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Marathon Ashland Petroleum (3165), Garyville

Releases of Ammonia

LDEQ Accident Number
Accident Date
Point Source(s) Notes Amount of Release

Distillate Hydroteating Unit
Cause: Leaking thermowell

Followup: No

Notes: Called inspector who found the leak; built encapsulation clamp; Report makes estimated leaks in pounds even though discharge was in drops

South Flare
Unit 59 South Flare
Cause: A tube leaked on the Unit 15 Hot Separator Overhead Fin Fans at 17:52 hours. At 18:00, the unit was undergoing emergency shutdown procedures and the U15 dump valve was opened to the flare. The incident was a Gas Oil leak in the Unit 15 Hot separator Overhead Fin Fan Exchangers. This leak caused a vapor release of hydrocarbons and hydrogen in addition to a small amount of hydrogen sulfide.

Followup: Yes

Notes: PDF was too large to upload. Unit 15 was depressurized to the South Flare to safely isolate the leaking Overhead Fin Fan. Once the unit pressure was sufficiently low in the unit, the Fin Fans were isolated and the leak stopped. An incident investigation will result in recommendations to prevent recurrence. The reportable quantities for hydrogen sulfide, compressed flammable gas, and compressed flammable liquid were exceeded during this event. A report on October 9, 2013, removed greenhouse gas emissions and revised the estimate of VOC emissions.
7.5 pounds

Unit 59 South Flare, Unit 45 Thermal Oxidizer, Unit 220 Thermal Oxidizer, Unit 234 Thermal Oxidizer, and Unit 33 Sour Water Tank
Cause: Chain of Events: 1/14/12: Hydrocarbon carryover from the Unit 19 Sour Water Stripper caused Unit 220 (sulfur unit) and Unit 45 Thermal Oxidizer to trip. As a result, a sulfur dioxide plume was released from the Unit 45 Thermal Oxidizer. During the release, hydrocarbons from the ammonia acid gas header were steamed out to the flare. Units were then shut down to limit environmental impact. 1/15/12: A similar incident took place approximately four hours after Unit 220 startup. During this incident, the flare valve on the fuel gas absorber knockout drum opened to flare to relieve pressure on the drum. Hydrocarbon from the carryover was also sent to the sour water storage tank, which resulted in the tank venting to the atmosphere. 1/16/12: The flare valve from the fuel gas absorber knockout drum was closed at approximately 9:30, and the incident was then determined to be secure. The entire incident is under investigation. Follow up report issued 2/26/2013 summarizes results of internal Marathon investigation.

Followup: Yes

Notes: During the initial upset (1/14/12), Cargill was notified of the plume. All work with the Marathon refinery was put on hold, and the plant's Air Monitoring Team (AMT) was dispatched. The data that they collected is attached to the report. The contents of the Unit 19 Sour Water Storage Tank and ammonia acid gas header were then purged to eliminate existing hydrocarbons. Similar actions were taken to mitigate emissions from the second incident (1/15/12). Units were shut down, the AMT was activated, and fire water was introduced to limit emissions from the sour water tank. This incident was determined to be secured (1/16/12) when the flare valve from the fuel gas absorber knockout drum was closed to the South Flare. An incident investigation was conducted to determine the cause or causes of the incident. Per this investigation, the root cause was identified as Equipment Difficulty-Problem Not Anticipated. The recommendation from this investigation was to review disposition of Fuel Gas Absorber knock-out drum liquid. Report states this action was completed 6/27/12. Only states that SO2 emissions were above reportable quantities.
1.6 pounds