Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3746
Chloroethene biodegradation in sediments at 4°C
Microbial reductive dechlorination of [1,2-14C]trichloroethene to [14C]cis-dichloroethene and [14C]vinyl chloride was observed at 4°C in anoxic microcosms prepared with cold temperature-adapted aquifer and river sediments from Alaska. Microbial anaerobic oxidation of [1,2-14C]cis-dichloroethene and [1,2-14C]vinyl chloride to 14CO2 also was observed under these conditions.
Authors
P. M. Bradley, S. Richmond, F. H. Chapelle
Comparison of Bacteroides-Prevotella 16S rRNA genetic markers for fecal samples from different animal species
To effectively manage surface and ground waters it is necessary to improve our ability to detect and identify sources of fecal contamination. We evaluated the use of the anaerobic bacterial group Bacteroides-Prevotella as a potential fecal indicator. Terminal restriction length polymorphism (T-RFLP) of the 16S rRNA genes from this group was used to determine differences in populations and to ident
Authors
L.R. Fogarty, M.A. Voytek
Effects of suburban development on runoff generation in the Croton River basin, New York, USA
The effects of impervious area, septic leach-field effluent, and a riparian wetland on runoff generation were studied in three small (0.38–0.56 km2) headwater catchments that represent a range of suburban development (high density residential, medium density residential, and undeveloped) within the Croton River basin, 70 km north of New York City. Precipitation, stream discharge, and groundwater l
Authors
Douglas A. Burns, T. Vitvar, J. McDonnell, J. Hassett, J. Duncan, Carol Kendall
Impact of land use and land cover change on groundwater recharge and quality in the southwestern US
Humans have exerted large‐scale changes on the terrestrial biosphere, primarily through agriculture; however, the impacts of such changes on the hydrologic cycle are poorly understood. The purpose of this study was to test the hypothesis that the conversion of natural rangeland ecosystems to agricultural ecosystems impacts the subsurface portion of the hydrologic cycle by changing groundwater rech
Authors
Bridget R. Scanlon, Robert C. Reedy, David A. Stonestrom, David E. Prudic, Kevin F. Dennehy
Percolation and transport in a sandy soil under a natural hydraulic gradient
Unsaturated flow and transport under a natural hydraulic gradient in a Mediterranean climate were investigated with a field tracer experiment combined with laboratory analyses and numerical modeling. Bromide was applied to the surface of a sandy soil during the dry season. During the subsequent rainy season, repeated sediment sampling tracked the movement of bromide through the profile. Analysis o
Authors
Christopher T. Green, David A. Stonestrom, Barbara A. Bekins, Katherine C. Akstin, Marjorie S. Schulz
Nitrogen and carbon flow from rock to water: Regulation through soil biogeochemical processes, Mokelumne River watershed, California, and Grand Valley, Colorado
Soil denitrification is an ecologically important nitrogen removal mechanism that releases to the atmosphere the greenhouse gas N2O, an intermediate product from the reduction of NO3- to N 2. In this study we evaluate the relationship between soil carbon and denitrification potential in watersheds with bedrock acting as a nonpoint source of nitrogen, testing the hypothesis that nitrate leaching to
Authors
J.M. Holloway, R. L. Smith
Part 2: A field study of enhanced remediation of Toluene in the vadose zone using a nutrient solution
The objective of this study was to test the effectiveness of a nitrate-rich nutrient solution and hydrogen peroxide (H2O2) to enhance in-situ microbial remediation of toluene in the unsaturated zone. Three sand-filled plots were tested in three phases (each phase lasting approximately 2 weeks). During the control phase, toluene was applied uniformly via sprinkler irrigation. Passive remediation wa
Authors
J.A. Tindall, E.P. Weeks, M. Friedel
Delineating copper accumulation pathways for the freshwater bivalve Corbicula using stable copper isotopes
Delineation of metal uptake routes in aquatic invertebrates is critical for characterizing bioaccumulation dynamics and assessing risks associated with metal exposure. Here we demonstrate that Cu stable isotopic ratios can be manipulated in both exposure media and algae to determine the efflux rate constant (ke) and to estimate Cu assimilation efficiency (AE) from ingested food in a freshwater biv
Authors
M.-N. Croteau, S. N. Luoma
Part 1: Vadose-zone column studies of toluene (enhanced bioremediation) in a shallow unconfined aquifer
The objectives of the laboratory study described in this paper were (1) to determine the effectiveness of four nutrient solutions and a control in stimulating the microbial degradation of toluene in the unsaturated zone as an alternative to bioremediation methodologies such as air sparging, in situ vitrification, or others (Part I), and (2) to compare the effectiveness of the addition of the most
Authors
J.A. Tindall, M.J. Friedel, R.J. Szmajter, S.M. Cuffin
Steam injection pilot study in a contaminated fractured limestone (Maine, USA): Modeling and analysis of borehole radar reflection data
Steam-enhanced remediation (SER) has been successfully used to remove DNAPL and LNAPL contaminants in porous media. Between August and November 2002, SER was tested in fractured limestone at the former Loring Air Force Base, in Maine, USA. During the SER investigation, the U.S. Geological Survey conducted a series of borehole radar surveys to evaluate the effectiveness of radar methods for monitor
Authors
C. Gregoire, J.W. Lane, P. K. Joesten
Comparison of a novel passive sampler to standard water-column sampling for organic contaminants associated with wastewater effluents entering a New Jersey stream
Four water samples collected using standard depth and width water-column sampling methodology were compared to an innovative passive, in situ, sampler (the polar organic chemical integrative sampler or POCIS) for the detection of 96 organic wastewater-related contaminants (OWCs) in a stream that receives agricultural, municipal, and industrial wastewaters. Thirty-two OWCs were identified in POCIS
Authors
D.A. Alvarez, P. E. Stackelberg, J. D. Petty, J.N. Huckins, E. T. Furlong, S.D. Zaugg, M. T. Meyer
Assessing the vulnerability of a municipal well field to contamination in a karst aquifer
Proposed expansion of extractive lime-rock mines near the Miami-Dade County Northwest well field and Everglades wetland areas has garnered intense scrutiny by government, public, environmental stakeholders, and the media because of concern that mining will increase the risk of pathogen contamination. Rock mines are excavated to the same depth as the well field's primary producing zone. The underly
Authors
R.A. Renken, K.J. Cunningham, M.R. Zygnerski, M.A. Wacker, A.M. Shapiro, R.W. Harvey, D.W. Metge, C.L. Osborn, J. N. Ryan