DNAPL delineation with soil and groundwater sampling

Chlorinated solvent contamination consisting primarily of trichloroethylene (TCE) is present at Launch Complex 34 (LC34), Cape Canaveral Air Station, Florida. The presence of dense nonaqueous phase liquid (DNAPL) was confirmed following groundwater and soil sampling for chlorinated volatile organic compounds (CVOCs) during preliminary site characterization. Detailed site characterization was conducted in two stages. The Stage 1 soil sampling in the suspected DNAPL zone was used to prepare a Stage 2 soil sampling plan based on a statistical design to map the DNAPL source zone boundaries, determine the horizontal and vertical distribution of the DNAPL, and estimate the total TCE and DNAPL masses. Groundwater(organic and inorganic) analysis and hydraulic parameter measurements were conducted to track the progress of the remediation, evaluate DNAPL migration potential, and evaluate aquifer quality before and after treatment. Depth-discrete soil and groundwater sampling was found to be an efficient way of characterizing the DNAPL source zone to enable the design of the remediation technology application, as well as to track remediation progress and effectiveness.