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Results for “Ground-water Report”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

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At least 1,225 records · Page 68Linked to original sources
USGS1995

Postflood occurrence of selected agricultural chemicals and volatile organic compounds in near-surface unconsolidated aquifers in the upper Mississippi River basin, 1993

The historic stream flooding and intense rainfall across the upper Mississippi River Basin during summer 1993 had an immediate effect on near-surface unconsolidated aquifers by raising the water levels closer to the land surface . The objective of this study was to determine if this flooding also had immediate effects on groundwater quality . Water samples were collected during September and October 1993 from 110 wells completed in near-surface unconsolidated aquifers and were analyzed for herbicides, herbicide metabolites, inorganic nutrients, and volatile organic compounds. The results of these samples were compared with those obtained during summer 1991 or 1992. The difference was not statistically significant in the frequency of herbicide detection, total herbicide concentration, nitrate concentration, or the frequency of volatile organic compound detection between water samples collected in 1991 and 1992 and those collected in 1993 when all 110 wells were considered collectively . However, water samples from the Missouri River alluvial aquifer had a fourfold increase in the frequency of herbicide detection . There also appears to be a relation between increases in total herbicide concentration and the occurrence of stream flooding near a well. Water samples from wells that had at least a 20-percent increase in dissolved-oxygen concentration had the greatest frequency of substantial changes in total herbicide concentration and substantial increases in nitrate concentration . Increased dissolved-oxygen concentration could indicate areas where recharge has increased as a result of extensive stream flooding and intense rainfall . An inverse relation was determined between well depth and changes (increase or decrease) in total herbicide concentration . Water in shallow wells more quickly reflect changes in water quality in response to changes in recharge. Significantly more urban residential and industrial land use was within a 30-meter radius of the well for wells in which volatile organic compounds were detected. Because water moves more slowly along ground-water flow paths compared with surface-water runoff, additional information is required to determine long-term effects of the 1993 flood on ground-water quality.

upper Mississippi River basin↗
USGS1995

Ground Water Atlas of the United States: Segment 1, California, Nevada

California and Nevada compose Segment 1 of the Ground Water Atlas of the United States. Segment 1 is a region of pronounced physiographic and climatic contrasts. From the Cascade Mountains and the Sierra Nevada of northern California, where precipitation is abundant, to the Great Basin in Nevada and the deserts of southern California, which have the most arid environments in the United States, few regions exhibit such a diversity of topography or environment. Since the discovery of gold in the mid-1800's, California has experienced a population, industrial, and agricultural boom unrivaled by that of any other State. Water needs in California are very large, and the State leads the United States in agricultural and municipal water use. The demand for water exceeds the natural water supply in many agricultural and nearly all urban areas. As a result, water is impounded by reservoirs in areas of surplus and transported to areas of scarcity by an extensive network of aqueducts. Unlike California, which has a relative abundance of water, development in Nevada has been limited by a scarcity of recoverable freshwater. The Truckee, the Carson, the Walker, the Humboldt, and the Colorado Rivers are the only perennial streams of significance in the State. The individual basin-fill aquifers, which together compose the largest known ground-water reserves, receive little annual recharge and are easily depleted. Nevada is sparsely populated, except for the Las Vegas, the Reno-Sparks, and the Carson City areas, which rely heavily on imported water for public supplies. Although important to the economy of Nevada, agriculture has not been developed to the same degree as in California due, in large part, to a scarcity of water. Some additional ground-water development might be possible in Nevada through prudent management of the basin-fill aquifers and increased utilization of ground water in the little-developed carbonate-rock aquifers that underlie the eastern one-half of the State. The potential problem of withdrawals in excess of natural recharge, however, will require careful management of ground-water withdrawals.

California, Nevada↗
USGS1955

An electrical device for computing theoretical draw-downs of ground-water levels

The construction, calibration and use of an electrical "slide rule" for computing theoretical drawdowns of ground-water levels are described. The instrument facilitates the computation of drawdowns under given conditions of discharge or recharge by means of the Theis nonequilibrium equation. It is simple to construct and use and can be a valuable aid in ground-water studies.

