The effectiveness of shallow groundwater areas to serve as a sink for NO3 is affected by many biological and physical properties. However, the direct impact of these properties on the fate of NO3 in shallow groundwater is not well understood, especially where the soils are intermittently saturated. This study was conducted to assess in situ reaction and transport of NOa-N in an intermittent sha...

Enhanced production of unconventional hydrocarbons in the United States has driven interest in natural gas development globally, but simultaneously raised concerns regarding water quantity and quality impacts associated with hydrocarbon extraction. We conducted a pre-development assessment of groundwater geochemistry in the critically water-restricted Karoo Basin, South Africa. Twenty-two sprin...

rise of groundwater levels in unconfined aquifers can cause dryland salinity to increase by several processes including; dissolution of windblown halite, and incorporation of saline clay pore water. The primary process of increased groundwater salinity is evaporation of shallow groundwater as it rises to within a few meters of the ground surface. in murray Basin, australia, the effect of drylan...

18 Groundwater contamination was characterised using a methodology which combines 19 shallow groundwater geochemistry data from 17 piezometers over a 2 yr period in a 20 statistical framework and hydrogeological techniques. Nitrate-N (NO3-N) 21 contaminant mass flux was calculated across three control planes (rows of 22 piezometers) in six isolated plots. Results showed natural attenuation occu...

The natural acidification of groundwater in some types of environment has accelerated by acid atmospheric emissions and cultivation during the last 200 years. The direct effects are seen in changes of the groundwater chemistry in four stages, (1) seasonal depression of pH, alkalinity and some cations in very shallow groundwater, (2) long-term increase of calcium, magnesium, nitrate and sulphate...

The spatial heterogeneity of dissolved arsenic (As) concentrations in shallow groundwater of the Bengal Basin has been attributed to transport of As (and reactive carbon) from external sources or to the release of As from within grey sand formations. We explore the latter scenario in this detailed hydrological and geochemical study along a 300 m transect of a shallow aquifer extending from a gr...

Most field-based approaches that address runoff generation questions have been conducted in steep landscapes with shallow soils. Runoff generation processes in low relief landscapes with deep soils remain less understood. We addressed this by characterizing dominant runoff generating flow paths by monitoring the timing and magnitude of precipitation, runoff, shallow soil moisture, and shallow a...

Environmental releases of antibiotics from concentrated animal feeding operations (CAFOs) are of increasing regulatory concern. This study investigates the use and occurrence of antibiotics in dairy CAFOs and their potential transport into first-encountered groundwater. On two dairies we conducted four seasonal sampling campaigns, each across 13 animal production and waste management systems an...

Characterization of groundwater quality allows the evaluation of groundwater pollution and provides information for better management of groundwater resources. This study characterized the shallow groundwater quality and its spatial and seasonal variations in the Lower St. Johns River Basin, Florida, USA, under agricultural, forest, wastewater, and residential land uses using field measurements...

The origin of dissolved arsenic in the Ganges Delta has puzzled researchers ever since the report of widespread arsenic poisoning two decades ago. Today, microbially mediated oxidation of organic carbon is thought to drive the geochemical transformations that release arsenic from sediments, but the source of the organic carbon that fuels these processes remains controversial. At a typical site ...