Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
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Extent of reaction in open systems with multiple heterogeneous reactions
The familiar batch concept of extent of reaction is reexamined for systems of reactions occurring in open systems. Because species concentrations change as a result of transport processes as well as reactions in open systems, the extent of reaction has been less useful in practice in these applications. It is shown that by defining the extent of the equivalent batch reaction and a second contribut
Authors
John C. Friedly
Large-scale natural gradient tracer test in sand and gravel, Cape Cod, Massachusetts: 1. Experimental design and observed tracer movement
A large-scale natural gradient tracer experiment was conducted on Cape Cod, Massachusetts, to examine the transport and dispersion of solutes in a sand and gravel aquifer. The nonreactive tracer, bromide, and the reactive tracers, lithium and molybdate, were injected as a pulse in July 1985 and monitored in three dimensions as they moved as far as 280 m down-gradient through an array of multilevel
Authors
Denis R. LeBlanc, Stephen P. Garabedian, Kathryn M. Hess, Lynn W. Gelhar, Richard D. Quadri, Kenneth G. Stollenwerk, Warren W. Wood
Sampling design for groundwater solute transport: Tests of methods and analysis of Cape Cod tracer test data
Tests of a one-dimensional sampling design methodology on measurements of bromide concentration collected during the natural gradient tracer test conducted by the U.S. Geological Survey on Cape Cod, Massachusetts, demonstrate its efficacy for field studies of solute transport in groundwater and the utility of one-dimensional analysis. The methodology was applied to design of sparse two-dimensional
Authors
Debra S. Knopman, Clifford I. Voss, Stephen P. Garabedian
Neotectonic effects on sinuosity and channel migration, Belle Fourche River, Western South Dakota
Short-term instability in the behaviour of a small, meandering alluvial channel is identified from the relation between sinuosity and either floodplain slope or channel slope within 17 reaches along an 81-kilometre section of the Belle Fourche River in western South Dakota. In reaches 1 to 4 and 11 to 17 the channel is relatively stable and sinuosity varies inversely with channel slope. In reaches
Authors
Basil Gomez, Donna C. Marron
Large-scale natural gradient tracer test in sand and gravel, Cape Cod, Massachusetts: 2. Analysis of spatial moments for a nonreactive tracer
A large-scale natural gradient tracer test was conducted to examine the transport of reactive and nonreactive tracers in a sand and gravel aquifer on Cape Cod, Massachusetts. As part of this test the transport of bromide, a nonreactive tracer, was monitored for about 280 m and quantified using spatial moments. The calculated mass of bromide for each sampling date varied between 85% and 105% of the
Authors
Stephen P. Garabedian, Dennis R. LeBlanc, Lynn W. Gelhar, Michael A. Celia
Comment on the treatment of residual water content in “A consistent set of parametric models for the two-phase flow of immiscible fluids in the subsurface” by L. Luckner et al.
Luckner et al. [1989] (hereinafter LVN) present a clear summary and generalization of popular formulations used for convenient representation of porous media fluid flow characteristics, including water content (θ) related to suction (h) and hydraulic conductivity (K) related to θ or h. One essential but problematic element in the LVN models is the concept of residual water content (θr; in LVN, θw,
Authors
John R. Nimmo
Assessing the solubilities and reaction kinetics of aluminous minerals in soils
The use of chemical thermodynamics and reaction kinetics is necessary to quantitatively model the transformation of aluminous minerals and their dissolved constituents in soils and other geochemical systems. Soils are thermodynamically open systems subject to atmospheric and biological forces and do not attain overall thermodynamic equilibrium with respect to either mass or time. However, local or
Authors
Howard M. May, D. Kirk Nordstrom
Evaluation of unsaturated zone air permeability through pneumatic tests
Predicting the steady state distribution of air pressure in the unsaturated zone resulting from a pneumatic test provides a method for determining air-phase permeability. This technique is analogous to the inverse problem of well hydraulics; however, air flow is more complicated than ground water flow because of air compressibility, the Klinkenberg effect, variations in air density and viscosity t
Authors
Arthur L. Baehr, Marc F. Hult
Effects of surfactants on the mobility of nonpolar organic contaminants in porous media
No abstract available.
Authors
J. A. Smith, D. Tucker, P. R. Jaffe, R.T. Mueller
A thermodynamic partition model for binding of nonionic organic compounds by organic colloids and implications for their sorption to soils and sediment
No abstract available.
Authors
U.P. Chin, Walter J. Weber, C. T. Chiou
Parameters involved in modeling movement of bacteria in groundwater
No abstract available.
Authors
Ronald W. Harvey
Particulate and colloidal organic material in Pueblo Reservoir, Colorado--Influence of autochthonous source on chemical composition
No abstract available.
Authors
J. F. Ranville, R.A. Harnish, D.M. McKnight