Publications

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 tributary

Nitrate (NO3) and other nutrients discharged by the Mississippi River are suspected of causing a zone of depleted dissolved oxygen (hypoxic zone) in the Gulf of Mexico each summer. The hypoxic zone may have an adverse affect on aquatic life and commercial fisheries. The amount of NO3 delivered by the Mississippi River to the Gulf of Mexico is well documented, but the relative contributions of diff

Selenium and salinity are water-quality issues in the Upper Colorado River Basin. Certain water bodies in the lower Gunnison River Basin, including the lower Gunnison River and the Uncompahgre River, exceed the State standard for selenium of 5 micrograms per liter. Remediation methods to reduce selenium and salt loading in the lower Gunnison River Basin were examined. A demonstration project in Mo

Algal community samples were collected at 15 sites in the Upper Colorado River Basin in Colorado as part of the National Water-Quality Assessment Program during water years 1996-97. Sites sampled were located in two physiographic provinces, the Southern Rocky Mountains and the Colorado Plateaus, and represented agricultural, mining, urban, and mixed land uses and background conditions. Algal sampl

Metals enter Little Cottonwood Creek in Salt Lake County, Utah, in drainage water that discharges from inactive mines in the watershed (fig. 1). As part of a study to evaluate the effects of this mine drainage on water quality, a sodium chloride tracer was injected into Little Cottonwood Creek during September 17-18, 1998. The purpose of the injection was to quantify stream discharge; to identify

Nitrate (NO3) and other nutrients discharged by the Mississippi River are suspected of causing a zone of depleted dissolved oxygen (hypoxic zone) in the Gulf of Mexico each summer. The hypoxic zone may have an adverse affect on aquatic life and commercial fisheries. The amount of NO3 delivered by the Mississippi River to the Gulf of Mexico is well documented, but the relative contributions of diff

Fountain and Monument Creeks, which drain parts of El Paso and Pueblo Counties in Colorado, have been sampled systematically by the U.S. Geological Survey for many years to obtain records of water-quality properties and constituents; the data are stored in the National Water Inventory System. Statistical summaries of these data indicate that they have spatial and temporal trends. Comparison of wat

The High Plains aquifer underlies 174,000 square miles in parts of eight States and includes eight primary hydrogeologic units, including the well-known Ogallala Formation. The High Plains aquifer is an important resource, providing water for 27 percent of the Nation?s irrigated agricultural lands in an otherwise dry landscape. Since the 1980?s there has been concern over the sustainability of the

A comprehensive water-quality sampling network was implemented by the U.S. Geological Survey from 1995 through 1997 at 12 tributary sites to the Alamosa River. The network was designed to address data gaps identified in the initial ecological risk assessment of the Summitville Superfund site. Tributaries draining hydrothermally altered areas had higher median values for nearly all measured propert

Spatial determinations of the metal loads in Wightman Fork can be used to identify potential source areas to the stream. In September 1997, a chloride tracer-injection study was done concurrently with synoptic water-quality sampling in Wightman Fork near the Summitville Mine site. Discharge was determined and metal concentrations at 38 sites were used to generate mass-load profiles for dissolved a

Nitrate (NO3) and other nutrients discharged by the Mississippi River combined with seasonal stratification of the water column are known to cause a zone of depleted dissolved oxygen (hypoxic zone) in the Gulf of Mexico each summer. About 120 water and suspended sediment samples collected in 1997 and 1998 from 24 locations in the Mississippi River Basin were analyzed for the isotope ratios δ15N an

Information on streamflow and surface-water and ground-water quality in Park County, Colorado, was compiled from several Federal, State, and local agencies. The data were reviewed and analyzed to provide a perspective of recent (1962-98) water-resource conditions and to help identify current and future water-quantity and water-quality concerns. Streamflow has been monitored at more than 40 sites i