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A glacial aquifer system in Woodbury, Connecticut, was studied to identify factors that affect the groundwater quality in the zone of contribution to a community public-supply well. Water samples were collected during 2002-06 from the public-supply well and from 35 monitoring wells in glacial stratified deposits, glacial till, and fractured bedrock. The glacial aquifer is vulnerable to contamination from a variety of sources due to the short groundwater residence times and the urban land use in the contributing recharge area to the public-supply well. The distribution and concentrations of pH, major and trace elements, stable isotope ratios, recharge temperatures, dissolved organic carbon (DOC), and volatile organic...
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Conventional arsenic remediation strategies primarily involve above-ground treatment that include costs involved in the disposal of sludge material. The primary advantages of in-situ remediation are that building and maintaining a large treatment facility are not necessary and that costs associated with the disposal of sludge are eliminated. A two-phase study was implemented to address the feasibility of in-situ arsenic remediation in Douglas County, Nevada. Arsenic concentrations in groundwater within Douglas County range from 1 to 85 micrograms per liter. The primary arsenic species in groundwater at greater than 250 ft from land surface is arsenite; however, in the upper 150 ft of the aquifer arsenate predominates....
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The subsurface transport of phosphorus introduced by the disposal of treated sewage effluent to ground-infiltration disposal beds at the Massachusetts Military Reservation on western Cape Cod was simulated with a three-dimensional reactive-transport model. The simulations were used to estimate the load of phosphorus transported to Ashumet Pond during operation of the sewage-treatment plant?from 1936 to 1995?and for 60 years following cessation of sewage disposal. The model accounted for spatial and temporal changes in water discharge from the sewage-treatment plant, ground-water flow, transport of associated chemical constituents, and a set of chemical reactions, including phosphorus sorption on aquifer materials,...
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Arsenic (As) distribution and toxicology in the environment is a serious issue, with millions of individuals worldwide being affected by As toxicosis. Sources of As contamination are both natural and anthropogenic and the scale of contamination ranges from local to regional. There are many areas of research that are being actively pursued to address the As contamination problem. These include new methods of screening for As in the field, determining the epidemiology of As in humans, and identifying the risk of As uptake in agriculture. Remediation of As-affected water supplies is important and research includes assessing natural remediation potential as well as phytoremediation. Another area of active research is...
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Recognition of arsenic (As) contamination of shallow fluvio-deltaic aquifers in the Bengal Basin has resulted in increasing exploitation of groundwater from deeper aquifers that generally contain low concentrations of dissolved As. Pumping-induced infiltration of high-As groundwater could eventually cause As concentrations in these aquifers to increase. This study investigates the adsorption capacity for As of sediment from a low-As aquifer near Dhaka, Bangladesh. A shallow, chemically-reducing aquifer at this site extends to a depth of 50 m and has maximum As concentrations in groundwater of 900 μg/L. At depths greater than 50 m, geochemical conditions are more oxidizing and groundwater has < 5 μg/L As. There is...
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