Microbial and spectral reflectance techniques to distinguish neutral and acidic drainage

Acid drainage from abandoned coal mines is affecting thousands of miles of rivers in the eastern United States. U.S. Geological Survey (USGS) scientists are finding that neutral drainage is sometimes being mistaken for acidic drainage because both involve the formation of iron oxide-rich materials. USGS scientists are adapting microbial techniques to learn about the processes that form the acidic and neutral iron oxide-rich flocculates and are developing spectral reflectance techniques that differentiate between acid and neutral materials. Federal and State regulatory agencies are using these data to help make land-use decisions.