Theme 1

Theme 1 - Site and Contaminant Characterization

1) Improved Methods for Characterization of Contaminated Sites

Development and field demonstration of improved technologies, methods and strategies for accommodating geologic and contaminant complexities such as contaminant mass distributions in low permeability zones, multiple sources; identification of sampling scales commensurate with the hydrologic complexity; use cores, analyses and borehole testing strategies to achieve cost effectiveness in site characterization for site conceptual modeling and site diagnosis for decision making.

2) Behavior and Fate of Industrial Contaminants in Sand and Gravel

Field studies of plumes and their source zones in granular aquifers (sand, gravel) at representative industrial sites using innovative methods to determine contaminant distributions, plume fluxes and natural attenuation; assess the effects on aquifers of back diffusion from low-permeability zones (silt, clay layers); determine the heterogeneity scales governing plume behavior; use numerical models with real site information to assess plume longevities and long term impacts (i.e. decades to centuries); site categorization for realistic expectations of long-term conditions without and with remediation.

3) Behavior and Fate of Industrial Contaminants in Fracture Rock

Field studies of plumes and their source zones in fractured rock at representative industrial sites with emphasis on sedimentary rock, using innovative methods to determine contaminant distributions in the fracture networks and low-permeability rock matrix blocks between fractures to quantify plume fluxes and natural attenuation and use numerical models to predict source zone and plume longevities and long term impacts without and with remediation.

4) Confining Beds (Aquitards) as Barriers to Contaminant Migration

Comprehensive studies of aquitards at representative industrial sites contaminated by DNAPLs where the aquitards are the key component governing contaminant migration in aquifer-aquitard systems, with emphasis on determining the nature, origin and role of secondary pathways such as fractures, root holes and bioturbation features. Creation of a framework for aquitard assessment involving use of detailed information of several types collected from a small number of coreholes.