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Marathon Ashland Petroleum (3165), Garyville

LDEQ Accident Report

Accident #143319
PDF AvailablePDF
State Police #12-06413
Accident Date2012-09-23
Report Date 2012-09-27
Follow-up Date 0000-00-00
Follow-up: No

Pollutants Released

Pollutant Duration Point Source Greenhouse Gas Criteria Pollutant Ozone forming chemical Amount of Release
Nitric Oxide8mEmissions from FlareNOYESNO0.2 pounds
Carbon Monoxide8mEmissions from flareNOYESNO0.8 pounds
Sulfur Dioxide8memissions from flare and Unit 45 Thermal OxidizerNOYESNO90.7 pounds
Volatile Organic Compounds (VOCs)8memissions from flareNONOYES1.4 pounds
Hydrogen Sulfide8memissions from flareNONONO0.1 pounds
Methane8memissions from flareYESNOYES0.2 pounds
Ethane8memissions from flareNONOYES0.2 pounds
n-Butane8memissions from flareNONONO0.2 pounds
n-Pentane8memissions from flareNONONO0.2 pounds
1-Pentene8memissions from flareNONOYES0.2 pounds
Pentene Plus8memissions from flareNONONO0.2 pounds
Natural Gas8memissions from flareNONONO28,000.0 pounds
n-Hexane8memissions from flareNONONOBRQ
Hydrogen8memissions from flareNONONOBRQ
Particulate Matter 108memissions from flareNOYESNOBRQ
Particulate Matter 2.58memissions from flareNOYESNOBRQ
Propane8memissions from flareNONOYES0.5 pounds
Isobutane8memissions from flareNONOYES0.1 pounds

Accident Classified As: Reportable Quantity

Cause of Problem: Equipment Failure

Marathon experienced a partial power outage caused by a malfunctioning substation in the refinery resulted in multiple pieces of equipment in the refinery losing power. Low pressure stripper Offgas flared in the South Flare due to partial power outage. Enterprise incident due to a plant farther downstream that had uncharacteristically ceased operation due to an upset condition. The pressure safety valve, as designed, released discharging natural gas to atmosphere due to high pressure on the pipeline caused by the upset condition farther down the line. Emission points involved were the Unit 59 North Flare and the Unit 45 Thermal Oxidizer.

Discharge Preventable - No

Marathon release was not preventable. The loss of power and the malfunction of substation was not anticipated. This substation is part of the refinery's preventative maintenance program. Enterprise incident was not preventable. They cannot predict upset conditions. The PSV functioned as designed.

Notes/Remedial Actions

Marathon power was restored and the equipment that was shutdown was restarted to minimize further releases. An incident investigation will result in recommendation items designed to prevent the recurrence of this event. High sulfur dioxide from one of the thermal oxidizer stacks in Unit 45 and in addition to a small amount of Unit 15 low pressure stripper offgas was flared which contains a small amount of hydrogen sulfide which is converted to sulfur dioxide in the North Flare. Emission points involved were the Unit 59 North Flare and the Unit 45 Thermal Oxidizer. Enterprise personnel immediately began the process of taking the plant down in order to end the release event. Amount of natural gas released is above reportable quantity.