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The apparatus and methods used for the automatic, colorimetric determinations of dissolved nutrients (nitrate plus nitrite, nitrite, ammonium and orthophosphate) in natural waters are described. These techniques allow for the determination of nitrate plus nitrite for the concentration range 0.02 to 8 mg/L (milligrams per liter) as N (nitrogen); for...

Suspended-solids concentration data were collected in San Francisco Bay during water year 1994. Optical backscatterance sensors and water samples were used to monitor suspended solids continuously at two sites in Suisun Bay, two sites in Central San Francisco Bay, and three sites in South San Francisco Bay. Sensors were positioned...

A dynamical-systems approach was developed and evaluated for computing ice-affected streamflow. The approach provides for dynamic simulation and parameter estimation of site-specific equations relating ice effects to routinely measured environmental variables. Comparison indicates that results from the dynamical-systems approach ranked higher than results from 11 analytical methods previously investigated on...

Landslides cause much damage to property throughout the metropolitan area of Cincinnati, Ohio. Most landslides occur in unconsolidated deposits, including colluvium, till, glacial lake clays, and man-made fill derived from colluvium and glacial deposits. Landslides in thin colluvium are widespread on steeper slopes that wall the valleys of the Ohio...

No abstract available....

Road-salt contamination of public and private water supplies has become a serious and costly problem, particularly in the Northeast and Midwest. For example, reports of road-salt contamination from 100 of the 351 municipalities in Massachusetts from 1983 through 1990 required an expenditure of about 2.5 million dollar to investigate and remediate. Nationally, an estimated 10 million dollar are spent annual...

Most functions of the U.S. Geological Survey (USGS), Water Resources Division (WRD) require employees to participate in numerous field activities ranging from routine meetings with cooperators, other federal and public officials, and private citizens to potentially hazardous assignments, such as making flood measurements and scuba diving to service underwater instruments....

Between December 1993 and March 1994, 27 wells were installed at 12 sites near the J4 test cell at Arnold Engineering Development Center in Coffee County, Tennessee. The wells ranged from 28 to 289 feet deep and were installed to provide information on subsurface lithology, aquifer characteristics, ground-water levels, and...

Water-quality data were collected and compiled for 59 surface-water stations in the Arkansas River Basin of Colorado. The purpose of the data collection was to describe selected water-quality characteristics of the Arkansas River from the headwaters downstream to the Colorado-Kansas State line. Data are presented for 19 Arkansas River stations,...

Twenty-three multiple-well (nested) monitoring sites were constructed in the western part of the Santa Clara-Calleguas Hydrologic Unit and ground-water basin between October 1989 and May 1994. This report is a compilation of the data collected at these sites from October 1989 through April 1995 and includes location and design of...

This report presents selected hydrologic data for the East Poplar oil field, located in the south-central part of the Fort Peck Indian Reservation in northeastern Montana. Data about the occurrence, quantity, and quality of ground and surface water are presented in tabular form. The tables contain records of privately owned...

A study was conducted to investigate general ground-water- quality conditions and contaminant locations in the Rio Grande Valley in the vicinity of Albuquerque, New Mexico. Water samples from 36 observation wells in 12 well nests were analyzed. The well nests are located along three roads near the Rio Grande--two...

Bay Mills Indian Community (BMIC) near Brimley, Mich. (fig. 1), with a population of about 1,000, needs hydrogeologic and ground-water-quality information to help assure a reliable ground-water supply for future economic development. Currently (1995), three wells supply water to a housing development adjacent to Mission Hill, but the remainder of...

The Silver Bell Mountains, 50 km northwest of Tucson, Arizona, are a mountain range in the transition from the higher-relief mountains of southeastern Arizona to the low-relief ranges of the western Arizona deserts. The Silver Bell Mountains include the area of the Silver Bell mining district (Richard and Courtright, 1966)...

No abstract available....

Cerro Rico de Potosi, Bolivia, is the world's largest silver deposit and has been mined since the sixteenth century for silver, and for tin and zinc during the twentieth century, together with by-product copper and lead. The deposit consists primarily of veins that cut an altered igneous body that we...

No abstract available....