Alex R. Thomas & Company Packing House - Executive Summary |
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EXECUTIVE SUMMARY 1. Accidental Release Prevention & Emergency Response Policies Alex R. Thomas & Company is a family-owned and operated pear packing house located in the heart of Mendocino County. Our packing house is located just outside the Ukiah city limit, to the south of town on Taylor Drive. In an agricultural area of the Ukiah Valley, our facility is three miles from the center of Ukiah. Our ammonia-based refrigeration facility includes a pre-cooler (Middle Ice) and cold storage warehouse (South Ice) for storage and shipment of produce, principally Mendocino County Bartlett Pears. Alex R. Thomas & Company is committed to receiving, storing and operating our ammonia refrigeration system in a manner that is safe to the operators and friendly to the environment. It is the policy of the company to provide and maintain a safe and healthful environment and to follow operating practices. The ammonia storage/receiver tank is located in a secured building, with access for authorized personnel only. Ammonia is received via truck from authorized and trained distributors. 2. Process Description Anhydrous ammonia is acutely hazardous as defined by the OSHA 29 CFR 1910.119 and the EPA 40 CFR 68 standards. The threshold quantity for these materials is established in appendix A of OSHA 1910.119 at 10,000-pounds. The CalARP program establishes a 500-pound threshold quantity. Our system contains an estimated 18,920 pounds of ammonia and is thus subject to the above regulations. This figured is derived from an ammonia replacement conducted by Hill Brothers Chemical Company on April 14, 2000. On this date, Hill Brothers completely emptied all existing ammonia in our system and replaced it with a grand total of 18,920 pounds of new ammonia. The bulk of our ammonia, approximately 12,500 pounds, is located in a large "receiver" in the Ammonia Compressor Room and is circulated as a liquid to each of the cooling rooms in South Ice. In addition, the ammonia circulates through pipes across the service area to Middle Ice where it is "vaporized" to a gas and then returned to the compressor room where it will be compressed, cooled and returned to the "receiver" as ammonia liquid again. The source of an ammonia leak may thus be found in the ammonia compressor room or any of the cooling rooms in the South Ice or in the Middle Ice. 3. The Worst Case Release Scenario and the Alternative Release Scenario We have calculated the worst case release scenarios based on the RMP Comp off-site consequences model downloaded from the federal Environmental Protection Agency at http://www.epa.gov/ceppo/. The following paragraphs provide details of the chosen scenarios. Worst Case Release Scenario Our system contains an estimated 18,920 pounds of anhydrous ammonia, liquefied by refrigeration. In the event of a complete release, e.g., a worst case scenario, the ammonia would release in two forms: liquid and gas. Part of the liquid portion released would create a white va por cloud and strong ammonia odor. Twenty-five percent or so of the released liquid would vaporize immediately - the remaining liquid will accumulate into very cool pools of liquid. The ammonia gas released is lighter than air and will be carried by air movement and rise slowly into the atmosphere. The main ammonia storage/receiver tank is inside the South Ice Ammonia Compressor Room, which provides passive mitigation by way of enclosure. Under the required wind and atmosphere conditions, as calculated by RMP*Comp, the toxic end point of such a release would be .2 miles from its origin. The toxic end point of such a release would reach the outside perimeter of our facility at Taylor Drive. According to 1990 Census Data, as computed by the MarPlot/LandView computer program suite (provided by the US Department of the Census and the US Geologic Survey) less than 10 people live onsite in this area. Our facility occupies much of the area within this .2 mile distance and there are no pu blic receptors between the origin and the toxic end point. Alternative Release Scenario Our ammonia system is protected by a variety of mechanical safety systems that should prevent an accidental release (spring loaded safety relief valves, isolation valves, purge valves). The data for the alternative release was modeled after an incident that occurred nearly six years ago. On July 18, 1994, an estimated 210 pounds of ammonia was released because a communication failure between the computer and the Input/Output rack. A high-pressure situation developed, and the computer attempted to turn on more condenser fans to reduce the pressure in the system. The I/O rack failed to respond to the computer's request, causing the excess pressure to blow off through a relieve valve. Alex R. Thomas & Company and its personnel successfully set our Emergency Response Plan in action, evacuating some 250 employees. However, 6 employees working in the immediate area of the release were sent to the ho spital, checked for ammonia inhalation, and promptly released without injury. As a result of the incident and new computer and I/O system was installed, and the compressors were re-configured to shut down before system pressure reaches a critical level. The Alternative Release Scenario is based on 210 pounds of ammonia released over 15 minutes - reaching an end point of 1/10th of a mile. This distance is onsite and there are no public receptors within this distance. 4. The Accident Release Prevention Program at the Facility The following sections briefly describe the release prevention program that is in place at our stationary source. Safety Information Alex R. Thomas & Company maintains a record of written safety information, which describes the chemical hazards, operating parameters and equipment designs associated with all aspects of our distribution facility. Hazard Review A What-If/Checklist methodology was used to carry out the hazard review at our facility. The review focuses on operating procedures, equipment functions and handling practices to identify possible hazards. The study was undertaken by a team of qualified personnel with extensive knowledge of facility operations and will be revalidated at a regular 5-year interval. Any findings related to the hazard reviews are addressed in a safe and timely manner. Operating Procedures For the purposes of safely conducting activities within our covered processes, Alex R. Thomas & Company