The association of arsenic with redox conditions, depth, and ground-water age in the glacial aquifer system of the northern United States

Groundwater quality in Geauga County, Ohio: status, including detection frequency of methane in water wells, 2009, and changes during 1978-2009

“…Smedley and Kinniburg (2002) suggested that slow-moving flow does not flush away arsenic after it is released from aquifer sediments, allowing it to accumulate in groundwater. Findings in Geauga County were consistent with those of Smedley and Kinniburg (2002) and Thomas (2007). Wells are the only two wells completed in a formation other than the Berea Sandstone for which both arsenic and tritium data are available and for which tritium concentrations are indicative of pre-1953 recharge ( fig.…”

“…Although most groundwater samples considered by ODNR were below the health-based benchmark of 10 µg/L, at least one sample from each of the following formations exceeded health-based standards: the Pottsville Formation, the Cuyahoga Group (maximum concentration of 20 µg/L in both formations), and the Berea Sandstone (maximum concentration of 24 µg/L). Groundwater age (or time since water recharged the groundwater system) is a factor that has been found to influence arsenic concentrations in other study areas (Smedley and Kinniburg, 2002;Thomas, 2007). Thomas (2007) noted that for wells tapping the glacial aquifer system in the northern United States (which includes the glacial deposits in Geauga County), the likelihood of arsenic exceeding the health-based standard in strongly reducing water was increased if the water samples were old (pre-1953 recharge as indicated by lack of measureable tritium).…”

“…Groundwater age (or time since water recharged the groundwater system) is a factor that has been found to influence arsenic concentrations in other study areas (Smedley and Kinniburg, 2002;Thomas, 2007). Thomas (2007) noted that for wells tapping the glacial aquifer system in the northern United States (which includes the glacial deposits in Geauga County), the likelihood of arsenic exceeding the health-based standard in strongly reducing water was increased if the water samples were old (pre-1953 recharge as indicated by lack of measureable tritium). Old groundwater can indicate sluggish groundwater flow.…”

Aquifer chemistry and transport processes in the zone of contribution to a public-supply well in Woodbury, Connecticut, 2002-06

“…Concentrations of dissolved As generally were low in the study area, which is typical of glacial aquifers in much of the eastern United States (Thomas, 2007). Dissolved As in groundwater is largely affected by adsorption processes, which can vary with redox conditions, pH, competing ions, and the sorption properties of mineral surfaces.…”

Interactions of Water Quality and Integrated Groundwater Management: Examples from the United States and Europe

“…Individual homeowners are responsible for maintaining their water supply systems and for any routine water-quality monitoring. The U.S. Geological Survey National Water Quality Assessment Program (NAWQA) included sampling of more than 2100 privately owned wells in the United States (DeSimone 2009) and found that about 7 % of privately owned wells contained arsenic greater than 10 μg/ L. In some areas, such as the methanogenic parts of the glacial aquifer system, up to 50 % of the privately owned wells had arsenic concentrations greater than 10 μg/L (Thomas 2007). The publicly supplied drinking water is managed because routine (From Van Halem et al 2009) monitoring identifies the high arsenic concentrations that need to be addressed, yet voluntary self-monitoring of privately owned wells is not routine.…”