SUMMIT MIDSTREAM PARTNERS, LLC

Incident Narrative

A LEAK WAS DISCOVERED ON THE STAMPEDE PIPELINE AT VALVE SITE #5 BY A LANDOWNER AT APPROXIMATELY 10:50 AM ON 3/18/16 IN DIVIDE COUNTY, NORTH DAKOTA. THE LEAK APPEARS TO BE CAUSED BY AN ACT OF VANDALISM DUE TO A PRESSURE GAUGE BEING SHOT OUT AT THE ABOVEGROUND VALVE SITE. THE LINE WAS SHUT-IN PRIOR TO THE ACCIDENT AND THE LEAK WAS DISCOVERED WHEN THE LINE WAS RESTARTED. THERE WERE NO INDICATIONS OF A PRESSURE DROP BY THE CONTROL ROOM. SPILL WAS ESTIMATED TO BE 150 BBLS. REMEDIATION OF THE IMPACTED SOIL WAS PERFORMED. SUPPLEMENT / FINAL REPORT: SUMMARY A CRUDE OIL LEAK WAS DISCOVERED ON THE STAMPEDE PIPELINE AT VALVE SITE #5 BY A LANDOWNER AT APPROXIMATELY 10:50 AM ON 3/18/16 IN DIVIDE COUNTY, NORTH DAKOTA. THE LEAK WAS REPORTED BY A LAND OWNER. VANDALISM WAS THE CAUSE OF THE LEAK. A LOCAL PRESSURE GAUGE AT VALVE SITE #5 ON THE PIPELINE WAS PUNCTURED BY A BULLET FIRED FROM A GUN. BACKGROUND: THE PIPELINE WAS BLOCKED IN AND NOT FLOWING WHEN THE GAUGE WAS SHOT AND INITIALLY STARTED LEAKING. ON 3/18/16 THE PIPELINE RESUMED FLOW AND SHORTLY AFTER THE PIPELINE RESTARTED THE CONTROL CENTER WAS NOTIFIED OF THE LEAK. THE CONTROL CENTER ISOLATED THE REMOTE VALVE AT THE START OF THE PIPELINE AT SUMMIT'S DIVIDE STATION AND THE REMOTE VALVE AT THE END OF THE PIPELINE AT THE GLOBAL RAIL FACILITY. AT THE TIME OF THE INCIDENT THERE WERE NO INDICATIONS OF A PRESSURE DROP BY THE CONTROL ROOM. RESPONSE AND AGENCY NOTIFICATION A SUMMIT REPRESENTATIVE WAS DISPATCHED TO THE VALVE SITE. UPON ARRIVAL, THE REPRESENTATIVE FOUND THE GAUGE LEAKING AN ISOLATED THE 1/2 INCH VALVE BELOW THE GAUGE TO STOP THE LEAK. AN INITIAL ASSESSMENT OF THE AREA WAS CONDUCTED TO DETERMINE SOIL IMPACT. A DETERMINATION THROUGH SOIL CALCULATION MODELS SHOWED THE LEAK TO BE MINOR IN NATURE, 4.7 BARRELS, AND THAT IT WOULD NOT MEET PHMSA TELEPHONIC REPORTING REQUIREMENTS OF $50,000 THRESHOLD. INSTEAD, THE REPORT WOULD BE FILED UNDER THE REQUIREMENTS OF PHMSA'S 30 DAY NOTIFICATION. IT DID HOWEVER MEET THE NDIC AND NDDH REQUIREMENTS AND A REPORT WAS FILED WITH STATE OF NORTH DAKOTA. REMEDIATION SITE REMEDIATION WAS STARTED ON 3/18/2016. ALL AFFECTED SOIL WAS THOUGHT TO HAVE BEEN EXCAVATED AND STORED BEFORE RELEASING THE CONTRACTOR ON 3/18/2016 END OF DAY. ON MONDAY 3/21/2016, THE REMEDIATION CONTRACTOR RETURNED TO CONDUCT SOIL TESTING. TESTS CONCLUDED THAT THE OIL HAD MIGRATED FURTHER OUT THAN THE ORIGINAL DETERMINED. ON 3/22/2016 EVIDENCE WAS FOUND THAT THE OIL LEAK FOLLOWED THE PATH OF THE PIPE AND UNDERGROUND. ON 3/23/2016 IT WAS DETERMINED THAT TESTING AND CLEANUP EFFORTS FOR THIS SPILL WOULD EXCEED $50,000 AND A TELEPHONIC REPORT WAS MADE TO THE NCR NOTIFYING PHMSA OF THE QUALIFYING SPILL. THE SITE ASSESSMENT AND SPILL CALCULATIONS DETERMINED THE SPILL TO BE 103 BARRELS. SUMMIT REPORTED 150 BARREL WHICH WAS 1.5 TIMES THE ESTIMATED SPILL VOLUME TO GIVE PHMSA A WORST CASE ESTIMATE. THE FINAL SPILL VOLUME WAS CALCULATED AT 120 BARRELS AND THE QUANTITY OF SOIL IMPACTED WAS 3,825 TONS. REPAIRS AND PREVENTATIVE ACTIONS THE GAUGE WAS ISOLATED APPROXIMATELY ONE HOUR AND FIFTEEN MINUTES AFTER NOTIFICATION OF THE LEAK. BOTH ENDS OF THE PIPELINE WERE IMMEDIATELY SHUT DOWN REMOTELY BY THE CONTROL CENTER. THE GAUGE WAS REMOVED AND THE VALVE WAS PLUGGED. SUBSEQUENTLY, SUMMIT HAS REMOVED ALL LOCAL PRESSURE GAUGES FROM THE PIPELINE TO PREVENT FUTURE VANDALISM ON OUR PIPELINE.