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Woodward-Clyde <br /> Consultants <br /> Anthony J. Landis <br /> Department of Toxic Substances Control <br /> December 21, 1992 <br /> Project No. 90189N <br /> Page 2 <br /> (MW-1, MW-2, MW-6 and MW-30) on this site. The seven monitoring wells (MW-1, <br /> MW-2, MW-4, MW-6, MW-14, MW-15 and MW-30) were first sounded to measure the <br /> depth from the top of the well casing to the groundwater surface. The monitoring wells <br /> were purged with a Teflon bailer. Each monitoring well was purged until it was either <br /> bailed dry (MW-4, MW-14 and MW-15) or until three well casing volumes of groundwater <br /> was extracted (MW-1, MW-2, MW-6 and MW-30). Approximately one to one and a half <br /> well casing volumes of groundwater could be extracted from monitoring wells MW-4, <br /> MW-14 and MW-15 before the wells were bailed dry. The recovery rates for monitoring <br /> wells MW-4, MW-14 and MW-15 were observed to be very slow. During the purging of <br /> the wells, groundwater samples were measured in the field for pH, temperature and specific <br /> conductance at approximately every well casing volume. After the wells were purged, the <br /> four sampled monitoring wells (MW-1, MW-2, MW-6 and MW-30) were allowed to recover <br /> for two to three hours before the wells were sampled. The portion of the groundwater <br /> samples collected for dissolved metals (copper and lead) analysis was field filtered through <br /> a pump with an in-line 0.45 µm filter. Monitoring wells MW-4, MW-14 and MW-15 were <br /> allowed to recover for approximately five hours. The groundwater from monitoring wells <br /> MW-4, MW-14 and MW-15 did not recover in this time period to allow for the wells to be <br /> sampled. <br /> These samples (MW-1, MW-2, MW-6 and MW-30) were submitted to California Analytical <br /> Laboratories, Inc. (a DHS-certified laboratory) located in West Sacramento, California for <br /> chemical analysis. An equipment/travel blank designated as MW-31 and a blind duplicate <br /> sample designated as MW-32 (duplicate sample for MW-6) were also submitted to the <br /> laboratory for analysis. Chain of custody documentation was maintained. The samples were <br /> analyzed for the following parameters: <br /> Specific Conductance (EPA Method 11-0.1) <br /> Total Dissolved Lead (EPA Method 239.2) <br /> Total Dissolved Copper (EPA Method 6010) <br /> Total Dissolved Solids (EPA Method 160.1) <br /> 90189N/9QUARTER/12-21-92 SAC <br /> A,V <br />