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Valero (26003), Norco

Releases in 2011

LDEQ Accident Number
Accident Date
Point Source/Release CauseNotes

Point Source(s):

Hydrogen Sulfide - 0
Benzene - 0
Propylene - 0
Volatile Organic Compounds (VOCs) - 0
Cause of Problem: Process Upset

On 11/19/11, Valero was starting up the Fluid Catalytic Cracking Unit (FCCU) after a power failure tripped the unit. At approximately 2:30 am while start up was in progress, Valero made a notification of startup flaring and that the roof and seals of Tank 67-1 had been damaged resulting in elevated levels of Hydrogen sulfide. Benzene and VOCs being emitted. As a result of the damage of Tank 67-1, hydrogen sulfide and total VOC's including benzene and propylene may have exceeded their respected reportable quantities. Emission calculations for this event are pending and will be included in a subsequent report. Limits for opacity were exceeded in these flares #1 and #2. Liquid vapor pressure on T-67-1 exceeded 11.1 psi.
Emissions from the refinery flares and Tank 67-1 were lost to the atmosphere and dispersed. Tank Farm Operators moved quickly to inspect Tank 67-1 and activated vapor suppression safety equipment. Operational moves were made to isolate the tank from service and air monitoring was conducted in the tank farm, at the facility fence line, and west of the facility. Supression foam was placed on the tank roof to suppress any vapors and the tank contents were mixed with lower vapor pressure material in order to reduce the overall vapor pressure of the stored liquid. Utility Operators maximized steam to the refinery flares to mitigate visible emissions resulting from the ongoing FCCU startup. NO Ldeq, SPOC report. No follow up.

Point Source(s):
Tank 130-8

Vacuum Gas Oil - 840 gallons
Cause of Problem: Piping or Tubing

On 11/1/11 Valero discovered that the suction line to tank 130-8 had developed a leak and had spilled approximately 20 bbls of vacuum gas oil (VGO) to the tank containment dike. A vacuum truck was used to recover pooled fluids, and the damaged section of line was repaired. Tank 130-8
Valero contained the spilled VGO within the tank dike and collected it with vacuum trucks. They verified that the dike drain valves were closed and immediately shutdown the transfer at the tank. They mobilized the onsite vacuum trucks to remove emulsified oil and water from he dike containment area of tank 130-8. A third party OSRO was mobilized to assist in the final cleanup. Also, approximately 86 tons of recovered waste was characterized and disposed of at a non-hazardous landfill. All VGO that was pumpable was collected and returned to the refining process. They developed the corrective following actions to prevent recurrence: (1) Inspect all tanks and piping in the tank farms to confirm no additional expansion joints of this type are in service. (2) Establish an inspection schedule for all hose and expansion joints in the tank farm, Batture, and loading locks. (3) Establish a schedule to replace hoses with engineered metallic expansion joints in the tank farms, batture, and docks.

Point Source(s):
Cooling Tower 800

Benzene - 1,027 pounds
Volatile Organic Compounds (VOCs) - 37,495 pounds
Cause of Problem: Corrosion

While conducting routine El Paso Method cooling tower monitoring on 10/4/11, Valero detected elevated hydrocarbon levels at Cooling Tower-800 (CT-800) but these were not above reportable quantity. They began manually sampling coolers and heat exchangers serviced by CT-800 in an attempt to identify the source. On 10/6/11 a Gasoline Desulfurization Unit (GDU) exchanger showed indications of a leak and it was isolated and removed from service. However, conditions did not improve and continued sampling revealed a leaking exchanger in the Fluid Catalytic Cracking Unit (FCCU). Once removed from service on 10/6/11 conditions in CT-800 returned to normal. Valero estimated that the RQ's for benzene and VOC's were exceeded on 10/6/11 based upon El Paso monitoring results collected that day. The leading exchanger bundle was inspected and results suggest the leak was due to low cooling water velocity and under deposit corrosion.
VOCs were released from CT-800 and dispersed. The heat exchangers believed to be leaking were isolated from service. Sampling was conducted at the cooling tower and at exchangers until emission rates returned to normal. The following corrective actions were identified to prevent recurrence of this event: (1) Re-analyze past exchanger inspection results and confirm recommendations. (2)Increase the frequency of calibration of residual chlorine analyzers on all cooling towers. (3) Improve exchanger leak identification training and internal reporting. The weather during this incident was a sunny, 81 degrees, with a wind speed of 7 mph.

