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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.
|Cause: There were multiple units that experienced upsets during the shutdown and startup activities surrounding Hurricane Isaac:
In preparation for Hurricane Isaac, the refinery units were at minimum rates anticipating a shutdown condition. As a result of these abnormal conditions, the refinery 150 PSIG steam header pressure was significantly low. The U205 Delayed Coker unit uses steam to purge resid and coke from the switch valve and ball valves on the coke drum structure. the low steam pressure ultimately led to the valve failing due to coke build up on the valve. On 8/28/2012 the unit was forced to go on bypass and internal circulation due to inability to switch feed to the offline drum. After the unit was on bypass the Wet Gas Compressor tripped three times. These trips resulted in releases to the flare. This resulted in a small amount of hydrocarbon material to be routed to the ground flare.
Propane Flaring: Due to atypical operating conditions and the shutdown of our third-party propane pipeline, MPC flared propane starting on August 31 at 06:52 AM intermittently until September 1 at 02:45 AM. The flaring of propane was required to balance refinery operations.
No reportable quantities were exceeded. The release calculations are provided in Attachment 4.
North Stick Flare Flame Outage: On September 1, the North Stick Flare flame was snuffed out with steam for a total of five minutes. This occurred while decreasing the amount of propane flaring mentioned above. No reportable quantities were exceeded. This event was reported verbally on September 1st and a follow-up written report was submitted on September 7, 2012 (see Attachment 5).
North Stick Flare Damage: The North Stick Flare was observed to have some abnormal flame patterns prior to Hurricane Isaac. However, during the hurricane it was noticed that one side of the flare tip had more significant flames. After the hurricane on September 11 th an inspection, via a remote helicopter, observed that a natural gas supply line to the pilots had a broken union.
This was causing natural gas to burn just below the flare tip. It is believed that the high winds experienced during the hurricane caused the union to completely break apart. A repair plan is being formulated to correct this issue.
MPC discharged untreated process area stormwater via Outfall 002 to the Lake Maurepas drainage system beginning on August 30, 2012 at 07:00 hrs intermittently until September 3, 2012 at 13:00 hrs. The amount of wastewater discharged is estimated to be 300,000 bbls (which is 12,600,000 gallons). Samples were collected prior to the discharge and after the start of discharge to verify that the water being discharged was sufficient quality to ensure no harm to environment. The discharge was monitored to ensure that there was no sheen on the water discharged off-site. It should be noted that prior to discharging the untreated process area stormwater, MPC had reached the on-site WWTP storage capacity of 619,995 bbls of water. In addition, MPC placed an out of service crude oil tank (500-2) back into service prior to the hurricane specifically to be used for wastewater and slop oil storage as needed. This tank was used for excess water storage prior to any wastewater being discharged off-site.|
Notes: This report is linked to two LDEQ incident numbers: 142430 and 142532. Unit 205 Coker sent to the North Ground Flare. The release was identified at approximately 06:35 hours on August 29. 2012 and lasted for approximately 1944 minutes (1d 8h 24m). The compound of concern was Propylene. Totals of 76.54 lbs and 86.15 lbs were released during the 2 24-hour periods involved. MPC considers these emissions to be covered under the temporary variance issued on August 27 of 2012. That variance authorized the temporary permit for the emissions: Sulfur Dioxide 13.3 tons; Nitrogen Oxide 0.9 tons; Carbon Monoxide 7.03 tons; Volatile Organic Compounds (VOCs) 8.51 tons; Hydrogen Sulfide 0.73 tons. There was also a variance for 3,750 long tons(8,400,000lbs) of sulfur to be stored on a "sulfur pad". These variances were considered the maximum allowed during that period, therefore they are not included in LABB pollutant totals in this report. As soon as conditions allowed, the compressor was restarted. Missed Monitoring/Repair/Inspections Due to the hurricane, personnel were not available to complete several regulatory required tasks, such as weekly