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Research about Georgia

Source-linked reports with geographic coverage including Georgia.

At least 433 records · Page 24Linked to original sources
USGS1991

Ground-water resources of the south metropolitan Atlanta region, Georgia

Ground-water resources of the nine county south metropolitan Atlanta region were evaluated in response to an increased demand for water supplies and concern that existing surface water supplies may not be able to meet future supply demands. Previous investigations have suggested that crystalline rock in the study area has low permeability and can not sustain well yields suitable for public supply. However, the reported yield for 406 wells drilled into crystalIine rock units in this area ranged from less than 1 to about 700 gallons per minute, and averaged 43 gallons per minute. The reported flow from 13 springs ranged from 0.5 to 679 gallons per minute. The yield of 43 wells and flow from five springs was reported to exceed 100 gallons per minute. Most of the high-yielding wells and springs were near contact zones between rocks of contrasting lithologic and weathering properties. The high-yielding wells and springs are located in a variety of topographic settings: hillsides, upland draws, and hilltops were most prevalent. The study area, which includes Henry, Fayette, Coweta, Spalding, Lamar, Pike, Meriwether, Upson and Talbot Counties, is within the Piedmont physiographic province except for the southernmost part of Talbot County, which is in the Coastal Plain physiographic province. In the Piedmont, ground-water storage occurs in joints, fractures and other secondary openings in the bedrock, and in pore spaces in the regolith. The most favorable geologic settings for siting highyielding wells are along contact zones between rocks of contrasting lithology and permeability, major zones of fracturing such as the Towaliga and Auchumpkee fault zones, and other numerous shear and microbreccia zones. Although most wells in the study area are from 101 to 300 feet deep, the highest average yields were obtained from wells 51 to 100 feet deep, and 301 to 500 feet deep. Of the wells inventoried, the average diameter of well casing was largest for wells located on hills and ridges, possibly indicating a preference for such topographic locations by cities and industrial users who typically develop larger diameter wells than do domestic users. Generally, for a given depth range or well diameter, the highest yielding wells were obtained in draws and valleys, followed by hills and ridges and slopes and flats. In 1985, wells and springs supplied about 16 million gallons per day or 37 percent of the total water withdrawn in the area. Average recharge to the aquifers in the upper Flint River basin, which constitutes 66 percent of the area, was estimated to be about 575 million gallons per day. Groundwater recharge in this basin ranged from 414 million gallons per day during an average dry year, to 77 million gallons per day during an average wet year. During the severe drought of 1954, the estimated recharge was 70 million gallons per day. Ground water in the study area generally is suitable for most uses. With the exception of local occurences of excessive iron, fluoride, and manganese, concentrations of total and/or dissolved constituents generally meets State and Federal drinking water standards. Ground-water quality may be affected by the presence of radionuclides associated with the decay of uranium found in igneous and metamorphic rocks.

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USGS1990

Modelling streamwater chemistry as a mixture of soilwater end-members - An application to the Panola Mountain catchment, Georgia, U.S.A.

Streamwater chemistry at Panola Mountain research catchment, Georgia, U.S.A., is explained as a mixture of representative soilwater solutions that are considered to be temporally invariant to a first approximation. The selection of three end-members from all sampled soil waters is evaluated by comparing the observed and predicted streamwater concentration of six solutes (alkalinity, sulfate, sodium, magnesium, calcium and dissolved silica), which are assumed to mix conservatively, and by assessing the consistency of the implied hydrograph separation with the hydrological mechanisms that are believed to be operating in this catchment. The percentage of variation in the streamwater solute concentrations explained by the end-member mixing analysis (EMMA) ranges from 82 to >97%, and the hydrograph separation is, intuitively, physically reasonable. If the correct end-members have been identified, the streamwater chemical response to different levels of acidic deposition can be predicted by examining the change in each end-member under different loads; no hydrological model is required. If a traditional hydrochemical model, which is driven by rainfall quantity and quality, is desired, this analysis provides an indication of the model structure that would be necessary to reproduce both streamwater and soilwater chemistry.

