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Treatability Study Report and Feasibility Evaluation for In Situ Petroleum Hydrocarbon Remediation Field Maintenance Shop #24, 8020 South Airport Way 5.4.2. Calculation of Aquifer Test Parameters The model used for the analyses was Cooper -Jacob Straight Line Method. The hydrogeology in the immediate area that wells FMS-MW5 and FMS-DPE1 are screened through is unconfined to semi -confined. Because the drawdown observed in the wells is small in comparison to the saturated thickness, the Cooper -Jacob Straight Line Method is applicable to unconfined to semi - confined water -bearing units (Jacob, 1950). Transmissivity is the rate at which a fluid of a specific viscosity and density is transmitted through a width of an aquifer at a specific hydraulic gradient. Transmissivity ranged from 11.3 gallons per day per foot (gpd/ft) at well FMS-MW5 and 36.9 gpd/ft at well FMS-DPE1. Hydraulic conductivity is the volume of water that will move through a porous medium in unit time, under unit hydraulic gradient, and perpendicular to the direction of flow (Kruseman and De Ridder, 2000). Hydraulic conductivity is the quotient of transmissivity and saturated thickness of the aquifer. The saturated thickness of the aquifer is assumed to be the wetted screen interval of the well. The hydraulic conductivity ranged from 0.41 gallons per day per square foot (gpd/ftz) at well FMS-MW5 and 1.2 gpd/ft2 at well FMS-DPE1. Specific capacity is the ratio between the pump rate and drawdown (the difference in feet between the static pre-test and relatively steady-state pumping water levels in the pumping well) and is a relative measure of efficiency to determine optimal pump rates. Because the groundwater level declined below the transducers installed in both wells FMS-MW5 and FMS-DPE1 during the pumping tests, a calculated groundwater level was used to determine the specific capacity of each well. For well FMS-MW5, the predicted maximum drawdown during pumping at 0.75 gpm was 24.2 feet. For well FMS-DPE1 the predicted maximum drawdown during pumping at 2.0 gpm was 26.4 feet. The specific capacity at well FMS-MW5 was 0.031 gpm per foot, and at well FMS-DPE1, 0.076 gpm per foot. Recovery analysis plots are presented for tests on both wells in Appendix H. The findings presented above for transmissivity, hydraulic conductivity and specific capacity are consistent with findings from historical soil and groundwater investigations at the site, and identify the aquifer as generally poor in character and characterized by semi -permeable fine sand and silty materials. It must be noted that the aquifer properties calculated in these hydrogeologic analyses are based on vacuum enhanced groundwater extraction, and therefore, should only apply to this site for evaluation of groundwater extraction under high vacuum conditions. 35 OTI E