Snowden Enterprises - Modesto - Executive Summary

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ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES 
 
Snowden Enterprises has an emergency response plan in effect.  The Emergency Response Plan (Plan) is detailed in the Emergency Planning and Response section of this PSM/RMP document.  This Plan was designed to meet the following objectives: 
 
1.)  To save lives. 
2.)  To minimize and avoid injuries. 
3.)  To protect the environment. 
4.)  To minimize property damage. 
 
Snowden Enterprises maintains a safety committee whose members are the designated emergency coordinators for the facility.  The Plan provides the response organization and notification procedures, evacuation routes, sulfur dioxide health hazards, and mitigation procedures which will be implemented to respond effectively to emergency situations that may arise at the facility.  This Plan is reviewed and updated at least once per year.  This Plan was reviewed and updated to ensure compliance with the PSM, RMP, and CalARP regulations, and to ensure that the plan is ke 
pt current. 
 
STATIONARY SOURCE AND REGULATED SUBSTANCE 
 
The process is located at 514 Hosmer Avenue in Modesto, California.  The Snowden Modesto facility repackages sulfur dioxide (which is delivered in 90 ton railcars) into cylinders which range in capacity from 10 pounds to 1 ton.  The process flow begins at the 90 ton rail car.  Liquid sulfur dioxide is transferred from the rail car into the two 25 ton receivers.  The sulfur dioxide liquid is then transferred from the receivers to the five fill stations; one-ton fill stations (2), 150 pound cylinder fill stations (2), and the specialty fill station.  The specialty fill station services smaller cylinders which range from 10 to 50 pounds.     
 
Sulfur dioxide compressors can apply pressure to either the rail car or the 25 ton receivers which enables the liquid to be transferred from either of the vessels.  A vacuum tank is connected to all of the fill stations, as well as the rail car and receivers, which allows a vacuum to be pulled o 
n any one of them.  Once the sulfur dioxide is transferred into its final container, it is stored in the "full storage" area of the warehouse until delivery. 
 
The sulfur dioxide is delivered approximately every 6 to 8 weeks in a 90 ton rail car by the Union Pacific Railroad Company.  The rail car is connected (piped) to the receivers only during sulfur dioxide transfer, which may occur 3 to 4 times per rail car.  Each fill station is operated on an "as needed" basis and may not be used daily. 
 
The maximum quantity of sulfur dioxide that is normally stored on site is 90 tons. 
 
HAZARD ASSESSMENT SUMMARY 
 
Worst Case Release Result Summary 
 
Scenario Description: Release of the maximum quantity of sulfur dioxide that can be stored in a vessel - 180,000 pounds (the entire contents of the railcar) in 10 minutes.  The railcar remains outside the warehouse; therefore, no passive mitigation measures were employed in the calculations.  The most pessimistic meteorological conditions were used: 1.5 
meters/second wind speed, and F stability.  Reference tables from the EPA's RMP Guidance for Wastewater Treatment Plants were used.  This potential release reaches off site of the facility boundaries and may impact population and environmental receptors. 
 
Alternative Release Result Summary 
 
Scenario Description: The alternative release scenario chosen for this facility is that of a 0.25 inch diameter orifice leading to an airborne release, representative of a pump seal leak, a gasket rupture, pinhole leak due to corrosion, flange seal leak, valve bonnet seal leak, etc.  It is assumed that this release occurs during the filling of 150 lbs tanks.  The release scenario is assumed to last one hour, thereby incorporating mitigation measures such as the emergency response plan and actually shutting down the system.  The facility is normally operated with its dock doors open, thereby eliminating the passive mitigation factor associated with an enclosed release.  The meteorological conditions 
used were 3 meters per second wind speed, and D stability.  Reference tables from the EPA's RMP Guidance for Wastewater Treatment Plants were used.  This potential release reaches off site of the facility boundaries and may impact population receptors. 
 
ACCIDENTAL RELEASE PREVENTION PROGRAM AND CHEMICAL-SPECIFIC PREVENTION STEPS 
 
Snowden Enterprises has a Process Safety Management program in place to manage the handling of sulfur dioxide.  In addition, common industry standards, policies, and procedures are utilized to ensure safe practices are being performed.  
 
FIVE YEAR ACCIDENT HISTORY 
 
Since the initial PHA Study (September 15, 1995), there have been no releases of sulfur dioxide that exceeded the Federal Reportable Quantity of 500 pounds or the California threshold of "any" release.  In addition, there have been no injuries resulting from a sulfur dioxide release.  
 
EMERGENCY RESPONSE PROGRAM 
 
The Snowden Enterprises has an emergency response plan in effect at the facility.  The 
Emergency Response Plan (Plan) is detailed in the Emergency Planning and Response section of the PSM/RMP document.  The Plan provides the response organization and notification procedures, evacuation routes, and mitigation procedures which will be implemented to respond effectively to emergency situations that may arise at the facility.  This Plan is reviewed and updated at least once per year.  This Plan will be reviewed and updated to ensure compliance with the PSM, RMP, and CalARP regulations, and to ensure that the plan is kept current. 
 
PLANNED CHANGES TO IMPROVE SAFETY 
 
The Process Hazard Analysis (PHA) Revalidation provided the mitigation measures outlined below to improve safety at the Snowden Enterprises facility.  The PHA Revalidation was comprised of one session that included a HAZOP study, a Plant Walkthrough, a "What-if" analysis, and a series of checklists.  Below is a summary of the recommendations resulting from the Process Hazard Analysis Revalidation study performed  
on March 24, 1999 at Snowden Enterprises, Inc. 
 
REV01:Prepare training certificates to show that operators are "Grand fathered" under the PSM initial training requirement.   Also, prepare on-the-job training certification forms for the operating procedures for new employee/operator training. 
 
REV02: Label all critical valves and include references to these valves in the operating procedures. 
 
REV03: Install a wind sock. 
 
The Plant Manager will be responsible to ensure that all recommendations are completed on or before April 1, 2000.
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