HR: 0830h
AN: H21D-0846    [PDF]
TI: NAPL Mass Reduction Effects on Contaminant Source Strength: Laboratory Experiments
AU: * Fure, A D
EM: adfure@ufl.edu
AF: Department of Environmental Engineering Sciences, 217 Black Hall, Gainesville, FL 32611
AU: Jawitz, J W
EM: Jawitz@ufl.edu
AF: Soil and Water Science Department, 2169 McCarty, Gainesville, FL 32611
AU: Annable, M D
EM: annable@ufl.edu
AF: Department of Environmental Engineering Sciences, 217 Black Hall, Gainesville, FL 32611
AB: The longevity of sites contaminated with chlorinated solvents, and the associated implication for plume management options, has made source zone remediation an attractive option. However, source zone remediation is challenging and recent field scale demonstrations of aggressive source zone remediation have pointed to the technical infeasibility of complete restoration of the source zone. Another approach to evaluating the success of source zone remediation is in a risk-based framework, where the technology is evaluated for its ability to reduce the source strength to a level where the risk to down-gradient receptors is lowered below a certain threshold. Virtually all field and laboratory research of source zone remediation to date has focused on the technology's ability to remove mass from the source zone and has not evaluated the impact of the remediation on source strength. This prevents the analysis of previous work in a risk-based framework. In this work we evaluate relationships between mass reduction and source strength (mass flux of contaminant) in two-dimensional laboratory flow cells with heterogeneous distributions of porous media. The flow cell features a segmented extraction well which allows for segmented measurements of water and contaminant flux. The flow cell is designed to investigate the effects of NAPL morphology and distribution (source-zone architecture) in relation to a heterogeneous flow field on mass reduction/flux reduction relationships. Results indicate a linear relationship between mass reduction and flux reduction with relationships for individual well segments oscillating about a mean trend describing the entire system. Results from a series of experiments, with varying degrees of heterogeneity are presented with an emphasis on contaminant flux plane response to changes in source-zone architecture.
DE: 1829 Groundwater hydrology
DE: 1831 Groundwater quality
DE: 1832 Groundwater transport
SC: Hydrology [H]
MN: 2003 Fall Meeting