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Marathon Ashland Petroleum (3165), Garyville

LDEQ Accident Report

Accident #156198
State Police #14-02266
Accident Date2014-05-23
Report Date 2014-05-30
Follow-up Date 2014-07-22
Follow-up: Yes

Pollutants Released

Pollutant Duration Point Source Greenhouse Gas Criteria Pollutant Ozone forming chemical Amount of Release
Sulfur Dioxide1h 5mU215 hydrocrackerNOYESNO5,278.0 pounds
Compressed Flammable Gas5h 47mTank 5000-6NONOYES13,735.0 pounds
NOx1h 5mU215 hydrocrackerNONOYES108.3 pounds
Carbon Monoxide1h 5mU215 hydrocrackerNOYESNO589.2 pounds
Volatile Organic Compounds (VOCs)1h 5mU215 hydrocrackerNONOYES230.6
Particulate Matter 101h 5mU215 hydrocrackerNOYESNO11.9 pounds
Particulate Matter 2.51h 5mU215 hydrocrackerNOYESNO11.9 pounds
Highly Reactive Volatile Organic Compounds (HRVOCs)1h 5mU215 hydrocrackerNONONO0.2 pounds
Hydrogen Sulfide1h 5mU215 hydrocrackerNONONO21.3 pounds

Accident Classified As: Reportable Quantity

Cause of Problem: Instrument Failure

An emergency shutdown device was triggered due to an incorrect reading on the Treating Reactor Bed 3 temperature indicator in the U215 hydrocracker which depressurized the unit to the South Ground Flare. In response to the shutdown, operations utilized the refinery slop line to deinventory the unit, routing material to Tank 500-6. Natural gas was inadvertently routed through the refinery slop line where Tank 500-6 received the vapor, causing a release through the tank seals. Human factors also played a role in the incident.

Discharge Preventable - Yes

Root causes were identified as equipment difficulty and procedures followed incorrectly.

Notes/Remedial Actions

Root causes identified as Equipment Difficulty-Design Specs and Procedures Followed Incorrectly. At the time of the release, the emergency shutdown system was activated as designed shutdown the hydrocracker. Multiple recommendations have been identified to prevent a recurrence. The Tech Services Department at MPC has been tasked with mitigating the hazards of a single point of failure due to false temperature indication (anticipated completion 1/31/15). The operations department will develop and implement a system to verify all steps are completed and signed off when following procedures. A team will be developed to conduct a hazard analysis on the entire refinery slop system to implement necessary safeguards to prevent unwanted material from entering the slop system.