This paper describes the Superfund Innovative Technology Evaluation (SITE) of pneumatic and hydraulic fracturing to augment and improve the extraction of volatile contaminants from soil. The fracturing procedures involve a physical pressurization process that creates fissures and channels in soils to enhance fluid or vapor flow in the subsurface. Fractures are placed at specific locations and depths inside the boreholes of wells to increase the effectiveness of in situ remedial technologies, especially soil vapor extraction (SVE). The fracturing technology is primarily beneficial in tightly packed geologic formations having low permeabilities. Results from several demonstrations indicated orders of magnitude increases in subsurface vapor flow and contaminated vapor extraction rates after soil fracturing.

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Bio-Recovery Systems, Inc. conducted a project under the Emerging Technology portion of the United States Environmental Protection Agency's (EPAs) Superfund Innovative Technology Evaluation (SITE) Program to evaluate the ability of immobilized algae to adsorb mercury from contaminated groundwater in laboratory studies and pilot-scale field tests. Algal biomass was incorporated in a permeable polymeric matrix. The product, AlgaSORB, packed into adsorption columns, exhibited excellent flow characteristics, and functioned as a "biological" ion exchange resin. A sequence of eleven laboratory tests demonstrated the ability of this product to adsorb mercury from groundwater that contained high levels of total dissolved solids and hard water components. However, use of a single AlgaSORB preparation yielded nonrepeatable results with samples collected at different times of the year. The strategy of sequentially extracting the groundwater through two columns containing different preparations of AlgaSORB was developed and proved successful in laboratory and pilot-scale field tests. Field test results indicate that AlgaSORB could be economically competitive with ion exchange resins for removal of mercury, with the advantage that hardness and other dissolved solids do not appear to compete with heavy metals for binding capacity.

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