inspections, PMs, monitoring, and repairs. The programs and the specific missed requirements are listed below: LDAR Program 5-day first attempt at repair requirement (five components) 15-day final repair requirement (twelve components) Waste Program Weekly satellite collection area inspection (two locations) Weekly hazardous waste storage area inspection Weekly non-hazardous waste storage area inspection Weekly universal waste area inspection Weekly used oil storage area inspection Stormwater Pollution Prevention Program Weekly refinery inspection Spill Prevention Control & Countermeasures Program Weekly inspection of the Contractor Village area MACT II - NSPS Subpart UUU Weekly PM for the pH meter used for compliance demonstration Benzene Waste Operation NESHAP Carbon Canister monitoring for breakthrough (eight events) 15-day repair requirement (four sumps) There is a separate report on this database for the sinking of the "Big Tuna" response boat. Response Boat Fuel Loss: The oil spill response boat became submerged in the Mississippi River on August 29th, due to a surge in the river level which resulted in the loss of ten gallons of gasoline. The reportable quantity for oil was exceeded. This event was reported verbally on August 31 and a written follow-up report was submitted on September 7, 2012 (See Attachment 3). (Attachment 3 was deleted from this file, and added to the report for this event)
|RBS Flare||Cause: False reading on the 66LT0511 level controller caused the two NC4 compressors to trip. The high pressure on the receiver, due to high liquid level, caused the 66PC0507 valve on the receiver to open the RBS flare. Approximately 6.67 lbs of VOCs were released as a result.|
Notes: The operator blew down transmitter 66LT0511 and opened the bypass valve on the receiver to send the liquid back to the RBS tank. The faulty level transmitter was taken out of service and repaired.
|North Ground Flare|
North Ground Flare, Heaters on Unit 243, Unit 43, and Unit 59
|Cause: According to the the 60-day report, the Triconix safety control system inadvertently tripped the Unit 247 Amine Unit Lean Amine Pumps. The pump shutdown caused lean amine to stop circulating to the Fuel Gas Treaters which caused high H2S-laden fuel gas to be sent to the Unit 243 Fuel Gas Drum. In addition, untreated fuel gas was sent to the Unit 43 Fuel Gas Mix Drum. The Fuel Fuel Gas Mix Drums were supplying fuel ga to 26 different process heaters and boilers with the refinery during the incident. As a result, each heater and boiler experienced an increase in SO2 emissions above the maximum allowable permitted lbs/hr rate. In addition, the Unit 247 Flash Drum overfilled into the vapor line to the Unit 210 Compressor Suction Drum, thus causing the compressor to temporarily shut down which resulted in venting to the North Ground Flare.|
Notes: The refinery Air Monitoring Team was dispatched inside and outside the refinery fenceline. All SO2 and H2S readings were non-detect except for one 4ppm SO2 reading on Marathon Avenue in the refinery. No elevated ambient air monitoring readings from MPCs four ambient air monitoring stations were detected during the event. Operations re-started the Unit 247 lean amine pumps and re-established amine circulation to the Amine Treaters. This recirculation brought the H2S amounts in the fuel down to acceptable levels. The reportable quantity for sulfur dioxide was exceeded during the event. In addition, the permitted SO2 and the NSPS Subpart J/Ja SO2 limit for the emission sources was exceeded for multiple hours. The opacity limits for the above listed heaters and boilers were exceeded. Report was unable to be uploaded. Recommendations made for the Root cause were:1) Human Performance- Revise the Unit 19 Start up procedure with more detailing events on when to the internal lean circulation line while starting up Unit 25 with the appropriate line terminology, label lines accordingly, and retrain operators with the revision. 2) Equitment Difficulty- Evaluate the design of the existing steam tracing for the analyzer, and recommend proper mitigation.
|Unit 259 South Ground Flare and Unit 259 North Ground Flare||Cause: The Unit 214 Kerosene Hydrotreater experienced an emergency shutdown at 16:18 hours on February 21, 2013. The process unit vented to the South Ground Flare for 94 minutes. The Unit 210 Crude Overhead Compressor shutdown at 16:39 hours on February 21, 2013 was re-started at 16:58 hours on February 21, 2013. The duration of Unit 210 venting to the North Ground Flare was 19 minutes.
