Publications

Organic petrography has been proposed as a tool for characterizing the heterogeneous organic matter present in soil and sediment samples. A new simplified method is proposed as a quantitative means of interpreting observed sorption behavior for phenanthrene and different soils and sediments based on their organic petrographical characterization. This method is tested under singe solute...

In the 20 years since cleanup of contaminated groundwater has been a high priority in the United States, recognition of both the scope of the problem and the technical difficulties involved has grown steadily. Estimates of the number of hazardous waste sites where groundwater may be contaminated vary between 300,000 and 400,000 nationwide [NRC, 1994]. Legislation passed in the 1980s by...

An analytical method using high-performance liquid chromatography/mass spectrometry (HPLC/MS) was developed by the U.S. Geological Survey in 1999 for the analysis of selected chloroacetanilide herbicide degradation compounds in water. These compounds were acetochlor ethane sulfonic acid (ESA), acetochlor oxanilic acid (OXA), alachlor ESA, alachlor OXA, metolachlor ESA, and metolachlor...

Historic mining in Little Cottonwood Canyon in Utah has left behind many mine drainage tunnels that discharge water to Little Cottonwood Creek. To quantify the major sources of mine drainage to the stream, synoptic sampling was conducted during a tracer injection under low flow conditions (September 1998). There were distinct increases in discharge downstream from mine drainage and major...

A study of the water resources of the Dutch Flats area in the western part of the North Platte Natural Resources District, western Nebraska, was conducted from 1995 through 1999 to describe the surface water and hydrogeology, the spatial distribution of selected water-quality constituents in surface and ground water, and the surface-water/ground-water interaction in selected areas. This...

One or more pesticides were detected with one or more volatile organic compounds (VOCs) in more than 95% of samples collected from 30 public supply and 95 monitoring wells screened in the unconsolidated surficial aquifer system of southern New Jersey, USA. Overall, more than 140,000 and more than 3,000 unique combinations of pesticides with VOCs were detected in two or more samples from...

The U.S. Geological Survey, in collaboration with the U.S. Environmental Protection Agency, the American Water Works Association, and the American Water Works Service Company, completed a targeted national reconnaissance survey of selected radionuclides in public ground-water supplies. Radionuclides analyzed included radium-224 (Ra-224), radium-226 (Ra-226), radium-228 (Ra-228), polonium...

The Norman Landfill was selected for study as part of the U.S. Geological Survey Toxic Substances Hydrology Program in 1994. The landfill is located south of the City of Norman on alluvial deposits of the Canadian River. Type of waste deposited in the landfill from 1922 to 1973 was largely unrestricted and may include substances now recognized as hazardous. Dissolved and suspended...

An aquifer test conducted in a sand and gravel, glacial outwash deposit on Cape Cod, Massachusetts was analyzed by means of a model for flow to a partially penetrating well in a homogeneous, anisotropic unconfined aquifer. The model is designed to account for all significant mechanisms expected to influence drawdown in observation piezometers and in the pumped well. In addition to the...

We report a new method for measurement of the isotopic composition of nitrate (NO3-) at the natural-abundance level in both seawater and freshwater. The method is based on the isotopic analysis of nitrous oxide (N2O) generated from nitrate by denitrifying bacteria that lack N2O-reductase activity. The isotopic composition of both nitrogen and oxygen from nitrate are accessible in this...

No abstract available.

This report describes a model for simulating transient, Variably Saturated, coupled water-heatsolute Transport in heterogeneous, anisotropic, 2-Dimensional, ground-water systems with variable fluid density (VST2D). VST2D was developed to help understand the effects of natural and anthropogenic factors on quantity and quality of variably saturated ground-water systems. The model solves