Susan Glassmeyer, Environmental Protection Agency Cincinnati, Cincinnati, OH, United States, J Scott Boone, Mississippi State Chemical Laboratory, Mississippi State, MS, United States, Edward T Furlong, USGS Denver Federal Center, Denver, CO, United States, Dana W Kolpin, USGS Iowa Water Science Center, Iowa City, IA, United States, Robert Benson, US Environmental Protection Agency Region 8, Denver, United States, Joyce Donohue, Environmental Protection Agency Washington DC, Washington, United States and Jane Ellen Simmons, Environmental Protection Agency Research Triangle Park, Research Triangle Park, United States