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15 June 2009 AGE-NC Project No.05-1306 Page 4 of 33 Groundwater Monitoring Well Installation Report,completed by the US Army Corps of Engineers. A copy of the M&B 2006 Groundwater Monitoring Well Installation Report,and well logs for M&B wells MW-I 1A,MW-12B and MW-17A are included in Appendix C. Active site remediation is currently underway at the M&B site to mitigate the migration of ground water contamination off-site.Additionally,soil excavation and ground water stabilization procedures are ongoing to further minimize the threat of the site to the surrounding water ways and sensitive receptors within the Stockton Deep Water Channel. The M&B site has impacted the Stockton Deep w Water Channel and the localized shallow, intermediate and deep ground water. Isoconcentration maps of the regional ground water plume for the M&B site, provided by the EPA website ate included in Appendix D. As a result of the M&B impacts, local ground water has a significant chemical impact, degrading the beneficial uses of the local ground water. z.. 2.4. SITE INVESTIGATIONS Soil and ground water assessment activities, including the drilling and logging of soil borings and the installation of ground water monitoring wells, were performed beginning in October 1997 by �- ATC,by Haley and Aldrich, Inc. (H&A),by Geomatrix, and by AGE on behalf of H&H, Inc, and Continental Grain Company. Between 1997 and 2002, ATC advanced twelve soil borings, collected soil and ground water samples, and installed six monitoring wells at the site: • October 1997- Six soil borings (SB-1 through SB-6)were advanced on site for collection of soil and grab ground water samples. Soil boring locations are depicted in Figures 2. Analytical results of soil samples reported total petroleum hydrocarbons quantified as diesel `r and gasoline (TPH-d and TPH-g)from borings SB-1 and S13-2 at maximum concentrations of 6,800 mg/kg (SB-1 at 20 feet bgs), and 120 mg/kg (SB-1 at 15 feet bgs), respectively. Grab water samples collected from boring SB-2 (SB-2 at 20 feet bgs) reported TPH-d at a concentration of 1,300,000 micrograms per liter(µg11).Grab groundwater samples collected from borings SB-1, SB-2 and SB-3 reported TPH-g at maximum concentration of 11,000 µg11 (SB-3 at 20 feet bgs). Analytical results of soil and grab water samples are summarized in Tables 1 and 3. • August 1998 - Three ground water monitoring wells (MW-1 through MW-3 were installed on-site to a depth of 28 feet bgs. Analytical results of soil samples reported TPH-d and TPH-g at maximum concentrations of 14,000 mg/kg(MW-2 at 20.5 feet bgs),and 870 mg/kg (MW-2 at 20.5 feet bgs), respectively. Detectable concentrations of toluene, ethylbenzene and xylenes were also reported in the soil samples collected from MW-2.Analytical results of soil samples are summarized in Table 1. Advanced GeoEnvironmental,Inc.