Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
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Size-selective predation on groundwater bacteria by nanoflagellates in an organic-contaminated aquifer
Time series incubations were conducted to provide estimates for the size selectivities and rates of protistan grazing that may be occurring in a sandy, contaminated aquifer. The experiments involved four size classes of fluorescently labeled groundwater bacteria (FLB) and 2- to 3-μm-long nanoflagellates, primarily Spumella guttula(Ehrenberg) Kent, that were isolated from contaminated aquifer sedim
Authors
N.E. Kinner, R.W. Harvey, K. Blakeslee, G. Novarino, L.D. Meeker
Type curves to determine the relative importance of advection and dispersion for solute and vapor transport
The relative importance of advection and dispersion for both solute and vapor transport can be determined from type curves or concentration, flux, or cumulative flux. The dimensionless form of the type curves provides a means to directly evaluate the importance of mass transport by advection relative to that of mass transport by diffusion and dispersion. Type curves based on an analytical solution
Authors
J.A. Garges, A. L. Baehr
Changes in the isotopic and chemical composition of ground water resulting from a recharge pulse from a sinking stream
The Little River, an ephemeral stream that drains a watershed of approximately 88 km2 in northern Florida, disappears into a series of sinkholes along the Cody Scarp and flows directly into the carbonate Upper Floridan aquifer, the source of water supply in northern Florida. The changes in the geochemistry of ground water caused by a major recharge pulse from the sinking stream were investigated u
Authors
B. G. Katz, J.S. Catches, T.D. Bullen, R. L. Michel
Difluoromethane, a new and improved inhibitor of methanotrophy
Difluoromethane (HFC-32; DFM) is compared to acetylene and methyl fluoride as an inhibitor of methanotrophy in cultures and soils. DFM was found to be a reversible inhibitor of CH4 oxidation byMethylococcus capsulatus (Bath). Consumption of CH4 in soil was blocked by additions of low levels of DFM (0.03 kPa), and this inhibition was reversed by DFM removal. Although a small quantity of DFM was con
Authors
L.G. Miller, C. Sasson, R.S. Oremland
Contribution of hydroxylated atrazine degradation products to the total atrazine load in midwestern streams
The contribution of hydroxylated atrazine degradation products (HADPs) to the total atrazine load (i.e., atrazine plus stable metabolites) in streams needs to be determined in order to fully assess the impact of atrazine contamination on stream ecosystems and human health. The objectives of this study were (1) to determine the contribution of HADPs to the total atrazine load in streams of nine mid
Authors
R.N. Lerch, P.E. Blanchard, E. M. Thurman
A comparison of zero-order, first-order, and monod biotransformation models
Under some conditions, a first-order kinetic model is a poor representation of biodegradation in contaminated aquifers. Although it is well known that the assumption of first-order kinetics is valid only when substrate concentration, S, is much less than the half-saturation constant, K(s), this assumption is often made without verification of this condition. We present a formal error analysis show
Authors
B.A. Bekins, E. Warren, E.M. Godsy
PHRQCGRF, a computer program for graphical interpretation of PHREEQC geochemical transport simulations (PC only)
No abstract available.
Authors
Joseph Vrabel, Pierre D. Glynn
Studies of the San Francisco Bay, California, estuarine ecosystem: Regional monitoring program results, 1997
As part of a regional monitoring program, water samples were collected in the San Francisco Bay estuary during 20 cruises from January through November 1997. Conductivity, temperature, light attenuation, turbidity, oxygen, and in-vivo chlorophyll fluorescence were measured longitudinally and vertically in the main channel of the estuary from south of the Dumbarton Bridge in the southern part of th
Authors
Jelriza I. Baylosis, Brian E. Cole, James E. Cloern
Water velocities and the potential for the movement of bed sediments in Sinclair Inlet of Puget Sound, Washington
Sinclair Inlet is a small embayment of Puget Sound in the State of Washington. The inlet, about 6.5 kilometers long and 1.5 kilometers wide, is the site of Puget Sound Naval Shipyard. There are concerns that bed sediments in the inlet may have been contaminated as a result of activities at the shipyard, and that these sediments could be resuspended by tide- and wind-driven currents and transported
Authors
Jeffrey W. Gartner, E. A. Prych, G. B. Tate, D. A. Cacchione, R. T. Cheng, W.R. Bidlake, J.T. Ferreira
Chlorofluorocarbons, sulfur hexafluoride, and dissolved permanent gases in ground water from selected sites in and near the Idaho National Engineering and Environmental Laboratory, Idaho, 1994-97
From July 1994 through May 1997, the U.S. Geological Survey in cooperation with the
Department of Energy, sampled 86 wells completed in the Snake River Plain aquifer at and
near the Idaho N ationa1 Engineering and Environmental Laboratory (INEEL). The wells were
sampled for a variety of constituents including one- and two-carbon halocarbons.
Concentrations of dichlorodifluoromethane (CFC-12),
Authors
Eurybiades Busenberg, Niel Plummer, Roy C. Bartholomay, Julian E. Wayland
Chemical analyses of hot springs, pools, geysers, and surface waters from Yellowstone National Park, Wyoming, and vicinity, 1974-1975
This report presents all analytical determinations for samples collected from Yellowstone
National Park and vicinity during 1974 and 1975. Water temperature, pH, Eh, and dissolved O2
were determined on-site. Total alkalinity and F were determined on the day of sample collection.
Flame atomic-absorption spectrometry was used to determine concentrations of Li, Na, K, Ca, and
Mg. Ultraviolet/visi
Authors
James W. Ball, D. Kirk Nordstrom, Everett A. Jenne, Davison V. Vivit
U.S. Geological Survey research at management systems evaluation areas, 1991-95
No abstract available.
Authors
Donald H. Wilkison