Geology topics
S.A. Longsworth
Publications and source records attributed to S.A. Longsworth.
Ground-water data for Georgia, 1986
Continuous water level records from 152 wells and water level measurements from an additional 750 wells in Georgia during 1986 provide the basic data for this report. Hydrographs for selected wells illustrate the effects that changes in recharge and discharge have had on the groundwater reservoirs in the State. Daily mean water levels are shown in hydrographs for 1986. Monthly mean water levels are shown for the 10-yr period 1977-86. During 1986, a prolonged drought resulted in water level declines throughout the State. Annual mean water levels were from 2.7 ft higher to 17.3 ft lower than in 1985, and record lows were measured in 33 wells in the summer and fall. The 1986 lows were from 0.02 ft to 29.2 ft lower than the previous record lows. The largest declines were measured in the Clayton aquifer in the southwestern part of the State. The declines can be attributed to reduced recharge and increased pumping that resulted from below-normal precipitation during the first half of the year. Water quality samples are collected periodically throughout Georgia and analyzed as part of areal and regional groundwater studies. Periodic monitoring of water quality in the Savannah and Brunswick areas indicates that the chloride concentration in the Upper Floridan aquifer there generally has remained stable. (USGS)
Hydrogeology, chemical quality, and availability of ground water in the Upper Floridan aquifer, Albany area, Georgia
Large withdrawals of groundwater in the 1500 sq mi Albany area of southwestern Georgia have lowered water levels in deep aquifers as much as 140 ft. This study was conducted to evaluate the development potential of the shallow Upper Floridan aquifer as an alternate source of groundwater, especially for public supply. The Upper Floridan stores and transmits large quantities of water, mainly in a zone of high permeability in the lower part of the aquifer. The transmissivity of the aquifer ranges from < 10,000 sq ft/day northwest of Albany, to as much as 150 ,000 sq ft/day south and southeast of Albany. Twenty-eight years of agricultural and industrial pumping has not produced a long-term decline of the water level in the Upper Floridan; the aquifer system remains at equilibrium. The Upper Floridan yields hard, calcium bicarbonate-type water but concentrations do not exceed State drinking water standards. In most of the study area , contaminants applied to or spilled on the land surface eventually can be expected to percolate through the overburden and reach the aquifer. Thus, it is important that wells be sited away from areas that have been used for the storage and disposal of potential contaminants and, probably to a lesser extent, the application of agricultural chemicals. In the area of greatest development potential east of the Flint River, wells may penetrate major groundwater conduits. By limiting drawdown during well development and during production, the likelihood of causing sinkholes to form can be minimized. Closed depressions, or sinks, throughout the Dougherty Plain probably are unsuitable as well sites, because (1) they are subject to flooding, (2) they collect water from upgradient areas and could concentrate potential contaminants, (3) water probably percolates through their bottoms and could transport contaminants into the aquifer, and (4) the depressions may overlie limestone cavities filled with sand or clay that could interfere with well yield, development, and production. (Author 's abstract)
Ground-water data for Georgia, 1985
Continuous water level records from 146 wells and water level measurements from an additional 1,100 wells in Georgia during 1985 provide the basic data for this report. Hydrographs for selected wells illustrate the effects that changes in recharge and discharge have had on the groundwater reservoirs in the State. Daily mean water levels are shown in hydrographs for 1985. Monthly mean water levels are shown for the 10-year period 1976-86. During 1985, annual mean water levels were generally lower than in 1984, and ranged from 11.4 feet lower to 0.6 feet higher. Much of the decline can be attributed to below-normal precipitation from mid-1984 to mid-1985. Water quality samples also are collected periodically throughout Georgia and analyzed as part of areal and regional groundwater studies. Along the coast, the chloride concentration in the Floridan aquifer system generally remained stable in the Savannah and Brunswick areas. (USGS)
Ground-water data for Georgia, 1984
Continuous water-level records from 155 wells and more than 800 water-level measurements made in Georgia during 1984 provide the basic data for this report. Selected wells illustrate the effects that changes in recharge and pumping have had on the various ground-water resources in the State. Daily mean water levels are shown in hydrographs for 1984. Monthly means are shown for the 10-year period 1975-84. Mean annual water levels ranged from 7 feet lower to 7 feet higher in 1984 than in 1983. Water-quality samples are collected periodically throughout Georgia and analyzed as part of a real and regional ground-water studies. Along the coast, chloride concentrations in the Floridan aquifer system generally remained steady. (USGS)
Ground-water data for Georgia, 1983
Continuous water-level records from 134 wells and more than 700 water-level measurements made in Georgia during 1983 provide the basic data for this report. Selected wells illustrate the effects that changes in recharge and pumping have had on the various ground-water resources in the State. Daily mean water levels are shown in hydrographs for 1983. Monthly means are shown for the 10-year period 1974-83. Mean annual water levels ranged from 9 feet higher to 6 feet lower in 1983 than in 1982. Water-quality samples are collected periodically throughout Georgia and analyzed as part of areal and regional ground-water studies. Along the coast, chloride concentrations in the upper and lower water-bearing zones of the Floridan aquifer system generally remained steady in the Brunswick and Hilton Head Island areas. (USGS)