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City of Stockton Redevelopment Agency B34604.01 a February 16, 2001 Page 5 covered with Teflon® and tight fitting plastic caps, and placed in a cooled ice chest, labeled and ' delivered to Twining's analytical laboratory under chain of custody control. A temporary monitoring well (TMW-1)will be drilled at 328 California Street near the northeast ' comer of the SITE. The well will be drilled to 65 feet BSG using a hollow-stem auger,portable drill rig consistent with the SOPS in Appendix A. Details regarding the installation and development of the temporary monitoring well are discuss td in subsection 4.2. Soil samples collected from each of the soil borings will be field screened consistent with our SOPS provided in Appendix A. Field screening procedures include observation of the soil for lithologic ' data, odor, and unusual stains, and head-space analysis with a photoionization detector (PID) to detect the presence of organic vapors. Selected soil samples will be preserved in the field for laboratory analysis consistent with our SOPS. The analytical results of soil samples collected from the soil borings are expected to provide data on the existence and concentrations of impacts to the soil at the SITES. Soil cuttings from the hand-augered soil borings will be used as backfill to abandon the boreholes following the completion of the sampling,and the boreholes will be finished to match existing SITE conditions. 4.2 Monitoring Well Installation and Development: One temporary groundwater monitoring well(TMW-1)will be installed at 328 California Street in the parking area near the northeast comer of the SITE. ' The borehole for TMW-1 will be drilled using a hollow-stem auger portable drill rig consistent with Twining's SOPS in Appendix A. The borehole will be drilled to a depth of 65 feet BSG and set 1 approximately 15 feet below first encountered groundwater estimated to be at 50 feet BSG. Twining's geologist will examine soil cuttings and discrete soil samples collected during drilling in order to prepare a lithologic log. This info ation will also be recorded on a California Water Well Drillers Report (well log), and copies will be submitted to the California Department of Water Resources and the CRWQCB. The temporary monitoring well will be constructed of 2-inch diameter schedule 40 PVC casing and ' screened at a 10 foot interval from the bottom(estimated to be between 55 and 65 feet BSG. The temporary monitoring well will be secured with a sand/gravel filter pack set from the bottom of the ' borehole to approximately 50 feet BSG(2 feet above the screened interval). A sanitary seal will not be installed since the temporary monitoring well will be abandoned in accordance with Twining's SOPS following the development and san.pling of the well. The well will be developed until the purged water is relatively sediment free, and measured field parameters (pH, electrical conductivity, and temperature) have stabilized. A groundwater sample ' will be collected after development is completed. A minimum of 10 well volumes will be purged prior to sampling. TMW-1 will be sampled consistent with procedures outlined in the SOPs. The