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• 4 .0 AQUIFER TEST (WORK PLAN) 4.1 PUMP TEST PROJECTIONS To economically evaluate the site a pump test on the aquifer will be performed during the start-up operations for the "Hirtz" Incinerator. Projections made from the Bouwer and Rice Slug test, presented in the May, 1990 report, indicated K values (hydraulic conductivity) ranging from 7.9 X 10-3 feet/day in monitor well MW-2 to 4 .06 feet/day in monitor well MW-1 . We know that the aquifer is not homogeneous . A aquifer flow velocity contour map has been generated from the data obtained from the Bouwer and Rice Slug -- Test calculations , see Figure 5C. Contaminated ground water will be pumped from monitor wells MW-1 and MW-3 at a total combined rate of 2000 gallons per day (1 . 4 gallons/minute) . The pumped water will be treated by air stripping using the "Convault" with heated air injectors and all volatile organic compounds, stripped from the ground water , will be destroyed by incineration by the "Hintz" incinerator. A vapor • recovery vacuum system attached to MW10 and tank excavation risers for in-situ vapor extraction will deliver the gasoline range vapors produced from the vapor extraction system to the "Hartz" incinerator for destruction. A pump rate of approximately 2000 gallons a day (1 .4 gallons per minute) will be maintained from monitor wells MW1 and MW3 during the first week of operation. This will enable us to collect data from the surrounding wells to establish the needed pump rate for capturing and treating the gasoline range contaminated ground water. The pumped ground water will be treated by the hot air stripping and then stored in a 15,000 gallon polytank for testing prior to disposal (approximately 14 ,000 gallons of treated ground water) . As was discussed in Update Report #3 and Figure 5D a pump rate of approximately 900 gallons per day should adequately capture and contain the hydrocarbon plume found beneath this site. Although pumping of Lhe ground water will prevent the plume fro,« spreading, to remediate the problem the source must be abated. At this site, as shown in previous monitoring reports , the capillary fringe and the vadose zone beneath the underground storage tanks (UST's ) are contaminated with gasoline range hydrocarbons . Also discussed in earlier reports, free floating product occasionally shows up in monitor wells MW1 , MW3 and MW10 . • In-Situ vapor extraction has been shown to be an effective method 6