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Marathon Ashland Petroleum (3165), Garyville

LDEQ Accident Report

Accident #159790
PDF AvailablePDF
State Police #14-04897
Accident Date2014-10-31
Report Date 2014-11-07
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
Hydrogen Sulfide2h 30mSour Water Tanks in Units 33 and 233NONONO620.0 pounds
Hydrogen2h 30mSour Water Tanks in Units 33 and 233NONONO2.0 pounds
Carbon Dioxide2h 30mSour Water Tanks in Units 33 and 233YESNONO65.0 pounds
Ethylene2h 30mSour Water Tanks in Units 33 and 233NONOYES59.0 pounds
Ethane2h 30mSour Water Tanks in Units 33 and 233NONOYES73.0 pounds
Methane2h 30mSour Water Tanks in Units 33 and 233YESNOYES45.0 pounds
Propane2h 30mSour Water Tanks in Units 33 and 233NONOYES81.0 pounds
Propylene2h 30mSour Water Tanks in Units 33 and 233NONOYES220.0 pounds
Isobutane2h 30mSour Water Tanks in Units 33 and 233NONOYES122.0 pounds
n-Butane2h 30mSour Water Tanks in Units 33 and 233NONONO72.0 pounds
1-Butene2h 30mSour Water Tanks in Units 33 and 233NONOYES51.0 pounds
trans-2-Butene2h 30mSour Water Tanks in Units 33 and 233NONONO49.0 pounds
cis-2-Butene2h 30mSour Water Tanks in Units 33 and 233NONONO35.0 pounds
Isopentane2h 30mSour Water Tanks in Units 33 and 233NONOYES30.0 pounds
Pentane2h 30mSour Water Tanks in Units 33 and 233NONOYES40.0 pounds
Cyclopentene2h 30mSour Water Tanks in Units 33 and 233NONOYES159.0 pounds
Butene2h 30mSour Water Tanks in Units 33 and 233NONOYES52.0 pounds

Accident Classified As: Reportable Quantity

Cause of Problem: Under Investigation

The incident took place when fixed and personal H2S monitors were alarming in the area of the Sour Water Tank in Units 33 and 233. After some time, it was determined that the non-degassed Sour Water was allowed to bypass the surge drum due to high pressure, which routed this material directly to the Sour Water Storage Tanks. This resulted in a vapor release from the Sour Waste Tanks, A root cause analysis is being conducted to determine why the incident occurred. The refinery's fence line Ambient Air Monitors did not pick up any excess emissions at the time of the incident. The incident released approximately 620 pounds of Hydrogen Sulfide.

Discharge Preventable - Under Investigation

Not known at this time, the results of the Root Cause Analysis will determine whether or not this was preventable.

Notes/Remedial Actions

Air monitoring was conducted in the area around the tank. A perimeter was established around the affected area. The flow of sour water to the Sour Water Tanks was decreased ending the vapor release from the tanks. The root cause analysis will result in recommendations designed to prevent the recurrence of this event.