Abstract
Characterization of dense non-aqueous phase liquid (DNAPL) in heterogeneous media represents a major challenge in the remediation process due to the complexity of DNAPL distribution in the subsurface. The partitioning interwell tracer test (PITT), which evaluates the relative transport of DNAPL-phase partitioning and conservative (i.e., non-partitioning) tracers, has recently been promoted as a way to quantify entrapped DNAPL mass in source zones. In some cases, the technique has been successfully applied to sites where DNAPL is present primarily at residual saturations. However, the effects of the geologic heterogeneity and DNAPL architecture on the performance and reliability of this technique have not yet been thoroughly examined. A systematic two-dimensional simulation study was conducted to evaluate the influence of DNAPL vertical distribution, well location, and geologic heterogeneity on the performance of the PITT for a total of 60 stochastic aquifer realizations. The aquifer hydraulic conductivity (K) distribution was defined using three different geostatistical parameter values describing the variance of the log K (