ARCHIVED REPORTS_XR0005218 - Laserfiche WebLink

Home Browse Search

4.0 FIELD INVESTIGATION AND RATIONALE 4.1 Soil Borings t A total of three soil borings, MW-1-P, MW-2-P and MW-3-P, were drilled by Park to depths 90 feet bgs (Figure 2 of Appendix A) Each one of these borings was converted to groundwater monitoring wells to depths of 90 feet bgs In addition, one soil boring, VEW-1-P,' was drilled to a depth of 20 feet bgs and subsequently installed with a vadose zone monitoring well (vapor ' extraction well) A detailed description of soils encountered in each of the four soil'borings are included on the boring logs in Appendix B Soil boring placement was based on previous data on the site, conditions encountered in the field and drilling ng accessibility Boring locations ' were approved by PHS/EHD prior to drilling Drilling and soil sampling protocols are included as Sections 1 and 2 of Appendix C 4.2 Groundwater Monitoring Well Installation, Development and Sampling ' The three groundwater monitoring wells installed by Park were located in close proximity to previously installed wells on the site The newly installed monitoring wells were used for groundwater sampling, direction of flow calculations and will potentially be used for future ' monitoring of groundwater quality and remedial measures Monitoring wells MW-1-P, MW-2-P and MW-3-P each have a total depth of 90 feet bgs Well construction details are included in Section 2 of Appendix C and a schematic of the well is shown on the boring log for each well in Appendix B ' The wells were surged for a period of 20 to 30 minutes prior to removal of water to free the fine grained particles within the well and filter pack. Approximately three well volumes of groundwater were pumped from the well and the generated water was placed in Department of ' Transportation (DOT)approved 55-gallon drums During well development the water level, Ph, electrical conductivity and temperature were noted Following well development and after the ' wells had sufficient time to recharge to 80% or greater of static level, groundwater samples were collected Groundwater monitoring data is presented in Groundwater Table I following- ' I B 1125Ji RPr 4