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The boring for each monitoring well was advanced with 8-inch outside diameter hollow stem <br /> augers When the augers were advanced to the desired depth of the well, the well casing was <br /> lowered down the center of the augers and set to the appropriate depth The annular space <br /> between the augers and the screened portion of the well was backfilled with Lonestar #2-12 <br /> sand As the filter pack was placed, the augers were withdrawn from the borehole so the sand <br /> flowed from the augers into the annular space of the borehole The filter pack was extended to <br /> approximately two feet above the top of the screened portion of the casing A two foot seal of <br /> bentonite clay was placed in the annular space above the filter pack Since the bentonite seal <br /> was positioned above the water table, five gallons of potable water was added to allow the <br /> 1 bentonite to gel The remaining annular space was backfilled to the surface with sand/cement <br /> slurry <br /> Each monitor well was finished with a Universal water-tight monitoring well manhole set into <br /> g g <br /> concrete A watertight, locking cap sealed with well casing inside the manhole Boring <br /> logs/well details are contained in Appendix III <br /> 3.1.3 Groundwater Sampling <br /> On April 1, 1991, the monitoring wells were monitored, developed, and sampled in accordance <br /> with RESNA's respective protocols (Appendix IV) Applied Analytical analyzed the samples <br /> for BTEX and TPHG utilizing EPA 8020 and 8015 methodologies, respectively Groundwater <br /> i <br /> analytical results are summarized in Table 4 Laboratory data sheets and chain-of-custody <br /> ' documentation are included in Appendix VI Field purge logs are included in Appendix VII <br /> 3.2 Phase 2 Activities <br /> On February 27 and 28, 1992, RESNA personnel installed three additional monitoring wells <br /> (MW4, MWS, MW6) to depths of approximately 30 feet below grade at the project site to <br /> further define the lateral and vertical extent of petroleum hydrocarbon contamination in soil and <br /> groundwater The boring/well locations are plotted on Figure 4 <br /> LCR49217L 5 <br />