Your options are new well very close to cousins pasture,pipeline to cousins well, or just sell the pasture . None are are a very good option . Would your cousin just buy it .he has water. Salt water contamination tends to spread in our area so your cousins well could be on borrowed time, Does anybody between your pasture and the city owned land have the same problem if they do you might have a case but if not you are out of luck and it will still be a long term fight. Your pasture in its present condition is basically worthless. I take that its not fit to farm.