The uncontrolled release of the industrial solvent methylene chloride, also known as dichloromethane (DCM), has resulted in widespread groundwater contamination in the United States. Here we investigate the role of groundwater bacterial communities in the natural attenuation of DCM at an undisclosed manufacturing site in New Jersey. This study investigates the bacterial community structure of g...

Assuming homogeneity in alluvial aquifers is convenient, but limits our ability to accurately predict stream-aquifer interactions. Research is needed on (i) identifying the presence of focused, as opposed to diffuse, groundwater discharge/recharge to streams and (ii) the magnitude and role of large-scale bank and transient storage in alluvial floodplains relative to changes in stream stage. The...

In eastern New England, high concentrations (greater than 10 microg/L) of arsenic occur in groundwater. Privately supplied drinking water from bedrock aquifers often has arsenic concentrations at levels of concern to human health, whereas drinking water from unconsolidated aquifers is least affected by arsenic contamination. Water from wells in metasedimentary bedrock units, primarily in Maine ...

Papers published in Hydrology and Earth System Sciences Discussions are under open-access review for the journal Hydrology and Earth System Sciences Abstract The proportion and origin of groundwater contribution to streamflow from agricultural catchments is relevant to estimation of the effects of nitrate leached from the soil on the quality of surface waters. This study addresses the partition...

The Geobacteraceae citrate synthase is phylogenetically distinct from those of other prokaryotes and is a key enzyme in the central metabolism of Geobacteraceae. Therefore, the potential for using levels of citrate synthase mRNA to estimate rates of Geobacter metabolism was evaluated in pure culture studies and in four different Geobacteraceae-dominated environments. Quantitative reverse transc...

Groundwater quality management is one of the most important issues in many arid and semi-arid regions, including Iran.Nitrate (NO3-) is one of the most common anions contaminating groundwater. This study aimed to range nitrateconcentrations in water resources in Bahabad plain in Yazd province. To evaluate the nitrate data in this descriptive study,260 nitrate samples from 13 wells in Bahabad we...

Humans have exerted large-scale changes on the terrestrial biosphere, primarily through agriculture; however, the impacts of such changes on the hydrologic cycle are poorly understood. The purpose of this study was to test the hypothesis that the conversion of natural rangeland ecosystems to agricultural ecosystems impacts the subsurface portion of the hydrologic cycle by changing groundwater r...

Nitrate concentration in groundwater has frequently been linked to non-point pollution. At the same time the existence of intensive agriculture and extremely intensive livestock activity increases the potential for nitrate pollution in shallow groundwater. Nitrate used in agriculture could cause adverse effects on human and animal health. In order to evaluate the groundwater nitrate pollution, ...

We measured denitrification, immobilization, and respiration in microcosms that simulated groundwater conditions in a riparian forest in Rhode Island. Measured rates were compared with rates of NOj" removal measured in a companion study using a groundwater monitoring well network and 10-mo injection of NOf and a bromide tracer to groundwater in the same riparian forest. Limiting factors for den...