United Farmers Mercantile Company, Villisca - Executive Summary

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United Farmers Mercantile Company 
Villisca, Iowa 
Risk Management Plan - Executive Summary 
The accidental release prevention policy at United Farmers Mercantile Company involves, but is not limited to technologies, procedures, and management practices.  All applicable procedures of the ANSI K-61.1 - 1989 revision of the "Safe Requirements for the Storage and Handling of Anhydrous Ammonia," as adopted by the Iowa Department of Agriculture and Land Stewardship (IDALS) are adhered to.  Our emergency response policy involves the emergency response services available in our community. 
This facility is in the business of selling anhydrous ammonia to farm customers as a form of nitrogen fertilizer.  The facility has two anhydrous ammonia storage tanks with a total capacity of 262,000 gallons water capacity.  The storage tanks (26,000 gallon and 30,000 gallons), several anhydrous ammonia nurse tanks, risers for filling nurse tanks, electrical panels, lighting, and safety equipment are all pa 
rts of this facility's anhydrous ammonia operation.  The facility is manned during the season and is operational through normal business hours. 
The off-site consequences analysis includes two anhydrous ammonia release scenarios, identified as "worst-case" release and "alternative" release scenario.  The first scenario is defined by EPA and shall assume the maximum quantity of a vessel is released as a gas in 10 minutes due to a catastrophic break.  The alternative release scenario is defined as a more likely accidental release of anhydrous ammonia caused by a transfer hose failure. 
The "worst-case" release scenario involves a catastrophic failure of the tank releasing the entire 140,000 pounds of anhydrous ammonia from the largest tank.  The off site consequences were calculated using "TFI's RMP Guidance for Ammonia Retailers".  The worst case scenario used EPA's recommended wind speed of 1.5 meters per second with an "F" atmospheric stability class.  A rural topography was selected  
as typical.  The distance to the endpoint was 2.68 miles. It is estimated that 1382 people would be affected by this release. 
The "alternative release" scenario assumed a hose breaks and leaks 7,200 pounds of anhydrous ammonia.  The EPA recommended wind speed of 3.0 meters per second with a "D" atmospheric stability class was used in this scenario.  Using rural topography and "TFI's RMP Guidance for Ammonia Retailers" the toxic endpoint is .46 mile.  The population with in that area is estimated to be 1332 people.  The assumption is that the duration of the release is 2 minutes because equipment, excess flow valves, and human intervention will stop the leak.   
United Farmers Mercantile Company has had no anhydrous ammonia leaks within the past five years.  Even though the company has had no releases it still coordinates annual visits with the local fire department to review the systems and procedures for response to a leak. 
United Farmers Mercantile Company has several key elements 
in its accident prevention plan: 
1. The anhydrous ammonia system adheres to the laws and regulations that are based on the 1989 revision of the ANSI K61.1 adopted in 1990 by the State of Iowa. 
2. Annual training is required of all personnel on handling, transferring, or transporting anhydrous ammonia.  The training includes properties of ammonia, safe handling practices, first aid, and emergency response. 
3. Use of good management practices as specified by industry standards and training aids. 
4. Frequent site inspections by management and safety consultants. 
5. Annual inspections by IDALS fertilizer inspectors include safety equipment, tanks, and handling equipment. 
6. Use of proper anhydrous ammonia personal protective equipment and safety equipment. 
Changes are made in the system when necessary or when required by regulation change.  Periodic evaluations of the procedures help to determine whether or not a change in operations should be made to provide increased safety to the opera 
tors and to the community.
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