COLONIAL PIPELINE CO

Incident Narrative

ON MAY 22, 2012, DURING A TANK MAINTENANCE ACTIVITY, TANK 411 WAS BEING FILLED TO PLACE THE ROOF ON HIGH LEGS. DURING THE FILLING OF THE TANK, PRODUCT WAS OBSERVED LEAKING FROM THE MANWAY. A TANK TO TANK TRANSFER WAS IMMEDIATELY STARTED TO PUMP THE PRODUCT IN TANK 411 BELOW THE HEIGHT OF THE MANWAY. THE LEAK STOPPED AND CLEAN UP ACTIVITIES BEGAN. ALL PRODUCT WAS CONTAINED WITHIN THE TANK DIKE. INCIDENT WAS REPORTED TO OPERATIONS MANGER AT 13:47. THERE WERE NO IMPACTS OR THREATENED IMPACTS TO SURFACE WATER BODIES OR GROUNDWATER. THE RELEASED PRODUCT TRAVELED FROM THE TANK FLANGE APPROXIMATELY 250 FEET AND POOLED IN THE CORNER OF THE TANK DIKE ON TOP OF A SMALL AREA OF IMPOUNDED WATER FROM A RECENT RAIN. THE CLAY SOILS WITHIN THE TANK DIKE WERE SATURATED BY THE RECENT RAIN WHICH LIMITED SOIL IMPACTS TO AN AVERAGE DEPTH OF 3 INCHES. THE POOL OF WATER AND PRODUCT IN THE CORNER OF THE TANK DIKE WAS RECOVERED WITH A VAC TRUCK, YIELDING 346 GALLONS OF PRODUCT AND 2600 GALLONS OF WATER. THE WATER AND PRODUCT WERE PUT IN THE STATION SUMP. SOIL IMPACTED BY THE RELEASE, ESTIMATED AT 340 TONS OF SOIL, WAS EXCAVATED AND STOCKPILED FOR OFF-SITE DISPOSAL/TREATMENT. ANALYSIS OF SOIL SAMPLES COLLECTED FROM THE STOCKPILE INDICATES THAT AN ESTIMATED 191 GALLONS OF RELEASED PRODUCT WERE ABSORBED INTO THE TANK DIKE SOILS. THE PORTION OF THE RELEASED PRODUCT LOST TO EVAPORATION WAS CALCULATED TO BE 33 GALLONS, BASED UPON FIELD OBSERVATIONS AND THE NATURE OF THE TRANSMIX HAVING A LOW PERCENTAGE OF GASOLINE (<10%). THE TOTAL RELEASE VOLUME OF 588 GALLONS IS BASED UPON THE VOLUME OF FREE PHASE PRODUCT RECOVERED VIA VAC TRUCK, THE AMOUNT CALCULATED TO HAVE ABSORBED INTO THE EXCAVATED TANK DIKE SOILS, AND THE EVAPORATION CALCULATIONS. NO ADDITIONAL REMEDIAL ACTIONS ARE ANTICIPATED.