Publications

The Chickies Quartzite, a Lower Cambrian-age formation compromised of quartzite and slate overlying a basal conglomerate, forms a narrow ridges and crops out discontinuously over 112 square miles in the Piedmont physiographic province of southeastern Pennsylvania. The formation is a low-yielding, fractured- rock, water-table aquifer recharged primarily by local precipitation. It is the sole source

Ground-water flow in the karst-terrane aquifers of southeastern Minnesota is not well defined. Variable fracture patterns in the bedrock affect permeability. Techniques to predict the effects of fracture patterns on ground-water flow in the karst-terrane aquifers of southeastern Minnesota are unavailable. The use of such techniques may be useful to officials responsible for the management and prot

Three aquifers and two confining units have been delineated within the drift underlying the area near the site of a former coal-tar distillation and wood-preserving plant in St. Louis Park, Minnesota. The hydrogeologic units of the drift, in descending order, are the upper drift aquifer, the upper drift confining unit, the middle drift aquifer, the lower drift confining unit. and the lower drift a

This report describes the equipment and procedures used for on-site filtration of surface-water and ground-water samples for determination of organic compounds. Glass-fiber filters and a positive displacement pumping system are suitable for processing most samples for organic analyses. An optional system that uses disposable in-line membrane filters is suitable for a specific gas chromatography/ma

A statewide study of flood magnitude and frequency in urban areas of Georgia was made to develop methods of estimating flood characteristics at ungaged urban sites. A knowledge of the magnitude and frequency of floods is needed for the design of highway drainage structures, establishing flood- insurance rates, and other uses by urban planners and engineers. A U.S. Geological Survey rainfall-runof

Rainfall and streamflow data collected in Lake County, Ill., from March 1990 through September 1993 were used to (1) calibrate a rainfall-runoff model for an area encompassing three watersheds (individual areas of 17.2, 35.7, and 37.0 mi2 (square miles) and (2) verify the regional model parameter set obtained from the calibration by applying the parameter set to rainfall-runoff models for an addit

The assimilative capacities of selected reaches of the Waccamaw River and the Atlantic Intracoastal Waterway near Myrtle Beach, South Carolina, were determined using results from water-quality simulations by the Branched Lagrangian Transport Model. The study area included tidally influenced sections of the Waccamaw River, the Pee Dee River, Bull Creek, and the Atlantic Intracoastal Waterway. Hydro

A reconnaissance study was conducted during 1992-93 to collect background hydrogeologic and agricultural-chemical data for the South Skunk River alluvial aquifer near Ames, Iowa. Observation wells were drilled to characterize the surficial geologic materials of a field-scale study site and to provide locations for collecting waterlevel and agricultural-chemical data. Walnut Creek, a tributary to t

Desert Valley is a 1,200-square-mile, north- trending, structural basin, about 30 miles northwest of Winnemucca, Nevada. Unconsolidated basin-fill deposits exceeding 7,000 feet in thickness constitute the primary ground-water reservoir. Dewatering operations at an open-pit mine began in the Spring of 1985 in the northeast part of Desert Valley. Ground-water withdrawal for mine dewatering in 1991 w

Located in the Devils Lake Basin, North Dakota, receives and stores runoff from the northern section of the basin and recharges Devils Lake. Hydrologic and water- quality conditions can vary greatly in the basin, resulting in potential economic damage. This report describes the seasonal and spatial variations in surface-water quality in the chain of lakes and its tributaries.   Long-term trends in

Calf Creek Spring provides drinking water to users of Calf Creek Campground, which is operated by the Bureau of Land Management in southcentral Utah. Use of all methods and tools available indicates that surface water from Calf Creek does not contribute to the discharge of Calf Creek Spring.Microscopic Particulate Analysis of spring water indicates that the spring has a low risk of surface-water c

Pesticides are used extensively in the largely agricultural Red River of the North (Red River) Basin, but, unlike many other agricultural basins, only small amounts are routinely detected in samples from streams in the basin. The pesticides detected comprise less than 2 percent of the amount applied and usually are at concentrations far less than established drinking water standards. Most of the d