COLONIAL PIPELINE CO — Hazardous liquid — incident on 2015-11-23

Hazardous liquid incident in GREENSBORO, GUILFORD County, NC. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 3.69 REFINED AND/OR PETROLEUM PRODUCT (NON-HVL) WHICH IS A LIQUID AT AMBIENT CONDITIONS released, $0 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.

Report number: 20150468.

Operator ID: 2552.

Reported incident date: 11/23/2015 10:30.

Location detail: LOCATION 0821

Cause detail: NON-THREADED CONNECTION FAILURE

Cause detail: ON 11/23/2015 AT 10:30 AN EMPLOYEE DETECTED PRODUCT ODOR DURING A ROUTINE STATION CHECK IN THE VICINITY OF THE LINE 3 UNIT 4 PUMP. THE EMPLOYEE FOUND PRODUCT INSIDE NEARBY ACCESS WELLS. THE CONTROL ROOM WAS IMMEDIATELY NOTIFIED AND RESOURCES WERE DISPATCHED FOR CLEANUP. LINE 3 WAS NOT SHUT DOWN SINCE THERE WAS NO VISUAL INDICATION OF AN ACTIVE LEAK SOURCE AND THERE WAS A POSSIBILITY THAT THE PRODUCT FOUND WAS FROM A RECENT RELEASE NEAR THE SAME AREA. BASED ON THE ESTIMATED RELEASE VOLUME EXCEEDING 25 GALLONS, THE NCDENR WAS NOTIFIED AT 12:59 AND A COURTESY NOTIFICATION WAS MADE TO GUILFORD COUNTY ENVIRONMENTAL HEALTH AT 13:03. A COURTESY CALL WAS ALSO MADE TO THE GREENSBORO FIRE DEPARTMENT LATER THAT AFTERNOON. AT 10:50 A CONTRACT CREW ARRIVED AT THE SCENE TO RECOVER PRODUCT AND BEGIN EXPLORATORY DIGGING. DURING EXCAVATION OF THE PUMP-SIDE SPRING ASSEMBLY OF THE LINE 3 UNIT 4 CHECK VALVE, PRODUCT LIGHTLY STREAMED FROM THE BOTTOM OF THE SPRING ASSEMBLY AND THEN STOPPED WITHIN MINUTES. EXCAVATION CONTINUED TO THE OTHER SIDE OF THE CHECK VALVE AND BY THE MORNING OF 11/24/2015 BOTH SPRING ASSEMBLIES HAD BEEN UNCOVERED WITH NO ACTIVE LEAK DETECTED. THE CHECK WAS INSPECTED AND CLOSELY MONITORED DURING SEVERAL UNIT OPERATIONS. NO LEAKS WERE OBSERVED. APPROXIMATELY 20 GALLONS OF FREE PRODUCT HAD BEEN COLLECTED WITHIN THE FIRST 24 HOURS BUT THE RATE HAD SLOWED BY THE MORNING OF 11/24/2015. DIGGING CONTINUED DURING DAYLIGHT HOURS ONLY ON 11/24 AND 11/25/2015 WITH MONITORING BY OPERATIONS PERSONNEL DURING THE THANKSGIVING HOLIDAY ON 11/26-11/29/2015. BY THE MORNING OF 11/30/2015, AN ADDITIONAL 24 GALLONS OF FREE PRODUCT HAD BEEN COLLECTED IN THE EXCAVATION AREA WITH NO VISIBLE SOURCE. EXCAVATION CONTINUED THROUGH 12/1/2015. AT 16:40 ON 12/1/2015, LINE 3 UNEXPECTEDLY SHUT DOWN DUE TO A BEARING SEAL FAILURE ALARM (UNRELATED TO THIS EVENT) ON THE LINE 3 OIL BOOSTER. DURING THE SHUTDOWN, PRODUCT BEGAN SPRAYING OUT OF THE CHECK VALVE SPRING ASSEMBLY. THE LINE WAS DRAINED AND REPAIR OF THE CHECK VALVE BEGAN. DURING THE REPAIR IT WAS DETERMINED THAT THE INTERIOR O-RINGS ON BOTH SPRING ASSEMBLIES HAD FLATTENED AND WERE THE LIKELY CAUSE OF THE RELEASE. REPAIRS WERE COMPLETED BY 00:50 ON 12/2/2015. THE LINE 3 OIL BOOSTER BEARING SEAL WAS INSPECTED AND FOUND IN GOOD CONDITION. THE BEARING SEAL ALARM HAD CLEARED ON ITS OWN DURING THE CHECK VALVE REPAIRS. LINE 3 WAS RESTARTED AT 01:00 ON 12/2/15. EXPLORATORY DIGGING CONTINUED FROM 12/2/2015 TO 12/18/2015, WITH INTERMITTENT POCKETS OF PRODUCT FOUND IN DIMINISHING QUANTITIES. TOTAL FREE PRODUCT COLLECTED WAS 114 GALLONS. ON 12/7/2015 AT 15:58 THE NRC WAS NOTIFIED AS SOON AS RESPONSE COSTS WERE ESTIMATED TO EXCEED $50,000. APPROXIMATELY 73 CUBIC YARDS OF IMPACTED SOIL WAS EXCAVATED AND PLACED ON PLASTIC WITH CONTAINMENT. SOIL SAMPLES WERE COLLECTED AND SENT TO A LAB FOR ANALYSIS. THE TOTAL VOLUME OF PRODUCT RELEASED TO THE SOILS IS CALCULATED AT 41 GALLONS. AN INCIDENT ANALYSIS OF THIS EVENT WAS CONDUCTED ON 1/7/2016. THE BASIC CAUSE OF THE INCIDENT WAS CONFIRMED AS THE FLATTENING OF INTERIOR O-RINGS ON THE CHECK VALVE SPRING ASSEMBLIES DUE TO NORMAL WEAR. THE DESIGN OF THE SPRING ASSEMBLY/SPRING COVER WAS ALSO FOUND TO BE A CONTRIBUTING FACTOR SINCE IT INCLUDES A GAP BETWEEN THE MAIN VALVE BODY AND THE SPRING ASSEMBLY. AS SUCH, THE SPRING ASSEMBLY COVER IS AN INEFFECTIVE PRESSURE CONTAINMENT DEVICE. THE WHEATLEY CHECK VALVE IN QUESTION IS UNIQUE TO THE OPERATING AREA. CORRECTIVE ACTIONS IDENTIFIED DURING THE INCIDENT ANALYSIS PROCESS INCLUDE: 1) DETERMINE IF OTHER VALVES WITHIN THE COMPANY ARE OF THE SAME DESIGN. 2)CONTACT THE VALVE MANUFACTURER FOR AN EXISTING SOLUTION FOR THE CONTAINMENT ISSUE OR DESIGN AN IN-HOUSE SOLUTION THAT COULD BE MANUFACTURED BY A MACHINE SHOP. 3)IF A CONTAINMENT SOLUTION CANNOT BE IMPLEMENTED, INCORPORATE ACCESS WELLS INTO THE BACKFILL EFFORTS SO THAT PERIODIC CHECKS COULD BE CONDUCTED IN ORDER TO QUICKLY DETECT ANY LOSS OF CONTAINMENT FROM THE CHECK VALVE IN THE FUTURE.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: EQUIPMENT FAILURE — NON-THREADED CONNECTION FAILURE.

PHMSA indexed costs: $145,310 reported total cost, $72,897.206 in 1984 dollars, $179,523.384 in current-year dollars.

PHMSA trend flags, standardized causes, and indexed costs are analytical fields added to operator-reported incident data. They do not represent final agency causal findings.