1. Department of Civil and Environmental Engineering, University of Wisconsin - Madison , Madison, WI 53706, USA
2. Department of Bacteriology, University of Wisconsin - Madison , Madison, WI 53706, USA
3. Department of Environmental Toxicology, University of California - Davis , Davis, CA 95616, USA
4. U.S. Geological Survey, Upper Midwest Water Science Center, Mercury Research Laboratory , Madison, WI 53726, USA
5. U.S. Geological Survey, Idaho Water Science Center , Boise, ID 83702, USA
6. Idaho Power Company , Boise, ID 83702, USA