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CLEARWATER G R O U P • Enveronmentnl Servrces • Collection and evaluation of current soil quality data in the area immediately above and below the current potentiometric surface, • Collection and evaluation of accurate groundwater quality data from appropriately screened monitoring wells, • Establishment of accurate groundwater gradient information Site Investigation-Scope and Methodology The following section of this letter report describes the work elements completed to evaluate current soil and groundwater quality impact All work was completed in accordance with the approved project workplan Soil Boring - Drilling and Sampling On June 4 and June 5, 2001 Clearwater supervised the drilling of four soil borings, the collection of soil samples from these borings and the completion of these borings as monitoring wells (MW-9 through MW-12) The soil bormgs were drilled in the areas shown on Figure 2 using a hollow stem auger CME - • 75 high-torque drill rig operated by Mitchell Drilling Environmental (MDE), a state licensed drilling contractor The soil borings were completed at 65 feet below ground surface (bgs), approximately 12 feet into the saturated zone The samples were collected at five foot intervals from all of the borings from 5 feet bgs to the completed depth using a California-modified split spoon sampler All drilling and sampling was completed in accordance with Clearwater protocols presented in Appendix A Soil samples were collected from each 5-foot interval and were logged for soil classification and screening purposes using a Thermodynarruc 580-B organic vapor meter The soil boring logs are presented in Appendix B All of the soil samples collected for chemical testing were submitted to the project lab for analysis by the following methodologies • TPH as gasoline by modified EPAM 8260 • BTEX by EPAM 8260 • MTBE by EPAM 8260 Monitoring Well Installation As shown on Figure 2,the four soil borings were converted into on-site monitoring wells (MW-9 through . MW-12) The wells were installed on June 4 and June 5, 2001 by MDE The wells were installed in Page 4