Publications

Mercury has been well known as an environmental pollutant for several decades. As early as the 1950's it was established that emissions of mercury to the environment could have serious effects on human health. These early studies demonstrated that fish and other wildlife from various ecosystems commonly attain mercury levels of toxicological concern when directly affected by mercury-containing emi

The U.S. Geological Survey (USGS), as part of its National Water-Quality Assessment (NAWQA) program has been collecting and analyzing water samples from streams in the South Platte River Basin in Colorado, Nebraska, and Wyoming to characterize the water-quality conditions within the basin. Nutrients (nitrogen and phosphorus compounds) have been a focus of this sampling effort because of their pote

The U.S. Geological Survey is conducting an assessment of water quality in the Trinity River Basin as part of the National Water-Quality Assessment Program. During the planning phase of this study, existing information on nutrients and suspended sediment was compiled and analyzed. A total of about 5,700 water-quality samples were analyzed from local, State, and Federal agencies. Of these, about 4,

A study of the Mississippi River alluvium near Muscatine, Iowa, was conducted to evaluate ground-water flow and water quality using data collected from June 1992 through June 1994. The study area included approximately 80 square miles in parts of Muscatine and Louisa Counties in Iowa and Rock Island and Mercer Counties in Illinois. A steady-state, ground-water flow model was constructed using Febr

Dye-tracer analyses were done in the Willamette River and nine tributaries of the Willamette River, from April 1992 to July 1993 during low to medium stream discharge conditions, to determine velocity and dispersion. These dye-tracer analyses provided information on time of arrival, peak concentration, and the occurrence and longevity of a constituent dissolved in streamflow at various discharges.

Fifty-four major streams discharging directly to the Gulf of Mexico and having drainage areas exceeding 200 square miles were identified in the United States. Forty-four U.S. Geological Survey streamflow-gaging stations along the Gulf of Mexico with at least 40 years of daily streamflow data also were identified. These stations include most of the major streams and comprise 95 percent of the drain

Annual mean streamflow and annual minimum and maximum daily mean streamflows were compared with associated annual index precipitation for sites on the main channels and tributaries of four major rivers that discharge directly into the Gulf of Mexico. Long- and short-term precipitation trends were identified for selected streamflow stations with at least 40 years of record. Long-term temporal trend

Borax Lake is located in southeastern Oregon, within the Alvord Valley Known Geothermal Resource Area. Borax Lake is a large hot spring; there are more than 50 smaller hot springs within about one-half mile to the north of the lake. Several geothermal exploration wells have been drilled near Borax Lake, and there is concern that development of the geothermal resources could affect the lake and nea

Two identical cone splitters, devices designed to split water and its suspended solids into equal aliquots for semi-volatile organic chemical and trace element analyses, were evaluated for their precision. The water-splitting evaluations consisted of experiments to test the effect of water volume, the effect of combining outlet ports, and the effect of different techniques of water introduction. T

INTRODUCTION The objective of the National Water Quality Assessment (NAWQA) Program of the U.S. Geological Survey is to describe the status and trends of the Nation's water quality with respect to natural features of the environment and human activities or land-use. Pesticides are a major water-quality issue in the San Joaquin Valley of California (fig. 1), and pesticide residues may be transpo

Because of the potentially harmful effect of improper waste disposal on water resources in the arid West, comprehensive laboratory and field studies are critical to identifying likely contaminant-release pathways and the potential for waste migration at arid sites. However, the quandary for those charged with assessment of the suitability of potential disposal sites is that site characterization a

No abstract available.