maintains written operating procedures, computerized monitoring of ammonia refrigeration systems and various alarm functions. These procedures address various modes of operation such as initial startup, normal operations, temporary operations, emergency shutdown, emergency operations, normal seasonal shutdown and seasonal startup. The information is regularly reviewed and is readily accessible to operators involved with the processes. Training Alex R. Thomas & Company has a comprehensive training program in p lace to ensure that employees that are operating ammonia processes are completely competent in the operating procedures associated with these processes. New employees receive basic training in process operations followed by on-the-job supervision until they are deemed competent to work independently. Refresher training is provided annually, when certification requires, or change warrants. Maintenance Alex R. Thomas & Company carries out documented maintenance checks on process equipment to ensure proper functioning. Maintenance activities are carried out by both qualified company personnel and outside contractors with previous training in these practices. Furthermore, personnel are offered specialized training as needed. Any equipment deficiencies identified by the maintenance checks are corrected in a safe and timely manner. Compliance Audits Alex R. Thomas & Company conducts audits on a regular basis to determine whether the provisions set out under the RMP rule are being im plemented. These audits are carried out at least every 5 years and any corrective actions required as a result of the audits are undertaken in a safe and prompt manner. Incident Investigation Alex R. Thomas & Company promptly investigates any incident that has resulted in, or could reasonably result in, a catastrophic release of ammonia. These investigations are undertaken to identify the situation leading to the incident as well as any corrective actions to prevent the release from recurring. All reports are retained for a minimum of 5 years. 5. Five-year Accident History On October 1, 1998 an ammonia refrigeration coil in Controlled Atmosphere Room 1 of the South Ice Cold Storage sprung an unheard of interior pinhole leak. An estimated 75 pounds of ammonia was released from 09:50 to 10:05. The room was not used for CA operations at the time, but rather as a temporary holding room for hot pears coming in from the field. A forklift driver returning from break observed a vapor c loud coming from the coil, at about the same time the alarm system went off. Following our Emergency Response Plan, the room and building were sealed off and evacuated. The King Valve, located on top of the ammonia receiver/storage tank in the South Ice Ammonia Compressor Room was shut off and the flow of ammonia to the coil was stopped. The Ukiah Valley Fire District was called onto the scene and the Mendocino County Department of Environmental Health was notified. Our ammonia services contractor, Robert Dehoney of Engineered Mechanical Systems, arrived and began positive pressure ventilation to clear the ammonia out of the room. UVFD inspected the scene and cleared after PPV was initiated. By 15:00 that day, the ammonia level in CA Room was brought to 20 PPM. As the room was used for temporary storage of hot fruit, the temperature set point was at around 45 degrees. However, the coil was in a defrost cycle, and the temperature of the room was most likely higher. Because of the def rost, there was a high level of humidity around the coil. Water attracts ammonia like a sponge, and this was most likely the cause of the vapor cloud. Using digital ammonia detector, the ammonia concentration in CA Room 1 was 695 parts per million at the time of the release. In the hallway, immediately outside CA Room 1, the ammonia concentration was 50 PPM. There were no injuries stemming from this release, nor was there any property damage. Much the fruit in the room was ruined, and the coil was replaced. Our Emergency Response Plan was executed successfully without deviation or incident. The cause of the coil's interior pinhole leak remains undetermined. An interior pinhole leak in a coil has never occurred at another facility. 6. Emergency Response Plan Alex R. Thomas & Company carries a written emergency response plan to deal with accidental releases of ammonia. The plan includes all aspects of emergency response including adequate first aid and medical treatment, evacuation s, notification of local emergency response agencies and the public, as well as post-incident decontamination of affected areas. Our facility's emergency response plan is based upon the OSHA PSM and EPA's RMP, compliance standard, IIAR Guide to Good Practices, and Material Safety Data Sheets for anhydrous ammonia. To ensure proper functioning, our emergency response equipment is regularly inspected and serviced. In addition, the Emergency Response Plan is promptly updated to reflect any pertinent changes taking place within our processes that would require a modified emergency response. Alex R. Thomas & Company maintains a professional rapport with the Ukiah Valley Fire District to ensure a safe, prompt and effective response to an accidental ammonia release. UVFD's personnel are highly trained emergency responders that can control and mitigate a release. UVFD's personnel are intimately familiar with our facility, due to the frequent training sessions we've hosted at our facility. In the past five years, we've hosted three of these sessions 7. Planned Changes to Improve Safety Several developments and findings have resulted from the implementation of the various elements of our accidental release prevention program. Listed below are some of the major steps we want to take to improve safety at our facility: ? As members of RETA and ILAR, we will continue training our personnel through their training programs, increasing our employees' level of training and awareness. ? Expand our emergency exercise during the pear season, held to ensure the training and safety of temporary seasonal employees, to include a simulated evacuation. ? Upgrade our computer monitoring system hardware and software. ? Update all of our ammonia safety and procedure manuals. ? Installation of a larger receiver, which will allow us to isolate all the ammonia in our system in the event of an ammonia emergency. ? Certain valves and components in our system need to be made more accessibl e with ladders. These changes expected to be implemented by July 1, 2001 |