I had a friend at the field school this past summer and he and I spent some time discussing water and water systems. We collect rainwater at the field school for drinking and washing, and when it runs low we get water from a stream or the river. At the time he was in the middle of building a pond on his land in southern Maine for storing drinking water. He mentioned that our species evolved drinking surface water, which is usually lower in salts and minerals than well water that comes from deep underground. He was of the belief that while surface water was more easily contaminated, it was generally better for you than well water. It was something I had never heard of or thought about before, so it stuck with me. I don’t have any answers and don’t know if he was right or not. But he definitely believed it, and he could be right.