SINCLAIR TRANSPORTATION COMPANY

Incident Narrative

IN NOVEMBER 2016 EXCESSIVE SNOW AND ICE BUILD UP ACCUMULATED ON THE EXTERNAL FLOATING ROOF OF TANK C4 AROUND THE BOTTOM OF THE ROLLING LADDER. LOCAL OPERATORS REQUESTED THAT THE LEVEL IN THE TANK NOT CHANGE UNLESS THEY WERE NOTIFIED TO AVOID DAMAGE TO THE ROLLING LADDER. THE LEVEL IN THE TANK STAYED ESSENTIALLY THE SAME UNTIL FEBRUARY. DURING THIS TIME (NOV. - FEB.) THE CRUDE OIL TEMPERATURE IN TANK C4 WENT FROM 58 DEG F TO 25 DEG F. AS THE CRUDE OIL BECAME COLDER LESS AND LESS MELTING OF THE SNOW AND ICE LOAD OCCURRED AND WITH EACH STORM MORE SNOW AND ICE ACCUMULATED ON THE SOUTHWEST PORTION OF THE ROOF. WARMER WEATHER DURING THE FIRST WEEK IN FEBRUARY STARTED TO MELT THE SNOW/ICE BUILD UP ON THE SOUTHWEST PORTION OF THE ROOF. ON FEBRUARY 8TH THE LOCAL AREA OPERATOR WENT DOWN ON THE ROOF, REMOVED THE PLUG FROM THE ROOF DRAIN, AND OPENED THE ROOF DRAIN VALVE ON THE OUTSIDE OF THE TANK. THIS VALVE WAS LEFT OPEN TO LET THE THAWING WATER TO EXIT THE TANK ROOF. AS MORE ICE AND SNOW MELTED MORE OF THE LOAD WAS CONCENTRATED TO A PORTION OF THE TANK AWAY FROM THE ROOF DRAIN AND IN THE AREA OF THE VACUUM/PRESSURE VENT. EVENTUALLY THE LOCALIZED SNOW/ICE/WATER LOAD IN THIS AREA CAUSED THE TOP OF THE VACUUM/PRESSURE VENT (18"") TO BE LOWER THAN THE LEVEL OF THE OIL IN THE TANK. NOW OIL WAS FLOWING ONTO THE ROOF AND EVENTUALLY THE OIL MADE ITS WAY TO THE ROOF DRAIN AND OUT OF THE OPEN ROOF DRAIN VALVE. MOST THE RELEASED OIL WAS CONTAINED IN THE TANK'S SECONDARY CONTAINMENT, HOWEVER, SOME WIND BORNE CRUDE OIL WAS CARRIED OFF SITE DUE TO HIGH WINDS AT THE TIME OF THE RELEASE.