pool. The saturation distribution obtained after the second SF period was quite similar to the one
obtained after the first SF period, indicating that additional removal of TCE through SF was
difficult as a result of the limited accessibility of the TCE in the pool. A gamma scan, obtained
after three weeks of pumping using the three-well configuration, shows that all the liquid TCE had
been removed from the coarse-grained sand. Computations based on extraction rates and measured
TCE concentrations show that only about 60% of the injected TCE was removed from the cell
during the experiment. Part of the missing 40% might have moved downwards into the
fine-grained sand as a result of pure phase mobilization. The experimental results suggest that
besides the positive effects of solubilization, possible detrimental processes such as pure phase
mobilization and dense aqueous-phase plume behavior should be considered during SF. q1999
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