I have 16 chickens that are free range around our place. I have a water pan out for them and a freshwater pond just across the fence that they could go to but they choose to run down the hill and under a fence to drink from our sewer lagoon! Why do they do this and how can I get them to drink fresher water? It grosses me out. Will what they drink effect the egg quality for my family? I'm pretty new to owning chickens, so I don't really know what to do, if anything. Thanks!