John Tauxe's Experience in Environmental
and Contaminant Transport Modeling
A recent example of probabilistic contaminant transport modeling done for
Neptune and Co.
can be found
here.
Neptune and Co.'s senior environmental and contaminant transport modeler is
John Tauxe,
who has experience with the following modeling platforms:
- Groundwater flow models:
- GWSIM: This Groundwater Simulator was used by John
to optimize water supply well pumping schemes.
- TWOLAY: This is a dual-layer dual-phase model
used for designing remediation schemes for sites
contaminated with light non-aqueous phase liquids
(LNAPLs) with free product floating on the groundwater
table.
- Groundwater flow and contaminant transport models:
- MODFLOW: The Modular Flow and transport program
has become a classic, and was developed
by the U.S Geological Survey
(USGS).
MODFLOW was used by John to develop a calibrated
flow field (matching field data) and to then optimize
a system for groundwater capture of contaminants.
- MOC: This Method of Characteristics model, developed
by the USGS was used by
John in the modeling of radionuclide contaminant
transport in support of a Performance Assessment of
Solid Waste Storage Area 6 at Oak Ridge National Laboratory
(ORNL).
- FTWORK: The Flow and Transport Work program was
used in the modeling of radionuclide contaminant
transport in support of a Performance Assessment of
the Class L-II Disposal Facility (CIIDF) at ORNL.
John played a supervisory role in the use of FTWORK.
- FRAC3D: Fracture 3-D was used by John in support
of a Remedial Investigation (RI) of Waste Area Grouping 1
at ORNL.
- Probabilistic environmental transport system modeling software:
- GoldSim: GoldSim
has replaced RIP as a state-of-the-art probabilistic
modeling platform. John has used GoldSim
to update the work done in RIP, and to add probabilistic
risk assessment into the model. He has also applied
GoldSim to contaminant transport problems at
LANL's MDA H, the Nevada Test Site, and the Navy's
former Naval Air Station at Alameda, CA. See examples
of John's (and other's) GoldSim modeling work
here.
- Surface water flow and routing models:
- DWOPER: The Dynamic Wave Operational Model was used
by John to perform flood routing through a series of
dams along the Lower Colorado River (in Texas) working
with the Lower Colorado River Authority
(LCRA).
- PRSYM: The Power Reservior System Model (later to be
reincarnated as RiverWare) was developed by
CADSWES
to model flow and power generation through reserviors.
John used PRSYM to evaluate alternative operational
strategies for a series of five hydropower dams
along the Missouri River at Great Falls, Montana.
- Specialized GIS groundwater modeling functions, developed
by John for the GRID module (ver. 7.0 et seq.) of the
Arc/Info Geographic Information System:
- DarcyFlow: The DarcyFlow function calculates a
distributed fluid flow field from grids of groundwater
potential (head), transmissivity, porosity, and thickness.
- ParticleTrack: Using the flow field generated by
DarcyFlow (or any other distributed flow field grid),
ParticleTrack tracks fluid "particles" through the flow
field, producing a vector coverage with attributes of
position and travel time elapsed.
- PorousPuff: This function performs rudimentary
gaussian advection and dispersion calculations for an
instantaneous point source in a flow field, assuming
that the centroid of the contaminant mass follows the
line generated by ParticleTrack.
- PorousPlume: This is similar to PorousPuff, but
assumes a constant point source rather than an instantaneous
one. Both PorousPuff and PorousPlume can be used in
superposition to simulate almost any geometry and time-
variation of contaminant sources and the transport
of groundwater contaminants in the saturated zone.
- Other modeling software:
- Mathcad: This mathematical tool is invaluable in devising
analytical solutions to differential equation problems, often
encountered in modeling.
- Excel: You'd be surprised what can be accomplished with
the lowly spreadsheet.
Last modified: 7 Feb 2005