Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3787
Chemical evolution of groundwater near a sinkhole lake, northern Florida: 1. Flow patterns, age of groundwater, and influence of lakewater leakage
Leakage from sinkhole lakes significantly influences recharge to the Upper Floridan aquifer in poorly confined sediments in northern Florida. Environmental isotopes (oxygen 18, deuterium, and tritium), chlorofluorocarbons (CFCs: CFC-11, CCl3F; CFC-12, CCl2F2; and CFC-113, C2Cl3F3), and solute tracers were used to investigate groundwater flow patterns near Lake Barco, a seepage lake in a mantled ka
Authors
Brian G. Katz, Terrie M. Lee, Niel Plummer, Eurybiades Busenberg
Chemical and isotopic methods for quantifying ground-water recharge in a regional, semiarid environment
The High Plains aquifer underlying the semiarid Southern High Plains of Texas and New Mexico, USA was used to illustrate solute and isotopic methods for evaluating recharge fluxes, runoff, and spatial and temporal distribution of recharge. The chloride mass-balance method can provide, under certain conditions, a time-integrated technique for evaluation of recharge flux to regional aquifers that is
Authors
Warren W. Wood, Ward E. Sanford
Measurements of aquifer-storage change and specific yield using gravity surveys
Pinal Creek is an intermittent stream that drains a 200-square-mile alluvial basin in central Arizona. Large changes in water levels and aquifer storage occur in an alluvial aquifer near the stream in response to periodic recharge and ground-water withdrawals. Outflow components of the ground-water budget and hydraulic properties of the alluvium are well-defined by field measurements; however, dat
Authors
D. R. Pool, J.H. Eychaner
Combining the Neuman and Boulton models for flow to a well in an unconfined aquifer
A Laplace transform solution is presented for flow to a well in a homogeneous, water-table aquifer with noninstanta-neous drainage of water from the zone above the water table. The Boulton convolution integral is combined with Darcy's law and used as an upper boundary condition to replace the condition used by Neuman. Boulton's integral derives from the assumption that water drained from the unsat
Authors
Allen F. Moench
Use of a square-array direct-current resistivity method to detect fractures in crystalline bedrock in New Hampshire
Azimuthal square-array direct-current (dc) resistivity soundings were used to detect fractures in bedrock in the Mirror Lake watershed in Grafton County, New Hampshire. Soundings were conducted at a site where crystalline bedrock underlies approximately 7 m (meters) of glacial drift. Measured apparent resistivities changed with the orientation of the array. Graphical interpretation of the square-a
Authors
J.W. Lane, F. P. Haeni, W.M. Watson
Effects of colloids on metal transport in a river receiving acid mine drainage, upper Arkansas River, Colorado, U.S.A.
Inflows of metal-rich, acidic water that drain from mine dumps and tailings piles in the Leadville, Colorado, area enter the non-acidic water in the upper Arkansas River. Hydrous iron oxides precipitate as colloids and move downstream in suspension, particularly downstream from California Gulch, which has been the major source of metal loads. The colloids influence the concentrations of metals dis
Authors
Briant A. Kimball
Comment on "Thermodynamics of organic chemical partition in soils"
No abstract available.
Authors
Cary T. Chiou
Transport of chromium and selenium in a pristine sand and gravel aquifer: Role of adsorption processes
Field transport experiments were conducted in an oxic sand and gravel aquifer using Br (bromide ion), Cr (chromium, injected as Cr(VI)), Se (selenium, injected as Se(VI)), and other tracers. The aquifer has mildly acidic pH values and low concentrations of dissolved salts. Within analytical errors, all mobile Cr was present as Cr(VI). All mobile Se was probably present as Se(VI). Adsorption of Cr
Authors
D.B. Kent, J.A. Davis, L.C.D. Anderson, B.A. Rea
Effect of Triton X-100 on the rate of trichloroethene desorption from soil to water
No abstract available.
Authors
James J. Deitsch, James A. Smith
Mechanism of formation of humus coatings on mineral surfaces 1. Evidence for multidentate binding of organic acids from compost leachate on alumina
Measurements of the infrared linear dichroism of carboxylate groups of organic acids from compost leachate adsorbed to an alumina surface and the enthalpy of adsorption of this reaction have been made. The linear dichroism measurements indicated that the carboxylate groups are not free to rotate. This limited rotation probably results from bidentate binding of the carboxylate groups. The molar ent
Authors
R. L. Wershaw, J. A. Leenheer, R.P. Sperline, Yuan Song, L.A. Noll, R.L. Melvin, G.P. Rigatti
Large-scale atmospheric forcing of recent trends toward early snowmelt runoff in California
Since the late 1940s, snowmelt and runoff have come increasingly early in the water year in many basins in northern and central California. This subtle trend is most pronounced in moderate-altitude basins, which are sensitive to changes in mean winter temperatures. Such basins have broad areas in which winter temperatures are near enough to freezing that small increases result initially in the for
Authors
Michael D. Dettinger, Daniel R. Cayan
XAS study of AsO43− and SeO42− substituted schwertmannites
Synthetic schwertmannite samples with varying amounts of arsenate and selenate substituting for sulfate were examined by XAS methods in an attempt to characterize the location of the anion complexes. Selenate appears to both substitute directly for sulfate within tunnels in the structure, and sorb onto the outside of crystallites. No disruption of the basic structure appears with selenate substitu
Authors
G.A. Waychunas, Ning Xu, C. C. Fuller, J.A. Davis, J.M. Bigham