ARCHIVED REPORTS XR0012611 - Laserfiche WebLink

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Since the Houwer and Rice Slug test indicated K values ranging from 7,9 X 10-3 feet/day in monitor well HW-2 to 4.06 feet/day in monitor well MW-1 we know that the aquifer is not homogeneous. To adequately define the aquifer parameters for this site we suggest a five day pump test that would pump ground water from monitor well MW-3 at a rate of 2000 gallons per day (1.4 gallons/minute). The extracted ground water will be treated with the RSI S.A-V-E- system and then stored in a 21,000 gallon Frac-tank for testing prior to disposal (approximately 10,000 gallons). As can be seen on Table 3 & Figure 5, a pump rate of approximately 900 gallons per day should adequately capture and contain the hydrocarbon plume found beneath this site. s Although pumping the ground water will prevent the plume from spreading, the source must be abated to remediate the problem. At ' this site, as shown in previous monitoring reports, the capillary fringe and the vadose zone benea'h the underground storage tanks (UST's) are contaminated with gasoline range hydrocarbons. And as discussed in earlier reports; free floating product was once found beneath this site. A remediation technology that both pumps and treats the ground water and also cleans the capillary fringe and vadose zone is the RSI "S.A.V.E." System (Remediation Service Int'l, Spray; Aeration; Vacuum; Extraction). Converting monitor well MW-10 into a vapor j extraction well should capture any free floating product that skimming failed to collect and also treat the vadose zone from `-� the 30 foot depth to the top of the ground water benea-h the ; contaminant source (UST's). Also, vapor extraction on the tank r excavation wells should help alleviate that area of contamination i i from the 22 foot depth to the 30 foot depth. By supplying oxygen 1 to the vadose zone, vapor extraction increases the native bacterial population, thus enhancing the natural biodegradation of hydrocarbons ("Various talk on Vapor Extraction during Hazmacon t April 17-19, 1990, Anaheim, California, see Volume II, j ! Measurement, Treatment, Minimizatin and Control Technologies"). Y Observations made by WEGE at other sites using vapor extraction i support this method of remediation. 29 i