Innovative technologies for subsurface remediation, including in situ techniques based on heating the subsurface to enhance the recovery of organic contaminants, are increasingly being evaluated for use at specific sites as the limitations to the conventionally-used techniques are recognized. The purpose of this Issue Paper is to provide to those involved in assessing remediation technologies f...

Vitamin B12 is an important component of media used to stimulate the growth of many anaerobic microbes that dechlorinate aliphatic compounds. Its delivery to the subsurface is therefore a concern for enhanced in situ bioremediation and bioaugmentation. In situ circulation of vitamin B12 and a chemical reductant has also been field tested for treatment of chlorinated methanes, ethanes, and ethen...

Adding surfactant into the displacing aqueous phase during surfactant-enhanced aquifer remediation of NAPL contamination and in chemical flooding oil recovery significantly changes interfacial tension (IFT) (σ) on water–oil interfaces within porous media. The change in IFT may have a large impact on relative permeability for the two-phase flow system. In most subsurface flow investigations, how...

Ground-water availability from the High Plains aquifer in Southwest Kansas Ground-water Management District 3 (GMD 3) is declining as it is elsewhere in the western part of the state (Figure 1). Water-use density, defined as the annual amount of water pumped from the aquifer per unit of land area, is high over much of the District and greatly exceeds annual recharge (McMahon et al., 2003). Subs...

Aquifer tests yield estimations of hydrogeological parameters through suitable analytical models from field data recorded as drawdown variations by time or distance. In practice, most often a single model iK adopted with a set of assumptions, and unfortunately, field data deviations from the model type curves are not considered in interpretations . This is a rather mechanistic approach which im...

[1] The estimation of catchment-averaged aquifer hydraulic conductivity values is usually performed through a base flow recession analysis. Relationships between the first time derivatives of the base flow and the base flow values themselves, derived for small and large values of time, are used for this purpose. However, in the derivation of the short-time equations, an initially fully saturate...

[1] Accurately determining well capture zones is of great importance in aquifer cleanup and for the protection of drinking water. Earlier models in delineating capture zones assumed the medium to be homogeneous. Recently, stochastic approaches have been applied to studying capture zones in heterogeneous media. The Monte Carlo method is commonly used to infer the probability distribution of the ...

Naturally occurring dissolved organic matter (DOM) and biosolids-derived DOM have been implicated in the mobility of metals in soils and aquifer materials. To investigate the effect of DOM on copper mobility in aquifer material, DOM derived from sewage biosolids was separated into two apparent molecular-weight (MW) fractions, 500 to 3500 Da (LMW) and > 14 000 Da (HMW). In each MW fraction, the ...

Playas are ephemeral, closed-basin wetlands that are hypothesized as an important source of recharge to the High Plains aquifer in central USA. The ephemeral nature of playas, low regional recharge rates, and a strong reliance on groundwater from the High Plains aquifer has prompted many questions regarding the contribution and quality of recharge from playas to the High Plains aquifer. As a re...

Various physico-chemical parameters, including fluoride (F(-)), were analyzed to understand the hydro-geochemistry of an aquifer in a semi-arid region of India. Furthermore, the quality of the shallow and deep aquifer (using tube well and hand pumps) was also investigated for their best ecological use including drinking, domestic, agricultural and other activities. Different multivariate techni...