Aquitards are capable of generating and preserving large amounts of chemicals. The release of the chemicals from the aquitards poses a potential contamination risk to groundwater that may be used as a drinking water source. This work aimed to identify the contribution of hydrogeochemical processes in the aquitards to groundwater hydrochemistry in the underlying confined basal aquifer by studyin...

This study presents a semi-analytical solution for the problem of leakage in an unconfined aquifer bounded below by an aquitard of finite or semi-infinite extent. The homogeneous anisotropic unconfined aquifer of infinite radial extent is pumped continuously at a constant rate from a well of infinitesimal radius. The aquitard is also homogeneous , anisotropic and of infinite radial extent. Flow...

Confined aquifers are overlain by low-permeability aquitards that are commonly assumed to protect underlying aquifers from microbial contaminants. However, empirical data on microbial contamination beneath aquitards is limited. This study determined the occurrence of human pathogenic viruses in well water from a deep sandstone aquifer confined by a regionally extensive shale aquitard. Three pub...

Calibrated models of aquifer-system compaction developed by Helm (1975, 1976, 1977, 1978) and by Williamson and others (1989) indicate that a narrow range of both aquitard inelastic skeletal specific storage values and aquitard elastic skeletal specific storage values have been used to successfully simulate aquifersystem compaction despite differences in depth, thickness, lithology, and stratig...

An analytical solution is developed for three-dimensional flow towards a partially penetrating largediameter well in an unconfined aquifer bounded below by a leaky aquitard of finite or semi-infinite extent. The analytical solution is derived using Laplace and Hankel transforms, then inverted numerically. Existing solutions for flow in leaky unconfined aquifers neglect the unsaturated zone foll...

r a 200 .029 : +1 208 cgiss.bo Summary A semi-analytical solution is presented for the problem of flow in a system consisting of unconfined and confined aquifers, separated by an aquitard. The unconfined aquifer is pumped continuously at a constant rate from a well of infinitesimal radius that partially penetrates its saturated thickness. The solution is termed semi-analytical because the exact...

The impact of ground water pumping on nearby streams is often estimated using analytic models of the interconnected stream-aquifer system. A common assumption of these models is that the pumped aquifer is underlain by an impermeable formation. A new semianalytic solution for drawdown and stream depletion has been developed that does not require this assumption. This solution shows that pumping-...

High-nitrogen loadings of rivers and aquifers systems are a major concern because of potential effects on human health and water quality impacts such as eutrophication of lakes and coastal zones. This nitrogen enrichment is commonly attributed to anthropogenic sources such as sewage and agricultural and industrial wastes. The aims of this study were to delineate spatial distribution of groundwa...

Introduction Conclusions References