Home Search Emissions Pollutants About the Database


Valero (26003), Norco

LDEQ Accident Report

Accident #155480
State Police #14-01800
Accident Date2014-04-23
Report Date 2014-04-29
Follow-up Date 2014-06-20
Follow-up: Yes

Pollutants Released

Pollutant Duration Point Source Greenhouse Gas Criteria Pollutant Ozone forming chemical Amount of Release
Sulfur Dioxide2 h 52mFlare 1, Flare 2, and Flare 3NOYESNO6,868.5 pounds
Hydrogen Sulfide2 h 52mFlare 1, Flare 2, and Flare 3NONONO36.9 pounds
Volatile Organic Compounds (VOCs)2 h 52mFlare 1, Flare 2, and Flare 3NONOYES134.9
Particulate Matter2 h 52mFlare 1, Flare 2, and Flare 3NOYESNO0.4 pounds
NOx2 h 52mFlare 1, Flare 2, and Flare 3NONOYES4.6 pounds
Carbon Monoxide2 h 52mFlare 1, Flare 2, and Flare 3NOYESNO24.9 pounds

Accident Classified As: Reportable Quantity

Cause of Problem: Process Upset

Valero experienced flaring from Flares No. 1, 3, and 4 when Coker Wet Gas Compressor (WGC) malfunctioned during a planned shut down. During the shut down the flow to the WGC increased when the sponge oil absorber was emptied. The emptied oil absorber increased the load to the 1st stage suction of the compressor, which caused the turbine speed to increase to compensate for the additional load. Later that evening, an operator heard gas going through LV-53-505 on the Sponge Oil Absorber and requested console operator to close the valve in order to decrease compressor loading. However, the valve was closed too quickly, which caused the WGC to trip offline and gases to be routed to the flare system. Report states that flares are "permitted for planned startup/shutdown operations in addition to flare operating limits". Those increased permit limits for each flare are included in the report. This accident resulted in the exceedance of the maximum hourly permitted emissions for hydrogen sulfide and sulfur dioxide, the 3-hour rolling average for hydrogen sulfide in the West Plant and CCR Fuel Gas and the reportable quantity for sulfur dioxide.

Discharge Preventable - Yes

The report states " This event was reasonably preventable"

Notes/Remedial Actions

Emissions were minimized by completing the shut down of the Coker Unit. Additionally the flare gas recovery unit collected and rerouted some of the gases back to refinery fuel gas. The following corrective actions have ben identified to prevent recurrence: Communicate incident to affect personal (Estimation completion date 7/31/140 Edit the Coker shutdown SOP to include a warning about high suction pressure/ high RPM scenario (Est. Completion date 7/31/14) Modify the distributed control system to display a warning when the compressor is approach a high suction pressure/high RM state (Est. Completion date 7/31/14) In addition to communicating the incident to all Coker personal, review the specifics with shift supervisors, console operators, and set up operators. Focus this communication on recognizing that gas flow through a liquid valve is unusual and may require cautious, measured moves to correct (Est. Completion date 7/31/14) Guardian OST. (Est. Completion date 6/20/14) Develop a WGC training overview for operators and supervisors (Est. Completion date 8/31/14) Review alarm points (Est. Completion date 7/31/14) Start monthly "what if" drills on the compressor operation (Est. Completion date 7/31/14) There is no record that any of these corrective actions have be mandated or not and the plan of action did not take into consideration of notifying the nearby communities.