Point Source(s):
3700 and 30 SRU

Sulfur Dioxide - 1,334 pounds
Hydrogen Sulfide - BRQ
Cause of Problem: Instrument Failure

The sulfur dioxide levels at 3700 and 30 unit thermal oxidizers were elevated due to failure of a pressure transmitter on the 3700 unit overhead accumulator. Valero estimated that the RQ for sulfur dioxide was exceeded at approximately 1:10 am and the RQ for hydrogen sulfide was not exceeded. The failing transmitter gave false indications in both the overhead accumulator pressure and the stripper overhead pressure. This prompted operational moves in the unit to shift loads in an effort to return the SRUs to stead operation.
After the local pressure gauges in the field were verified, it was determined that a single pressure indication was malfunctioning and operational moves were made to restore normal operating conditions. The following corrective actions were identified to prevent recurrence of this incident: (1)Repair both the overhead accumulator and the stripper overhead pressure transmitters and have separate pressure readings on the DCS. (2)Revise the DCS page to reflect both pressure indications. (3) Ensure the DCS and logic changes are covered by the management of change (MOC) process. (4) Conduct training with Operators on this incident. (5)Have the pressure control valve 37-4182-A inspected during the 2014 turnaround.

Point Source(s):
Coker "A" drum

Hydrogen Sulfide - 192 pounds
Volatile Organic Compounds (VOCs) - 564 pounds
Methane - 927 pounds
Ethane - 454 pounds
Cause of Problem: Process Upset

Process vapors were released through a crack in the Coker "A" drum, the integrity of which is included as part of the preventative maintenance program. Therefore, this event qualifies as a reasonably unforeseeable upset. The crack occurred at an elevated altitude, and process vapors were completely dispersed near the vicinity of the Coker structure where the release occurred. The refinery estimated that 85% of the release was steam, since the product was well into the quenching portion of the process.
Emissions from the drum crack escaped to the atmosphere and were dispersed. The refinery shifted from 4-drum to 3-drum operation and reduced charge rates as appropriate. As of 10/14/11, the cracked drum has been repaired and returned to service. New engineering data indicates that designs that include a thicker sidewall will provide superior performance and minimize any vessel cracking. The refinery has purchased these drums, and they are on schedule for installation (replacing the old drums) in the first quarter of 2012. The refinery also has a program of routine non-destructive testing that attempts to predict potential problem areas in these drums.

Point Source(s):

Sulfur Dioxide - 170 pounds
Isobutane - 27,893 pounds
Cause of Problem: Process Upset

A higher capacity pump was used on June 17th, the night before the incident, to pump down the level of spent sulfuric acid in the alkylation unit degassing drum to T-50-3 and exceeded the capacity of the tank's thermal oxidizer (TO). When the pressure exceeded the PVRV set point (24 oz/sq inches) the accumulated gases were vented to the atmosphere. Tk50-3
The flow of spent acid from the alkylation unit to T-50-3 was stopped allowing the pressure within the tank to decrease below the set point of the PVRV. The PVRV was subsequently monitored to check that it had completely closed after the pressure decreased to normal levels. Valero identified the following corrective actions: (1) Install downstream flow monitor on spent acid rundown line so operators can monitor the rate of spent acid rundown. (2) Reroute acid pot flush from the degassing drium to the spend acid settler to reduce hydrocarbon carry through. (3) Maintain level in the spent acid degassing drum at 20% or greater when pumping to T-50-3. (4) Set alarm on the spent acid Coriolis meter density to stop or reduce spent acid flow when hydrocarbon carry through appears likely. (5) Evaluate increasing PVRV set pressure from 1/5 psig on T-50-3. (6) Evaluate increasing the size of the TO on T-50-3 to handle additional vapor load.

Point Source(s):
1600 TOX

Sulfur Dioxide - 973 pounds
Cause of Problem: Equipment Failure

Due to failure of a pressure relief device, the refinery's 1600 TOX tripped and resulted in elevated sulfur dioxide levels. They estimate that the reportable quantities for sulfur dioxide were exceed around 10:45 am on 5/27/11. Based upon a failure analysis conducted by the manufacturer, it is believed that the device experienced an instantaneous pressure increase which cause the device to burst below the marked burst pressure.
Operators blocked in the process line with the malfunctioned device and restarted the TOX. The following corrective actions have been identified to prevent recurrence of this incident: (1) Develop Installation Guidelines, based upon manufacturer recommendations, to ensure devices are properly installed in the field (2) Develop Operating Guidelines, based upon manufacturer recommendations, for controlling the pressurization rate seen by the device through proper valve operation (3) Conduct training with Maintenance and Operations personnel on the two above established guidelines. The permitted maximum hourly sulfur dioxide rate and reportable quantity were exceeded. The concentration limit (250 ppm/ 12 h) was not exceeded.

