I don't know what to tell ya. Where I live there are piles like this being buried all the time with worse stuff than just auto batteries. In the country it is just easier and less time consuming to bury this stuff than actually hauling it in or having someone else do it. My uncle used to do this for people when he had his excavator, if a farm building was falling down you would dig a pit and push the building in it. sometimes you would burn them some times you would just bury them but when you did this you always went around and found anything that wasnt needed and in the way and was tossed in the pit as well including all kinds of scrap and toxic stuff. (I am not saying my uncle has ever buried toxic stuff just that was and still is a common practice out here).