Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3787
On conducting the modified ‘Slug’ test in tight formations
The method introduced by Bredehoeft and Papadopulos (1980) for conducting a modified ‘slug’ test in tight formations does not assure the condition of approximate equilibrium necessary at the start of the test. In addition, compressibility in the shut-in well can be significantly larger than the compressibility of water, which Bredehoeft and Papadopulos indicate should be used in the calculations.
Authors
C.E. Neuzil
Does the benthos control phytoplankton biomass in South San Francisco Bay?
South San Francisco Bay, USA, is a shallow coastal embayment that receives large inputs of nutrients (N. P, Si) and small local inputs of freshwater. Phytoplankton dynamics are typically characterized by a spring bloom when surface chlorophyll a increases from < 5 to > 40 mg m-3. The bloom persists for 2 to 4 wk, and then dissipates. Phytoplankton biomass remains low (chlorophyll a < 5 mg m-3) fro
Authors
James E. Cloern
Volatilization of organic compounds from streams
Mass-transfer coefficients for the volatilization of ethylene and propane were correlated with the hydraulic and geometric properties of seven streams, and predictive equations were developed. The equations were evaluated using a normalized root-mean-square error as the criterion of comparison. The two best equations were a two-variable equation containing the energy dissipated per unit mass per u
Authors
Ronald E. Rathburn, D. Y. Tai
Acid rain, air pollution, and tree growth in southeastern New York
Whether dendroecological analyses could be used to detect changes in the relationship of tree growth to climate that might have resulted from chronic exposure to components of the acid rain-air pollution complex was determined. Tree-ring indices of white pine (Pinus strobus L.), eastern hemlock (Tsuga canadensis (L.) Cart.), pitch pine (Pinus rigida Mill.), and chestnut oak (Quercus prinus L.) wer
Authors
L.J. Puckett
The effect of sulfate on aluminum concentrations in natural waters: some stability relations in the system Al2O3-SO3-H2O at 298 K
While gibbsite and kaolinite solubilities usually regulate aluminum concentrations in natural waters, the presence of sulfate can dramatically alter these solubilities under acidic conditions, where other, less soluble minerals can control the aqueous geochemistry of aluminum. The likely candidates include alunogen, Al2(SO4)3 · 17H2O, alunite, KAl3(SO4)2(OH)6, jurbanite, Al(SO4)(OH) · 5H2O, and ba
Authors
D. Kirk Nordstrom
Fate of acetone in water
The physical, chemical, and biological processes that might affect the concentration of acetone in water were investigated in laboratory studies. Processes considered included volatilization, adsorption by sediments, photodecomposition, bacterial degradation, and absorption by algae and molds. It was concluded that volatilization and bacterial degradation were the dominant processes determining th
Authors
R. E. Rathbun, D. W. Stephens, D.J. Shultz
Enrichment and association of lead and bacteria at particulate surfaces in a salt-marsh surface layer
The particle-laden surface layer (approx 150-370 mu m) and subsurface waters of a South San Francisco Bay salt marsh were sampled over 2 tidal cycles and analyzed for particle numbers and particulate-associated and total concentrations of Pb and bacteria. Laboratory studies examined the ability of a bacterial isolate from the surface layer and a bacterial 'film-former' to sorb Pb at environmentall
Authors
R.W. Harvey, Leonard W. Lion, L.Y. Young, J.O. Leckie
Subsurface injection of liquid waste in Florida, United States of America
In 1979, liquid waste was injected into the subsurface of Florida by 10 injection systems at an aggregate average rate of 165,000 m3/d. All the systems inject into carbonate rocks that contain salty water. Extensive precautions are taken in the construction of the injection wells and in the monitoring of their operation to provide assurance that overlying and laterally contiguous freshwater resour
Authors
John Vecchioli
Role of numerical simulation in analysis of ground-water quality problems
The increasing public awareness and concern about the hazards of toxic chemicals contaminating aquifers has created an increased need for predictive capabilities to analyze ground-water contamination problems. Several digital models to simulate the movement and concentration of ground-water contaminants have been documented recently. Most simulate the transport and dispersion of a nonreactive solu
Authors
Leonard F. Konikow
Role of solute-transport models in the analysis of groundwater salinity problems in agricultural areas
Undesirable salinity increases occur in both groundwater and surface water and are commonly related to agricultural practices. Groundwater recharge from precipitation or irrigation will transport and disperse residual salts concentrated by evapotranspiration, salts leached from soil and aquifer materials, as well as some dissolved fertilizers and pesticides. Where stream salinity is affected by ag
Authors
Leonard F. Konikow
A transient laboratory method for determining the hydraulic properties of 'tight' rocks-I. Theory
Transient pulse testing has been employed increasingly in the laboratory to measure the hydraulic properties of rock samples with low permeability. Several investigators have proposed a mathematical model in terms of an initial-boundary value problem to describe fluid flow in a transient pulse test. However, the solution of this problem has not been available. In analyzing data from the transient
Authors
P. A. Hsieh, J.V. Tracy, C. E. Neuzil, J. D. Bredehoeft, Stephen E. Silliman
A transient laboratory method for determining the hydraulic properties of 'tight' rocks-II. Application
In Part I a general analytical solution for the transient pulse test was presented. Part II presents a graphical method for analyzing data from a test to obtain the hydraulic properties of the sample. The general solution depends on both hydraulic conductivity and specific storage and, in theory, analysis of the data can provide values for both of these hydraulic properties. However, in practice,
Authors
C. E. Neuzil, C. Cooley, Stephen E. Silliman, J. D. Bredehoeft, P. A. Hsieh