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REV: 10-05-2022 VR <br />The “D” Wells Area location is indicated in Exhibit C. Consultant shall treat approximately <br />1/3 of the aerial footprint of the “D” Wells Area by injecting a mixture of abiotic ZVI and <br />EVO, while the remaining 2/3 shall be treated by injecting only EVO. The transition from <br />injecting combined ZVI/EVO to injection only EVO occurs southwest, slightly upgradient <br />of monitoring well D-6. <br />Consultant shall advance injection points in rows of treatment nodes approximately <br />perpendicular to the inferred direction of contaminant transport. The layout of the grid <br />pattern for injection points in the “D” Wells Area is detailed in Figures contained in Exhibit <br />C. Technical information required to execute ERB injections is summarized in Tables 1 <br />and 2 in Exhibit D. <br />Consultant shall inject using Hepure’s Ferox Flow and TerraSystems EVO. Consultant <br />shall mix ZVI with EVO and potable water for fluidization. <br />1.3.1. Injection Point Design and Layout, “D” Well Area ZVI/EVO Injections – Consultant <br />shall inject ZVI/EVO mixture into the chlorinated solvent plume within the “D” <br />Wells Area designated for injecting a ZVI/EVO mix according to the following <br />specifications: <br />A total of 93 temporary injection points shall be advanced using direct-push <br />technology to a depth of approximately 18-ft bgs; <br />The injection points shall be located downgradient from the PRB <br />Emplacement Area and continue up to the EVO transition line as indicted in <br />Figure 5; <br />Delivery point spacing shall be 12 to 14 ft on center; and laid out in a grid <br />pattern with approximately 11 treatment rows while maintaining the individual <br />probe point spacing requirement of 12 to 14 ft; <br />Sequential rows shall be offset (odd vs even) to produce a zig-zag pattern; <br />The emplaced thickness shall be approximately 12.0 ft, injecting at 2-ft <br />intervals; and <br />The treatment surface area shall encompass approximately 11,300 ft2. <br />The orientation and placement of proposed injection point locations shall be <br />slightly adjusted to accommodate existing structures such as monitoring <br />wells, curb dividers, medians and landscape islands while preserving the zig- <br />zag pattern. Exact injection point locations shall be reviewed and approved <br />by the Public Works Director or designee before injection. <br />Approximately 55 pounds of ZVI and 28 gallons of EVO mixture shall be <br />injected at each probe point, totaling an estimated 5,115 lbs of ZVI and 2,604 <br />gallons of EVO, injected through 93 injection points. Consultant has selected <br />and estimates an injection rate for each individual injection point to range <br />between 3 and 5 gpm. The ZVI/EVO mixture shall be injected at an estimated <br />initiation pressure between 70 and 90 psi with a target maintenance injection <br />pressure of 65 to 75 psi. Consultant shall adjust injection volumes and <br />pressures based on actual injection rates achieved in the field. <br />1.3.2. Injection Point Design and Layout, “D” Well Area EVO Injections – Consultant <br />shall inject EVO only downgradient of the transition line from ZVI/EVO to EVO <br />according to the following specifications (and as described in Figure 5 of Exhibit <br />C): <br />ATTY/AGR.2022.348/Regenesis Bioremediation Products (Page 16 of 34)