Technical Approach

This limited-scope project will develop a passive flux meter (PFM) for measuring 1,4-dioxane fluxes and groundwater specific discharge. The team will adapt field-tested concepts from PFMs designed to measure the fluxes of hydrophobic organics. Laboratory studies will be conducted focusing on current and modified PFM approaches with validation under controlled laboratory conditions. The team will evaluate the limitations of using a standard design of the PFM with selected sorbents for measuring 1,4-dioxane and groundwater fluxes and evaluate modifications to the standard approach that will enhance the capture of 1,4-dioxane in the passive flux meter sorbent to improve accuracy. Methods to consider include low permeability media to extend deployment duration, incorporation of a diffusion sampling domain into the passive flux meter, and consideration of a reactive media designed to enhance 1,4-dioxane capture. A field evaluation involving the new design will be conducted in coordination with SERDP-funded projects focusing on remedial evaluations at 1,4-dioxane contaminated sites. The field trial will include a transect of wells located within an existing 1,4-dioxane plume to characterize the spatial variability of contaminant flux and provide a measure of the total mass discharge and associated uncertainty.