Point Source(s):
30, 3700, and1600 Unit Thermal Oxiders, Flares 1 and 2
1600 TOX and Flares 1 and 2
Flares 1 and 2

Sulfur Dioxide - 12,495 pounds
Nitrogen Oxide - 1,215 pounds
Volatile Organic Compounds (VOCs) - 7,334 pounds
Carbon Monoxide - 783 pounds
Particulate Matter 10 - 100 pounds
Benzene - 73 pounds
Hydrogen Sulfide - 4,129 pounds
Propylene - 21 pounds
Cause of Problem: Process Upset

Due to multiple equipment high levels during startup of the Gasoline Desulfurizing Unit (GDU), hydrocarbons were introduced into the refinery's sulfur dioxide removal system and to the Sulfur Recovery Units (SRU) feeds resulting in unit upsets. Sulfur dioxide levels at the 1600, 3700 and 30 Unit Thermal Oxidizers were elevated from 3:24 pm on 5/20/11 until 8:00 am on 5/21/11. This caused smoking from the 1600 TOX stack from approximately 3:55 until 4:10 and the unit was shut down during this time. The 3700 and 30 Unit TOXs were also shutdown at approximately 3:40 and 4:13 respectively. Additionally, these process upsets also impacted the refinery's fluid catalytic cracking unit resulting in flaring for portions of this incident.
Valero did not show their limit for SO2, CO, NOx, PM, and VOC in the Thermal Oxidizer and flarecap. No limit was shown for Benzene in the Thermal Oxidizer. No limit was shown for H2S and Propylene in the flarecap. Accurate estimates could not be made. All values are below the total emitted and may be grossly deflated. During the event Valero received an odor complaint and took action to prevent and minimize any public nuisance. Field monitoring did not reveal any detectable quantities of VOCs or sulfur dioxide. Operational moves were made to the sulfur recover plants to shutdown the thermal oxidizers safely. Operators maximized steam to the refinery flares to mitigate visible emissions. During the incident fence-line monitoring was conducted by Valero and there were no detectable concentrations found. The following corrective actions were identified to prevent recurrence of this incident: (1) Modify the startup procedure for the GDU to ensure a shift supervisor monitors the unit radio channel (2) Include in the SRU standing orders that amine upsets be communicated to the shift supervisor and the shift superintendent (3) Modify GDU SOP's to amplify actions required for the amine system (4) Configure a separate console to receive all GDU alarms (5) Implement alarm management to allow high priority alarms to be flagged (6) Consider installing an auto shut off on the amine absorbers bottoms plant wide (7) Consider installing a bypass on the feed to untreated gasoline storage to improve feed control to the GDU during start up (8) Train the SRU operators on the rich DEA flash drum weir configurations. The hydrogen sulfide and sulfur dioxide permitted rates and reportable quantities were exceeded. There were released of nitric oxide, benzene, and VOCs released above reportable quantities. Opacity and visible emission limits were exceeded for flares 1 and 2 and the GRP007 SRU/TOCAP-SRU TO/CAP. The SRU sulfur dioxode concentration limit (250 ppm/ 12 h) for 30 and 1600 Unit TOXs and the EP and WP Fuel Gas hydrogen sulfide (162 ppm/3 h) were also exceeded.

Point Source(s):
Coker LPG line

Methane - 6 pounds
Ethane - 147 pounds
Propane - 436 pounds
Propylene - 159 pounds
Isobutane - 107 pounds
n-Butane - 437 pounds
1-Butene - 140 pounds
Isobutylene - 105 pounds
trans-2-Butene - 61 pounds
cis-2-Butene - 42 pounds
3-Methyl-1-Butene - 21 pounds
Isopentane - 72 pounds
1,3-Butadiene - 5 pounds
n-Pentane - 122 pounds
1-Pentene - 14 pounds
2-Methyl-1 Butene - 25 pounds
trans-2-Pentene - 22 pounds
cis-2-Pentene - 63 pounds
2-Methyl-2-Butene - 11 pounds
Hexane - 81 pounds
Hydrogen Sulfide - 39 pounds
Ethylene - 8 pounds
Cause of Problem: No Information Given

Valero had blinded and de-inventoried the Coke LPG line as part of a project to elevate the Prospect Road pipe bridge that connects their East Plant and West Plant. The blinds were removed several days prior to the incident but valves in the pipe system remained closed. Valero believes that gas leaked by one of the valves and accumulated in a section of pipe after the blind had been removed on the West Plant side of the project area thus trapping gas between two closed valves. On the day of the incident, the project operator opened the downstream valve in the pipe bridge that was closest to the FCCU in order to commission a new section of pipe; the upstream valve remained. When the valve was cracked open, gas that had accumulated in the pipe leaked out into the FCCU which was undergoing construction at the time of the incident.
Coker liquified petroleum gas (LPG) which is composed mainly of butenes and propenes was released from pipe openings in the FCCU area and dispersed. Emissions were minimized by isolating the coker LPG line. Valero identified the following corrective actions and target completion dates were identified as a result of the root cause failure analysis of this incident: (1) Issue safety alert on this incident to all personnel (2) Review incident with operators and discuss need for good communications when lining up piping to units (3) Develop a battery limits blind list for the FCCU for use during future turnarounds (4) Develop a battery limits list for Complex III (Crude-Vacuum-Coker units) for use during future turnarounds

