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Motiva Enterprises (1406), Norco

Causal Factor: Instrument Failure

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

Coker Unit
Cause: Incident was due to a level controller malfunction.

Followup: Yes

Notes: A level controller malfunctioned, allowing the liquid to go into a blowdown system which vents into the atmosphere. About 15 barrels of crude was released and contained. Unknown quantities of Xylene and Hydrogen Sulfide were released.


West Ops Ground Flare (EPN #9-84)
Cause: An overhead analyzer and a differential pressure meter that normally monitor and control the propylene producing column were out of service for maintenance and inspection. Without these two indicators operations could not effectively tell if the column was operating properly. The production of unspecified product led to flaring. Flaring by GO-1 at Motiva's West Operations Ground Flare occurred due to Shell Chemical's GO-1 operations being asked to discontinue sending material to OL-5 until the process was back in control.

Followup: No

Notes: Called in by telephone on 07/25/2005 by Shell Chemical. Remedial actions: Material was flared at the West Ops Ground flare. Motiva maintains they were not in control of the incident and that a follow up letter was sent by Shell Chemical.
Carbon Monoxide: 123.0 pounds
Nitrogen Oxide: 209.0 pounds
Particulate Matter: 29.0 pounds
Volatile Organic Compounds (VOCs): 143.0 pounds
Butadiene: 17.0 pounds
Benzene: 8.0 pounds
Toluene: 1.0 pounds

F-485 Motor Alkylate Tank
Cause: The incident was due to the inadvertent landing of the external floating roof of tank F-485 onto its legs due to low gauging. The F-485 motor alkylate tank was low gauged and set on its legs, causing two 2" vents to open to the atmosphere for a duration of 12 minutes.

Followup: No

Notes: No information given.

Volatile Organic Compounds (VOCs): 1.1 pounds

Relief valve
Cause: It's believed the computer control caused an upset which opened a relief valve to the flare.

Followup: Yes

Notes: Motiva shut down the NHT unit and investigated the problem. The relief valve was blocked in and removed, then shipped for repaired.


HCU flare EPN 4-84
Cause: There was an instrument failure on the Hydro-cracker Unit (HCU) recycle gas compressor (K-1928). Because of this instrument failure excess flaring from the HCU flare (EPN 4-84) allowed release of the following gases: propylene, VOC's , and Nitrogen Oxides. Note: there were two follow up reports provided. The first followup report on 10-29-2009 was written to respond to a verbal notification. This report stated that ongoing sampling would be conducted. The second report on 11-19-2009 was written to report findings from sampling conducted at the incident site

Followup: Yes

Notes: after the flaring incident was noticed the HCU recycle gas compressor was shutdown and repairs were done to fix the speed controller .


incinerator stack in sulfur plant
Cause: there was an air trip transmitter failure that caused the Sulfur-3 unit to trip online unexpectedly. Due to this online trip, a release of sulfur dioxide (SO2) into the air occurred from both the S-3 and S-2 tail gas incinerators .

Followup: Yes

Notes: The sulfur gas was diverted from the S-3 unit to the S-2 unit. The transmitter was repaired by maintenance so that the S-3 unit could become fully operational. it was noted that material went offsite as the sulfur material was released into the air


Light Olefins Feed Tank
Cause: A tank being de-invetoryed Light Olefins Feed (derivitive of crude oil) the product being sucked out using a on site vaccumm truck overfilled and an overflow isolated a leak when the gauge failed. Approximately 84 gallons of Light Olefins Feed(benzene/toluene) relaeased.

Followup: No

Notes: LDEQ provided but no Refinery Letter included. Motivca states that "the spill was contained and cleaned within secondary containment." Contained in a dike and a vacuum truck was already on site for the procedure.
Crude Oil: 84.0 gallons

4-84 Hydrocracker Flare (FE-301)
Cause: On September 3, 2013, the first and second stages of Motiva's Hydrocracker Unit (HCU) shut down. The shutdown was caused by an instrumentation failure that controlled the lube/seal oil system for the HCU recycle compressors. On September 6, 2013, the Hydrocracker unit began startup operations.


Notes: Immediately after the unit was shut down and secured, maintenance and engineering immediately investigated and identified the instrumentation failure. The instrumentation and engineering groups are developing an inspection list for the next planned unit shutdown to look for deficiencies in the unit instrument systems. No reportable quantities were exceeded; however the permitted maximum hourly emission rate limit was exceeded for Benzene and Sulfur Dioixide.
Benzene: 0.9 pounds
Carbon Monoxide: 4,057.1 pounds
Hexane: 13.4 pounds
NOx: 745.6 pounds
Particulate Matter 10: 140.4 pounds
Sulfur Dioxide: 252.8 pounds

Volatile Organic Compounds (VOCs): 1,964.5 pounds

Residual Cat Cracking Unit
Cause: On September 5, 2014 Motiva Enterprises in Norco reported a potential release of n-butane adn 2-butene. On August 14, 2014 the Residual Cat Cracking Unit (RCCU) had an unanticipated flaring event at the RCCU Elevated Flare when the RCCU's Debutanizer Overhead Accumulator began to unexpectedly overpressure. Pumps located at the Debutanizer received a false indication that a valve was in the closed position causing the pumps to shut down. Once the pumps shut down, the liquid level in the Debutanizer Overhead Accumulator increased with the unit column pressure. The valve on the Debutanizer Overhead Accumulator was opened to the flare to relieve the column pressure and to prevent any relief valves (RVs) in the unit from relieving to the atmosphere.

Followup: No

Notes: Operations investigated and verified that the system reading was false and the valve was not closed. Action was taken to bypass the valve and the pumps were able to start again. Once the pumps were restarted, the pressure stabilized in the unit and the flaring stopped. The electrical department investigated the issue and discovered that the wiring was no longer in good condition. The electrical department replaced the wiring to the pump valve indicator.
Carbon Monoxide: 497.3 pounds
NOx: 91.4 pounds
Particulate Matter: 17.2 pounds
Sulfur Dioxide: 7.8 pounds
Volatile Organic Compounds (VOCs): 321.4 pounds