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|LDEQ Accident Number
|Point Source(s)||Notes||Amount of Release|
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.|
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.
Unit 59 North Flare
|Cause: The initiating incident was a pump seal fire in the Gasoline Desulfurization Unit (Unit 55). The fire was fueled by a leaking seal on the pump. Extinguishing the fire was delayed by inability to close an EIV on the suction side of the pump. This resulted in emergency shutdown of the unit. Two other events also occurred on this day including an upset in Sulfur Plant Unit 234 and a flame-out of the North Flare. Due to the fire and emergency shutdown of the Gasoline Desulfurization Unit, the Fluid Catalytic Cracking Unit cut feed, sending vent gas to the North Flare. Process vent gas was sent to the North Flare which increased the steam to the flare suddenly, snuffing the flare out.|
Notes: PDF too large to upload (109 pages) To re-light the North Flare, steam was gradually decreased and natural gas was added to the flare gas to allow the two available igniters to relight the North Flare. Parts to repair the North Flare pilot system were already on order when this incident occurred. The North Flare was taken out of service when the parts were received and repaired on October 31, 2012. Spare pilot and igniter assemblies are now in stock so that repairs can be made in a timely fashion if an incident like this is to occur again. Total amount of pollutants released was 59438.44 lbs, but 90% was claimed to be efficiently burned off, resulting in 5943.59 lbs that were actually released. The reportable quantity for Highly Reactive Volatile Organic Compounds (HRVOCs) (100 pounds) was exceeded during the 24 hour period.
|RBS Flare||Cause: The pressure safety valve for Tank 250-2 had opened, so the operator blocked in the PSV.|
Notes: No offsite impact was associated with the event.
|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.|
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.
|No LDEQ Reported|
|Unit 250 North Ground Flare||Cause: On July 24, 2013, the Unit 210 Crude Overhead Compressor shut down at 16:11 hours and was restarted at 16:26 hours. A second shutdown occurred at 16:48 hours and was restarted at 17:02 hours. A third shutdown occurred at 17:25 hours and was re-started at 17:56 hours. The duration of Unit 210 venting to the North Ground Flare was 60 minutes.
Approximately 613 pounds of sulfur dioxide were released (over the reportable quantity of 500 pounds).|
Notes: Liquid was drained from the Unit 210 Compressor Suction Drum. The Unit 210 Crude Overhead Compressor was re-started. A very similar event occurred on March 25, 2013 with emissions from the same point source. This report retrieved from EDMS was labeled with the LDEQ number corresponding to the March 25, 2013 incident (LDEQ # 147603). The March 25th event also involved multiple shutdowns of the Unit 210 Crude Overhead Compressor, and the report labeled that event as preventable. It is interesting to note that a similar event labeled preventable occurred less than four months later.
|No LDEQ Reported|
|Crude Unit Overhead Accumulator||Cause: On July 21, 2013, an overpressure condition in the Crude Unit Overhead Accumulator due to the shutdown of the Sats Gas Unit.|
Notes: An initial report for this incident, which included details on what happened and what pollutants were emitted in what quantities, was submitted to LDEQ on July 26, 2013. This follow-up report corrects emissions data submitted by Marathon which originally included greenhouse gas emissions in the incident calculations.
|Unit 259 North Ground Flare||Cause: On July 15, 2013, due to a crude oil switch, a high level occurred in the Unit 222 Sats Gas Plant (SGP) Compressor Suction Drum which caused the Sats Gas PLant Compressor to temporarily shutdown. This resulted in some flaring of the overhead gas to the North Ground Flare for about 55 minutes.
