1. Bureau of Drinking Water and Groundwater─Groundwater Section, Wisconsin Department of Natural Resources, Madison, Wisconsin 53707, United States
2. Center for Watershed Science and Education, College of Natural Resources, University of Wisconsin─Stevens Point, Stevens Point, Wisconsin 54481, United States
3. Environmental Health Division─Organics, Wisconsin State Laboratory of Hygiene, Madison, Wisconsin 53707, United States
4. Department of Statistics, University of Wisconsin─Madison, Madison, Wisconsin 53707, United States
5. Bureau of Environmental Analysis and Sustainability − Laboratory Certification, Wisconsin Department of Natural Resources, Green Bay, Wisconsin 54313, United States
6. Center for Environmental Measurement and Modeling, U.S. Environmental Protection Agency, Athens, Georgia 30605, United States