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' Consistent with the approved work plan, the three boreholes at the MBR WWTP were drilled to total depths of about 30 to 35 feet below land surface ' because water table depths are slightly greater upslope of the Mossdale subarea. ' Decontamination Procedures ' Decontamination procedures entailed rinsing the drilling equipment between sites with potable water. The rinseate and drill cuttings were spread on the ground near each well construction site. In developed areas, the rinseate and borehole ' cuttings were transported and disposed in a nearby application field or undeveloped area of the site. ' Soil Sampling and Borehole Logging ' A split-spoon sampler provided continuous geologic cores for inspection and sampling. The texture and moisture content of the drill cuttings was recorded in the field, and detailed soil descriptions utilizing the Unified Soil Classification ' System are reported graphically on the well boring logs (Appendix A). Borehole samples were collected by HydroFocus, Inc. personnel and transported ' from the field to extract the pore-water using a vacuum pump and filter. The pore water was extracted within 72-hours of sample collection, and the electrical conductivity of the water utilized to estimate the Total Dissolved Solids ' concentration of the soil water (pore extract results are provided in Appendix C). The pore-water extracts provide insight into the depth distribution of groundwater salinity at the monitoring well locations'Z. Pore water samples from three ' boreholes (MWM-4, -8, and -11) appear to show decreasing salinity with depth, four boreholes (MWM-5, -15, -19 and -26) appear to show increasing salinity with depth, and no discernable trend was visibly identified in samples from the ' remaining boreholes. Additional analyses of well water samples and groundwater flow directions provided by quarterly monitoring data will be useful for more fully understanding these observed spatial trends in groundwater ' salinity. t2.2 Well Construction Details All wells were constructed from 4-inch diameter, Schedule 40 PVC well casings ' and placed within the 10-inch diameter borings. All but one well (MBRMW-1) were screened with 0.010-inch factory cut slots; MBRMW-1 was screened with 0.020-inch factory cut slots in an attempt to increase well yield. The bottom of ' 12 Multiple core extracts were obtained from all but three well boreholes; due to logistical constraints, no core samples were collected for extraction from boreholes for MWM-25, MBRMW- ' 1 and MBRMW-2. 1