HARVEST MIDSTREAM COMPANY

Incident Narrative

A 20 BARREL OIL SPILL OCCURRED ON THE PEARSALL LINE BETWEEN THREE RIVERS AND MIDWAY NEAR THE TOWN OF MATHIS ON SATURDAY AFTERNOON 10/27/18 AT 16:26PM. A RANCHER CALLED 811 TO REPORT A 10 FOOT DIAMETER OIL SPILL ON THREE RIVERS TO MIDWAY SEGMENT OF THE PEARSALL PIPELINE SYSTEM. THE LINE WAS SHUT DOWN AND FIELD PERSONNEL WERE DISPATCHED TO INVESTIGATE. THE LEAK OCCURRED UNDER A PREVIOUS REPAIR MADE BY THE PREVIOUS OPERATOR OF THE LINE. THE LINE WAS RETURNED TO SERVICE 10/30/18, 10:53. THE DATE OF THE ACCIDENT FOR REPORTING PURPOSES IS 10/28/18 AT 11:00 AM. AT THIS TIME THE DETERMINATION WAS MADE THAT THE COST ASSOCIATED WITH THIS ACCIDENT WOULD BE GREATER THAN $50,000 AND CONFIRMED THE ESTIMATED VOLUME OF 20 BBLS. THE DIRECT CAUSE OF THE LEAK IS INTERNAL CORROSION. VISUAL INSPECTION OF THE FAILED PIPE SPOOL INDICATES THE LEAK OCCURRED DUE TO ELECTROCHEMICAL OR MICRO-BIOLOGICAL CORROSION AND WAS CONFIRMED THOUGH THE 3RD PARTY LAB METALLURGICAL EVALUATION. THE SYSTEM CAUSE OF THE LEAK IS INTERMITTENT FLOW. REVIEW OF THE ILI DATA INDICATES THE LEAK OCCURRED IN A LOW SPOT IN THE LINE. DURING THE SUMMER MONTHS THE PEARSALL PIPELINE SYSTEM IS SHUT DOWN FOR 2 TO 3 HOURS PER DAY BECAUSE OF ELECTRICAL GRID CONSTRAINT (I.E. POTENTIAL TO BROWN OUT RESIDENTIAL CUSTOMERS) RESULTING IN INTERMITTENT FLOW IN THE LINE SEGMENT. THESE BRIEF PERIODS CAN RESULT IN THE WATER AND SEDIMENT TO DROP OUT IN LOW POINTS. FUTURE PREVENTION THE ASSOCIATED SECTION OF PIPE WAS REPLACED, PIGGING FREQUENCY HAS BEEN ADJUSTED TO HELP REDUCE THE WATER AND SEDIMENT THAT DROP OUT IN THE LOW SPOTS, AND TREATING OF THE UPSTREAM BREAKOUT TANK WITH BIOCIDES.