Aurora Cooperative - Sedan - Executive Summary
The Aurora Cooperative Elevator Company's accidental release prevention policy involves a unified approach that integrates technologies, prodecures, and management practices. The Aurora Cooperative emergency response plan involves the response services available in the community. Aurora Cooperative bulk Anhydrous Ammonia faciliites have been strategically located to provide a local retail facility for this form of affordable nitrogen fertilizer for agricultue. This location, East of Edgar made up of one 26,000 gallon pressurized storage vessel and one loadout riser. It serves the Clay and Nuckolls County areas. This facility is normally unmanned, except during fertilizer season, although the adjacent grain elevator and office are normally manned during business hours. The offsite consequence analysis includes consideration of two anhydrous ammonia release scenarios, identified as "worst case release" and "alternative scenario". The first scenario is defined by EPA, which states |
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 defines 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 is decreased to a "non-toxic" level. For this purpose, Aurora Cooperative has chosen to use RMP-Comp Version 1.05 to determine the distance to the toxic endpoint (.14mg/l or 200 ppm). To determine the population affected by a potential release, we used maps extracted from Landview 3 software. The worst case release for Aurora Cooperative - Sedan involves a failure of the 26,000 gallon pressurized storage vessel while it contains 85% (maximum allowed capacity) of it's capacity. The alternative release scenario is based on the failure of a three inch transfer hose, assuming c
omplete failure of the in-line check valve and that the excess flow valve takes two minutes to close.