01118cam a22002418a 4500 0607870435 DLC 551 FOR 1997 A059 Or. Hinkle, Stephen R. Comparison of chlorofluorocarbon age-dating with particle-tracking results of a regional ground-water flow model of the Portland Basin, Oregon and Washington / Comparison of chlorofluorocarbon age dating with particle-tracking results of a regional ground-water flow model of the Portland Basin, Oregon and Washington Denver, Colo. : U.S. Dept. of the Interior, U.S. Geological Survey : For sale by Branch of Information Services [distributor], [1997] v, 47 p. : ill., maps (some col.) ; 28 cm. U.S. Geological Survey water-supply paper ; Shipping list no.: 97-0374-P. Groundwater flow Groundwater tracers Chlorofluorocarbons Snyder, Daniel T. Intergovernmental Resource Center of Clark County (Wash.) Geological Survey (U.S.) EK 14579 14579