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Geofagw.td "ecfnus Inc Page 3 <br /> Groundwater Monitonng Report <br /> Project No 425 2 <br /> August 15, 2000 <br /> Table 2 of Appendix A summarizes the intermediate depth groundwater gradients and levels <br /> to date Table 2 also summarizes the groundwater level data from the deep well, MW-202 <br /> -Figure 2 is a map showing both the water table and intermediate groundwater gradients <br /> 1.1.2 Vertical Groundwater Gradients <br /> Vertical groundwater gradients were calculated using MW-2 / 102 (shallow/intermediate well <br /> pair) and MW-102 / 202 (intermediate/deep well pair) During the June 2000 event the <br /> ' vertical groundwater gradient in the shallow/intermediate well pair was in an upward direction <br /> with a magnitude of eight times that of the horizontal gradient The vertical gradient in the <br /> intermediate/deep well pair was also upward at a magnitude 2 5 times that of the horizontal <br /> ' gradient <br /> This site has experienced both negative (downward) vertical gradients and positive (upward) <br /> ' vertical gradients Typically the negative vertical gradients are 1 75 to 2 times greater than <br /> gradients in a horizontal direction and the positive vertical gradients are an order of magnitude <br /> greater than horizontal <br /> Refer to Table 3 of Appendix A for a summary of the vertical gradient calculations <br /> 1.2 Groundwater Sampling Procedure <br /> On June 20, 2000 Del-Tech Geotechnical Support personnel arrived on-site, opened the wells, <br /> and measured the depth to water with an electrically actuated sounding tape The water level <br /> reading was recorded to an accuracy of 0 01 foot In wells where free-floating product was <br /> suspected, a clear disposable bailer was used to gauge the interface <br /> Stagnant water in the well casing was purged using a Centrifugal pump as recorded in the field <br /> logs (Appendix C) The rate of well purging was monitored The wells were purged of at <br /> ' least three casing volumes or until the groundwater parameters (temperature, conductivity, <br /> and pH) had stabilized (Appendix C) indicating that water, representative of actual aquifer <br /> 1 conditions, were entering the well Groundwater parameter stabilization was characterized by <br /> three successive readings within 10% <br /> ' Before a sample was collected, the well's water level was allowed to recharge to at least 80% <br /> of its initial level All water removed from the monitoring wells and not used as a sample, was <br /> placed in a 55 gallon DOT (Department of Transportation 17-H) approved container that is <br /> properly labeled and temporarily stored on-site <br /> 1 <br />