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USGS1990

Effect of faults on fluid flow and chloride contamination in a carbonate aquifer system

A unified, multidiscipline hypothesis is proposed to explain the anomalous pattern by which chloride has been found in water of the Upper Floridan aquifer in Brunswick, Glynn County, Georgia. Analyses of geophysical, hydraulic, water chemistry, and aquifer test data using the equivalent porous medium (EPM) approach are used to support the hypothesis and to improve further the understanding of the fracture-flow system in this area. Using the data presented herein we show that: (1) four major northeast-southwest trending faults, capable of affecting the flow system of the Upper Floridan aquifer, can be inferred from structural analysis of geophysical data and from regional fault patterns; (2) the proposed faults account for the anomalous northeastward elongation of the potentiometric surface of the Upper Floridan aquifer; (3) the faults breach the nearly impermeable units that confine the Upper Floridan aquifer from below, allowing substantial quantities of water to leak vertically upward; as a result, aquifer transmissivity need not be excessively large (as previously reported) to sustain the heavy, long-term pumpage at Brunswick without developing a steep cone of depression in the potentiometric surface; (4) increased fracturing at the intersection of the faults enhances the development of conduits that allow the upward migration of high-chloride water in response to pumping from the Upper Floridan aquifer; and (5) the anomalous movement of the chloride plume is almost entirely controlled by the faults.

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USGS1990

Water resources data, Georgia, water year 1989

Water resources data for the 1989 water year for Georgia consists of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs; ground-water levels; and precipitation quality. This report contains discharge records of 118 gaging stations; stage for 27 gaging stations; stage and contents for 18 lakes and reservoirs; water quality for 105 continuing-record stations; peak stage and discharge only for 73 crest-stage partial-record stations and 8 miscellaneous sites water levels of 25 observation wells; and water quality for 1 precipitation-quality site. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in Georgia.

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USGS1990

Flood frequency of the Savannah River at Augusta, Georgia

To fill an increasing need for reliable information on floods of various recurrence intervals on the Savannah River a flood-frequency relation was developed for the long-term gaging station at Augusta, Georgia. The flood-frequency analysis was complicated by the fact that the Savannah River upstream of Augusta has experienced increasing regulation of flow caused by three large dams constructed since 1952. The pre-impoundment period was important to the flood-frequency analysis because it included a number of large floods that, even when adjusted for regulation, exceed all floods since 1952. A reservoir routing model was used to adjust nine such floods for the effects of regulation, and to develop a relation for estimating regulated peak discharges for additional unregulated floods. The 1% chance exceedance flood for regulated conditions on the Savannah River at Augusta was computed as 180,000 cu ft/sec. (USGS)

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USGS1989

Geochemical survey of the Chattahoochee Roadless Area, Towns, Union, and White counties, Georgia

Th U.S. Geological Survey made a reconnaissance geochemical survey of the Chattahoochee Roadless Area (fig. 1) to search for unexposed mineral deposits which might be recognized by a geochemical signature in the abundance or distribution patterns of trace elements. As part of a regional geochemical reconnaissance, M/ Hurst (University of Georgia) collected 51 fine-grained stream-sediment samples and 45 planned-concentrate samples of alluvial gravels in the Chattahoochee study area (see figure 1). A.E. Nelson, in conjunction with detailed geologic mapping (Nelso, 1983), collected 10 rock-chip samples for geochemical analysis in addition to a large number of hand specimens for thin-section study. In order to evaluate isolated anomalies indicated by the earlier sampling, R.P. Koeppen, D.M. Sutphin, and P.D. Schruben collected several additional panned-concentrate, stream-sediment, and rock samples from the area in 1986. Both the geologic study by Nelson (1983) and this geochemical survey provide the basis for our mineral-resource assessment of the Chattahoochee Roadless Area (Nelson and others, 1983).

