[1] Most analytical and numerical models developed to analyze pumping test data focus on saturated flow below the water table. Traditionally the soil above the initial water table prior to pumping has been thought to have little influence on the test results and has usually been ignored. It is hypothesized that, if the unsaturated zone is capped by low-permeability soil, airflow in the unsatura...

Groundwater management and protection has been facilitated by computational modeling of aquifer vulnerability and monitoring aquifers using groundwater sampling. The DRASTIC (Depth to water, Recharge, Aquifer media, Soil media, Topography, Impact of vadose zone media, and hydraulic Conductivity) model, an overlay and index GIS model, has been used for groundwater quality assessment because it r...

A new inverse method is developed to simultaneously estimate heterogeneous hydraulic conductivities, source/sink rates, and unknown boundary conditions for steadystate flow in an unconfined aquifer. Unlike objective function-based techniques, the new method does not optimize any data-model misfits. Instead, its formulation is developed by honoring physical flow principles as well as observation...

Proposed withdrawal of groundwater from the surficial aquifer system confined zone, or the upper and lower Brunswick aquifers in eastern Camden County, Georgia, could result in drawdown extending beneath the Cumberland Sound and potentially could affect groundwater levels and natural resources at Cumberland Island National Seashore. Using a nonequilibrium formula, estimated drawdown after 5 yea...

A novel methodology for the interpretation of pumping tests in leaky aquifer systems, referred to as the double inflection point (DIP) method, is presented. The method is based on the analysis of the first and second derivatives of the drawdown with respect to log time for the estimation of the flow parameters. Like commonly used analysis procedures, such as the type-curve approach developed by...

The Abbotsford-Sumas Aquifer is a shallow, predominantly unconfined aquifer that spans regions in southwestern British Columbia, Canada and northwestern Washington, USA. The aquifer is prone to nitrate contamination because of extensive regional agricultural practices. A 22-month ground water nitrate assessment was performed in a 10-km2 study area adjacent to the international boundary in north...

Three indigenous groundwater bacterial strains and Pseudomonas putida harboring plasmids TOL (pWWO) and RK2 were introduced into experimentally contaminated groundwater aquifer microcosms. Maintenance of the introduced genotypes was measured over time by colony hybridization with gene probes of various specificity. On the basis of the results of colony hybridization quantitation of the introduc...

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. iii Figures 1-4. Maps showing: 1. Study area, regions within the study area, and all well...

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...