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vertical migration of water. The liner was installed approximately 1 foot below the ground surface (bgs) and was overlain by approximately 3 inches of sand, 6 inches of base rock, and 3 inches of an asphalt surface cap (Sierra Pacific, 1997). 5.2 2006 Pilot Test In 2006, a pilot test was performed southwest of the north pond to evaluate if zero-valent iron (ZVI) and chitin mixture (Adventus EHCTM) could reduce COC concentrations in the A-zone groundwater (Geosyntec, 2007). The ZVI-chitin mixture was injected under pressure at 12 locations near well E-1. The mixture was injected through direct push drilling rods between 60 and 80 feet bgs, primarily into the silt layer between the A and B zones (see Figure 4). Performance monitoring wells PM-1 and PM-2 were installed 10 and 20 feet downgradient of the injection area, respectively, and were also screened between 60 and 80 feet bgs between the A and B zones. The post-injection analytical results indicated nitrate-N concentrations were reduced in wells PM-1 and PM-2 from approximately 200 to 50 milligrams per liter(mg/L), but rebounded approximately one year after the injection (Geosyntec, 2008). Concentrations of the other CDCs remained stable and all COC concentrations increased in up-gradient well E-1. Groundwater elevations in the test area decreased approximately 12 feet during the pilot test. Based on the results, it was determined the ZVI-chitin mixture was not a viable remedial strategy for COCs in the A-zone. 6.0 PILOT TEST AND MONITORING WELL INSTALLATION 6.1 Remediation Technology The pilot test will evaluate the potential to reduce concentrations of the COCs with enhanced anaerobic bioremediation and chemical degradation. The injection solution will consist of a mixture of water, 3-D Microemulsion®(3DME) and Chemical Reducing SolutionTM (CRS). Both 3DME and CRS are manufactured by Regenesis and have been used in the Central Valley to deplete nitrate concentrations and facilitate reductive dechlorination in groundwater. Product information sheets for 3DME and CRS are included in Appendix A. In February 2017, the RWQCB was provided analytical data for the CRS reagent. 6.1.1 Enhanced Bioremediation 3DME is comprised of fermentable carbon sources (lactic acid and fatty acids) that stimulate microbial growth and result in the sequentially staged release of hydrogen from the acids. The hydrogen can be used as an electron donor that fuels the reductive dechlorination process when the environment is sufficiently anaerobic. The stimulation of microbial activity resulting from the addition of the fermentable carbon results in depletion of dissolved oxygen (DO) and lowering of the oxidation reduction potential (ORP). As the system becomes more anaerobic, denitrifying bacteria will begin to use nitrate as the terminal electron acceptor and nitrate concentrations in the groundwater will be depleted. As nitrate concentrations decline, anaerobic bacteria will sequentially begin to use the more energetically favorable electron acceptors, manganese, ferric iron, sulfate, and finally chlorinated organic compounds (e.g. 1,2,3-TCP and 1,2-DCP). Once in the groundwater, 3DME can stimulate degradation of chlorinated compounds for 2 to 5 years (Regenesis, 2009). CPS Stockton, California 3 Pilot Test Work Plan t�2