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Y <br /> Monitoring Well Installateon Report - Chevron Service Station#9-3232 <br /> November 20, 1998 <br /> Well Installation <br /> Groundwater monitoring wells MW-1 through MW-3 were constructed using 2-mch diameter <br /> schedule 40 polyvinyl chloride (PVC)casing and 20 feet of 0 02-inch machine-slotted well screen <br /> The annular space around each well scteen was packed with Lonestar #3 graded sand The <br /> sandpack in each well was followed by a bentonite transition seal and then neat cement to <br /> approximately 1 foot bgs The top of each well is protected by a vault box, locking well cap, and <br /> lock Well construction details are included with the boring logs in Appendix B <br /> Well Monitoring, Development, and Samp-lling <br /> Wells MW-1 through MW-3 were monitored, developed, and sampled on November 4, 1998 <br /> Depth to groundwater in the newly installed wells was measured and each well checked for the <br /> presence of floating product prior to development No free product was observed Groundwater <br /> samples were collected ftom the wells immediately after development Copies of the well <br /> development and field monitor ing data sheets are included in Appendix C Monitoring data are <br /> summaiized in Table 2 <br /> Wellhead Sui vey <br /> Newly installed wells MW-1 though MW-3 were surveyed relative to Mean Sea Level (MSL) by <br /> Virgil Chavez Land Surveying (PLS #6323) Horizontal coordinates were also measured <br /> Surveyor's report is included in Appendix D <br /> RESULTS OF THE SUBSURFACE INVESTIGATION <br /> Soil encountered dui ing this investigation consisted predominately of tine to medium grained sand <br /> and sandy silt Sandy silt sti ata approximately 5 to 15 feet thick were encountered at depths <br /> between approximately 18 and 45 feet bgs Detailed descriptions of the subsurface materials <br /> encountered dui ing drilling are presented on the boring logs (Appendix B) <br /> Gioundwater was first encountered in the well borings between 35 and 44 feet bgs During the <br /> Novembei 4, 1998 monitor ing, development, and sampling event, depth-to-groundwater was <br /> measured between 31 93 and 36 07 Leet bgs Based on these data, groundwatei appears to flow <br /> toward the southwest at a gradient of 0 05 ft/ft <br /> 'i A61 01 2 <br /> 3 <br />