Costco Wholesale - Tolleson - Executive Summary |
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ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES The Costco Wholesale facility has an emergency action plan in effect. The Emergency Action Plan (Plan) is detailed in the Emergency Planning and Response section of the PSM/RMP document which is maintained at the facility. 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. Costco Wholesale 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, ammonia 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 and RMP regulations. Co stco Wholesale has coordinated emergency response efforts with the local fire department and with the contracted refrigeration operation and maintenance firm. In the case of an ammonia-related emergency, it is the policy of Costco Wholesale to evacuate and to allow the fire department/HazMat Team to respond to the emergency. The refrigeration contractor will be available for guidance and assistance. STATIONARY SOURCE AND REGULATED SUBSTANCE Construction of the ammonia refrigeration system at Costco Wholesale was completed in July 2000. The facility is new and operations are scheduled to commence once the refrigeration system is fully functional. The facility serves as a distribution point for chilled goods that are shipped to Costco Wholesale retail outlets. The facility is located at 8400 Sherman Street in Tolleson, Arizona, about 1.5 miles south of the Interstate 10 freeway. The immediate area is primarily agricultural and light industrial. The ammonia system was constructe d in accordance with all applicable federal, state, and local regulations including the Uniform Fire and Mechanical Codes. The ammonia refrigeration system uses approximately 18,000 pounds of ammonia for cross dock operations, warehouse cold storage, and freezer storage. The majority of the system is located in the machine room including vessels, compressors, and associated piping. The condensers are mounted on the engine room roof, and all of the evaporators are located in their respective cold storage rooms/areas. The refrigeration cycle begins with the transfer of high pressure liquid ammonia from the high pressure receiver to the high temperature pump accumulator. The high pressure receiver also supplies liquid ammonia to the compressors for oil cooling. As the ammonia enters the high temperature pump accumulator, it is expanded through a hand expansion valve, reducing the pressure (and hence the temperature) in order to maintain a predetermined internal pressure. The high t emperature pump accumulator feeds a similar vessel that maintains an intermediate pressure, the medium temperature pump accumulator. The pressure is further reduced between the medium temperature accumulator and the low temperature pump accumulator. Each accumulator vessel supplies pumped liquid ammonia to a distinct set of evaporators. The high temperature accumulator serves sixteen (16) cross dock/cold storage evaporators. The medium temperature accumulator typically serves eight (8) 28?F cooler evaporators (that can also be supplied by the high temperature accumulator as needed), and the low temperature accumulator serves six (6) -10?F freezer evaporators. Fans in each evaporator are used to blow air across and through the coils which partially vaporizes the liquid ammonia as heat from the room is transferred to the ammonia. The resulting two-phased (liquid/vapor) ammonia from each set of evaporators is returned to each accumulator respectively in which constant pressures (tem peratures) are maintained based on the suction pressure of the corresponding compressors. The vapor from the accumulators is then drawn to seven (7) compressors where the pressure and temperature of the gas is increased. All seven compressors work in combination to compress the vapor pulled from the three accumulator vessels. Compressor discharge (high pressure ammonia vapor, or hot gas) is routed to three (3) condensers where it is condensed to a high pressure liquid and drained back to the high pressure receiver. Hot gas is also used for defrost of the freezer and cooler evaporators. An auto purger periodically purges the system of non-condensibles (i.e. air) collected in the system. Dual pressure relief valve assemblies are installed on each vessel to relieve high pressure ammonia to a water diffusion tank through a common header in case of a high pressure event. HAZARD ASSESSMENT SUMMARY * Worst Case Release Result Summary Scenario Description: Release of the maxi mum quantity of ammonia that can be stored in a vessel - 18,000 pounds in 10 minutes. (The capacity of the High Pressure Receiver is greater than 18,000 pounds of ammonia, but the amount released is limited by the charge of ammonia in the system.) The most pessimistic meteorological conditions were used: 1.5 meters per second wind speed, and F stability. Reference tables in the EPA-approved Risk Management Program Guidance for Ammonia Refrigeration were used to determine the maximum distance to the toxic endpoint of 200 ppm in rural conditions. This release reaches off site and may impact population receptors. No environmental receptors were affected by this potential release. * Alternative Release Result Summary Scenario Description: A release of ammonia from resulting from a 1/4 inch diameter hole in a pipe. The release rate of ammonia due to the pressure of the tank is 126 pounds per minute. The meteorological conditions used were 3 meters per second wind speed, and D stability. Reference tables in the Risk Management Program Guidance for Ammonia Refrigeration were used to determine the maximum distance to the toxic endpoint of 200 ppm in rural conditions. This release reaches off site and may impact population receptors. No environmental receptors were affected by this potential release. ACCIDENTAL RELEASE PREVENTION PROGRAM AND CHEMICAL-SPECIFIC PREVENTION