Assessment of ethylene dibromide, dibromochloropropane, other volatile organic compounds, radium isotopes, radon, and inorganic compounds in groundwater and spring water from the Crouch Branch and McQueen Branch aquifers near McBee, South Carolina, 2010-2012

Abstract

27. Graphs showing trends in radium-226 and radium-228 and radium isotope concentrations in groundwater from public

Groundwater availability, geochemistry, and flow pathways to public-supply wells in the Atlantic Coastal Plain and bedrock aquifers, Aiken County and part of Lexington County, South Carolina, 2015–2019

“…The groundwater geochemistry of Aiken County was also described in a report on the groundwater quality of South Carolina (Speiran and others, 1987) and was compared with that of rainwater (Newcome, 2004). The groundwater quality is also similar to that of the groundwater quality reported from the deeper ACP aquifers in the Inner Coastal Plain aquifers in adjacent counties (Feder and Lee, 1981;Lee, 1984;Curley, 1990) and the Sandhills along the Fall Line (Landmeyer and Campbell, 2014). High iron levels in groundwater occurred in some wells (Speiran and others, 1987).…”

“…The presence of specific conductance was also not related to total-radium concentrations; the PSW with the highest specific conductance had the lowest total-radium concentration. This lack of a positive correlation between total radium isotopes, dissolved oxygen, and specific conductance does not support the positive correlation between elevated radium isotopes and the oxic, mineralized groundwater observed in groundwater in the ACP in other States (Szabo and others, 2012a, b), nor in studies done by the authors in other parts of the Coastal Plain of South Carolina (Landmeyer and Campbell, 2014).…”

“…The effect of a sediment-depositional environment on groundwater quality in the study area was investigated by Speiran and Aucott (1994). The detection of radium isotopes in groundwater from the Crouch Branch and McQueen Branch aquifers has been noted to occur in Chesterfield County (Landmeyer and Campbell, 2014).…”

“…The CFC-based groundwater-age dates were used to calibrate the locations where the groundwater-flow pathways for each well reached the simulated water table to constrain which simulated groundwater-flow pathways were the most representative of the groundwater velocity field for each well and its unique pumping history (Sanford, 2011). This approach was like the one used by Sanford (2011) and applied in Landmeyer and Campbell (2014).…”

“…The higher specific conductance indicates the interaction of groundwater with aquifer minerals or residual fertilizers applied at the land surface. The low average pH can be explained as a result of ambient, naturally acidic rainwater caused by the dissolution of atmospheric carbon dioxide during precipitation and that the sediments in the subsurface have been highly weathered since the Late Cretaceous period (Landmeyer and Campbell, 2014). As such, there is little buffering capacity in the subsurface, as the dissolution minerals, such as feldspars (that tend to increase the pH of water), were already removed by weathering.…”