Publications

Unconfined and the upper confined aquifers in glacial drift are the primary sources of water in a 1,600 square-mile area including parts of Beltrami, Cass, Clearwater, and Hubbard Counties, Minnesota. The unconfineddrift aquifer consists of coarse sand and gravel in the center of the study area. The total area underlain by the unconfined-drift aquifer is approximately 550 square miles. The unconfi

This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the Red Lake Indian Reservation Tribal Council, to evaluate the water resources of the contiguous Red Lake Indian Reservation. Water resources of the contiguous Red Lake Indian Reservation meet the present (1989) needs for potable supply and other household uses. In addition, they provide ecological

Accurate delineation of recharge areas for wells is an important requisite to protecting ground-water quality. Zones of transport and zones of contribution are two types of recharge areas that can be delineated. Analytical-calculation, numerical-modeling, and hydrogeologic-mapping methods were used to delineate recharge areas for two high-capacity (greater than about 200 gallons per minute) wells

The quality of surface and ground water can be related to various physical factors such as land use, soil type, geology, and depth to water table. Land use in Dakota County, Minnesota, is changing: urbanization and industrialization in the north and increasing irrigation and application of agricultural chemicals in the central part of the county. The U.S. Geological Survey, in cooperation with the

The upper Mississippi River basin from Royalton to Hastings, Minnesota, includes seven subbasins in east-central Minnesota that cover an area of 8,500 square miles. Results of a study, using data from the Minnesota Pollution Control Agency, Metropolitan Waste Control Commission, and the U.S. Geological Survey, indicate that selected water-quality characteristics differ significantly among subbasin

Ground-water flow in the confined- and unconfined-drift aquifers in the Brooten-Belgrade area of west-central Minnesota was simulated with a three-dimensional finite-difference ground-water-flow model. Model results indicate that about 96 percent of the total inflow to the modeled area is from precipitation. Discounting evapotranspiration, 63 percent of the total outflow is ground-water discharge

Ground-water flow in the St. Peter-Prairie du Chien-Jordan aquifer was studied in a 700 square-mile area surrounding Rochester, Minnesota. The aquifer consisting of sandstone, limestone, and dolomite is locally confined by the Decorah-Platteville-Glenwood sequence of shales and limestones. Regional flow in the aquifer is from a ground-water divide on the western, southern, and eastern sides of the

No abstract available. 

In 1991, the U.S. Geological Survey (USGS) began to implement a full-scale National Water-Quality Assessment (NAWQA) program. The long-term goals of the NAWQA program are to describe the status and trends in the quality of a large, representative part of the Nation's surface- and ground-water resources, and to provide a sound scientific understanding of the primary natural and human factors affect

Groundwater inflow and outflow contributions to the hydrologic budget of lakes can be determined using a stable isotope (18O/16O) mass balance method. The stable isotope method provides a way of integrating the spatial and temporal complexities of the flow field around a lake, thereby offering an appealing alternative to the traditional time and labor intensive methods using seepage meters and an

A three-dimensional groundwater flow and solute transport model was calibrated to a plume of water described by measurements of δ18O and used to calculate groundwater inflow and outflow rates at a lake in northern Wisconsin. The flow model was calibrated to observed hydraulic gradients and estimated recharge rates. Calibration of the solute transport submodel to the configuration of a stable isoto

A reconnaissance study was conducted of 22 streams tributary to Green Bay to determine whether any of the streams contribute toxic substances to the bay. This effort was part of a comprehensive investigation of Green Bay funded by the U.S. Environmental Protection Agency, Great Lakes National Program Office. The U.S. Geological Survey sampled the bottom sediments and water columns of 11 streams tr