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ExxonMobil Chemical Plant (286), Baton Rouge

Releases of Hexane

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

flare seal drum
Cause: Release from a very small pinhole leak in a ten-inch header to a flare seal drum.


Notes: Amount of pollutants released is unknown. Believe that the amount of release will not break the RQ but are unsure.

Cause: As a result of Hurricane Gustav the Baton Rouge Resins Finishing Plant (BRFP) experienced significant facility damage and power interruptions that required operations to safely shutdown. Hurricane Gustav is clearly considered an "act of god." The Baton Rouge Resin Finishing Plant only had generators for electrical power to maintain a small number of instruments and critical pumps. There was no power available for the compressors that collect vent gases from storage tanks and route them to the site's flare. The seal leg on the flare seal drum prevented the relatively small breathing losses from reaching the flare for combustion. The flare pilots were extinguished during the storm but we have established the ability to relight it. However due to natural gas supply availability and the inability to route the vent streams to the flare tip we elected to allow the flare pilots to remain unlit until we restored power to the vapor recovery compressors. Power was restored to BRFP at 230 pm on 9/6/08 and the flare pilots were relit. All tanks that were venting to the atmosphere were routed to the flare.

Followup: No

Notes: BRFP was safely and systematically shutdown due to hurricane Gustav. Learning from this event will be incorporated into future hurricane preparations. BRFP was unable to complete some of the timing obligations due to Hurricane Gustav. It has prevented from meeting all the timing obligations of the required September monitoring. At the time the primary focus of mechanical resources was on storm related repairs to enable safe startup of unit operations. The plant was to accomplish the LDAR monitoring within the next 60 days. In addition, the availability of parts is also a difficult logistics problem so the focus was on their resources toward startup. BRFP was safely and systematically shutdown due to Hurricane Gustav. Learnings from this event will be incorporated into future hurricane preparations. .
584.0 pounds


WILA tanks #8 and 9
Cause: The release was caused by the pumping of low flash material into WILA Tanks 8 and 9. The material evolved a greater amount of vapor than the tank's vapor recovery system could manage. The evolution of the vapor caused the pressure in the tanks to exceed that of the pressure vent set point.

Followup: No

Notes: Introduction of low flash point material into these tanks was immediately halted. They could not expect the flash material to evolve too much vapors. Tanks could not handle the vapors and valve lifted. Operators will be trained to communicate better to prevent the overpressure happening again. RQs exceeded for benzene. Total release of hydrocarbons is 600 pounds.
37.0 pounds

RL-1 Cooling Tank
Cause: Heat exchanger E-110A of the halobutyl rubber unit was determined to be the source of the leak and was isolated to stop the release.

Followup: No

Notes: Routine halobutyl unit hexane inventory monitoring performed on July 19th revealed potential hexane losses, investigation was initiated. Standard initial evaluations of data validity and material balances were performed. Operational investigation into the loss was also completed, included surveying the area using an optical imaging camera and testing the cooling water for Total Organic Carbon content. Unit material balances revealed potential hexane release began on July 12th, and leak rate calculations were completed utilizing normal engineering calculations of hole size, leak rate, and total release since July 12th. As requested by LDEQ, Industrial Hygiene monitoring was performed at the cooling tower upon discovery of the leak. This monitoring established there were no offsite impacts as a result of this release. This incident is under investigation to determine the root cause and prevent recurrence. The exchanger will be returned to service.
225.9 pounds

Halobutyl Finishing Unit
Cause: A thermocouple failed, which resulted in the release. Halobutyl Finishing Unit Thermotreatment unit tripped.

Followup: No

Notes: The thermocouple was replaced allowing the unit to be restarted around 8:30am. no injuries, complaints, or offsite impact resulted from this event. Amount of chemicals released is unknown. After evaluation, it has been determined that all emissions were permitted and no reportable qualities were exceeded.