Open-File Report↗
USGS1982

Water resources of the Gig Harbor Peninsula and adjacent areas, Washington

The study area is a remnant of a glacial-drift plain nearly surrounded by marine embayments. A water-resources appraisal was made because the area is experiencing rapid population growth. Additional ground water is available for use in the study area. At least 11 cubic feet per second, five times the 1978 rate of use, can probably be obtained. Ground-water quality is generally very good, with minor problems of excess iron, manganese, dissolved solids, chloride, and coliform bacteria. Total flow through the hydrologic system is at an average rate of 254 cubic feet per second, which includes 93 cubic feet per second of ground-water recharge. (USGS)

Open-File Report↗
USGS1982

Dissolved-solids concentration in water from the upper permeable zone of the Tertiary limestone aquifer system, southeastern United States

The Tertiary limestone aquifer system of the southeastern United States is a thick sequence of carbonate rocks that range from Paleocene to Miocene in age and are hydraulically connected in varying degrees. The upper permeable zone of the aquifer system consists of the Tampa, Suwannee, Ocala, and Avon Park Limestones. Based on analyses of water samples from 591 selected wells, a map is presented which shows dissolved-solids concentration in ranges of 0-250, 251-500, 501-1,000, and greater than 1,000 mg/. Dissolved-solids concentrations and hydrochemical facies developed within the aquifer system are related to the predevelopment and modern-day ground-water flow system.

Alabama, Florida, Georgia, South Carolina↗
USGS1997

User's guide for MODTOOLS: Computer programs for translating data of MODFLOW and MODPATH into geographic information system files

MODTOOLS is a set of computer programs for translating data of the ground-water model, MODFLOW, and the particle-tracker, MODPATH, into a Geographic Information System (GIS). MODTOOLS translates data into a GIS software called ARC/INFO. MODFLOW is the recognized name for the U.S. Geological Survey Modular Three-Dimensional Finite-Difference Ground-Water Model. MODTOOLS uses the data arrays input to or output by MODFLOW during a ground-water flow simulation to construct several types of GIS output files. MODTOOLS can also be used to translate data from MODPATH into GIS files. MODPATH and its companion program, MODPATH-PLOT, are collectively called the U.S. Geological Survey Three-Dimensional Particle Tracking Post-Processing Programs. MODPATH is used to calculate ground-water flow paths using the results of MODFLOW and MODPATH-PLOT can be used to display the flow paths in various ways. MODTOOLS uses the particle data calculated by MODPATH to construct several types of GIS output. MODTOOLS uses particle information recorded by MODPATH such as the row, column, or layer of the model grid, to generate a set of characteristics associated with each particle. The user can choose from the set of characteristics associated with each particle and use the capabilities of the GIS to selectively trace the movement of water discharging from specific cells in the model grid. MODTOOLS allows the hydrogeologist to utilize the capabilities of the GIS to graphically combine the results of the particle-tracking analysis, which facilitates the analysis and understanding of complex ground-water flow systems.

Open-File Report↗
USGS1999

Hydrology of the coastal lowlands aquifer system in parts of Alabama, Florida, Louisiana, and Mississippi

Existing data on water levels, water use, water quality, and aquifer properties were used to construct a multilayer digital model to simulate flow in the aquifer system. The report describes the geohydrologic framework of the aquifer system, and the development, calibration, and sensitivity analysis of the ground-water-flow model, but it is primarily focused on the results of the simulations that show the natural flow of ground water throughout the regional aquifer system and the changes from the natural flow caused by development of ground-water supplies.

Alabama, Florida, Louisiana, Mississippi↗
USGS2007

Ground-Water Quality in the Vicinity of Coal-Refuse Areas Reclaimed with Biosolids in Fulton County, Illinois

The Metropolitan Water Reclamation District of Greater Chicago has applied biosolids, followed by revegetation, to reclaim three coal-refuse areas. Most of the reclamation at the three sites was done from 1989 through 1992, and included the application of lime, clay, and various loads of biosolids up to 1,000 dry tons per acre. Water samples collected from 12 monitoring wells installed in the vicinity of the three reclaimed coal-refuse areas were analyzed to better understand the hydrogeology and water-quality effects. Ground water probably flows along preferential paths in the disturbed coal-refuse areas, and is impeded by undisturbed glacial till. Most of the samples contained elevated concentrations of sulfate, iron, and manganese, constituents associated with ground water in coal-mined areas. Concentrations of aluminum, cadmium, nickel, or zinc were somewhat elevated in samples from four wells, and greatest in water samples with pH less than 5. The smaller nutrient concentrations indicate that the applied biosolids are not identifiably affecting nutrients or metal concentrations in shallow ground water near the refuse piles. The coal refuse likely is the primary influence on the chemical characterization of ground-water in the area.

Scientific Investigations Report↗
USGS1977

Hydrologic evaluation of the upper Duchesne River Valley, northern Uinta Basin area, Utah

The upper Duchesne River valley was studied during 1971-74 as part of an investigation of the northern Uinta Basin area, Utah and Colorado. The purpose of the study was to determine the relation of ground water to surface water, to estimate the quantity of ground water that moves to the Duchesne River, and to assess the probable effect of increased ground-water withdrawal on streamflow.

Utah↗