Difficulty in addressing contamination in low permeability soils may be alleviated to some degree by controlled pneumatic or hydraulic fracturing of the soil. However, engineered hydraulic fractures generally cannot be spaced more closely than about 5 feet, which means that chemical oxidants must still penetrate a substantial thickness of low permeability soil to come into contact with the contamination. Deep soil mixing with large diameter drill augers is the most effective method currently available to increase contact between adsorbed contaminants and the oxidants. In any case, long term post-injection monitoring of contaminant levels in groundwater is critical to evaluating the success of putting Fenton's Reagent into.
