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4 <br /> MONITORING WELL CONSTRUCTION <br /> The potentiometric surface elevations in the three existing monitoring wells will be measured <br /> prior to or during the start of well construction activities. The monitoring well borehole will <br /> be drilled and same ed using a truck mounted Mobile B-61 drilling rig and minimum 6inch <br /> diameter hollow stem augers. See Figure 1 for the location of the proposed monitoring well. <br /> Depth integrated soil samples will be collected every 5 feet from the borehole for laboratory <br /> analyses using a MOSS sampler fitted with six (6) 2.5"x 6" brass liners. Auger flytes and other <br /> tools used in the borehole drilling and sampling operations will be thoroughly steam cleaned <br /> before initial use. The sampler and brass liners will be washed in a mixture of Liquinox and <br /> clear water, rinsed in clear water, rinsed in distilled water, rinsed in deionized water, and <br /> allowed to air dry prior to their initial use and prior to subsequent use downhole. The use of <br /> phosphate-based cleaners, such as TSP, will not be allowed due to the documented laboratory <br /> analyses interference effects caused by the phosphate compounds in these types of cleaners. <br /> Soil samples will be collected continuously with the MOSS sampler. The MOSS sampler will <br /> be advanced with the auger string 3 feet, removed from the borehole and hollow-stem auger <br /> string, and broken down into its component parts. The soil sample collected in the brass liner <br /> at the 5foot interval will be sealed, capped, labeled, logged on a chain-of-custody form, placed <br /> in an ice chest containing frozen cold packs and kept at 4°C for transport to a State of <br /> California certified analytical laboratory. Appendix A presents the proposed sampling and <br /> analytical protocol. The contents of the five (5) remaining brass liners will be extruded and <br /> logged using the Unified Soil Classification System and Munsell color charts. <br /> A soil sample will be collected in a brass tube below the potentiometric surface to determine <br /> the sample's degree of saturation by standard geotechnical methods. The sample will be <br /> rle�un"2-21 Page 1 <br />