PORTLAND PIPE LINE CORPORATION

Incident Narrative

ON 4/26/2023 AT 17:12, A PORTLAND PIPE LINE CONTROLLER MONITORING THE PIPELINE SYSTEM USING SCADA AND CPM LEAK DETECTION NOTICED PRESSURES WERE DROPPING SLOWLY AT THREE CONSECUTIVE PUMP STATIONS ALONG THE 24-INCH CRUDE OIL PIPELINE, WITH PRESSURE REMAINING STABLE AT DOWNSTREAM PUMP STATIONS AND ALONG THE DOWNSTREAM PIPELINE ITSELF. THE THIRD STATION, SHELBURNE STATION, IS LOCATED IN COOS COUNTY, SHELBURNE, NEW HAMPSHIRE. AT 17:33, THE CONTROLLER CLOSED THE REMOTELY OPERATED INCOMING MAIN LINE BLOCK VALVE AT SHELBURNE STATION AND PRESSURES AT THE UPSTREAM STATIONS CEASED TO DROP. COMPANY, OSRO, AND LOCAL FIRST RESPONDER PERSONNEL AND EQUIPMENT WERE NOTIFIED AND DISPATCHED TO THE SHELBURNE PUMP STATION. COMPANY PERSONNEL ARRIVED FIRST AT 18:30 AND CONFIRMED THE PRESENCE OF OIL ON THE GROUND ABOVE BURIED PUMP STATION SUCTION PIPING, LOCATED WITHIN THE CONFINES OF THE STATION PROPERTY. COMPANY PERSONNEL CLOSED THE MANUALLY-OPERATED OUTGOING MAIN LINE BLOCK VALVE AND THEN CLOSED THE LOCALLY-MOTOR-OPERATED PUMP STATION SUCTION AND DISCHARGE VALVES. AT 18:53, A NRC NOTIFICATION WAS MADE (NRC REPORT NUMBER 1365722). THE INITIAL REPORT ESTIMATED A RELEASE VOLUME OF 100 GALLONS BASED ON THE LIMITED INFORMATION AVAILABLE AT THE TIME. NOTIFICATIONS WERE ALSO MADE TO NEW HAMPSHIRE DEPARTMENT OF ENVIRONMENTAL SERVICES AND THE LOCAL EMERGENCY RESPONDER. DURING THE INITIAL RESPONSE, COMPANY PERSONNEL OBSERVED THAT OIL FLOWED ACROSS THE PUMP STATION YARD PAVEMENT AND THROUGH THE STATION FENCE, CONTINUING ALONG A STATION DITCH FOR APPROXIMATELY 250 FEET. IN COORDINATION WITH OSRO PERSONNEL WHO ARRIVED AT THE SITE AT 18:45, SORBENT BOOM AND PADS WERE DEPLOYED, AND NO OIL FLOWED OFF-SITE. EXCAVATION AND CLEANUP ACTIVITIES COMMENCED. AT THE TIME OF THE RELEASE, THE PIPELINE WAS ALREADY SHUT DOWN AS PART OF NORMAL OPERATIONS. FOLLOWING CONFIRMATION OF THE PRODUCT RELEASE AND FURTHER INVESTIGATION, THE PIPE WAS EXCAVATED AND IT WAS DETERMINED THAT THE RELEASE OCCURRED AS A RESULT OF A PINHOLE PERFORATION AT THE 6-O'CLOCK POSITION IN AN ELBOW AT THE LOW POINT OF THE SUCTION PIPING. A REPAIR CLAMP WAS INSTALLED PENDING REMOVAL OF THE PIPE FOR FURTHER INSPECTION AND METALLURGICAL ANALYSIS. UPDATE 20231213: PART A ESTIMATED VOLUMES; PART D ESTIMATED PROPERTY DAMAGE; PART G APPARENT CAUSE; AND PART K CONTRIBUTING FACTORS. AS DESCRIBED IN PART G, THE METALLURGICAL REPORT DETERMINED THE APPARENT CAUSE WAS GALVANIC CORROSION, AND DETERMINED THAT MICROBIOLOGICALLY INFLUENCED CORROSION WAS A CONTRIBUTING FACTOR. CRUDE OIL SEDIMENT WAS PRESENT AT THE BOTTOM OF THE PIPING, AND THE SEDIMENT WAS FOUND TO CONTAIN BACTERIA OF THE TYPES THAT ARE CONDUCIVE TO CORROSION OF LINE PIPE STEEL AND FITTINGS. EXCAVATION AND BACKFILLING AT THE SITE WERE COMPLETED IN NOVEMBER. PORTLAND PIPE LINE CONTINUES TO WORK CLOSELY WITH THE NEW HAMPSHIRE DEPARTMENT OF ENVIRONMENTAL SERVICES ON ENVIRONMENTAL MONITORING ACTIVITIES.