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Publications

Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).

Filter Total Items: 4047

Effects of focused recharge on the transport of agricultural chemicals at the Princeton, Minnesota Management Systems Evaluation Area, 1991-92

Rates of water movement through the unsaturated zone greatly affect the amount and concentrations of agricultural chemicals that may reach the water table. For example, recharge can flush chemicals to the water table which have accumulated in the unsaturated zone during dry periods. A better understanding of how topography influences recharge and the movement of agricultural chemicals is needed. I
Authors
G. N. Delin, M.K. Landon

Reconnaissance data for selected herbicides, two atrazine metabolities, and nitrate in surface water of the Midwestern United States, 1989-90

Water-quality data were collected from 147 rivers and streams during 1989-90 to assess selected preemergent herbicides, two atrazine metabolites, and nitrate in 10 Midwestern States. This report includes a description of the sampling design, data collection techniques, laboratory and analytical methods, and a compilation of constituent concentrations and quality-assurance data. All water samples w
Authors
E.A. Scribner, E. M. Thurman, D. A. Goolsby, M. T. Meyer, M. S. Mills, M.L. Pomes

Ground-water quality at the Management Systems Evaluation Area (MSEA) near Princeton, Minnesota, 1991

The northern cornbelt sand-plains Management Systems Evaluation Area (MSEA) program is a multiagency, multistate initiative to evaluate the effects of modified and prevailing fanning systems on water quality in a sand-plain area in Minnesota and at satellite areas in North and South Dakota, and Wisconsin (Delin and others, 1992). The primary objective of the northern cornbelt sand-plains MSEA is t
Authors
Matthew K. Landon, Geoffrey N. Delin, J.A. Lamb, Laodong Guo

Ground-water-quality assessment of the Central Oklahoma Aquifer, Oklahoma: Geochemical and geohydrologic investigations

The National Water-Quality Assessment pilot project for the Central Oklahoma aquifer examined the chemical and isotopic composition of ground water, the abundances and textures of minerals in core samples, and water levels and hydraulic properties in the flow system to identify geochemical reactions occurring in the aquifer and rates and directions of ground-water flow. The aquifer underlies 3,000
Authors
David L. Parkhurst, Scott C. Christenson, George N. Breit

A dual drawworks controller for borehole tomography

No abstract available.
Authors
T.P. Grover, R.P. Kipfinger, D.L. Wright

Surface chemistry of ferrihydrite: Part 2. Kinetics of arsenate adsorption and coprecipitation

The kinetics of As(V) adsorption by ferrihydrite was investigated in coprecipitation and postsynthesis adsorption experiments conducted in the pH range 7.5-9.0. In coprecipitation experiments, As(V) was present in solution during the hydrolysis and precipitation of iron. In adsorption experiments, a period of rapid (<5 min) As(V) uptake from solution was followed by continued uptake for at least e
Authors
C. C. Fuller, J.A. Dadis, G.A. Waychunas

Dissolved inorganic nitrogen composition, transformation, retention, and transport in naturally phosphate-rich and phosphate-poor tropical streams

The composition, transformation, and transport of dissolved inorganic nitrogen (DIN) was compared in waters associated with two lowland streams in Costa Rica. The Salto River is enriched by geothermal-based soluble reactive phosphorus (SRP), which raises the concentration up to 200 μg/L whereas Pantano Creek, an unimpacted tributary, has an SRP concentration <10 μg/L. Ammonium concentration in spr
Authors
F.J. Triska, C. M. Pringle, G. W. Zellweger, J.H. Duff, R. J. Avanzino

Patterns of hydrological exchange and nutrient transformation in the hyporheic zone of a gravel-bottom stream: examining terrestrial- aquatic linkages

The terrestrial-aquatic interface beneath a riparian corridor was investigated as a region of hydrological and biological control of nutrient flux. Dissolved oxygen (DO) concentration in the hyporheic zone ranged from <1.0 to 9.5 mg l-1 due to permeability variations in bankside sediments. DO concentration was related to the proportion of stream water in the lateral hyporheic zone, indicating that
Authors
F.J. Triska, J.H. Duff, R. J. Avanzino

Deposition of aerially applied BT in an oak forest and its prediction with the FSCBG model

Data are provided from 17 single-swath aerial spray trials that were conducted over a fully leafed, 16-m tall, mixed oak forest. The distribution of cross-swath spray deposits was sampled at the top of the canopy and below the canopy. Micrometeorological conditions were measured above and within the canopy during the spray trials. The USDA Forest Service FSCBG (Forest Service-Cramer-Barry-Grim) mo
Authors
Dean E. Anderson, David R. Miller, Yansen Wang, William G. Yendol, Karl Mierzejewski, Michael L. McManus