Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 4094
Transport of chromium and selenium in the suboxic zone of a shallow aquifer: Influence of redox and adsorption reactions
Breakthrough of Cr(VI) (chromate), Se(VI) (selenate), and O2 (dissolved oxygen) was observed in tracer tests conducted in a shallow, sand and gravel aquifer with mildly reducing conditions. Loss of Cr, probably due to reduction of Cr(VI) to Cr(III) and irreversible sorption of Cr(III), occurred along with slight retardation of Cr(VI), owing to reversible sorption. Reduction of Se(VI) and O2 was th
Authors
D.B. Kent, J.A. Davis, L.C.D. Anderson, B.A. Rea, T.D. Waite
Effect of atrazine on potential denitrification in aquifer sediments
Agriculturaf use of fertilizers and herbicides has often resulted in nitrate and atrazine contamination of the shallow aquifers that underlay cultivated fields. In several cases, the concentrations of atrazine and nitrate dissolved in ground water are positively correlated (Spalding ef al., 1979; Chen and Druliner, 1987; Spalding et al., 1989). Because simultaneous application of nitrate fertilize
Authors
P. M. Bradley, F. H. Chapelle, M.L. Jagucki, P. B. McMahon
Use of molecular techniques to evaluate the survival of a microorganism injected into an aquifer
A PCR primer set and an internal probe that are specific for Pseudomonas sp. strain B13, a 3-chlorobenzoate-metabolizing strain, were developed. Using this primer set and probe, we were able to detect Pseudomonas sp. strain B13 DNA sequences in DNA extracted from aquifer samples 14.5 months after Pseudomonas sp. strain B13 had been injected into a sand and gravel aquifer. This primer set and probe
Authors
S.M. Thiem, M.L. Krumme, R. L. Smith, J.M. Tiedje
Comparison of drilling reports and detailed geophysical analysis of ground-water production in bedrock wells
The most extensive data base for fractured bedrock aquifers consists of drilling reports maintained by various state agencies. We investigated the accuracy and reliability of such reports by comparing a representative set of reports for nine wells drilled by conventional air percussion methods in granite with a suite of geophysical logs for the same wells designed to identify the depths of fractur
Authors
Frederick Paillet, Russell Duncanson
Modeling of soil water retention from saturation to oven dryness
Most analytical formulas used to model moisture retention in unsaturated porous media have been developed for the wet range and are unsuitable for applications in which low water contents are important. We have developed two models that fit the entire range from saturation to oven dryness in a practical and physically realistic way with smooth, continuous functions that have few parameters. Both m
Authors
Cinzia Rossi, John R. Nimmo
Movements of water, solutes, and stable isotopes in the unsaturated zones of two sand plains in the upper Midwest
Four month-long field experiments investigated movements of water and solutes through unsaturated sand plains near Princeton, Minnesota, and Oakes, North Dakota. Atrazine and bromide were applied to bare soils and soils planted with corn. The field plots were irrigated according to local farming practices. At the end of each experiment, unsaturated soils were analyzed for atrazine and bromide conc
Authors
Stephen C. Komor, Douglas G. Emerson
The use of simulation and multiple environmental tracers to quantify groundwater flow in a shallow aquifer
Measurements of the concentrations of chlorofluorocarbons (CFCs), tritium, and other environmental tracers can be used to calculate recharge ages of shallow groundwater and estimate rates of groundwater movement. Numerical simulation also provides quantitative estimates of flow rates, flow paths, and mixing properties of the groundwater system. The environmental tracer techniques and the hydraulic
Authors
Thomas E. Reilly, Niel Plummer, Patrick J. Phillips, Eurybiades Busenberg
Field and modeling studies of multiphase fluid flow at the Bemidji, Minnesota crude-oil spill site
No abstract available.
Authors
Hedeff I. Essaid, William N. Herkelrath, L.A. Dillard
Mantle helium in the groundwater of the Mirror Lake Basin, New Hampshire, USA, 1994
Helium isotope analyses of ground waters from the Mirror Lake drainage basin in central New Hampshire (USA) show helium in excess of air-saturated water by up to 200x. The freon ages of these waters are younger than 50 years, consistent with the local hydrology. This excess helium has an isotope ratio of ^3He/^4He = 1.65 ± 0.10 x 10^(-6). It is shown that this component cannot be the result of cos
Authors
T. Torgersen, S. Drenkard, K. Farley, P. Schlosser, Allen M. Shapiro
Distribution and occurrence of organic acids in subsurface waters
No abstract available.
Authors
P.D. Lundegard, Yousif K. Kharaka
Three-dimensional D4Z renumbering for iterative solution of ground-water flow and transport equations
No abstract available.
Authors
Kenneth L. Kipp, J.S. Otto, Thomas F. Russell
Wastewater treatment and groundwater contamination
No abstract available.
Authors
J.A. Field, Larry B. Barber