Principal Investigator: Seth Rose (Georgia State University)
Sponsor: GWRI
Start Date: 1993-08-01; Completion Date: 1993-08-01;
Keywords: Environmental Tritium, Stable Oxygen Isotope Ratios,Ground Water, Surface Water, Well-Pumping
Description:
Systematic temporal isotopic (δ180 and 3H) and geochemical variation was analyzed within precipitation, shallow ground water, baseflow and deeper ground water from the southeastern Piedmont Province of Georgia. These samples, acquired predominantly during 1992, provide a valuable addition to a growing set of environmental isotopic data for this region. There was a substantial degree of isotopic variation (mostly random) observed between successive precipitation events; however,only a relatively small degree of variation observed within shallow ground water, baseflow and deeper ground water acquired from four production wells. Typically δ180 and 3H values varied by ~5% within ground water between successive 1.5 – 3.0 month sampling periods. Stable oxygen isotope ratios within deeper ground water (derived from production wells) systematically decreased by ~0.5 to 1.0 per mil during the summer months. However, accompanying trends were not observed with respect to either tritium or major ion concentrations. There is little to infer from these data that ground-water pumping rates appreciably affects the age distribution (generally 15-35 years) of ground water within these small Piedmont basins. Ground water becomes isotopically well homogenized (however, not perfectly homogenized) as the result of dispersion and the exchange of water upon clay mineral surfaces.