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'• 18 July 2002 AGE-NC Prglect No 96-0254 Page 12 of 17 6 1 1 Ground Water Treatment Methods IThe documented presence of dissolved hydrocarbons will require treatment for the recovered water I Two of the most common methods of water treatment are air stripping and carbon adsorption Air stripping Involves removal of volatile organic compounds from ground water by promoting the transfer of contaminants from the dissolved phase to the vapor phase The process usually works well ' with volatile organic compounds, but less successfully with longer-chained hydrocarbons, such as commonly occur In diesel fuel Carbon adsorption utilizes granular activated carbon to simply "filter"organic compounds out of ground water ' A third, but less common method of above-ground treatment of water Is bioremediation Contaminated ground water is "treated" by adding hydrocarbon-degrading microbes or by ' augmenting natural hydrocarbon degradation activities with the Introduction of nutrients ' 6 12 Feasibility Testing On 28 August 2000,a limited aquifer pump testwas performed at the site Thedepth-to-groundwater lie• was measured In wells MW2B, MW3 and MW4 using a Solinst water level meter A two-Inch diameter Grundfossubmersible pump was then lowered into well MW1B Pressure transducers were then placed in wells MWIA,MW 1 B and MW7 and connected to a data logger to record drawdown ' data from the wells,the height of the water column In each well was measured by the datalogger In one-minute time Intervals Purge water was placed in a 4,000-gallon"Baker"above-ground storage tank ' The pumping rate was calculated to be approximately 10 gallons per minute (gpm) during the ' 28 August 2000 test The pumping rate was determined by measuring the time required to fill a 5- gallon bucket from the pumping discharge hose A maximum drawdown of approximately 2 89 feet was observed in MW-1B after 330 minutes of pumping A maximum drawdown of approximately 0 15 feet was observed In MW-lA after 264 minutes of pumping Wells MW-1A and MW-1B were the onlywells during the extraction test that were observed to have ' measurable drawdown Using the Jacob Straight-Line Time-Drawdown Method, the drawdown versus time for wells MW-lA and MW-1B was graphed on semi-loganthmic paper,from which the transmissrvity and storativity were subsequently calculated The transmissivlties for wells MW-1A ' and MW-1B were calculated to be 293 gal/day-ft and 6,769 gaUday-ft,respectively The storatrvity for MW-lA was calculated to be 0 78 (unitless) ' A radius of Influence could not be determined for this pump test due to the lack of drawdown • observed in the surrounding wells Approximately 550 gallons of water were removed from MW 1 B during the eight-hour test Field data Is included In Appendix C Advanced GeoEnnronmenial,Inc I