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�/ 13 July 2012 AGE-NC Project No.96-0236 Page 11 of 13 • Changes in field parameters were generally not measured in MW-4, suggesting reactions were limited to the area of injection wells DPE-1, DPE-2, and observation wells MW-1A and MW-2. Field parameters are summarized in Table 2. • During the 41h and final post-ISCO monitoring event, the following metals were reported from injection wells DPE-1 and DPE-2 at concentrations notably above background levels: zinc, boron, aluminum, calcium, magnesium, manganese, sodium, cobalt, copper and nickel. Additionally, iron significantly increased in DPE-1, while barium notably decreased in DPE-1. Notably, calcium, magnesium and sodium increased significantly in observation wells MW-1 A and MW-2.All other metal constituents appeared within range of baseline sampling results in the observation wells. Analytical results of metals are summarized in Table 4. • Generally, all anions reported in wells MW-1A, MW-2, MW-4, DPE-1 and DPE-2 decreased over time based on the samples collected following ISCO injections. Ammonia was detected in DPE-1 and DPE-2 during the final and 4" post-ISCO injection monitoring event. Anion ground water monitoring results are summarized in Table 5. • Chromium, bromide and bromate were either non-detect or decreased in concentration over time during the pilot injections and post-injection monitoring. Additionally,hexavalent chromium was not detected in any samples collected during the pilot test. Based on these results, water quality does not appear to be adversely effected by the ISCO injections. • TPH-g concentrations in well MW-1A appeared to increase during the ISCO pilot test; conversely, the BTEX concentrations detected from MW-1A appeared to remain stable or slightly decreased. • TPH-g and BTEX constituents increased in observation well MW-2 in comparison to baseline sampling concentrations reported in the well. Based on field parameters collected during injections and post-injections, an influence achieved at MW-2 merely by the gravity feeding injection method used at DPE-1 and DPE-2. Furthermore, increases in hydrocarbon concentrations in the well are likely attributed to desorption of adsorbed contaminants into ground water as the media dispersed through impacted soils, surrounding the injection wells. • Comparing baseline and post-ISCO analytical data, TPH-g concentrations increased in MW-4 from a baseline concentration of 110,000 Ng/I to 300,000 pg/I. However, BTEX concentrations in the well MW-4 appeared to decrease an average of 17% (benzene) to 54% (ethylbenzene). Based on the above results, the hydrocarbon plume in the area of downgradient well MW-4 was effected by the ISCO application at wells DPE-1 and DPE-2. Advanced GeoEnvironmenhl,Inc.