Publications

The upper Alamosa River Basin contains areas that are geochemically altered and have associated secondary sulfide mineralization. Occurring with this sulfide mineralization are copper, gold, and silver deposits that have been mined since the 1870's. Weathering of areas with sulfide mineralization produces runoff with anomalously low pH and high metal concentrations; mining activities exacerbate th

Since the construction of Dillon Reservoir, in Summit County, Colorado, in 1963, its drainage area has been the site of rapid urban development and the continued influence of historical mining. In an effort to assess changes in water quality within the drainage area, sediment cores were collected from Dillon Reservoir in 1997. The sediment cores were analyzed for pesticides, polychlorinated biphen

The central High Plains aquifer is the primary source of water for domestic, industrial, and irrigation uses in parts of Colorado, Kansas, New Mexico, Oklahoma, and Texas. Water-level declines of more than 100 feet in some areas of the aquifer have increased the demand for water deeper in the aquifer. The maximum saturated thickness of the aquifer ranged from 500 to 600 feet in 1999. As the demand

In July 1999, a tracer-injection study was conducted concurrently with synoptic sampling to generate mass-load profiles in Wightman Fork near the Summitville Mine site. The mine site is located in the San Juan Mountains of southwestern Colorado at an elevation of about 3,500 meters above sea level. Metal loads increased substantially along the 2,815-meter study reach along the boundary of the mine

The historical and current (1998) water-quantity, water-quality, and aquatic-ecology conditions in the Gore Creek watershed are described as part of a study by the U.S. Geological Survey, done in cooperation with the Town of Vail, the Eagle River Water and Sanitation District, and the Upper Eagle Regional Water Authority. Interpretation of the available water-quantity, water-quality, and aquatic-e

Sulfonylurea (SU), sulfonamide (SA), and imidazolinone (IMI) herbicides are recently developed herbicides that function by inhibiting the action of a key plant enzyme, stopping plant growth, and eventually killing the plant. These compounds generally have low mammalian toxicity, but crop and non-crop plants demonstrate a wide range in sensitivity to SUs, SAs, and IMIs, with over a 10,000-fold diff

A comprehensive sampling network was implemented in the Alamosa River Basin from 1995 to 1997 to address data gaps identified as part of the ecological risk assessment of the Summitville Superfund site. Aluminum, copper, iron, and zinc were identified as the constituents of concern for the risk assessment. Water-quality samples were collected at six sites on the Alamosa River and Wightman Fork by

No abstract available.

Now available on the Internet is a web site for the U.S. Geological Survey's (USGS) National Water-Quality Assessment (NAWQA) Program-High Plains Regional Ground-Water Study. The purpose of the web site is to provide public access to a wide variety of information on the USGS investigation of the ground-water resources within the High Plains aquifer system. Typical pages on the web site include the

This report describes the environmental characteristics and water-quality characteristics of 12 hydrologic benchmark network streams in the Western United States. This information was compiled to aide in the interpretation and application of water-quality data collected as part of the Hydrologic Benchmark Network Program.

Over the last 25 years, industry and government have made large financial investments aimed at improving water quality across the Nation. Significant progress has been made; however, many water-quality concerns remain. In 1991, the U.S. Geological Survey (USGS) began implementing a full-scale National Water-Quality Assessment Program to provide consistent and scientifically sound information for m

No abstract available.