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S E C 0 R 2003 Feasibility Test Summary Report . September 18, 2003 Page 4 So: R = k(hf'-h;Z) 101,055(Q) The following input values were used for the calculation. a =0.75 gpm K = 10.1 gal/daylft2 h; =57 ft-23ft =34ft hf =34 ft—4.24 ft = 33.76 ft r = 53 ft Based on the above input values and test assumptions, a groundwater radius of influence was estimated to be up to 85 feet. 3.1.3 Aquifer Test Conclusions Based on the results of the aquifer test, groundwater extraction from MW-9A could provide hydraulic control over an area of 56 feet and prevent offsite migration of dissolved hydrocarbons. 3.2 Two-Phase Extraction Test ' TPE is the process by which soil vapor and groundwater are extracted together using a high vacuum applied to a pipe (slurp tube) that is lowered into the water table in an extraction well. 3.2.1 Scope of Two-Phase Extraction Test On February 4 and 5, 2002, SECOR performed a four-day TPE test on monitoring wells MW-9A and MW- 9S using SECOR's mobile treatment system (MTS). SECOR's MTS unit consists of a 300 standard cubic feet per minute (scfm) 25 horse power (hp) extraction blower, a 100 gallon liquid/vapor separator, a 50 gpm liquid transfer pump, and a 300 scfm ' thermaVcatalytic oxidizer as the vapor abatement device prior to discharge to the atmosphere. Groundwater entrained in the vapor stream was pumped from the liquid/vapor separator to the 20,000- gallon holding tank. Upon completion of the test, the water was transported to an appropriate water ' recycling facility. Physical and chemical parameters including applied vacuum, flow rates (air and water), and flame ionization detector (FID) readings at the extraction well were collected routinely. Vacuum gauges were placed at nearby observation wells in order to monitor the induced negative pressure gradient. Groundwater levels in observation wells were gauged to monitor the drawdown affects induced by TPE on the extraction wells. Copies of the pilot test field data sheets are included as Attachment G. ' Influent soil vapor samples were collected periodically and analyzed by a California state certified laboratory for calculating mass removal rates of chemicals in the soil vapor. Soil vapor samples were analyzed for total petroleum hydrocarbons as gasoline (TPHg), benzene, toluene, ethyl-benzene, total xylenes (BTEX), and methyl tertiary butyl ether (MtBE).