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Geosyntec° <br /> consultants <br /> Pumping tests conducted by the Navy at Sites 3,4, and IAS-I I had drawdown responses <br /> to pumping observed in monitoring wells screened at different depth intervals than the <br /> extraction well, indicating a high degree of hydraulic interconnection and supporting the <br /> interpretation of a single water-bearing zone (PRC, 1997a; Tetra Tech, 2002). For <br /> example, at Site IAS-I 1,well W-082 screened from 38 to 48 feet bgs was pumped at 8.5 <br /> gallons per minute (gpm) and an immediate drawdown response to pumping was <br /> observed at W-058 screened from 5 to 9 feet bgs and located approximately 15 feet from <br /> W-082 (PRC, 1997a). Navy pumping test data from the 1997 PRC report is included in <br /> Appendix C. <br /> A selection of monitoring wells at Site 3 were historically sampled for groundwater <br /> geochemistry parameters. The geochemistry of samples collected from monitoring wells <br /> W-002 screened from 28 to 39 feet bgs, W-025 screened from 12.5 to 20 feet bgs, and <br /> W-052 screened from 10 to 21.4 feet bgs are all similar, providing another line of <br /> evidence that the monitoring wells at RRI are screened within a single interconnected <br /> water-bearing zone (Figure 9). The geochemistry also indicates that groundwater and <br /> surface water are connected, as discussed below in Section 2.3.5.2. <br /> The geologic logs from borings at RRI were reviewed and the soil at RRI consists of <br /> interbedded peats, clays, silts, and sands with no distinctive or consistent layering in the <br /> top 70 to 80 feet bgs. This supports that the wells are screened within a heterogenous <br /> zone.Additionally,the logs provide no indication of the presence of laterally continuous <br /> clay or sand units separating the top 70 to 80 feet bgs into separate aquifers. Consistent <br /> with the Navy 2002 CSM, the soils appear to consist of laterally and vertically <br /> discontinuous sedimentary packages. Geologic cross sections prepared by the Navy as <br /> part of the 2002 CSM are included in Appendix D. <br /> 2.3.4.1 Properties <br /> Soil physical parameter laboratory tests and pumping tests were conducted by the Navy <br /> to determine the hydraulic properties of the sediments in the water-bearing zone. Of the <br /> 277 soil samples collected by the Navy for physical parameter laboratory analysis, 202 <br /> soil samples (73%) were classified as predominately clay or silt, and 75 soil samples <br /> (27%) were classified as sand (Tetra Tech, 2002). The range of vertical (Kv) and <br /> horizontal (Kh) hydraulic conductivities estimated by the Navy based on the laboratory <br /> analysis and pumping tests are summarized below in Table 2. <br /> RRI Groundwater Monitoring Work Plan 11 1 June 2018 <br />