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Y , M1I amec A diamond core drill will be used to remove sections of the concrete prior to drilling. Boring locations Al through A3, 131 through B3, and C1 through C3 will be for injections associated with monitoring wells MW-5A, MW-513, and MW-5C, respectively. the soil borings will be advanced using a direct push rig or sonic drilling rig to approximately the same depth as the bottom of the well screen of the corresponding monitoring well (i.e., 45, 75, and 105 feet bgs for the A, B, and C borings, respectively). When the boring has advanced to its maximum depth, the bottom of the drill string will be pulled back about 5 feet and injection will commence. Iterations of pulling the drill string back 5 feet followed by injection will continue until the bottom of the drill string is at approximately the same depth as the top of the well screen of the corresponding monitoring well (i.e., 25, 65, and 95 feet bgs for the A, B, and C borings, respectively). I IRC, as provided by the manufacturer, is a liquid with syrup-like consistency. To make less viscous and therefore easier to inject, it will be heated in a water bath to a temperature of at least 95 degrees Fahrenheit prior to injection. The amount of HRC to be injected at each depth was calculated based on the concentration of CVOCs in groundwater at this location and the length of the screened interval in the corresponding MW-5 monitoring well. However, given the relatively low concentrations of CVOCs in the wells, these amounts were less than the minimum dosage rate per foot of boring (4 pounds/foot of HRC and 2 pounds/foot of HRC primer) that Regenesis recommends for efficient dispersal of the HRC in the aquifer. Consequently, Regenesis recommends that HRC be applied at the minimum dosage rate at each injection boring. The minimum dosage rate was used to calculate the following injection amounts for the borings: 0 80 pounds of HRC and 40 pounds of HRC primer for each of the A borings, and 0 40 pounds of HRC and 20 pounds of HRC primer for each of the B and C borings. HRC primer is similar to HRC but dissolves more quickly so reducing conditions favorable to dechlorination can be established in the aquifer more quickly. Following the HRC injections, the borings will be decommissioned in accordance with SJCEHD requirements that include grouting the borings from the bottom of the boring to the surface with neat cement grout using a tremie pipe from the base of the boring. Concrete patch will be applied to the top of the boring to match the grade of the surrounding sidewalk. Soil and water generated from drilling activities will be placed in 55-gallon drums for characterization and subsequent disposal. AMEC Geomatrix, Inc. IM 300W132901Archive\13290-49.DOC 13