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I 04 September 2007 AGE-NC Project No. 95-0121 Page 3 of 9 Prior to mobilization, each pilot boring and well location will be clearly marked and a utility clearance obtained through Underground Service Alert. 2.2, PILOT BORINGS AND WELL INSTALLATIONS Based on soil and ground water data collected during the investigation of petroleum-hydrocarbon impact, the proposed ground water monitoring wells will be screened within the deep water zone below the deepest existing screened monitoring well at the site as follows: • Proposed well with a screen interval 95 to 105 feet bsg, located near existing well MW- 10 to define the central portion of the dissolved plume; • Proposed well with a screen interval 95 to 105 feet bsg, located near existing wells MW-4 and MW42 to define the down-gradient edge of the plume and • Proposed well with a screen interval 95 to 105 feet bsg, located between existing wells MW-3 and MW-6 to define the up-gradient edge of the plume. Proposed well locations are depicted on Figure 3. Following well installation, each well will be developed to maximize water flow into the well and minimize the amount of fine-grained sediment drawn into the well during pumping or bailing. Procedures for well installation and development are presented in Sections 3.2. and 3 .3 ., respectively. 2.3 . PROPOSED REMEDIATION METHOD AND FEASIBILITY STUDY The proposed remedial feasibility pilot study includes a high vacuum dual phase extraction system intended to remove hydrocarbons from the vadose, capillary fringe and upper saturated zones. After configuration of existing ground water extraction well EW- 1 for DPE, AGE proposes to conduct a 5-day DPE pilot test to acquire information regarding the radius of influence and contaminant concentrations of soil vapor and ground water; the data will be utilized for the proper design of a remediation system. The DPE pilot test specifications are presented in Section 3 .4. Recovery of hydrocarbons from the subsurface is often difficult due to the fact that hydrocarbons can exist in the vapor-, dissolved- and liquid-phase. Liquid-phase hydrocarbons both dissolve into groundwater andvaporize into pore spaces between sediment grains. Dissolved phase hydrocarbons also vaporize into pore spaces until equilibrium is established between the liquid, dissolved and vapor phases. Remediation methods effective in treating one phase may not be efficient for the Advrncrd GeoEnvironmontak Inc.