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1, Quik Stop Market No. 132 January 6, 1993 Project No. F7132.34 Page 3 16 were used during well construction. The screened interval of the monitoring well was ' determined in the field by the RESNA geologist based on the characteristics of the saturated zone being monitored. After the casing was installed, clean No. 2/12 silica sand was poured through the auger, as the auger was being removed, to fill the annulus between the casing and the borehole wall to approximately 2 feet above the screened interval. Approximately 1 foot of 1/4- inch bentonite pellets was then placed on top of the sand and hydrated to form a seal. A cement grout seal was then placed in the remaining annulus to within 1 foot of the surface. A traffic-rated, water-tight protective vault was placed over the well at or slightly above ground level and the space around the cover was filled in with concrete. All monitoring wells were equipped with an air-tight, expansion type, locking well cap. Borings logs and monitoring well construction details are found in Appendix B. ' Well Development and Groundwater Sampling P P g ' On December 10, 1992, the newly installed wells were developed to remove fine- grained material and turbid water, and to improve the hydraulic communication with t the surrounding formation. A hand bailer and surge block were used to develop the wells. A minimum of 20 well volumes of groundwater were removed from each well. No surface sheen or other visible signs of contamination characteristic of petroleum hydrocarbons was noted in the groundwater removed. The volume of water removed {� from each well and other observations are noted on the development field sampling log which is included in Appendix C. On December 21, 1991, groundwater monitoring wells MW-1R, MW-2, MW-5, MW-6, and MW-7 were sampled according to the RESNA Groundwater Sampling Protocol (Appendix D). As stated in a letter from the San Joaquin County Public Health Services (SJCPHS) to Mr. Jack Griffith of Quik Stop Markets, Inc., dated November 17, 1992, sampling of MW-3 and MW-4 has been reduced to semi-annually and was not ' required at this time. However, groundwater level measurements were obtained from these wells. No floating product, surface sheen, or odor characteristic of petroleum hydrocarbons was observed. The volume of water removed and other observations are noted on the field sampling log which is included in Appendix C. Site Survey ' The elevations of the PVC well casings and the adjacent ground surface were surveyed on December 14, 1992 by Ron Archer Civil Engineer, Inc., of Pleasanton, California. 1 The elevations were recorded to the nearest 0.01 foot on the City of Stockton datum. The reference benchmark was a brass disc set in a standard monument casing located 40 feet southerly from the centerline intersection of W. Hammer Lane and Mariners Drive with an elevation of 2.619 feet above mean sea level. The property boundaries, the location of the monitoring wells, and other significant site features were also surveyed. A copy of the original survey map is included in Appendix E.