On 8/28/2011 at approximately 6:00 am, Walters' Ag Service had knowledge of an ammonia release due to an attempted theft of the anhydrous ammonia. It was determined that 1500 lbs of ammonia, or 15 times its RQ, was released into the environment. The NRC was not notified until 10:25 am - which is 4 hours and 25 minutes after the release was discovered - instead of within the required two hour window.