Shawnee Feed Center - Executive Summary

| Accident History | Chemicals | Emergency Response | Registration | Source | Executive Summary |

Shawnee Milling Company operates rural feed stores offering anhydrous ammonia to local farmers.  Onsite storage and dispensing of this toxic chemical varies in quantities based on seasonal application demand.  For approximately 3-4 months of the year, maximum quantities of anhydrous ammonia is reduced to less than 20% (25,000 pounds)  of the maximum quantity of 123,600 pounds held in storage. 
The company ensures that tanks and components are regularly maintained by qualified contractors.  The facility is regularly inspected by both employees, its insurance carrier, and the State of Oklahoma Department of Agriculture. 
This facility would have a maximum of 123,600 pounds of anhydrous ammonia onsite at its peak sales periods.  Administrative operating procedures limit  the 30,000 gallon tank storage to 85% of its capacity.  Nurse tanks are not typically filled in advance of customer request. 
The facility's prevention program includes: 
*     Only trained employees permitted to dispense 
anhydrous ammonia 
*     Routine inspections conducted of storage and dispensing operations 
*     Locks on storage tank to prevent unauthorized use 
*     Pump shutoff switches at multiple locations for easy and immediate emergency shutoff 
*     Transfer hoses have excess flow valves at the riser  
*     Breakaway connectors with automatic shutoff valves to prevent accident release 
*     Transfer trucks required to use wheel chocks  
*     Tank, connections and hoses maintained free of leaks 
*     Area maintained free of ignitables 
*     Safety barricades in place in front of piping to prevent accident vehicle or equipment contact 
*     The perimter of the facility is protected by security system 
The worst case scenario is structural damage to the bulk storage tank containing, at peak operating periods, up to 123,600 pounds of NH3.  Failure would result in a near-full release of ammonia within 10 minutes in a rural environment.  The toxic endpoint has been calculated to be 5.6 miles from 
the tank at which point it would be dispersed enough to no longer pose a hazard to the public.  Public receptors include residences, schools, hospitals, recreation areas and major commerical, office and industrial areas.  There are no environmental receptors within the distance to endpoint. 
The more probable alternative accidental release would involve a transfer hose failure that could potentially result in up to a 100 pound release of anhydrous ammonia before an emergency shutoff valve could be activated.  The toxic endpoint would be limited to 0.2 miles which would expose less than 1/2 dozen persons and no other commerical or public facilities. 
This facility has not had a reportable accidental release in the last five years. 
This facility follows the emergency response plan established by the Pottawatomie County Emergency Planning Committee.  Employees are not permitted to respond to any accidental release that would require the donning of respirators and full body protection.   
Employees are instructed to notify emergency response authorities in the event of an accidental release and to evacuate the area as appropriate. 
Summary of prevention program: 
*  Only trained employees permitted to dispense anhydrous ammonia 
*  Routine inspections conducted of storage and dispensing operations 
*  Locks on storage tanks to prevent unauthorized use 
*  Pump shutoff switches at multiple locations for easy and immediate shutoff 
*  Transfer hoses have excess flow valve at the riser 
*  Transfer trucks required to use wheel chocks 
*  Tank, connections and hoses free of leaks 
*  Area maintained free of ignitables 
*  Safety barricades in place in front of piping to prevent accidental vehicle or equipment contact 
*  Perimeter security system
Click to return to beginning