The Millers Pond test site, in northeastern Burke County, Georgia, was constructed during 1991-92 to better characterize the geologic, hydrologic, and water-quality characteristics of a multi-aquifer system in Coastal Plain sediments. These data are presented for 1992-93. The test site consists of a continuously cored 859 feet (ft) deep hole thatpenetrated the entire thickness of Coastal Plain sediments, and seven test wells developed at depths ranging from 80 to 735 ft. Lithologic and paleontologic examination of core indicated that there are at least 11 district lithologic units of Lake Cretaceous through Eocene age at the site, having a total thickness of 852 ft. The test wells were screened in the Upper Three Runs aquifer, Dublin aquifer system, and Midville aquifer system. Upon completion and development of each well, a 72-hour aquifer test was conducted, water samples were collected and analyzed for chemical constituents, and continuous water-level recorders were installed. Water-level fluctuations in wells completed in the confined aquifers at the Millers Pond test site were coincident and appear to mostly represent a mass-loading response to fluctuations of Savannah River stage, about 2 miles east of the site. Water-levels in the Upper Three Runs (water table) aquifer, however, showed little similarity to water levels in wells completed in the deeper confined aquifers, and are apparently influenced by precipitation, evapotranspiration, and possibly pumping. Water from each of the seven zones screened at the Millers Pond test site is of good quality and low in dissolved solids. Concentrations of iron, however, exceed the U.S. Environmental Protection Agency's secondary drinking-water standards in all zones except the Upper Three Runs aquifer. Water from the Upper Three Runs (water table) aquifer contained 730 picoCuries per liter (pCi/L) of tritium. Tritium at concentrations slightly above the 1 pCi/L detection limit were measured in two wells screened in the upper part of Dublin aquifer system. Although layers of clay and silt separate the screened intervals of wells completed in the Dublin and Midville aquifer systems, the uniform distribution of head, similarity of water-level fluctuations and water chemistry, and drawdown response during aquifer tests, indicate that parts of the two aquifer systems are hydraulically connected. Conversely, the uppermost part of the Dublin aquifer system seems to be hydraulically separated from adjacent water-bearing zones.
Additional publication details
USGS Numbered Series
Ground-water resources of the Paintrock irrigation project, Wyoming, with a section on the quality of the water