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13 July 2012 AGE-NC Project No.96-0236 Page 10 of 13 following is a summary of the results: • TPH-g were detected in all five samples at concentrations ranging from 1,000 pg/I (DPE-2) and 260,000 pg/I (MW-4). • BTEX constituents were detected in all five samples at maximum concentrations of 14,000 pg/I benzene, 6,500 pg/I toluene, 2,600 pg/I ethylbenzene and 16,700 pg/I total xylenes (MW-4). • TAME and 1,2-DCA were detected in wells MW-1A, MW-2, MW-4 and DPE-1 at maximum concentrations of 29 pg/I and 200 pg/I, respectively (MW-4). • Various metals/anions were reported in all samples analyzed for these constituents and are summarized in Tables 4 and 5. Notably, cobalt, copper, nickel and zinc were reported for the second straight post-ISCO injection monitoring event in well DPE-1. Further, ammonia was reported for the second straight post-ISCO injection monitoring event in well DPE-1 and for the first time in well DPE-2. Chromium and hexavalent chromium were not reported in samples collected during the 16 May post-ISCO monitoring event. 5.0. CONCLUSIONS Based upon data collected during this ISCO pilot test, AGE concludes the following: • Generally, pH levels decreased in injection well DPE-1 from a baseline reading of 6.82 to 1.35 as a response to acid dosing during ISCO injection events; pH levels decreased from a background reading of 6.74 to 1.31 in injection well DPE-2. Additionally, pH decreased in nearby observation wells MW-1A and MW-2 which likely indicates influence from the ISCO injections. Based on in-well parameter collection, pH levels appeared to rebound to background levels following cessation of ISCO injection activities. Field parameter pH is summarized in Table 2. • Based on field parameters collected during ISCO injection event nos. 1-4, temperature, ORP and DO increased significantly in injection wells DPE-1 and DPE-2 throughout the pilot injections and remained elevated during post-injection sampling. However, ORP and DO concentrations in observation wells MW-1A and MW-2 appeared to fluctuate, which could indicate that both wells were marginally influenced by the ISCO injection events. Field parameters ORP and DO are summarized in Table 2. Advanced GeoEnvironmental,Inc.