Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3746
Denitrification and hydrologic transient storage in a glacial meltwater stream, McMurdo Dry Valleys, Antarctica
In extreme environments, retention of nutrients within stream ecosystems contributes to the persistence of aquatic biota and continuity of ecosystem function. In the McMurdo Dry Valleys, Antarctica, many glacial meltwater streams flow for only 5–12 weeks a year and yet support extensive benthic microbial communities. We investigated NO3− uptake and denitrification in Green Creek by analyzing small
Authors
M.N. Gooseff, Diane M. McKnight, R.L. Runkel, J.H. Duff
Calculation of individual isotope equilibrium constants for geochemical reactions
Theory is derived from the work of Urey (Urey H. C. [1947] The thermodynamic properties of isotopic substances. J. Chem. Soc. 562–581) to calculate equilibrium constants commonly used in geochemical equilibrium and reaction-transport models for reactions of individual isotopic species. Urey showed that equilibrium constants of isotope exchange reactions for molecules that contain two or more atoms
Authors
D.C. Thorstenson, D.L. Parkhurst
Ground water chlorinated ethenes in tree trunks: Case studies, influence of recharge, and potential degradation mechanism
Trichloroethene (TCE) was detected in cores of trees growing above TCE-contaminated ground at three sites: the Carswell Golf Course in Texas, Air Force Plant PJKS in Colorado, and Naval Weapons Station Charleston in South Carolina. This was true even when the depth to water was 7.9 m or when the contaminated aquifer was confined beneath ∼3 m of clay. Additional ground water contaminants detected i
Authors
D. A. Vroblesky, B.D. Clinton, J.M. Vose, C.C. Casey, G. J. Harvey, P. M. Bradley
Aquifer vulnerability to pesticide pollution: Combining soil, land-use and aquifer properties with molecular descriptors
This study uses an extensive survey of herbicides in groundwater across the midwest United States to predict occurrences of a range of compounds across the region from a combination of their molecular properties and the properties of the catchment of a borehole. The study covers 100 boreholes and eight pesticides. For each of the boreholes its catchment the soil, land-use and aquifer properties we
Authors
F. Worrall, D.W. Kolpin
Airflows and turbulent flux measurements in mountainous terrain: Part 2: Mesoscale effects
The location of the Niwot Ridge Ameriflux site within the rocky mountains subjects it to airflows which are common in mountainous terrain. In this study, we examine the effects of some of these mesoscale features on local turbulent flux measurements; most notably, the formation of valley/mountain flows and mountain lee-side waves. The valley/mountain flows created local non-stationarities in the w
Authors
A.A. Turnipseed, D.E. Anderson, S. Burns, P.D. Blanken, Russell K. Monson
Use of qualitative and quantitative information in neural networks for assessing agricultural chemical contamination of domestic wells
A neural network analysis of agrichemical occurrence in groundwater was conducted using data from a pilot study of 192 small-diameter drilled and driven wells and 115 dug and bored wells in Illinois, a regional reconnaissance network of 303 wells across 12 Midwestern states, and a study of 687 domestic wells across Iowa. Potential factors contributing to well contamination (e.g., depth to aquifer
Authors
A. Mishra, C. Ray, D.W. Kolpin
Estimation of hydraulic conductivity in an alluvial system using temperatures
Well water temperatures are often collected simultaneously with water levels; however, temperature data are generally considered only as a water quality parameter and are not utilized as an environmental tracer. In this paper, water levels and seasonal temperatures are used to estimate hydraulic conductivities in a stream-aquifer system. To demonstrate this method, temperatures and water levels ar
Authors
G.W. Su, James Jasperse, D. Seymour, J. Constantz
Stable metal isotopes reveal copper accumulation and loss dynamics in the freshwater bivalve Corbucula
Characterization of uptake and loss dynamics is critical to understanding risks associated with contaminant exposure in aquatic animals. Dynamics are especially important in addressing questions such as why coexisting species in nature accumulate different levels of a contaminant. Here we manipulated copper (Cu) stable isotopic ratios (as an alternative to radioisotopes) to describe for the first
Authors
M.-N. Croteau, S. N. Luoma, B.R. Topping, C.B. Lopez
Geochemistry, radiocarbon ages, and paleorecharge conditions along a transect in the central High Plains aquifer, southwestern Kansas, USA
Water samples from short-screen monitoring wells installed along a 90-km transect in southwestern Kansas were analyzed for major ions, trace elements, isotopes (H, B, C, N, O, S, Sr), and dissolved gases (He, Ne, N2, Ar, O2, CH4) to evaluate the geochemistry, radiocarbon ages, and paleorecharge conditions in the unconfined central High Plains aquifer. The primary reactions controlling water chemis
Authors
P. B. McMahon, J.K. Böhlke, S. C. Christenson
Persistence of pharmaceutical compounds and other organic wastewater contaminants in a conventional drinking-water-treatment plant
In a study conducted by the US Geological Survey and the Centers for Disease Control and Prevention, 24 water samples were collected at selected locations within a drinking-water-treatment (DWT) facility and from the two streams that serve the facility to evaluate the potential for wastewater-related organic contaminants to survive a conventional treatment process and persist in potable-water supp
Authors
P. E. Stackelberg, E. T. Furlong, M. T. Meyer, S.D. Zaugg, A.K. Henderson, D.B. Reissman
Frequency spectral analysis of GPR data over a crude oil spill
A multi-offset ground penetrating radar (GPR) dataset was acquired by the U.S. Geological Survey (USGS) at a crude oil spill site near Bemidji, Minnesota, USA. The dataset consists of two, parallel profiles, each with 17 transmitter-receiver offsets ranging from 0.60 to 5.15m. One profile was acquired over a known oil pool floating on the water table, and the other profile was acquired over an unc
Authors
B.L. Burton, G.R. Olhoeft, M.H. Powers
Redox transformations of arsenic oxyanions in periphyton communities
Periphyton (Cladophora sp.) samples from a suburban stream lacking detectable dissolved As were able to reduce added As(V) to As(III) when incubated under anoxic conditions and, conversely, oxidized added As(III) to As(V) with aerobic incubation. Both types of activity were abolished in autoclaved controls, thereby demonstrating its biological nature. The reduction of As(V) was inhibited by chlora
Authors
T.R. Kulp, S.E. Hoeft, R.S. Oremland