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|LDEQ Accident Number
|Point Source(s)||Notes||Amount of Release|
|Includes U21, U43, U55, U212, and U243||Cause: On 10/21/11 the Propane Shipping Pump, 63-1537-01, was shutdown due to vibration problems which limited propane throughout the refinery. Operations made moves to cut charge rates and lined up the propane to the fuel gas system. Intermittently flared from Units 21, 43, 55, 212, and 243. No known off site impacts. Incident investigation is being conducted to determined the why the incident occurred.|
Notes: Opened 21P6431C, sweet fuel gas valve to flare to reduce pressure on fuel gas header and lower the level in 43-1202 (3:22am -4:09 am) bullet. Unit 63 shutdown propane shoppin pump, 63-1537-01, and U22 & U222 propane was routed to the bullet, 21HC6431 sweet fuel gas valve opened to the south flare from (8:21 am - 3:30pm). Fuel Gas Mix Drum 243-PC-0180B opened to flare due to Unit 205 sending excess propane to fuel gas header. Valve opened intermittently during this time from (11:15 am- 4:28pm) not opened above 10%. C3 propane from Domains 1 and 9 in refinery fuel gas causing high fuel gas pressure and 43PC5355 opened to flare three times (11:20am-11:30am), (11:53am-12:20pm), (12:45pm-1:05pm). Unit 55 Flare sweet refinery fuel gas from C3 propane in RFG Domain 1 and 9, 10/22/11 (11:28 am -3:55pm), 10/22/11 (7:42pm)- 10/23/11 (4:07am). An incident investigation will result in recommendation items designed to prevent the recurrence of this event. Values for carbon monoxide and nitrogen oxides do not match the sum of the daily reports. They are higher than the sum of the reportable values.
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.
|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.
|Unit 259 North Ground Flare||Cause: On April 20, 2013 the Unit 210 Crude Unit experienced an upset due to a change in the incoming crude state. The flaring in U210 and U222 associated with the upset started at 7:12 AM on April 20, 2013 and was complete at 8:35 AM on April 20, 2013. The duration of Unit 210 and 222 venting to the North Ground Flare was 83 minutes. Approximately 75 pounds of sulfur dioxide were released.
The Unit 210 Crude Unit experienced an upset due to a change in the incoming crude state. The incoming crude had a greater quantity of light components as well as some water. The upset resulted in high liquid levels in vessels upstream of the crude off-gas compressors and the sals gas compressor. In order to minimize the amount of liquid sent to the compressors, which could cause a shutdown of the compressor, a portion of the liquid generated in the upset was routed to the North Ground Flare knock out drum. This action reduced the severity of the incident.|
Notes: The crude tank line up was modified to remove the tank thought to be the cause of the water and light ends going to the Crude Unit. In addition, the crude charge rate was reduced to help manage the unit upset. The routing of liquids to the flare knock out drum was an attempt to minimize the results of the upset and prevent equipment shutdowns which would ahve resulted in a much more significant release. An additional followup on 10/23/13 corrected the initial followup report's emissions data regarding greenhouse gas releases.
|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.|
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.
|Sour Water Tanks in Units 33 and 233||Cause: 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.|
Notes: 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.