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' lo tcdTecFintcs Inc �eog Page 4 Soli & Groundwater Inveghgation Report J M Equipment Project No 507 2 July 5, 2001 ' 2.2 Monitoring Well Installation ' To investigate the lateral definition of gasoline range petroleum hydrocarbons in the groundwater at this site, GTI installed two water table monitoring wells One well was placed to the northwest (MW-10) and one was placed southwest (MW-7) of the former UST (Figure 2, Site Map) A deep well, MW-109, was placed in the location of the former UST ' to define the vertical extent of the groundwater plume The new wells and existing wells construction details are illustrated below i _NVe_WNo—. _D`ia7T1F Screen slot Sand Packraps. rout ea Seal W-2On file SJC PHS/ EHD �I --2"/3-5— 1 - 2 —sand–f-17. I A-3 - YAW-5__2"733 35 0-02-G"— 93 san 735 —1�3 0" san T3-35' -7 —2'73U"--- �3f3'- - 020s�-8- - 0" 2-II2�-sem-1 =33' - -9 23� 02_W" As 11leawred on may 15,200 1 The monitoring wells were constructed using 2 0-inch diametei PVC casing with flush ' threads The screened intervals extended from the water table to twenty feet below the water table Groundwater was encountered at approximately 13 5 feet bgs A #3 sand filter pack suriounded and extended two feet above the 0 020 inch screened interval and was topped by a two foot bentonite chip transition seal installed on top of the filter pack and hydrated A surface seal was achieved by pouring a neat cement grout on top of the transition seal The wells were secured with locking watertight caps encased in flush mounted traffic rated well boxes On May 29, 2001, Don Light of Del Tech mobilized to the site to develop the new monitoring wells (using mechanical surging and pumping methods) until a cleat stream of ' water was obtained All development and purge water was containerized in 55-gallon DOT approved containers and stored on site until its disposition can be arranged The-results of the groundwater analyses will be presented in a quarterly monitoring report ' for the 2°d Quarter, 2001 (June) event 3.0 RESULTS OF INVESTIGATION The geology as it relates to the analytical data is discussed in the conclusion section below Table l in Appendix A contains a full summary of the soil analytical data and the laboratory data sheets are included in Appendix C Appendix D contains the geophysical parameter analytical results A site map with soil boring and monitoring well locations is included as Figure 2