Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3746
Transport and time lag of chlorofluorocarbon gases in the unsaturated zone, Rabis Creek, Denmark
Transport of chlorofluorocarbon (CFC) gases through the unsaturated zone to the water table is affected by gas diffusion, air–water exchange (solubility), sorption to the soil matrix, advective–dispersive transport in the water phase, and, in some cases, anaerobic degradation. In deep unsaturated zones, this may lead to a time lag between entry of gases at the land surface and recharge to groundwa
Authors
Peter Engesgaard, Anker L. Højberg, Klaus Hinsby, Karsten H. Jensen, Troels Laier, Flemming Larsen, Eurybiades Busenberg, Niel Plummer
Microbial precipitation of dolomite in methanogenic groundwater
We report low-temperature microbial precipitation of dolomite in dilute natural waters from both field and laboratory experiments. In a freshwater aquifer, microorganisms colonize basalt and nucleate nonstoichiometric dolomite on cell walls. In the laboratory, ordered dolomite formed at near-equilibrium conditions from groundwater with molar Mg:Ca ratios of <1; dolomite was absent in sterile exper
Authors
Jennifer A. Roberts, Philip C. Bennett, Luis A. Gonzalez, G.L. Macpherson, Kitty L. Milliken
Degradates provide insight to spatial and temporal trends of herbicides in ground water
Since 1995, a network of municipal wells in Iowa, representing all major aquifer types (alluvial, bedrock/karst region, glacial drift, bedrock/nonkarst region), has been repeatedly sampled for a broad suite of herbicide compounds yielding one of the most comprehensive statewide databases of such compounds currently available in the United States. This dataset is ideal for documenting the insight t
Authors
D.W. Kolpin, D.J. Schnoebelen, E.M. Thurman
Electrical imaging of tracer migration at the Massachusetts Military Reservation, Cape Cod
Electrical resistivity tomography (ERT) is examined as a method to provide spatially continuous information about aquifer properties through imaging of tracer flow and transport in an unconfined aquifer. Field data were collected at the Massachusetts Military Reservation, Cape Cod, Massachusetts, during the summer of 2002. High resolution images in both space and time of the movement of an electri
Authors
Kamini Singha, Andrew Binley, John W. Lane, Steven M. Gorelick
Object-based inversion of crosswell radar tomography data to monitor vegetable-oil injection experiment
Crosswell radar tomography methods can be used to dynamically image ground-water flow and mass transport associated with tracer tests, hydraulic tests, and natural physical processes. Dynamic imaging can be used to identify preferential flow paths and to help characterize complex aquifer heterogeneity. Unfortunately, because the raypath coverage of the interwell region is limited by the borehole g
Authors
John W. Lane, Frederick D. Day-Lewis, Roelof J. Versteeg, C.C. Casey
Microbial mercury cycling in sediments of the San Francisco Bay-Delta
Microbial mercury (Hg) methylation and methylmercury (MeHg) degradation processes were examined using radiolabled model Hg compounds in San Francisco Bay-Delta surface sediments during three seasonal periods: late winter, spring, and fall. Strong seasonal and spatial differences were evident for both processes. MeHg production rates were positively correlated with microbial sulfate reduction rates
Authors
Mark Marvin-DiPasquale, Jennifer L. Agee
Questa baseline and pre-mining ground water investigation: 11. Geochemistry of composited material from alteration scars and mine-waste piles
Composited, surficial material was collected from alteration scars, a less intensely altered site, and mine-waste piles. All samples were analyzed for forty elements by inductively coupled plasma-atomic emission spectrometry, total sulfur and quantitative X-ray diffraction. This work was performed in cooperation with the New Mexico Environment Department.
Authors
Paul H. Briggs, S. J. Sutley, Keith Eric Livo
Atmospheric deposition of nutrients, pesticides, and mercury in Rocky Mountain National Park, Colorado, 2002
Nutrients, current-use pesticides, and mercury were measured in atmospheric deposition during summer in Rocky Mountain National Park in Colorado to improve understanding of the type and magnitude of atmospheric contaminants being deposited in the park. Two deposition sites were established on the east side of the park: one at an elevation of 2,902 meters near Bear Lake for nutrients and pesticides
Authors
Alisa Mast, Donald H. Campbell, George P. Ingersoll, William T. Foreman, David P. Krabbenhoft
Preliminary assessment of microbial communities and biodegradation of chlorinated volatile organic compounds in wetlands at Cluster 13, Lauderick Creek area, Aberdeen Proving Ground, Maryland
A preliminary assessment of the microbial communities and biodegradation processes for chlorinated volatile organic compounds was con-ducted by the U.S. Geological Survey in wetlands at the Cluster 13, Lauderick Creek area at Aberdeen Proving Ground, Maryland. The U.S. Geological Survey collected wetland sediment samples from 11 sites in the Lauderick Creek area for microbial analyses, and used ex
Authors
Michelle M. Lorah, Mary A. Voytek, Tracey A. Spencer
Heat as a tool for studying the movement of ground water near streams
Stream temperature has long been recognized as an important water quality parameter. Temperature plays a key role in the health of a stream’s aquatic life, both in the water column and in the benthic habitat of streambed sediments. Many fish are sensitive to temperature. For example, anadromous salmon require specific temperature ranges to successfully develop, migrate, and spawn [see Halupka and
Diffusion and drive-point sampling to detect ordnance-related compounds in shallow ground water beneath Snake Pond, Cape Cod, Massachusetts, 2001-02
Diffusion samplers and temporary drive points were used to test for ordnance-related compounds in ground water discharging to Snake Pond near Camp Edwards at the Massachusetts Military Reservation, Cape Cod, MA. The contamination resulted from artillery use and weapons testing at various ranges upgradient of the pond.The diffusion samplers were constructed with a high-grade cellulose membrane that
Authors
Denis R. LeBlanc