Aurora Cooperative - Hubbell - Executive Summary |
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The Aurora Cooperative Elevator Company's accidental release prevention policy involves a unified approach that integrates technologies, procedures, and management practices. The Aurora Cooperative emergency response plan involves the response services available in the community. Aurora Cooperative bulk anhydrous ammonia facilities have been strategically located to provide a local retail facility for this form of affordable nitrogen fertilzier for agriculture. This location located in Hubbell, Nebraska is made up of one (1) 18,000 gallon and one (1) 12,000 gallon pressurized storage vessels and related piping ( and storage of up to fifty (50) 1,500 gallon nurse tanks. It serves southern Thayer County in Nebraska and Northern Republic and Washington Counties in Kansas. This facility is normally unmanned, except during ferilizer season, although the office facilities located 300 feet west are normally manned during business hours. The offsite consequence analysis includes the cons ideration of two anhydrous ammonia release scenarios, identified as "worst case release" and "alternative scenario". the first scenario is defined by EPA, which states that the "owner or operator shall assume that the...maximum quantity of the largest vessel...is released as a gas over a 10 minute period, due to an unspecified failure". The alternative release scenario is defined as "more likely to occur than the worst case scenario". Atmospheric dispersion modeling has to be performed to determine the distance traveled by the anhydrous ammonia released before it's concentration decreases to a "non-toxic" level. For this purpose, Aurora Cooperative has chosen to use RMP-Comp Version 1.06 to determine the distance to the toxic endpoint (.14 mg/l or 200 ppm). To determine the population affected by a potential release we will use maps extracted from Landview 3 software. The worst case release scenario for Aurora Cooperative - Hubbell Anhydrous Ammonia facility involves the failure of the 18,000 gallon pressurized storage vessels while it is at 85% (maximum allowed capacity) of it's capacity. The alternative release scenario is based on the failure of a three inch transfer hose, assuming that the check valve fails completely and the excess flow valve in the storage tank takes 2 minutes to close. |