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I r08 December 2004 . AGE-NC Project No 98-0511 ' Page 2 of 6 2 2 1 Soil Boring The pilot boring for well MW-8 was advanced to 30 feet bsg using a CME-75HT drill rig, equipped ' with 8 25-inch diameter hollow-stem augers The drill rig and three-man crew were supplied by Cascade Drilling, Inc of Rancho Cordova, California Auger returns generated by drilling were containerized in properly labeled, DOT-approved 55-gallon drums and stored on-site 2 2 2 Monitoring Well Installation ' Pilot boring MW-8 was completed as a ground water monitoring well using two-inch diameter PVC casing with 0 010-inch slotted screen installed from approximately 10 feet to 30 feet bsg with blank casing extended to the surface The filter pack (No 2112 Lonestar sand) was installed from approximately 8 feet to 30 feet bsg A nominal 2-foot bentonite chip plug was then installed above the filter pack and hydrated The well was grouted to near the surface with portland cement and a water-tight,traffic-rated well box was installed over the well An as-built well construction diagram is illustrated on Figure 3 10 2 2 3 Well Head Survey On 27 July 2004, a California state-licensed survey engineer from Baumbach and Piazza surveyed the elevation at the top of the well casing and the location of monitoring well MW-8 Elevation was surveyed to the nearest 0 O1-foot relative to San Joaquin County Bench Mark # 21 3, surveyed at 17 78 feet above mean sea level (MSL) Coordinate locations (x and y) of well locations were calculated to the nearest 0 1-foot using coordinate datum NAD 83 from global positioning satellite (GPS) observations The results of the well survey are included in Table 1 2 2 4 Monitoring Well Development There is no record of MW-8 being developed in the second quarter of 2004,so MW-8 was developed on O 1 December 2004 utilizing a stainless steel hand bailer and a two-stage pump Ground water was purged from the well until it was visually sediment free Forty gallons of water were removed from the well Ground water temperature,pH, and conductivity were measured at regular intervals during ' purging using an Oakton water analyzer Total depth of the well was measured before and after development to note any changes due to the presence of fine-grained materials A field sheet is included in Appendix B Purged water was stored on-site in properly labeled, 55-gallon DOT- approved drums IAdvanced GeoEnvironmental,Inc