In the United States, approximately 10 million pounds of 1,4-dioxane are produced each year. It is being detected in groundwater at dozens of sites across the country. Once thought to be relatively benign, new science says otherwise. Costs to clean it up are high, and communities are grappling with how to deal with it. In this installment of “The Green Room,” WEMU explores the experiences of two cities: Ann Arbor, Michigan, and Tucson, Arizona.