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USGS1989

Geochemical survey of the Blood Mountain Roadless Area, Union and Lumpkin counties, Georgia

The U.S. Geological Survey (USGS) made a reconnaissance geochemical survey of the Blood Mountain Roadless Area to search for unexposed mineral deposits which might be recognized by a geochemical signature in the abundance of distribution patterns of trace elements. Forty five fine-grained stream-sediment samples and 45 panned-concentrate samples were collected in the Blood Mountain study area (fig. 1). A.E. Nelson, in conjunction with detailed geologic mapping, collected 13 rock-chip samples for geochemical analysis, in addition to a large number of hand specimins for thin-section study. Nelson's geologic study (1983), combined with this geochemical survey, provide the basis for our mineral-resource assessment of the Blood Mountain Roadless Area (Koeppen and others, 1983).

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USGS1989

Humic substances in the Suwannee River, Georgia; interactions, properties, and proposed structures

Humic substances as a collective term and humic and fulvic acids as specific terms are not household words. For about a century, these terms belonged to the domain of the soil scientist. Even^though their chemical structures remained elusive, they were recognized as important entities in soil. During the past decade or so, there has been a renewed interest in humic substances in soil and water. Such interest has been the result of improved analytical instrumentation, and by a need to understand the structure and function of natural organic substances in water. A responsibility of the U.S. Geological Survey is to assess the Nation's water resources; this includes water quality, which is the study of material in water. Such material may be suspended, colloidal, or in true solution. Because humic substances are a major carbon source in water, they have received attention by Geological Survey scientists. This attention has been a major focus by members of the Geological Survey's organic-chemistry group. For more than a decade, this group has collected samples, made analyses, and worked toward determining the structures and function of humic substances in water. Their work has brought worldwide recognition to the field, and in 1981, through Geological Survey support, they helped organize the International Humic Substances Society, which held its first meeting in Estes Park, Colorado, in August 1983. At the second meeting of the Society in Birmingham, England, in August 1984, it became apparent that Geological Survey scientists were rapidly advancing the study of the chemistry of humic substances. It seemed appropriate, therefore, to publish this Open-File report on humic and fulvic acids from the Suwannee River in Georgia. The results represent our most definitive findings to date (1986). Though this work is not conclusive, it is state-of-the-science. Hopefully, our reporting on this work will aid in moving the science of humic substances forward as others read of our progress, findings, and theories. If so, this Open-File report will have served its purpose.

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USGS1989

Ground-water data for Georgia, 1988

Continuous water-level records from 144 wells and water-level measurements from an additional 617 wells in Georgia during 1988 provide the basic data for this report. Daily mean water-level hydrographs for selected wells illustrate the effects that changes ln recharge and discharge have had on the ground-water reservoirs in the State during 1988. Monthly mean water levels are shown for the 10-year period 1979-88. Maps showing the potentiometric surface of the Upper Floridan aquifer for Hay 1988 and the Claiborne and Clayton aquifers for October 1988 also are presented. Annual mean water levels in Georgia generally were below those measured in 1987; water levels ranged from 6.9 feet higher to 7.3 feet lower. Record-low water levels were measured during the last half of 1988 in 18 wells tapping the crystalline rock aquifer, the Cretaceous rock aquifer system, the Midville aquifer system, and the Clayton, Upper Floridan, and upper Brunswick aquifers. These record lows were from 0.1 to 1.4 feet lower than the previous record lows. A prolonged drought resulted in decreased recharge to the aquifers and increased ground-water pumping, which caused water levels to decline. Water-quality samples collected periodically throughout Georgia are analyzed as part of areal and regional ground-water studies. Maps showing chloride concentrations in the Upper Floridan aquifer in October 1988 in coastal Georgia and in the Savannah and Brunswick areas are presented. Periodic monitoring of water quality in the Savannah and Brunswick areas indicates that chloride concentrations in the Upper Floridan generally have remained stable.

Georgia↗
USGS1989

Water resources data for Georgia, water year 1988

Water resources data for the 1988 water year for Georgia consists of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs; ground-water levels; and precipitation quality. This report contains discharge records of 114 gaging stations; stage for 19 gaging stations; stage and contents for 18 lakes and reservoirs; water quality for 107 continuing-record stations; water-quality for 4 miscellaneous station; peak stage and discharge only for 76 crest-stage partial-record stations and 8 miscellaneous sites; base-flow discharge measurements at 149 miscellaneous sites; water levels of 26 observation wells; and water quality for 1 precipitation-quality site. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in Georgia.

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