There are hundreds of thousands of abandoned mines across the country, and many of them could pose risks to people, wildlife and water resources. Bruce Rittmann, Fulton Schools professor of civil, environmental and sustainable engineering, and director of ASU’s Swette Center for Environmental Biotechnology, explains how toxic materials can be leached from rocks in the mines by groundwater or rainfall and end up in nearby waterways. Click on the audio track posted with the report to hear Rittmann’s comments.