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0 LFR Inc. east of MW-012A, further indicate that reductive dechlorination is continuing past cis- ' 1,2-DCE and vinyl chloride. The groundwater results for the 13 wells sampled in the B-zone aquifer during the December 2006 event indicated that cis-1,2-DCE was detected in 6 of the 13 groundwater samples. The cis-1,2-DCE concentrations ranged from 0.73 µg/1 in MW- 20313-1 to 18 µg/1 in MW-20913, with the exception of MW-205B and MW-207B, which had detected concentrations of 1,000 µg/1 and 550 µg/1, respectively. These two samples with detected cis-1,2-DCE concentrations also have detected PCE and TCE concentrations that are on the same order of magnitude. As documented in the previous section, four groundwater samples were recently collected and analyzed for the full suite of geochemical parameters. Ethane and ethene concentrations were detected at the highest concentrations in groundwater from B-zone wells MW-205B (ethane: 3.8 µg/l and ethene: 0.28 µg/1) and MW-020B (ethane: 0.16 µg/l and ethene: 0.12 µg/1). Ethane was not detected in wells MW-108A and MW-208B (<0.025 µg/1), located in the proposed ERD treatment zone and downgradient. Ethene was detected in wells MW-108A and MW-208B at concentrations of 0.029 µg/l and 0.038 µg/I, respectively. The presence of ethane and ethene within the three B-zone wells indicates that active and complete anaerobic reductive dechlorination is occurring. The presence of ethene and hydrogen within A-zone well MW-108A indicates that conditions may be favorable for anaerobic degradations but that adequate food source may not be available. Thus, with the injection of a substrate, the A zone should respond favorably to ERD. 3.4 ERD Substrate Selection LFR has implemented ERD remedies under a variety of hydrogeological and geochemical conditions. LFR personnel have experience with ERD products that have specifically been designed for this purpose, including HRC from Regenesis, Emulsified Oil Solution (EOS) from EOS Remediation, Inc., CAPI8TM from DBI Remediation Products, and Adventus' EHC product. Additionally, LFR has successfully used industrial and food-grade products, including ethanol, sodium and potassium lactate, cheese whey, molasses, and others, to promote biologically favorable anaerobic reducing environments to support ERD. All of these substrates have been shown to be effective in creating anaerobic environments within groundwater and stimulating the growth of microorganisms ultimately responsible for the dechlorination of PCE to innocuous end products. While many of these substrates would likely be effective in treating the core of the Lincoln Center plume, LFR sought to identify the best product to achieve project goals. 3.4.1 Substrate Suitability A central feature of the Phase V IRA ERD injection is the installation of 22 injection wells to depths of 65 to 80 feet bgs, with the goal of providing a large amount of Page 14 wp-PM1V_IRA-Sep07-Final-06750.dm:lfr