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I j <br /> Mr. Many Hanzell Project 803026 <br /> September 8, 2000 <br /> Page 6 <br /> locations of the Proposed air sparge wells are shown on Figure 2. The sparge wells will <br /> be advanced to a depth of approximately 57 feet bgs and examples] with <br /> 1-mch diameter Schedule 40, Push-joint polyvinyl chloride (PVC) casing and slotted <br /> PVC serene (0.020-inch slot width). The screen interval is anticipated to extend Rom a <br /> depth of 55 to 51 fat bgs. Well installation procedures are presented in detail in <br /> Appendix A. The sparge wells will be incorporated into the fuel au Warge remediation <br /> system. <br /> Ambient air will be. injected into the sparge wells using an oil less compressor equipped <br /> with a pressure regulator, flow meter and presence gauge. Helium from a pressurized <br /> helium vessel will be blended with the injection air at a rate of approximately one cfn. <br /> The combined injection flow rate and injection pressure will be monitored aM recorded <br /> to develop a flow rate versus Pressure retationsbip. An aWroj late injection pressure <br /> will be determined in the field. The injection flow rate in not anticipated excaedias <br /> 10 to 15 cfn. <br /> Three shallow vadem zop monitoring wells will be installed to monitor oxygen, <br /> hebod , methane, and carbon dioxide concentrations in the vadom zone soil gas. These <br /> soil gas parameters will be measured before, during, and after spargiug. Monitoring <br /> wells will be advanced to a depth of 24 f bgs and constructed with 1-inch diameter <br /> Schedule 40, flush-joint PVC casing and slotted PVC screen (0.020-inch slot width). <br /> The screen interval will extend from a depth of 15 In 24 fat bgs. Well installation <br /> procedures are presented in detailed he Appendix A. Ttu; locations of the proposed <br /> shallow vadme zone armad ring wells are shown an Figure 2. These wells will be <br /> abandoned after the completion of the air sparge test. <br /> Existing groundwater monitoring wells will be used to monitor dissolved oxygen and <br /> oxidatiodreducticn potential (ORP) in groundwater before, during, and act Verging. <br /> Lama the air injection portion of the air spmge test is complete, the dissolved oxygen <br /> concentration in groundwater and the helium and oxygen concentrations in the soil gas <br /> will continue to be mordmred to observe a decay rate that provides an assecsmmd of the site specific bio-attenuation one. <br /> GROUNDWATER MONITORING PROGRAM SCHEDULE AND ANALYTICAL <br /> REQUIREMENTS <br /> Cumenfly, groundwater monitoring wells MW-1 through MW-] are included in the <br /> quarterly groundwater monitoring program Water samples collated from these welts <br /> cre analyzed for volatile organic compounds (VOCs) (fall list) including oxygenates by <br /> U.S. Environmental Protection Agency (EPA) Test Method 8260, and for TPHg by EPA <br /> nmAroAmro/I <br /> umaa.reas jmxtssmsmasawe <br />