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Parsons Engineering Science, Inc Monitorima Well Installation Monitoring well MW-4 was installed in boring SB-9 The well was constructed of 2- inch inside diameter (ID), flush-point Schedule 40 polyvinyl chloride (PVC) well screen and casing (Photo 2, Appendix B) The bottom of the well was set at 43 5 feet The well was completed with 20 feet of factory-milled slotted casing (0 020-inch) The well screen was positioned from 43 5 to 23 5 feet, with 10 feet above and 10 feet below the water table The assembled well pipe was installed through the augers and 2112 quartzite sand was backfilled through the annulus between the well pipe and the auger (Photo 3, Appendix B) The sand pack was extended 2 feet above the top of the well screen Above the sand pack, bentonite pellets were backfilled to form a three-foot-thick seal (Photo 4, Appendix B) A cement bentonite grout was backfilled from the top of the bentonite seal to the ground surface The PVC casing was completed with a vented locking cap and covered by a flush- mounted steel protective curb box The protective curb box was grouted into place to limit disturbance to the PVC well pipe (Photo 5, Appendix B) The soil boring log, monitoring well completion summary and California Department of Water Resources (DWR) well drillers log are contained in Appendix C After the new well was installed, a water level reading was measured with a clean electric contact probe The depth of the water was measured from the top edge of the ' permanent PVC well casing The reference point was surveyed and an elevation determined relative to previously established top of well casing elevations on site These data were utilized to prepare a groundwater elevation contour map and estimate the horizontal groundwater flow direction All investigation derived wastes (soil and water) were stored in labeled Department of Transportation (DOT)-approved 55 gallon 17-H type drums and securely staged onsite for future disposal by Greyhound Groundwater Sampling and Analysis The newly installed monitoring well and previously installed monitoring wells were sampled during the 1996 third quarter groundwater monitoring event on September 4, 1996 Each well was purged prior to sampling until three to five well volumes of water had been removed, and allowed to recover to near static levels before sampling Groundwater monitoring field notes are provided in Appendix D Water from each well was collected using a disposable PVC bailer Samples from the wells were analyzed for TPH-D by modified EPA Method 8015 and for BTEX by EPA Method 8020A A Chain-of-Custody record accompanied each sample from preparation of the sample container at the laboratory, to sample collection in the field and back to the laboratory PARESSYR01 VOLT R 1wP1727607 80969127607803 ww6 6