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02 September 2010 AGE-NC Project No. 95-0184 Page 3 of 7 2.2. PROPOSED GROUND WATER REMEDIATION PROCESS Generally, the proposed In-Well Air Sparging (in-well ground water stripping) method comprises four steps: (1)exerting a sufficient vacuum to pull ground water into a well from a desired extraction zone (ground water adjacent to wells EW-1 and EW-2); (2)treating the ground waterwith a mechanical force to volatilize contamination; (3)channeling the treated ground water to a desired injection zone within the well casing above the water table; and (4) applying adequate volume and pressure to inject treated ground water across the injection zone and back into the formation at the water table elevation within the well. In-well aeration type processes represent improvements to conventional pump-and-treat technologies. In-well aeration has the potential to be more cost-effective and efficient than conventional pump-and-treat technology but will be subject to similar limitations. 2.3. IN-WELL AIR-SPARGING PRINCIPLE The in-well aeration process involves introducing ambient air, into a well under vacuum, resulting in an in-well airlift pump effect. The equipment includes a vacuum air-stripping reactor, an above-ground blower, and waste air treatment system-this statement (SVE equipment installed). Ambient air is pulled by the SVE generated vacuum, through the multi-stage stripper (called a labyrinth stripper) via a pipe connected to the stripping chamber located in the portion of the well above the water table. The rising air bubbles within the inner portions of the chamber enhance the suction effect from the well bottom via a pickup tube and this effect can be further enhanced by the use of a pneumatic-pump. Air injection in the pickup tube at a level near the water table decreases the average fluid density of ground water, collected from the deeper portions of the well. Due to the lower density, the air and water mixture rises. At a level in the well above the water table, the air enriched with volatile hydrocarbons separates from the groundwater and exits the well through active soil vapor extraction.The ground water flows out of the upper screened portions of the well above the water table and migrates down to the lower portions of the well screen. The air injection provides an airlift pumping action and air stripping to remove hydrocarbons. The airlift pumping effect establishes a circulation pattern of oxygen-saturated water in the aquiferthat may enhance the biodegradation rate. Combined with SVE,the in-well aeration method mechanically strips volatile hydrocarbons from ground water without the addition of any chemical solutions into the environment. In-well aeration is a widely accepted method of volatilizing hydrocarbons in areas with high dissolved concentrations and sandy soils. Based upon these elevated dissolved petroleum hydrocarbons and the presence of relatively sandy soil at the site, this technology will be appropriate. Advanced GeoEnvironmen[al,Inc.