MARATHON PIPE LINE LLC

hazardous_liquid Incident —

Incident Information

Report Date
OperatorMARATHON PIPE LINE LLC
Commodity—
Pipeline Typehazardous_liquid

Location

State
Coordinates31.16600, -90.77640

Cause

CauseEQUIPMENT FAILURE
Subcause—

Casualties

Fatalities0
Injuries0

Costs

Property Damage
Lost Commodity
Public/Private Damage
Emergency Response
Environmental Remediation
Other Costs

Location Map

Incident Narrative

THE STAIN/RELEASE WAS INTERMITTENT BUT TOTAL RELEASE VOLUME IS ESTIMATED TO BE LESS THAN ONE GALLON. MPL COMPLETED ITS INVESTIGATION INTO THE RELEASE AND DETERMINED THAT THE CAUSE OF THE ACCIDENT WAS DUE TO A PINHOLE LEAK IN A DEFECTIVE WELD OVERLAY PATCH IN THE FLOOR CRITICAL ZONE. THE WELD WAS PERFORMED BY THE PREVIOUS OPERATOR AS A REPAIR IN THE MID-1990'S WHICH RESULTED IN WELD POROSITY, CAUSING A PINHOLE LEAK TO FORM. IT IS MPL'S ASSUMPTION THAT THE LEAK HAD INITIALLY BEEN PLUGGED BY SLAG, PUTTY, AND/OR LINER MATERIAL. HOWEVER, AN API 653 INTERNAL INSPECTION AND ASSOCIATED REPAIRS WERE PERFORMED BY MPL IN AUGUST 2015 WHICH LIKELY UNPLUGGED THE PINHOLE AND ALLOWED PRODUCT TO LEAK THROUGH THE DEFECTIVE WELD. MPL ASSUMES THAT THE FLOOR LINER CONTRIBUTED TO THE VERY SMALL LEAK RATE. THE TANK HAS BEEN DRAINED, CLEANED AND ISOLATED FROM THE PIPELINE AND IS CURRENTLY NON-OPERATIONAL. THE ""ITEM INVOLVED IN ACCIDENT"" AND ""ACCIDENT TYPE"" WERE ADDED TO PARTS C.3. AND C.6., RESPECTIVELY. ACCIDENT COSTS WERE ADDED TO PART D.8. CAUSE INFORMATION WAS ADDED TO PART G.6.

About This Pipeline Incident

Pipeline incident data is reported to the Pipeline and Hazardous Materials Safety Administration (PHMSA). All significant incidents involving fatalities, injuries, or property damage over $50,000 must be reported.

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