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Marathon Ashland Petroleum (3165), Garyville

Causal Factor: Equipment Design

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

Unit 34 termal oxidizer
Unit 34 thermal oxidizer
Cause: The Amine Unit 47 shutdown when amine circulation was lost because of a control valve failing to close.

Followup: No

Notes: The shutdown of Unit 45 Sulfur Recover unit reduced the acid gas (hydrogen sulfide-H2S) processing capacity by 1/3. To reduce the acid gas Marathon implemented "sulfur shedding procedures", involving reducing feed desulfurization units and the Coker . A manual bypass valve was opened to restore circulation. Sulfur dioxide limit (250 ppm) on Unit 34 thermal oxidizer and hydrogen sulfide limit 160ppm on the fuel gas system were exceeded.


Unit 59 North Flare
Cause: A root cause analysis is being conducted to determine why this incident occurred. The Louisiana Refining Division's Investigative Summary Report states that the initiating event was the troubleshooting common alarm on the Bently Nevada radial vibration proximitor card to include a module self-test for diagnostic information.

Followup: Yes

Notes: Operations restarted the Wet Gas Compressor. The root cause analysis will result in recommendation items designed to prevent the recurrence of this event. The refinery stated that lessons learned included: On a Bently Nevada 3500 system, a module self-test or replacement will cause the output signal to go to 0ma. If the output signal is wired to a Triconex system, it will report the transmitter as being an unreliable signal (bad transmitter of bad pv). VOC chemical breakdown is provided. Only the RQ for SO2 was exceeded during this release.
Sulfur Dioxide: 2,581.0 pounds
Nitrogen Oxide: 9.3 pounds
Carbon Monoxide: 50.5 pounds
Volatile Organic Compounds (VOCs): 82.2 pounds
Particulate Matter 10: 1.0 pounds
Particulate Matter 2.5: 1.0 pounds
Highly Reactive Volatile Organic Compounds: 7.8 pounds

Flow indicator 15FI0214
Cause: On May 19, the impulse lines on flow indicator 15FI0214 pulled away from the root valve. Blow taps on the valve blew off and released make-up hydrogen to the atmosphere. The causal factors leading to the failure of the tubing was Equipment Difficulty/Design Specs/Problem Not Anticipated. There were issues with the metallurgy of the tubing and the elevation of the transmitter in relation to the orifice taps.

Followup: Yes

Notes: Water from the fire monitors was sprayed on the release to help disperse the gas and prevent ignition. The board operator began depressurizing the unit through the dump valve in preparation for emergency shutdown. The line was isolated from the rest of the process unit to prevent further release of make-up hydrogen. To prevent recurrence, the following recommendations were made: 1) relocate the transmitter above the orifice taps on 15FE0214, and 2) replace stainless steel components of 15FT0214, including the impulse tubing with Hastelloy to prevent chloride-induced stress corrosion cracking. Also to tag the instrument tubing to indicate that the material is Hastelloy. Approximately 6.214 pounds of compressed flammable gas and 28 pounds of hydrogen sulfide were released.
Methane: 829.2 pounds
Ethane: 797.6 pounds
Propane: 1,063.9 pounds
n-Butane: 382.4 pounds
Isobutane: 412.7 pounds
n-Pentane: 105.5 pounds
Pentene Plus: 556.6 pounds
Hydrogen: 1,847.9 pounds
Hydrogen Sulfide: 28.8 pounds
Isopentane: 218.5 pounds

Marine Vapor Combustor Hydroseal Pot
Cause: The release occurred when the suction line from the Marine Vapor Combustor Hydroseal Pot disconnected from the hose fitting causing spill of diesel fuel to the ground. Approximately 3.71 barrels of diesel fuel was released onto the ground.

Followup: Yes

Notes: The suction line was reattached and secured by the operator as soon as the spill was discovered. An incident investigation was conducted to determine the cause or causes of the incident. Per the investigation, the root cause was identified as Design/Understanding need Improvement. The following recommendations will be implemented: 1) Coach/Train operators on the requirements of tying down cam lock fittings. 2) Evaluate installing a second hydroseal pump or a larger pump to maintain hydroseal drum level. 3) Train dock operators on header flushing procedure changes to prevent hydrocarbon from accessing the vapor system. 4) Evaluate installing a check valve between the dock drain piping and the separator 5) Coach/Counsel supervisors on the expectations of spill reporting. All of the recommendations are to be completed by July 18, 2013.
Diesel Fuel: 1,079.0 pounds

Unit 259 North Ground Flare
Cause: 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.

Followup: Yes

Notes: 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.
Sulfur Dioxide: 3,385.0 pounds
Methane: 1.5 pounds
Ethane: 21.6 pounds
Ethylene: 0.4 pounds
Propane: 74.3 pounds
Propylene: 1.5 pounds
n-Butane: 54.6 pounds
Isobutane: 22.2 pounds
1-Butene: 0.4 pounds
trans-2-Butene: 1.2 pounds
cis-2-Butene: 0.1 pounds
n-Pentane: 6.6 pounds
Pentene Plus: 1.7 pounds
Carbon Dioxide: 215.8 pounds
Carbon Monoxide: 79.4 pounds
Hydrogen: 0.0 pounds
Nitrogen: 0.3 pounds
Hydrogen Sulfide: 36.7 pounds
NOx: 14.6 pounds
Volatile Organic Compounds (VOCs): 168.6 pounds
Particulate Matter 10: 1.6 pounds
Particulate Matter 2.5: 1.6 pounds
Highly Reactive Volatile Organic Compounds (HRVOCs): 1.9 pounds