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ARCADIS Mr. Roberto Cervantes <br /> October 21, 2011 <br /> Comment#3 <br /> "Figure 9a only shows CPT data for shallow samples. CEMC needs to include a <br /> figure showing data for deeper samples, similar to Figure 10a in the report." <br /> Response to Comment#3 <br /> Several field activities were conducted at each CPT location in accordance with the <br /> Site Investigation Work Plan: advancement of nine CPT-UVOST soil borings to <br /> collect lithologic data and perform hydrocarbon screening, advancement of eight <br /> hydropunch borings to collect grab groundwater samples, advancement of 10 hand <br /> auger soil borings to collect shallow soil samples. In addition, direct push continuous <br /> core borings were advanced at two CPT locations to compare laboratory analytical <br /> results to UVOST screening results (ARCADIS, 2011). <br /> Figure 9A presents shallow soil sample analytical data collected via hand augers at <br /> ten CPT locations. Figure 10A presents deep soil sample analytical data collected <br /> from two direct push continuous core borings at two CPT locations and four <br /> monitoring well borings (ARCADIS, 2011). The remaining eight CPT locations only <br /> have LNAPL screening data at depth; therefore, there is no additional analytical data <br /> to present on Figure 10A. <br /> Additional Assessment Activities <br /> The objective of this additional assessment is to further delineate the distribution of <br /> constituents of interest(COI) at the Site. ARCADIS recommends the advancement <br /> of four soil borings and the installation of pre-packed wells to collect grab <br /> groundwater samples. SB-1 and SB-2 will be advanced to approximately 35 feet bgs <br /> to collect groundwater at that depth. SB-3 will be advanced in two separate adjacent <br /> boreholes (SB-3A and SB-36)to collect groundwater at approximately 20 feet bgs <br /> and 35 feet bgs. ARCADIS will continuously collect soil at each proposed soil boring <br /> for lithological identification to target the desired groundwater bearing zone. The <br /> proposed soil boring locations are presented on Figure 1 and soil boring location <br /> rationales are summarized in Table 1. <br /> ARCADIS also recommends the installation of three groundwater monitoring wells <br /> (MW-5, MW-6, and MW-7). The proposed monitoring well locations are presented <br /> on Figure 1. ARCADIS will collect soil samples from each monitoring well borehole <br /> for laboratory analysis at the depths summarized in Table 2. The pre-packed well <br /> Page: <br /> 4/7 <br /> G IProjectslCHEVRON1401 N.San Jose SVECHNICALIRWOCBRTMResponse to RYYOCB Comments doc <br />