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Extraction Well Installation <br /> Summary Report and Injection <br /> ARCADIS Well Installation Work Plan <br /> Former Occidental Chemical <br /> Corporation Facility <br /> Lathrop, California <br /> Redevelopment activities were conducted at EW-04 on August 15 to 16 and October 3 to 4, 2012.A <br /> camera survey of the well was conducted on August 17 and October 8,2012. Redevelopment activities <br /> conducted at EW-04 on August 15 to 16, 2012 included brushing, surging, bailing, and pumping. <br /> Approximately 4,550 gallons of groundwater were pumped from EW-04 to remove fine-grained <br /> sediment and obtain an estimate of specific capacity. Pumping indicated a specific capacity of 0.6 <br /> gpm/ft. On October 3, 2012, approximately 18 feet of sediment was removed from the well bottom and <br /> redevelopment activities, including brushing,surging, bailing, and pumping,were conducted again. <br /> Approximately 4,500 gallons of groundwater were pumped during this event and indicated a specific <br /> capacity of approximately 1.5 gpm/ft.The camera survey conducted on October 8, 2012 indicated <br /> moderate to severe fouling in the screened intervals. The well redevelopment activities did yield <br /> improvement in specific capacity; however, not to a level suitable to accommodate the proposed <br /> injection rates. Based on those findings,ARCADIS will not convert EW-04 to an injection well and <br /> proposes installation of an additional injection well at an alternative location in the vicinity of EW-04 <br /> (Figure 2 and 3). <br /> 4. Injection Well Installation Work Plan <br /> The purpose of proposed injection well INJ-14 is to accelerate the groundwater remedy by introducing <br /> treated oxygenated water into targeted zones to both enhance in-situ aerobic biodegradation of <br /> sulfolane and achieve accelerated pore-volume flushing of COCs towards the extraction wells.To <br /> accomplish this objective, ARCADIS proposes to install injection well INJ-14 at an alternative location <br /> south of EW-04(Figure 2 and 3).This section presents the proposed scope of work to install INJ-14. <br /> 4.1 Pre-Field Activities <br /> Prior to well installation activities, underground utility clearance,security measures, and contaminant <br /> control measures will be conducted as described below. <br /> 4.1.1 Underground Utility Clearance <br /> Underground utilities will be identified by the following lines of evidence: <br /> • Contact Underground Service Alert of Northern California and Nevada at least 48 hours in advance <br /> of sampling activities. <br /> • Obtain a detailed site utility plan and discuss locations of utilities with the property owner, Pilkington <br /> Glass. <br /> • Conduct a detailed visual site inspection. <br /> lelhmp SII installation mport_fna1_(0-2P1a)do 8 <br />