COSTS MAY MEET OR EXCEED $50,000. ON JUNE 15, 2023, AT APPROXIMATELY 16:15 CST, THE 48-HOUR NRC NOTIFICATION WAS MADE (NRC NO. 1370206), WHICH INCLUDED INFORMATION THAT AN ESTIMATED 500 GALLONS OF PRODUCT CONTAMINATION EXISTED. COLONIAL RECEIVED THE JANUARY 23, 2024 LAB ANALYSIS REPORT, WHICH, SOUGHT TO CALLY THE FORENSIC ANALYSIS REPORT YIELDED INCONCLUSIVE RESULTS AS ASSOCIATED TO DETERMINING THE HISTORICAL ORIGIN OF THE PRODUCT. AS A RESULT OF OPERATIONS OVER A LONG PERIOD OF TIME PRIOR TO TANK MAINTENANCE AND IN CONJUNCTION WITH THE LAB ANALYSIS, THE CAUSE WAS FOUND TO BE INCONCLUSIVE. THE TANK FLOOR WAS REPLACED. COLONIAL RECEIVED THE JANUARY 23, 2024 LAB ANALYSIS REPORT, WHICH SOUGHT TO CHEMICALLY CHARACTERIZE THE HYDROCARBON SIGNATURE (INCLUDING THE AGE) OF THE RELEASED PRODUCT. THE FORENSIC ANALYSIS REPORT YIELDED INCONCLUSIVE RESULTS AS TO THE WEATHERING AND CHEMICAL BREAKDOWN OF THE RELEASED PRODUCT; THEREFORE, THE TIME OF RELEASE WAS UNABLE TO BE DETERMINED WITH ANY CERTAINTY. IT IS BELIEVED THERE WAS AN EQUIPMENT FAILURE INVOLVING THE FLOOR BOTTOM, HOWEVER, COLONIAL IS UNABLE TO DEFINITIVELY CONCLUDE THAT THE RELEASE WAS HISTORIC IN NATURE (I.E., THE EARLY 2000S). COLONIAL IS SUBMITTING THIS REPORT OUT OF AN ABUNDANCE OF CAUTION AS RELATIVE TO THE INCONCLUSIVE RESULTS ASSOCIATED TO THE LAB ANALYSIS REPORT.