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transition from laminar to turbulent flow and also represents a point of diminishing returns Beyond this point, even significant increases in vacuum tend to yield only minor increases in flow Once the optimum extraction flow rate has been established,the SVE pilot test will be conducted to establish the relationship between distance from the extraction well and vacuum in the vadose zone This relationship will then be used to estimate the effective radius of influence corresponding to the selected flow rate and well construction Radius of influence is typically estimated by interpolating the distance from the extraction well, which corresponds to a minimum vacuum of 0 05 inches of water This interpretation can be iperformed graphically on a semi-log plot of vacuum vs distance To establish the relationship between vacuum and distance, soil vapors will be extracted at a fixed flow rate and vacuum from the SVE well Following stabilization of soil vapor flow conditions, vacuum readings will be recorded for several existing vadose zone monitoring points located at known distances from the SVE well Stabilization will be evaluated by frequently monitoring vacuum readings at the monitoring points When vacuum readings have remained essentially constant for at least one hour, conditions will be considered stable Two soil vapor samples will also be collected for laboratory analysis of BTEX and total petroleum hydrocarbons TPH, by USEPA Method TO14 One sample will be collected approximately 30 minutes after startup and another at the conclusion of the SVE pilot testing activities Results of the laboratory analyses will be used to calculate projected removal rates, carbon usage, and air emissions based on the design flow rate of the full-scale system Potential breakthrough of contaminant air emissions will be monitored using a photoionization detector(PID) at points immediately downstream of each carbon vessel 3.3 Combined AS/SVE Pilot Test After stabilization of SVE flow, the SVE blower will remain in operation while a brief step-AS test is performed to establish sparging breakout pressure and optimum sparging flow rate The AS testing will be conducted on - existing well SP-1 This well is constructed of 48 feet of blank '/4-inch diameter PVC material attached to a 2 feet long ceramic air diffuser Construction of SP-1 is detailed in the Figures section The step-AS test will involve injecting air into SP-1 at several different injection pressures while observing the corresponding flow rates As injection pressures are increased, a point will be reached at which flow is initiated This injection pressure is defined as the breakout pressure and should ii Pilot Testing Work Plan 1717 South Center Street-Stockton,California Prepared by Philip Services Corp H 5EN 24001321121382EG1Pmj3 ctsLSrockCenllp$loite tplm doc July 23,2002