Point Source(s):
West Plant Sump

Hazardous Waste - 11 gallons
Cause of Problem: Weather

On 3/29/11, Valero discovered that the west plant sump was overflowing. Upon identification of the incident, the on-duty shift superintendent implemented the necessary mitigating procedures. The spilled material overflowed the battery limits of the delayed coking unit during a heavy rain storm accompanied by local flooding. The stormwater runoff carried the spilled material over the refinery's perimeter berms and into the Prospect Road and 8 gallons were captures onsite before it could escape.
NO LDEQ report. Three refinery letters. No SPOC Report. Valero completed an incident investigation for this incident and identified several corrective actions to be implemented in order to prevent recurrence of this event. These include rerouting piping to alleviate hydraulic loading of this sump, evaluating additional oil-water separation projects, and evaluating additional waste water surge capacity. Valero estimates that about 11 gallons of material was spilled. Of the 11 gallons released to the ground, approximately 3 gallons escaped to the ditch along Prospect Road where it was collected by vacuum trucks. Recovered oil was sent to the refinery rerun system for subsequent processing. Absorbent booms used in the spill response will be sent offsite for disposal.

Point Source(s):
3700 SRU Malfunction

Sulfur Dioxide - 1,573 pounds
Cause of Problem: Equipment Failure

The sulfur dioxide levels at the 3700 Thermal Oxidizer (EQT 0195) were intermittently elevated from approximately 3/24/11 from 8:40 am until 11:30 am. Valero estimates that the reportable quantity for sulfur dioxide was exceeded at 9:25 am. This event was attributed to a miscommunication between night and day-shift operators, as well as process pressure controller that needed calibration (tuning).
Operators moved quickly to make manual control over automatic control valves that may have contributed to this event. Operational moves were conducted on a separate sulfur recover plant to help stabilize the upset. The following measures have been identified to help prevent recurrence:(1) Tune pressure controller for amine acid gas header to 3700 SRU (2) Communicate incident and reinforce the use of shift notes when communicating important details

Point Source(s):
30 sulfur recovery unit

Sulfur Dioxide - BRQ
Cause of Problem: Process Upset

On 3/24/11, LDEQ was notified by the Valero St. Charles Refinery that the reportable quantity for sulfur dioxide may have been exceeded during the startup of the 30 Sulfur Recovery Unit. According to the follow-up notification letter submitted by Valero this was a courtesy notification. No reportable quantities were exceeded as a result of this release.
No Information Given.

Point Source(s):
CCU Flange

Hydrogen Sulfide - 30 pounds
Cause of Problem: Human Factors

On 3/6/11 at approximately 6:04pm, Mr. Charles Knock of Valero made notification that two contract employees working in the catalytic cracking unit (CCU) during maintenance availability had been exposed to hydrogen sulfide. In addition to the exposure, contractors also sustained other injuries related to falling and were hospitalized. Trooper Sparks met with Valero representatives on the day of the incident. State Police and Occupational, Safety, and Health Administration (OSHA) officials have met with Valero representatives as part of the ongoing investigation into the cause of this event. It appears that the contractors were exposed to hydrogen sulfide escaping from an improperly installed blind during steaming of the line.
The discharge was detected at 3/6/11 at 3:00pm. Affected workers were transported to area hospitals at approximately 3:35 pm. The leaking piping system was secured approximately 93 hours later and during that time no appreciable quantities of hydrogen sulfide were measured. Hydrogen sulfide dispersed into the atmosphere. Measured hydrogen sulfide in the vicinity of the incident revealed that the concentrations in the air were substantially dissipated prior to leaving the process unit and posed no threat to the public. Work in the immediate area was stopped while an investigation was conducted to identify the source of the hydrogen sulfide. When the source was identified, he defectively installed blind was replaced under observation by the State Police. Monitoring was conducted to confirm that the replacement blind was not leaking. Measures to prevent recurrence will be identified as part of a pending investigation. There were two injuries from this incident, one of which resulted in a fatality. State officials are investigating the fatality to determine the cause of death. The second injured person was treated at an area hospital and released.

Point Source(s):
Hose on Dock 5

Light Cycle Oil - 84 gallons
Cause of Problem: Piping or Tubing

Hose had leak on back dock at hydrocarbon line on Dock 5.
Sheen observed on river. Less than one barrel of diesel estimated to have been released to the water. One barrel contained on the dock.