For those of you that have wells you can buy a water testing kit quite cheap. I got one from Amazon made by First Alert, the same company that makes smoke detectors.
I bought it because the closest camp ground to me is a small little used county park. It has, hidden in the trees, a old style well with a hand pump. (Those are getting quite rare) If I go camping out there with kids the love to operate the pump up and down and are amazed you can get water that way. I don't drink the water myself but give it to my dogs and I was wondering how safe it was. The test showed it to be perfectly safe but, quite hard.
The dogs don't care.