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L F R 14 ARCADIS company <br /> • Collecting concentration data from soil-vapor samples to estimate the VOC mass removal rates <br /> that will dictate VOC mass loading rates for sizing of the emission control systems. The <br /> primary factors for estimating VOC mass removal rates include the following: <br /> • distribution of VOCs in soil vapor <br /> • extent of area to be remediated <br /> • vapor flow rates <br /> • VOC concentrations in extracted vapor <br /> Two basic test methods will be used to help meet these objectives: (1) stepped-rate test for <br /> estimating vent capacities and system curves, and (2) constant rate test for evaluating vent areas of <br /> influence, vent efficiency, and soil air permeabilities. If the initial response indicates that a <br /> reasonable vacuum can be drawn, the test will continue to collect data regarding the potential <br /> radius of influence of an SVE system in that portion of the Site and to collect soil-vapor samples <br /> for chemical analysis. The overall objectives and specific tasks of the SVE pilot test are presented <br /> below. <br /> Scope of Work <br /> Soil-Vapor Well Installation <br /> To achieve the goals stated above, LFR proposes to install four soil-vapor wells (Figure 3). The <br /> soil-vapor wells will be installed inside the facility using a limited-access drill and/or hand auger. <br /> Soil-vapor wells will be screened approximately 2 to 10 feet bgs. An LFR geologist will record a <br /> description of lithology as drilling progresses. After the desired depth of the borehole is reached, a <br /> 2-inch-diameter casing will be installed and the annular space between the well screen and the <br /> formation will be filled with No. 2 1/2 Monterey sand to approximately the top of the screened <br /> interval. Approximately 1 foot of bentonite pellets will be placed above the sand pack and hydrated <br /> to form a coherent seal. The remaining annular soace above the bentonite seal will be filled with <br /> cement grout. A locking well cap will be placed on top of the well casing, and the well will be <br /> v� completed using a flush-mounted Christy box. <br /> Permits for these wells will be obtained as necessary from the San Joaquin County Environmental <br /> Health Department. <br /> wp-CS-SVE-May09-09366,dm:deh 5 <br />