Deadly Game (1977)

A Military convoy is transporting something apparently for disposal. They pass by Sheriff Abel Marsh's town and they are passing by property that's owned by Amy Franklin, who is the girlfriend of Abel's Deputy, Malcolm. Before they know it, everything around the property is uninhabitable. The Army returns to clean things up, and make restitution. But there is one nagging question, was this an accident, or was it deliberate? That is something Abel is most interested in finding out.