Dean Milk Company, INC - Executive Summary |
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EXECUTIVE SUMMARY Description of Facility and Regulated Substance Handled: Dean Milk Co/Louisville, Kentucky processes milk, milk products and drinks. The facility utilizes anhydrous ammonia as a refrigerant to maintain the proper temperature of milk, milk products and drinks within the facility. Anhydrous ammonia is an effective refrigerant that has been used for many years by most food processing facilities. Ammonia is normally a gas at ambient temperatures but, is handled as a gas liquefied under pressure. The refrigeration system consists of a high-pressure receiver, evaporators, compressors, piping, and valves. Accidental Release Prevention and Emergency Response Policies: Dean Milk Co is committed to promoting safety for the plant, its' employees and the surrounding area. The facility is complying with OSHA's Process Safety Management Standard (PSM), Title 29 Code of Federal Regulations (CFR) 1910.119, and EPA's Risk Management Program regulations (RMP), Title 40 CFR Part 6 8. The purpose of these programs is to ensure that the refrigeration system is operated safely in order to prevent releases of ammonia from the system. In addition, these programs serve to develop procedures to minimize releases in the event that they do occur and to outline appropriate emergency action to take in the event of a release. Worst Case Release Scenario: EPA's "Risk Management Program Guidance for Ammonia Refrigeration" (November 1998) and the "International Institute of Ammonia Refrigeration's (IIAR) Risk Management Guidelines" (1998) were the primary documents used to develop the worst case release scenario. The worst case release is one that is unlikely to occur. The purpose of the worst case release analysis is to support a dialogue with the community on release prevention. It is a conservative analysis and is not to serve as a rational basis for actual emergency response planning. The worst case release scenario (as defined by EPA) is the release of the largest quan tity of ammonia from a vessel or process line failure that results in the greatest distance to a toxic endpoint. The worst case release scenario for the refrigeration process is assumed to be a case where the total quantity of ammonia in the largest vessel in the system is released. The release scenario was performed assuming that the vessel was filled to capacity, without controls. The vessel, however, is normally filled to 60% capacity. There are no passive mitigation systems (dikes, berms, drains, sumps or enclosures) considered in the analysis since the vessel is located outdoors. In addition, Dean Milk has installed a sophisticated system of ammonia sensors that sounds an alarm in the event of a small release. These sensors are capable of detecting releases of ammonia at low levels, and are connected to a computer. In this way, potential releases of ammonia are minimized. The toxic endpoint used for this scenario must be where the ambient concentration of ammonia is 0.14 mg/L o r less. This endpoint is a concentration below which nearly all individuals could be exposed for one hour without serious health effects. Based on Exhibit 4-4 in EPA's guidance, a release from the receiver would result in a situation where public receptors would be within the distance to the toxic endpoint. Alternative Case Release Scenario: The alternative case release scenario selected is one in which a relief valve lifts to relieve pressure in the system. EPA's "Risk Management Program Guidance for Ammonia Refrigeration" (November 1998) and the "International Institute of Ammonia Refrigeration's (IIAR) Risk Management Guidelines" (1998) were the primary documents used to develop the alternative release scenario. The alternative release scenario is one that is more likely to occur than the worst case release scenario. The alternative release scenario must meet two criteria: 1) Must be more likely to occur than the worst case scenario, and 2) Must reach an endpoint off site, unless no such criteria exist. Since the facility has installed ammonia sensors in the cooler and in the compressor room, it is assumed that a release would last only ten minutes, which is EPA's default for such a release scenarios. The toxic endpoint used for the scenario must be where the ampient concentration of ammonia is 0.14 mg/l or less. Based on EPA's guidance, the alternative release scenario would result in a situation where public receptors would be within the distance to the toxic endpoint. Accidental Release Prevention Program and Chemical-Specific Prevention Steps: As a part of its PSM Program, Dean Milk Co has established numerous programs that serve to prevent accidental releases of ammonia. These programs include: 7 Process Safety Information 7 Process Hazard Analysis 7 Operating Procedures 7 Training 7 Mechanical Integrity 7 Management of Change 7 Pre-Startup Review 7 Compliance Audits 7 Incident Investigations 7 Employ ee Participation 7 Hot Work Permits 7 Contractor Safety Emergency Response Information: As a part of the PSM Program, the facility maintains an Emergency Action Plan that was prepared in order to improve responsiveness to an emergency incident, and to increase the reliability of actions taken during an incident. The plan includes all aspects of emergency action including adequate first aid and medical treatment, evacuations,notification of local emergency response agencies as well as the public. In the event of an emergency involving the ammonia system, it is the policy of the facility to request assistance as necessary by calling 911 which will notify the Camp Taylor Fire Department, Louisville and Jefferson County LEPC, Louisville police department. LEPC has included Dean Milk Co in its local emergency operation plan. Five-Year Accident History: Dean Milk Co has ha d an excellent record in preventing accidental releases over the last 5 years. Due to our stringent release prevention policies, there has been no accidental releases during this period that had an adverse impact on the community. Steps to Improve Safety: Several developments and findings have resulted from the implementation of the various elements of our accidental release prevention program. Some of the major steps taken to improve safety at our facility include: Blocking off key components and piping, New ammonia monitoring system and ammonia system component tracking display. Improvements to the ammonia training program include: Ammonia system specific triaining for maintenance personnel. These changes are consistant with other programs that support a safe ammonia system. In addition, the facility will continue to operate and maintain the system in accordance with IIAR Guidance and will continue to implement its OSHA PSM Program in conjunction with the Risk Management Program. |