The first incident began at 09:05 hours on July 15, 2013, and was secured by 10:00 hours. The second incident began at 19:32 hours on July 15, 2013, and was secured by 19:33 hours.|
Notes: For Incident 1, the level in the Sats Gas Plant Compressor Suction Drum was lowered and the Sats Gas Plant Compressor was re-started. For Incident 2, operating personnel made operating changes to the unit to bring it out of upset conditions. These incidents will be investigated and an action plan to prevent recurrence will be generated. Follow up report submitted 10/23/13 states that original report included Greenhouse Gas emissions, however these emissions are not required to be evaluated for reportable quantity because they are not permitted pollutants. The report updates the calculations without greenhouse gases included.
|Unit 259 North Ground Flare||Cause: ON July 15, 2013, an upset in Crude Unit 210 caused the Crude Compressor Suction Drum to vent to the North Ground Flare for approximately one minute.
The first incident was due to a crude oil switch causing the Unit 22 Sats Gas Plant Compressor to shutdown on high level. The second incident was due to an upset in the Unit 210 Crude Unit that cause the Unit 210 Crude Compressor Suction Drum to vent to the North Ground Flare.|
Notes: Operating personnel made operating changes to the unit to bring it out of upset conditions. October 23, 2013 additional follow-up report corrects emissions data submitted by MPC. MPC erroneously included greenhouse gas (GHG) emissions in the incident calculation. GHGs are not permitted pollutant and are not required to be evaluated for reportable quantities.
|Unit 259 North Ground Flare||Cause: Unit 222 Sats Gas Plant experienced an upset due to an over-pressure condition on the debutanizer column. As a result, pressure relief valves lifted, sending debutanizer overhead material to the refinery's North Ground Flare. Root cause was a faulty pressure transmitter.|
Notes: The Board Operator decreased pressure on the debutanizer column. The faulty transmitter was replaced. Initial reports from January, 2013 stated no permit limits were exceeded concerning released pollutants. Final calculations from April 4, 2013 determined otherwise.
|Cause: An emergency shutdown device was triggered due to an incorrect reading on the Treating Reactor Bed 3 temperature indicator in the U215 hydrocracker which depressurized the unit to the South Ground Flare. In response to the shutdown, operations utilized the refinery slop line to deinventory the unit, routing material to Tank 500-6. Natural gas was inadvertently routed through the refinery slop line where Tank 500-6 received the vapor, causing a release through the tank seals.
Human factors also played a role in the incident.|
Notes: Root causes identified as Equipment Difficulty-Design Specs and Procedures Followed Incorrectly. At the time of the release, the emergency shutdown system was activated as designed shutdown the hydrocracker. Multiple recommendations have been identified to prevent a recurrence. The Tech Services Department at MPC has been tasked with mitigating the hazards of a single point of failure due to false temperature indication (anticipated completion 1/31/15). The operations department will develop and implement a system to verify all steps are completed and signed off when following procedures. A team will be developed to conduct a hazard analysis on the entire refinery slop system to implement necessary safeguards to prevent unwanted material from entering the slop system.
Railcar Inlet Valve
|Cause: After loading a propylene railcar, the operator noticed that the inlet valve was leaking and could not be closed. The railcar was depressured to the flare so it could be disconnected and the valve repaired.|
Notes: None. The contents of the railcar were vented to the North Flare Stack. The railcar was sent for repairs.
|Unit 59 North Flare (EQT#0162)||Cause: During propylene truck offloading activities, truck rack personnel began the normal Unit 65 process by opening a line to the flare to begin the transfer process. The line should be closed after the transfer to storage begins. However, the Unit 65 personnel failed to close the flare line and an amount of material went to the flare instead of to storage.|
Notes: Upon discovery, the line that was open to the flare was closed and the procedure was reviewed with the operator to prevent reoccurrence.
|Unit 212 platformer, reactor 2 outlet flange||Cause: On January 16, 2014, at 02:58 hours during the Unit 212 Platformer shutdown procedure, an H2 leak developed from the Reactor 2 Outlet flange during the H2 sweep cooldown step, which resulted in a flange fire.|
Notes: Steam was applied to the flange to extinguish the flame and the flange was hot bolted to secure the leak. The reactor circuit was depressured to the south ground flare, which took approximately 30 minutes.