Calibration of a groundwater flow and contaminant transport computer model: Progress toward model validation

Technical Report · Fri Sep 01 04:00:00 EDT 1989

DOI:https://doi.org/10.2172/5568205· OSTI ID:5568205

Lee, R. R. ^[1]; Ketelle, R. H. ^[1]; Bownds, J. M. ^[1]; Rizk, T. A. ^[2]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2. North Carolina State Univ., Raleigh, NC (United States)

A groundwater flow and contaminant transport model calibration was performed to evaluate the ability of a typical, verified computer code to simulate groundwater tracer migration in the shallow aquifer of the Conasauga Group. Previously, standard practice site data interpretation and groundwater modeling resulted in inaccurate simulations of contaminant transport direction and rate compared with tracer migration behavior. The site's complex geology, the presence of flow in both fractured and weathered zones, and the transient character of flow in the shallow aquifer combined to render inaccurate assumptions of steady-state, homogeneous groundwater flow. The improvement of previous modeling results required iterative phases of conceptual model development, hypothesis testing, site field investigations, and modeling. The activities focused on generating a model grid that was compatible with site hydrogeologic conditions and on establishing boundary conditions based on site data. An annual average water table configuration derived from site data and fixed head boundary conditions was used as input for flow modeling. The contaminant transport model was combined with the data-driven flow model to obtain a preliminary contaminant plume. Calibration of the transport code was achieved by comparison with site tracer migration and concentration data. This study documents the influence of fractures and the transient character of flow and transport in the shallow aquifer. Although compatible with porous medium theory, site data demonstrate that the tracer migration pathway would not be anticipated using conventional porous medium analysis. 126 figs., 22 refs., 5 tabs.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE Office of Energy Research (ER)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5568205
• Report Number(s): ORNL/TM--11294; ON: DE90000982
• Country of Publication: United States
• Language: English

Related Subjects

510200* -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
CALIBRATION
COMPUTERIZED SIMULATION
CONTAMINATION
ENVIRONMENTAL TRANSPORT
FLOW RATE
FORECASTING
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GROUND WATER
HYDROGEN COMPOUNDS
MASS TRANSFER
MATHEMATICAL MODELS
MONITORING
NATIONAL ORGANIZATIONS
OPTIMIZATION
ORNL
OXYGEN COMPOUNDS
PLUMES
RADIONUCLIDE MIGRATION
SIMULATION
US AEC
US DOE
US ERDA
US ORGANIZATIONS
WATER