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5.0 WELL INSTALLATION ATC retained the services of Spectrum Exploration, of Stockton, California, to advance two soil boreholes and install deep and shallow groundwater monitoring wells MW-9 and MW-10, respectively, that comprised a two-well cluster. These monitoring wells were installed on August 7, 2001. Underground Services Alert (USA) was notified of the proposed drilling activities to ensure that no utility lines were located within the immediate vicinity of the soil borings, and Cruz Brothers Sub- Surface Locators, Inc. of Sacramento, California provided a subsurface survey of utility lines and other buried objects in and near the planned well locations. Before the well were installed, ATC obtained the permits from the San Joaquin County. Copies of the permits from the San Joaquin County are included in Appendix A. Installation of two groundwater monitoring wells (MW-9 and MW-10) was completed under the supervision of San Joaquin County Public Health Services Inspector Samuel _ Savig. The soil borings for the wells were advanced with a drill rig equipped with hollow stem augers to depths of approximately 16 and 30 feet bgs for the upper and lower aquifer wells, respectively. The groundwater monitoring wells were completed first using 2-inch diameter, Schedule- 40 polyvinyl chloride (PVC) casing. The upper aquifer well MW-10 was set with a 10-foot section of 0.020-inch slotted screen set at 5 to 15 feet bgs with 5 feet of Schedule 40 PVC blank to the surface. Sand pack material consisting of 2116 Monterey sand, was installed from 16 to 3 feet. Hydrated Bentonite Pellets were placed from 3 to 2 feet bgs. Neat Cement Grout then was placed from 2 feet to 1 foot bgs. The well MW-10 was secured at the surface with a flush-mounted, traffic-rated well box. Well construction details are presented in Figure 3. The soil boring for installation of monitoring well MW-9 was advanced to 30 feet bgs. Because of the instability of the soil in the borehole the groundwater monitoring well had to be set on two feet of sand ' material consisting of 2116 Monterey sand. The lower aquifer well was set with a 10-foot section of 0.020-inch slotted screen set at 18 to 28 feet bas with 18 feet of Schedule 40 PVC blank to the surface. Sand pack material consisting of 2116 Monterey sand, was installed from 28 feet to 16 feet. Hydrated Bentonite Pellets were placed from 16 feet to 13 feet bgs. Neat Cement Grout then was placed from ({ kiln 8 Pn1,rr..uXIK: TOP�O%13nP£PnRT%%21NW.S,.fl&�rin�.—I Well In•+Ilannn.•LK