Publications

Ground-water samples were collected during the summer of 1995 from 29 wells in the western part of the Cambrian-Ordovician aquifer in the Western Lake Michigan Drainages study unit of the National-Water Quality Assessment Program. Analyses of ground-water samples from these wells were used to provide an indication of waterquality conditions in this heavily used part of the aquifer. Ground-water sa

Peak flows were simulated for Scott Creek, just upstream from Sylva, in Jackson County, North Carolina, in order to provide Jackson County officials with information that can be used to improve preparation for and response to flash floods along the reach of Scott Creek that flows through Sylva. A U.S. Geological Survey rainfall-runoff model was calibrated using observed rainfall and streamflow dat

This report presents a model, MOC3D, that simulates three-dimensional solute transport in flowing ground water. The model computes changes in concentration of a single dissolved chemical constituent over time that are caused by advective transport, hydrodynamic dispersion (including both mechanical dispersion and diffusion), mixing (or dilution) from fluid sources, and mathematically simple chemic

As part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) program, an inventory of the biological and contaminant investigations for the Upper Colorado River Basin study unit was conducted. To enhance the sampling design for the biological component of the program, previous studies about the ecology of aquatic organisms and contaminants were compiled from computerized liter

The Garrison Diversion Unit project was authorized as part of the Pick-Sloan Missouri River Basin program to divert water from Lake Sakakawea to irrigation areas in North Dakota. A special Garrison Commission was created to evaluate an environmental concern that return flow from the irrigation areas might contain metals in toxic concentrations. This report summarizes the results of detailed invest

This report summarizes aquatic biological studies relevant to water-quality assessment that have been done in the Western Lake Michigan Drainages from 1891 to 1996. The objective of the summary was to compile sources of biological data for the U.S. Geological Survey's National Water-Quality Assessment Program. The studies are divided into four categories: (1) populations and community structure of

Large quantities of ground water are available for use from three regional aquifer systems in the central Midwest of the United States. Parts of the lowermost aquifer contain nearly immobile brine and may be hydrologically suitable for material storage or waste disposal. Results of numerical modeling and geochemical analyses confirm general concepts of ground-water flow in the regional aquifer sys

Stream water was locally recharged into shallow groundwater flow paths that returned to the stream (hyporheic exchange) in St. Kevin Gulch, a Rocky Mountain stream in Colorado contaminated by acid mine drainage. Two approaches were used to characterize hyporheic exchange: sub-reach-scale measurement of hydraulic heads and hydraulic conductivity to compute streambed fluxes (hydrometric approach) an

[No abstract available]

Arid sites commonly are assumed to be ideal for long-term isolation of wastes. Information on properties and variability of desert soils is limited, however, and little is known about how the natural site environment is altered by installation of a waste facility. During fall construction of two test trenches next to the waste facility on the Amargosa Desert near Beatty, NV, samples were collected

The occurrence and distribution of selected pesticides and their metabolites were investigated through the collection of 837 water-quality samples from 303 wells across the Midwest. Results of this study showed that five of the six most frequently detected compounds were pesticide metabolites. Thus, it was common for a metabolite to be found more frequently in groundwater than its parent compound.

Existing methods for measuring water imbibition rates are inadequate when imbibition rates are small (e.g., clay soils and many igneous rocks). We developed an improved laboratory method for performing imbibition measurements on soil or rock cores with a wide range of hydraulic properties. Core specimens are suspended from an electronic strain gauge (load cell) in a closed chamber while maintainin