SFPP, LP

Incident Narrative

ON 11/20/20, THE CONTROL ROOM BEGAN TO SEE THE OVERS/SHORTS RUNNING NEGATIVE ON LS-16 FROM CONCORD TO SAN JOSE. THE LINE WAS SHUT DOWN AT 1551 IN ORDER TO INVESTIGATE AND CONDUCT SEVERAL STATIC PRESSURE TESTS. AT 1920 IT WAS DETERMINED THAT A SECTION OF THE LINE BETWEEN CONCORD STATION AND THE HILLGRADE BLOCK VALVE WAS UNABLE TO HOLD ADEQUATE PRESSURE, AND A THREATENED RELEASE NOTIFICATION WAS MADE TO OES/NRC. THE LINE WAS PATROLLED DURING THIS TIME BY GROUND-BASED RIGHT-OF-WAY PATROLS WHICH COULD NOT FIND ANY INDICATION OF A RELEASE BETWEEN CONCORD AND THE HILLGRADE BLOCK VALVE. THE GROUND PATROL ALSO INCLUDED SNIFFING AT KNOWN STOPPLE LOCATIONS FOR THE PRESENCE OF PETROLEUM VAPORS. WITH NO PHYSICAL INDICATIONS OF A RELEASE OR ANY PETROLEUM ODORS/VAPORS OBSERVED ALONG THE RIGHT-OF-WAY, THE INITIAL INVESTIGATIONS POINTED TO PRESSURE BLEEDING BACK INTO CONCORD STATION AND PRODUCT TEMPERATURE CHANGES AS THE SOURCE OF THE PRESSURE DROP BETWEEN CONCORD STATION AND THE HILLGRADE BLOCK VALVE. ON THE MORNING OF 11/23, AN ADDITIONAL TEST WAS CONDUCTED TO CONFIRM PRODUCT TEMPERATURE CHANGES AS THE SOURCE OF THE PRESSURE DROP IN THE LINE. THIS CONFIRMATION TEST FAILED. SUBSEQUENTLY, THE LINE WAS PURGED WITH NITROGEN AND A TRACER GAS AT 1500 ON 11/24 IN AN ATTEMPT TO PINPOINT ANY WOULD-BE LEAK LOCATION. THE LEAK WAS DISCOVERED AT 2203 BY GROUND PATROLS, AND CREWS ARRIVED AND BEGAN EXCAVATING THE LINE WHERE THE RELEASE WAS DISCOVERED. RELEASE CONFIRMATION WAS MADE TO OES/NRC AT THIS TIME. UPON EXCAVATION, A 5.5 INCH CRACK IN THE LINE WAS DISCOVERED AND THE LINE SECTION WAS CUT OUT AND SHIPPED TO A METALLURGICAL LAB FOR FURTHER ANALYSIS. A REPLACEMENT SECTION WAS WELDED INTO PLACE ON 11/25 AND THE LINE WAS REFILLED AND PLACED BACK INTO SERVICE ON THE MORNING OF 11/26. THE OFFICIAL CAUSE OF WHAT CAUSED THE CRACK WILL BE PENDING AFTER FURTHER METALLURGICAL ANALYSIS. ON 12/2 AN ODOR COMPLAINT OF GASOLINE WAS REPORTED AT APPROXIMATELY MILEPOST 7.5 ALONG THE IRON HORSE TRAIL ADJACENT TO A STORM CHANNEL IN WALNUT CREEK. AFTER SHUTTING DOWN THE LINE, RUNNING ANOTHER NITROGEN PURGE WITH TRACER GAS AND CONDUCTING EXTENSIVE TESTING AND INVESTIGATION, IT WAS DETERMINED THAT THERE WAS NOT A 2ND RELEASE AND THAT THE PRODUCT HAD MIGRATED TO THE LOCATION UPSTREAM FROM THE ORIGINAL RELEASE LOCATION THAT OCCURRED ON 11/20. UPDATE 1/13/2021- THE METALLURGICAL ANALYSIS CONCLUDED THAT THE CRACK THAT FORMED AT A FIELD BEND LIKELY OCCURRED DUE TO HIGH PH STRESS CORROSION CRACKING. LONG TERM REMEDIATION IS TAKING PLACE UNDER THE AUSPICES OF STATE AND LOCAL AGENCIES.