Publications

Twenty-two of 43 pesticides analyzed were detected in 128 water samples collected from Tucsawhatchee Creek, the Little River, and the Withlacoochee River. These streams drain agricultural basins in south-central Georgia and were sampled from March 1993 through June 1995. Herbicides were detected more frequently than insecticides. The most frequently detected herbicides were atrazineand metol

No abstract available.

This report and the attached 3 1/2-inch diskette contain, in compressed format, the data sets for the model of ground-water flow in the Cretaceous-age Coastal Plain aquifers of South Carolina. The data sets can be uncompressed using a program provided with this report. The uncompressed files require approximately 3.7 megabytes of disk space on an IBM-compatible microcomputer1 using the MS-DOS oper

Spatial distributions of metals and trace elements, nutrients, and pesticides and polychiorinated biphenyls (PCB's) in bed sediment were characterized using data collected from 1969 through 1990 and stored in the U.S. Geological Survey's National Water Data Storage and Retrieval (WATSTORE) system and the U.S. Environmental Protection Agency's Storage and Retrieval (STORET) system databases. Bed-se

The U.S. Geological Survey (USGS) is the Federal Government's primary source of data on the quantity and quality of the Nation's water resources, its principal civilian map making agency, and its primary provider of information on natural hazards and mineral, energy, and biological resources. The USGS makes unbiased scientific information available equally to all interested parties. Most USGS work

No abstract available.

The wedge of sediments present beneath the Coastal Plain of South Carolina and adjacent parts of Georgia and North Carolina consists of sand, silt, clay, and limestone. These strata have been subdivided into six regional aquifers: the surficial aquifer, the Floridan aquifer system, the Tertiary sand aquifer, the Black Creek aquifer, the Middendorf aquifer, and the Cape Fear aquifer. Intervening co

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

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

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.

A nonnormal and heteroscedastic Tobit model is used to determine the primary factors that affect nitrate concentrations in near-surface aquifers, using data from the U.S. Geological Survey collected in 1991. Both normality and homoscedasticity of errors are rejected, justifying the use of a nonnormal and heteroscedastic model. The following factors are found to have significant impacts on nitrate

As part of a multidisciplinary program to assess the potential long-term impacts of offshore oil and gas exploration and production activities in the Gulf of Mexico, sediment chemical analyses and porewater toxicity tests were conducted in the vicinity of five offshore platforms. Based on data from sea urchin fertilization and embryological development assays, toxicity was observed near four of th