1. U.S. Geological Survey, NH-VT Water Science Center, 361 Commerce Way, Pembroke, New Hampshire, 03275, Waste Management Division, Department of Environmental Services, State of New Hampshire, 29 Hazen Drive, P.O. Box 95, Concord, New Hampshire 03302-0095, and U.S. Geological Survey, Box 25046 Denver Federal Center Mail Stop 964, Denver, Colorado, 80225-0046