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Marathon Ashland Petroleum (3165), Garyville

LDEQ Accident Report

Accident #147603
PDF AvailablePDF
State Police #13-25112
Accident Date2013-03-25
Report Date 2013-03-28
Follow-up Date 2013-05-22
Follow-up: Yes

Pollutants Released

Pollutant Duration Point Source Greenhouse Gas Criteria Pollutant Ozone forming chemical Amount of Release
Sulfur Dioxide40 MUnit 259 North Ground FlareNOYESNO3,385.0 pounds
Methane40 MUnit 259 North Ground FlareYESNOYES1.5 pounds
Ethane40 MUnit 259 North Ground FlareNONOYES21.6 pounds
Ethylene40 MUnit 259 North Ground FlareNONOYES0.4 pounds
Propane40 MUnit 259 North Ground FlareNONOYES74.3 pounds
Propylene40 MUnit 259 North Ground FlareNONOYES1.5 pounds
n-Butane40 MUnit 259 North Ground FlareNONONO54.6 pounds
Isobutane40 MUnit 259 North Ground FlareNONOYES22.2 pounds
1-Butene40 MUnit 259 North Ground FlareNONOYES0.4 pounds
trans-2-Butene40 MUnit 259 North Ground FlareNONONO1.2 pounds
cis-2-Butene40 MUnit 259 North Ground FlareNONONO0.1 pounds
n-Pentane40 MUnit 259 North Ground FlareNONONO6.6 pounds
Pentene Plus40 MUnit 259 North Ground FlareNONONO1.7 pounds
Carbon Dioxide40 MUnit 259 North Ground FlareYESNONO215.8 pounds
Carbon Monoxide40 MUnit 259 North Ground FlareNOYESNO79.4 pounds
Hydrogen40 MUnit 259 North Ground FlareNONONO0.0 pounds
Nitrogen40 MUnit 259 North Ground FlareNONONO0.3 pounds
Hydrogen Sulfide40 MUnit 259 North Ground FlareNONONO36.7 pounds
NOx40 MUnit 259 North Ground FlareNONOYES14.6 pounds
Volatile Organic Compounds (VOCs)40 MUnit 259 North Ground FlareNONOYES168.6 pounds
Particulate Matter 1040 MUnit 259 North Ground FlareNOYESNO1.6 pounds
Particulate Matter 2.540 MUnit 259 North Ground FlareNOYESNO1.6 pounds
Highly Reactive Volatile Organic Compounds (HRVOCs)40 MUnit 259 North Ground FlareNONONO1.9 pounds

Accident Classified As: Reportable Quantity

Cause of Problem: Equipment Design

The two root causes identified were the benzene stripper lower level controller malfunctioned and the operator did not have sufficient response time. On March 25, 2013 the Unit 210 Crude Overhead Compressor shut down at 18:03 hours and was restarted at 18:26 hours. A second shutdown occurred at 19:23 hours and was re-started at 19:41 hours. The duration of Unit 210 venting to the North Ground Flare was 40 minutes. Approximately 3,385 pounds of sulfur dioxide were released (above the reportable quantity of 500 pounds). On March 25, 2013 at 17:45 hours, issues developed in the Unit 210 Desalter vessels. As a result of the event, liquid was carried over from the Desalters to downstream Unit 210 vessels. Eventually, liquid filled the Unit 210 Overhead Compressor Feed Knockout drum which shut down the Overhead Compressor. The ambient air monitoring stations located by the ground flares did not detect a significant increase in sulfur dioxide emissions.

Discharge Preventable - Yes

The results of the Root Cause Analysis will determined the event was preventable.

Notes/Remedial Actions

Liquid was drained from the Unit 210 Crude Overhead Compressor Feed Knockout Drum. The Unit 210 Crude Overhead Compressor was re-started. While sulfur dioxide was the only chemical released above reportable quantity, NOx, monoxide, VOCs, PM10, PM2.5,HRVOCs, and hydrogen sulfide were released over the permit limit. An accident investigation was conducted to determine the cause(s) of the incident. The two root causes identified were 1. Equipment difficulty, design, problem not anticipated (Benzene stripper lower level controller malfunctioned); and 2. human engineering, non-fault tolerant system, errors not recoverable (operator did not have sufficient response time). The following recommendations will be implemented: 1. redesign or upgrade the benzene stripper level indicator 210L10197 to provide backup level indication for 210LC0187 due 12/20/13; 2. add soft stops to 210L1097 to limit flow from the 1st stage Desalter to the Benzene Stripper- complete; and 3. evaluate the hydraulics of the Benzene Stripper bottoms circuit and consider developing a project to eliminate constraints in the system- due 12/20/13.