ENBRIDGE PIPELINES (OZARK) L.L.C.

Incident Narrative

ON FEBRUARY 22, 2013 AT APPROXIMATELY 10:30, AN ENBRIDGE EMPLOYEE OBSERVED OIL IN THE CUSHING CENTRAL TERMINAL IN THE MANIFOLD 111 VICINITY. INITIALLY IT WAS SUSPECTED TO BE HISTORIC IN NATURE. HYDO VACUUMING ACTIVITIES OF THE SOIL CONTINUED IN ATTEMPT TO CONFIRM THAT THIS WAS INDEED HISTORICAL. BY MARCH 4 THE SOURCE HAD NOT YET BEEN DETERMINED AND STILL SUSPECTED TO BE HISTORIC. ON THIS DATE IT BECAME CLEAR THE INCIDENT WAS GOING TO EXCEED THE REPORTING THRESHOLD OF $50,000 AND 5 GALLONS. AT THIS POINT A PRECAUTIONARY CALL WAS MADE TO THE NRC. AFTER CONTINUED INVESTIGATION, A FLANGE WAS IDENTIFIED AS A POSSIBLE SOURCE ALTHOUGH IT WAS NOT LEAKING AT THE TIME IT WAS UNCOVERED. ADDITIONAL HYDRO VACUUMING AND MONITORING CONTINUED OVER THE NEXT FEW WEEKS WITH NO LEAK SOURCE IDENTIFIED. ON MARCH 22 PRESSURE WAS APPLIED TO THE LINE IN AN ATTEMPT TO VERIFY WHETHER THE FLANGE WAS OR WAS NOT THE SOURCE. AFTER PRESSURIZATION IT WAS DETERMINED THAT THE FLANGE CONNECTION WAS INDEED LEAKING. IT WAS DETERMINED THAT THE TORQUEING OF THE CONNECTION HAD RELAXED OVER TIME. THE FLANGE BOLTS WERE RE-TORQUED AND THE SMALL AMOUNT OF OIL THAT HAD LEAKED OUT OF THE FLANGE WAS CLEANED UP AND THE SYSTEM WAS PUT BACK INTO SERVICE. AS A PREVENTATIVE MEASURE, THE GASKET WAS REPLACED APRIL 6. REMOVAL OF CONTAMINATED SOIL FROM THE RELEASE SITE WAS COMPLETED ON APRIL 10. DUE TO THE UNUSUAL NATURE OF THIS INCIDENT, THE DATE ENTERED IN PART A, QUESTION 4 IS THE DATE THAT OIL WAS FIRST OBSERVED, BUT THOUGHT TO BE HISTORICAL. THE DATE ENTERED IN PART A, QUESTION 18 IS THE DATE DISCOVERY OF THE SOURCE WAS IDENTIFIED AND IT WAS DETERMINED IN FACT TO BE AN ACTUAL LEAK AND NOT HISTORICAL IN NATURE. ENBRIDGE HAS BEEN IN CONTACT WITH THE PHMSA SOUTHWEST REGION ACCIDENT COORDINATOR TO VERIFY THAT, IN THIS INSTANCE, THIS WOULD BE THE CORRECT COURSE OF ACTION.