Well data, surface-water discharges, and nitrate concentrations, February 1986 - September 1987, in parts of the Pasco Basin, Washington

The U.S. Geological Survey, in cooperation with the State of Washington Department of Ecology, is conducting a study of parts of the Pasco basin, Washington, to determine: (1) effects of dams, surface-water application, canal seepage, and pumpage on groundwater levels; (2) quality of groundwater and probable sources of large concentrations of nitrate; (3) presence of pesticides in the groundwater systems; (4) directions and general rates of movement of undesirable chemicals and/or chemical concentrations in the groundwater system; and (5) possible results of various management alternatives for dealing with high groundwater levels and large concentrations of nitrate in groundwater. This report contains basic data collected from the start of the project in February 1986 through September 1987. The groundwater level network consisted of about 500 wells that were measured in February 1986, September 1986, and February 1987. Water levels were measured monthly in about 70 wells, and 5 wells were monitored with continuous recorders. Groundwater and surface water samples were collected and analyzed for nitrate concentrations and specific conductance. Most of the water level network wells and selected surface-water sites were sampled in September 1986. Selected wells were sampled periodically from September 1986 through September 1987. (USGS)