STEPS The Costco Wholesale ammonia refrigeration system has many safety features. Much of the safety of the system is inherent in the policies and procedures that govern the operation of the system. For example, the Costco Wholesale facility operates in accordance with OSHA's Process Safety Management regulation. Refrigeration contractors, experts in the ammonia refrigeration industry, are contracted at the facility to maintain the system and perform any repairs. The Costco Wholesale facility including each ammonia system was designed and constructed in accordance with the Uniform Mec hanical Code which specifically outlines requirements for the safe operation of the ammonia refrigeration system. These safety features include a water diffusion tank, ammonia sensors in the machine room as well as sensors in the cold storage areas, and automatic shut down systems that prevent equipment damage and ammonia releases. In addition, the majority of the ammonia inventory is maintained inside the machine room and just outside of the machine room (condensers). All pressure vessels are equipped with pressure relief valves that automatically engage in case of a high pressure situation and vent through a common header to a water diffusion tank. In addition to the Uniform Mechanical Code, the facility will operate in accordance with the International Institute of Ammonia Refrigeration (IIAR) guidelines. In particular, the IIAR Bulletin 110, "Startup, Inspection, and Maintenance of Ammonia Refrigeration Systems." FIVE YEAR ACCIDENT HISTORY This facility including the ammoni a refrigeration system is new as of July 2000. There have been no ammonia-related accidents at the facility. EMERGENCY RESPONSE PROGRAM Costco Wholesale has an emergency action plan in effect at the facility. The Emergency Action 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. Costco Wholesale 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, ammonia 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 com pliance with the PSM and RMP regulations, as well as to incorporate facility changes due to the renovation of the facility. In case of an ammonia release emergency, Costco Wholesale plans to evacuate all employees stationed in the cold storage warehouse and alert the local emergency responders (fire department). The emergency response efforts will also be coordinated with the managers on the dry side of the distribution warehouse, as each side (cold, dry) are part of one building. Costco Wholesale plans to coordinate emergency response efforts with the fire department on a periodic and ongoing basis. PLANNED CHANGES TO IMPROVE SAFETY The Process Hazard Analysis provided mitigation measures to improve safety at the Costco Wholesale facility located at 8400 W. Sherman Street in Tolleson, Arizona. Many of the recommendations are complete and implemented as of the system startup date. All recommendations are scheduled to be complete by July 1, 2001. R01 Coordinate emergency re sponse efforts with the local emergency responders (fire department) on a periodic and ongoing basis. R02 Ensure that the employees in the Shipping Office are aware of the ammonia monitoring computer and what to when an alarm is activated. R03 Include a periodic test and calibration of the ammonia detectors in the facility's maintenance program. R04 Ensure that every employee at the facility has the following information: general awareness of ammonia at the facility, how to report an ammonia release, where to go when they are told to evacuate. R05 Ensure that flammable materials are not stored in the engine room. R06 Ensure that relief valves are replaced or recertified on a 5 year schedule. Also, replace any relief valve that engages to vent pressure. R07 Ensure that a visual inspection is included in the maintenance program for all vessels. Paint all vessels as needed. R08 Consider the feasibility of an un-interruptible power source (i.e. battary backup) for the ammonia detectors in the engine room. R09 Exercise important hand valves on an annual basis. Include the activity in the annual maintenance schedules. R10 Ensure that safety shower/eye wash stations are located in and outside the engine room. R11 Ensure that a water source (i.e. portable water bottle, hose, eye wash station) is located on the roof near the Condensers. R12 Ensure that an annual test is performed on the mechanical high level shut down float switches on the pump accumulator vessels. R13 Consider implementing a daily log sheet for the engine room to be completed by a Costco employee. R14 Ensure that an oil draining procedure is documented and followed, including refrigeration contractors. R15 Ensure that all evaporator coils are periodically maintained by cleaning the pans and coils. R16 Establish a maintenance program for all ammonia equipment that includes manufacturer recommendations and/or industry standards. R17 Ensure tha t the Condensers are periodically maintained including a water treatment service and cleaning out the water reservoir. R18 Consider implementing a procedure to ensure that a (contracted) ammonia operator checks in with a Costco supervisor prior to performing work on the roof (or in another isolated location). R19 Ensure that the valves in the Emergency Refrigerant Control Box are labeled as to the corresponding upstream vessel. R20 Consider periodically testing the water in the diffusion tank for pH (with litmus paper). Also, maintain internal algae growth with a bleach solution. R21 Ensure that all piping is labeled as to the contents and the flow direction. R22 Install wind socks (or other wind direction indicators) in locations that can be seen from all potential emergency exits (i.e. engine room roof, receiving roof, shipping roof). R23 Install ammonia safety placards on all doors to the ammonia engine room. R24 Ensure that (at least) annual evacuation drills are held at the facility. |