The OP has to make his own choices I guess, but I will offer an observation. For years on US129 from Cleveland Ga to Blairsville, Ga (very curvy and mountainous) there were a couple or three places where clear and cold spring water flowed out of a crack in the rock. One place even had a steel pipe and an enclosed stone trough that held a few inches of water in it. You could see cars with license plates from metro-Atlanta stopping and filling plastic jugs with the 'spring' water. These places are no longer there. The 'healthy' water was likely not has healthy as they figured. With the wild hog population, deer and bear population continuing to grow, the giardia has also grown. The GSMNP has signs posted cautioning visitors from drinking the ground water there for the same reason. If you intend to do this, at least add a few ounces of chlorine to the tank before you fill it.