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IN r A S S O C I A T E S I N C Similar to the VES, the actual radius of influence for each sparge well will vary and the effective radius of influence will be evaluated following long-term operation of the AS system ' In-situ air sparging is the process of injecting air into the saturated zone via sparge wells Sparge wells are designed with a screen interval at a depth approximately 15 to 20 feet below the water ' table Pressurized air is forced out through the screen and into the saturated zone The air forms bubbles that rise to the unsaturated zone, carrying trapped and dissolved contaminants Vapor extraction wells in the unsaturated zone capture sparged air which is then treated through the vapor extraction system The AS system will include a compressor, associated piping, control valves, pressure gauges, flow meters, instrumentation and controls, and a remediation shed shared with the VES Based on ATC's experience at similar sites and the results of the pilot tests, a Gast 6066-P 122A rotary vane compressor would be sufficient to operate the air sparge component of the system The compressor would create a maximum of 20 pounds per square inch pressure and a maximum airflow ' rate of 55 standard cubic feet per minute A process and instrumentation diagram for the VES is shown on Figure 12 ' 5.2.3 Remediation System Layout Components of the vapor extraction and air sparge system would be located in an enclosed shed on the west side of the site This will preclude public access and reduce noise A network of subsurface piping will be used to convey off gas from the extraction wells to the remediation shed The trenching system layout is shown on Figure 13 The same trenches will be used for the air sparge system Piping ' will be used to convey air to the sparge wells for injection to the subsurface Piping will be installed at a maximum depth of two feet as shown on Figure 14 A two-foot by two-foot well vault will be installed over each vapor extraction and air sparge well A ball valve will be installed at each well head ' to control the airflow in or out of the well In addition, a sampling port will be installed at each vapor extraction well for monitoring purposes ' Equipment operation will require the installation of an electrical power source and meter base Site system requirements include a 220V, single phase 150 amp power source and meter base A NEMA 4, UL Listed Control Panel will be located at the shed 6.0 REMEDIATION SYSTEM CONSTRUCTION Upon review and approval of the remediation system design plans and specifications by PHS/EHD, the city of Stockton intends to put out a request for proposal for the construction and operation and ' maintenance of the remediation system The selected consultant will be required to complete the tasks described in this section and previously described in the Final Remediation Plan 6.1 Building,Air Pollution Control District.and Well Installation Permits An Authority to Construct and Permit to Operate application will be completed and submitted to the San Joaquin Valley Umfied Air Pollution Control District (SJVUAPCD)to allow for construction and installation. of the proposed VES The application includes a site history, VES specifications, and W 162574 On1CAP report dm 9