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13 September 2012 AGE-NC Project No.99-0682 Page 15 of 17 • BTEX constituents were detected in samples collected from MW-1A, MW-8 and MW-10 at maximum concentrations of 8,400 pg/I benzene, 33,000 pg/I toluene, 3,600 pg/I ethylbenzene and 37,000 pg/I total xylenes (MW-8); xylenes were detected in the samples collected from MW-6 at a concentration of 7.3 pg/I. • TAME was detected in samples collected from wells MW-8 and MW-10 at a concentrations of 140 pg/I and 7.2 pg/I, respectively. • 1,2-DCA was detected in the samples collected from well MW-8 at a concentration of 140 pg/I, respectively. • Various metals were detected in samples collected from wells MW-1A, MW-2, MW-6, MW-8,and MW-10; Fe and Al concentrations in well MW-8 decreased to the lowest levels since the ISCO pilot test began but remain above baseline concentrations; Fe concentrations in MW-1A increased compared to the previous sampling event but remain below baseline concentrations. CrVI,Cr and Cu were not detected above laboratory reporting limits in the samples collected (Table 4). • Anions (bromate, bromide, chloride, nitrate, nitrate as nitrogen, nitrate as NO3-, sulfate, ammonia, and TDS) were detected in the samples collected from wells MW-1 A,MW-6, MW-7, MW-8 and MW-10,with the exception of ammonia from wells MW-1A and MW-2. Concentrations of bromate and bromide were detected below baseline concentrations in wells MW-1 A and MW-8. Concentrations of bromate and bromide were detected near baseline concentrations well MW-6. Additionally, concentrations of chloride and nitrates decreased compared to the previous sampling event in 12 July 2012, but remain above baseline concentrations in samples collected from well MW-8 (Table 5). 5.0. CONCLUSIONS Based upon data collected during this ISCO pilot test, AGE concludes the following: • Generally, pH levels decreased in injection well MW-1A from a baseline reading of 6.74 to a final reading of 5.55 as a response to acid dosing during ISCO injection events; pH levels decreased from a background reading of 7.03 to 5.74 in injection well MW-8. Additionally, pH slightly decreased in observation well MW-6, which likely indicates influence from the ISCO injections performed at well MW-1A. Field parameter measurements of pH are summarized in Table 1. • Based on field parameters collected during ISCO injection events nos. 1-4, temperature, ORP and DO increased significantly in injection wells MW-1A and Advanced GeoEnvironmental,Inc.