![An Insidious Threat](https://cole-tpomag.imgix.net/https%3A%2F%2Fwww.tpomag.com%2Fuploads%2Fimages%2F100_0370.jpg?crop=focalpoint&fit=crop&fp-x=0.5&fp-y=0.5&h=620&ixlib=php-1.1.0&q=75&w=1024&s=7dcf21d28a169f767b0ff6de708c700a)
A small campground that maintains a public water system with 26 full-time customers came to us concerned that its clients were complaining of digestive tract irritation. A number also had skin abnormalities, such as dark and light spots on their skin and small corns on their...