Cause: Several title V operating permit compliance matters and potential RQ exceedances resulting from upset conditions caused by Hurricane Isaac: During a post-hurricane Isaac storm survey, the PV vent on Tank 867 was discovered leaking. Emissions from the PV vent were approximately 49 pounds of flammable vapor. During a post-hurricane Isaac storm survey, socks on floating roof tank 783 were found missing and/or torn as a result of high winds. The missing/torn socks were replaced on September 19, 2012. Emissions from the missing/torn tank socks were approximately 1.9 pounds of VOC. During a post-hurricane Isaac storm survey, multiple tank hatches were discovered either missing or open as a result of high winds. Due to Hurricane Isaac, the Continuous Emissions Monitoring System (CEMS) analyzers may have experienced less than 90% data availability. Also the data calibration drift check on the analyzers may have been missed. The HFU TTU was bypassed for approximately 1 hour due to failure to maintain TTU temperature of 1600 degrees Fahrenheit. This bypass resulted in approximately 0.08 tons of hexane being released.

Followup: Yes

Notes: There were several compliance matters and potential RQ exceedances resulting from upset conditions caused by Hurricane Isaac. The PV vent on Tank 867 was repaired and returned to service on September 5,2012. The missing socks on tank 783 were replaced on Septermber 19, 2012. The tank hatches that were discovered missing were replaced as soon as possible to prevent any further emissions to the atmosphere. The tank that were found open were closed and remonitored using the HAWK camera. In attachment 1 of the written notification you will find a summary of the emissions from the tank hatches that were discovered missing or open. remediation of Continuous Emissions Monitoring System (CEMS) - EMCP is working to determine the extent to which the CEMS analyzers may have malfunctioned before, during, and after the storm. This information will be included in the CEMS quarterly report. HFU TTU was bypassed for approximately 1 hour resulting in a hexane release. The letter from EMCP asks that LDEQ exercise enforcement discretion and no such penalties be issued for actions and events related to Hurricane Isaac response and recovery efforts. LABB has the 30 day follow up report, as well as the subsequent LDEQ verbal report, but no subsequent written notifications that serve as a follow up to clarify the total pollutants released from the tank hatches that still needed to be repaired as of the October 4th written notification.
160.0 pounds

Tank 21 and Rain Basin 1
Cause: A failed bleeder plug was found at Tank 801 in the BRCP's Aromatics Tankfield. Approximately 411 barrels of steam cracked naptha reached the sewer system via this bleeder. All material was retained in waste water treatment facility. While the naphtha was being pumped to tanks #778, #26, #22 and #21, a rain event occurred, which overwhelmed the facility's ability to pump the liquid to the tanks. Therefore, the material was diverted to the Rain Basin I surface impoundment. Of the water pumped into the basin, there were 1,712 lbs of benzene and 419 lbs of toluene.

Followup: Yes

Notes: The water was to be pumped to the waste water treatment plant for treatment before being discharged to outfall 001. Firefighting foam was placed on top to reduce volatilized chemicals. Half the materials spilled were recovered. All values are based on the vaporized material and represents a very small amount of loss. The material is being pumped and moved to onsite storage to facilitate recovery and treatment of the material. All recovered liquid material is being placed in tanks 778, 21, 22, and 26, all of which are properly configured and permitted to store this material. On June 14, 2012, the site began the process of understanding the constituents of the steam cracked naptha that may have been released to the air by performing material balance calculations. During the first 24-48 hours of the incident response, the intial assumptions were that a majority of the material was being contained with minimal evaporative losses. Emissions reporting was based on the initial vaporization of material from the leak duration. Sample of the stored and liquid material were collected from multiple areas and storage facilities to help develop a more definitive material balance of the total steam cracked naptha released. As a precaution, at 1230pm on Jun 14, 2012, approximately 400 employees and contractors in the impacted areas of the complex were tested for potential exposure. ExxonMobil believes that none of these individuals will have any adverse impacts. The site conducted regular monitoring at the fence line every four hours and in three unit areas on an hourly basis during the incident response activites. All fence line readings remain below detection. ExxonMobil Industrial Hygiene personel continue to conduct air monitoring and are verifying safe conditions for areas were personnel are working. Fenceline monitoring will be conducted until the steam cracked naptha material in tank 21 and RB-1 have been treated through the Refinery Wastewater Treatment facilities. Firefighting foam was added to the sewer system every 1-2 hours to minimize the amount of evaporative losses. This foam did not impact wastewater treatment operations or capabilities in the quantities utilized during this incident.
2,588.0 pounds