On February 21, 2013, at 16:18 hours, a power failure caused the Unit 214 Kerosene Hydrotreater to experience an emergency shutdown. As a result of the event, liquid was carried over from Unit 214 to the Unit 210 Crude Overhead Compressor system. The 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.
The main parts of this accident were the emergency shutdown of the 214 Kerosene Hydrotreater and flaring from the Unit 210 Crude Overhead Compressor.
The causal factor for the Unit 214 Power Failure and subsequent emergency shutdown was determined to be Equipment Difficulty/Tolerable Failure. The Causal factor for the Unit 210 flaring event was determined to be Human Performance Difficulty/Management System/SPAC Not Used/Enforcement Needs Improvement.|
Notes: Power was restored to the Unit 214 Kerosene Hydrotreater and the unit was re-started. Liquid was drained from the Unit 210 Crude Overhead Compressor Feed Knockout Drum. The Unit 210 Crude Overhead Compressor was re-started. An incident investigation will result in recommendation items designed to prevent the recurrence of this event. In the 60 day follow up report dated 4/22/13, the following remedial actions were listed in response to the release: Unit 214 portion of the upset: 1) Maintenance corrective actions immediately following release. Electricians and instrument Techs responded to the Satellite building. Power panel 214-PP-B01 main breaker and substation 214-MCC-B01 were reset establishing power to the first power supply. 214-HVAC-B008 was repaired and brought back online. 2) Operations corrective actions after the release. Unit 214 board operator started procedures for shutting down unit. Unit 214 valves 214FC0007 (Heavy Coker Naptha Feed Valve) and 214FC0006 (Kerosene from tankage valve) were closed 15 minutes after the start of the release. Operations awaited Maintenance's confimation that the unit was ready to restart. Unit 210 portion of the upset: 1) Unit 210 operators followed the event reponse matrix to verify the compressor suction drum (210-1202) level, the compressor suction drum valve position, and whether or not the suction drum pumps were running. Operations than began working to get the level down in the suction drum in preparation for restarting the OFFGAS compressors. For the Unit 214 portion of the incident the following recommendations were made: 1) Update the Marathon Standard Practice to require a cicuit breaker cooridination study for all 480V power panel installations for future projects - due 12/31/13; and 2) Evaluate the cicuit breaker coordination for all existing 480V power panels throughout the refinery and determine necessary solutions to achieve coordination where required - due 8/30/14 3) For the Unit 210 portion of the incident the following recommendation was made: Review and Reinforce the Emergency Shutdown Procedures for Unit 214 with the Board Operators - complete. An additional followup on 10/23/13 corrected the initial followup report's emissions data regarding greenhouse gas releases.
|FCCU wet gas compressor first stage||Cause: A loose wire in a satellite building caused the Fluid Catalytic Cracking Unit (FCCU) wet gas compressor first stage spillback to open, which led to high fractionator pressure. The safety instrumented system (SIS) tripped the FCC unit on high fractionator pressure. During the FCC unit startup, the debutanizer pressured up and had to be vented to flare due to lack of heat in the upstream stripper reboiler (heating medium is BPA from the fractionator) which sent ethane to the debutanizer.
The flaring event due to the FCCU Shutdown began on June 7, 2014 at 14:37 hours and stopped on June 7, 2014 at 15.48 hours for a duration of 70 minutes. The flare event due to the FCCU startup began on June 7, 2014 at 18:21 hours and stopped on June 7, 2014 at 20:18 hours for a duration of 117 minutes. The total duration of the flaring was 187 minutes.|
Notes: The SIS system reacted as designed to shutdown the FCCU due to the opening of the compressor spillback valve. During FCCU startup the operating procedure was followed to minimize emissions to the extent possible. An incident investigation will result in recommendation items designed to prevent the recurrence of this event.