Nuclear magnetic resonance (NMR) logging provides a new means of estimating the hydraulic conductivity (K) of unconsolidated aquifers. The estimation of K from the measured NMR parameters can be performed using the Schlumberger-Doll Research (SDR) equation, which is based on the Kozeny-Carman equation and initially developed for obtaining permeability from NMR logging in petroleum reservoirs. T...

Alluvial aquifers in mountainous regions cover typically a limited area. Their contribution to catchment storage and outflow is rarely isolated; alluvial groundwater discharge under gauging stations is generally assumed negligible; and hydrological models tend to lump alluvial storage with other units. The role of alluvial aquifers remains therefore unclear: can they contribute significantly to...

Arsenic is a contaminant in the groundwater of Holocene aquifers in Bangladesh, where approximately 57 million people drink water with arsenic levels exceeding the limits set by the World Health Organization. Although arsenic is native to the sediments, the means by which it is released to groundwater remains unresolved. Contrary to the current paradigm, ferric (hydr)oxides appear to dominate t...

The partitioning interwell tracer test (PITT) was introduced into the practice of contaminant hydrogeology in 1994, since which time about 50 PITTs have been conducted in the field. Confirmation of results of vadose-zone and ground-water zone PITTs by subsequent field testing of aquifers in Utah and New Mexico have demonstrated the reliability of the technique for operational purposes, i.e., th...

Using a comprehensive data set (dissolved CH4, δ(13)C-CH4, δ(2)H-CH4, δ(13)C-DIC, δ(37)Cl, δ(2)H-H2O, δ(18)O-H2O, Na, K, Ca, Mg, HCO3, Cl, Br, SO4, NO3 and DO), in combination with a novel application of isometric log ratios, this study describes hydrochemical and thermodynamic controls on dissolved CH4 from a coal seam gas reservoir and an alluvial aquifer in the Condamine catchment, eastern S...

The potential impacts of CO2 on freshwater aquifers outlined by Little and Jackson, 2010 appear, incorrectly, to slay all hope of storing CO2 below ground and retaining safe drinking waters. Without doubt the effects of CO2 addition to drinking water aquifers deserve careful investigation. However, the experiments preformed by Little and Jackson are fatally flawed and there are a number of misl...

Deep aquifers in South and Southeast Asia are increasingly exploited as presumed sources of pathogen- and arsenic-free water, although little is known of the processes that may compromise their long-term viability. We analyze a large area (>1,000 km(2)) of the Mekong Delta, Vietnam, in which arsenic is found pervasively in deep, Pliocene-Miocene-age aquifers, where nearly 900 wells at depths of...

There are approximately 470,000 km(2) of karst aquifers that feed many large springs in North China. Turbulent flow often exists in these karst aquifers, which means that the classical ground water model based on Darcy's law cannot be applied here. Ground water data are rare for these aquifers. As a consequence, it is difficult to quantitatively investigate ground water flow in these karst syst...

Karst aquifers with high primary-porosity matrix, such as the Floridan aquifer, have the potential for movement of water between conduits and matrix, with important implications for karst development and the maintenance of groundwater quality. The Santa Fe River Sink and River Rise conduit system, along with the surrounding unconfined Floridan aquifer in north-central Florida, provides a study ...

The principles of hydrocarbon exploration and production provide well established and tested principles and technologies to investigate storage of fluids in the subsurface. CO2 can be stored in the subsurface using settings of: A) thick permeable coal seams; B) depleted oil and gas fields; C) saline aquifers of regional extent, with an overlying seal. The North Sea Sleipner project shows that C...