ARCHIVED REPORTS_XR0007076 - Laserfiche WebLink

Home Browse Search

14 February 2006 • AGE-NC Project No 95-0141 Page 4 of 5 The areal extent of TPH-g-and 1,2-DCA-impacted shallow and deep ground water is illustrated on Figures 5 and 6 Laboratory results of water samples analyzed are summarized in Table 2 The laboratory reports for the quarterly monitoring event (CTEL Project Numbers CT214-0511036), quality assurance and quality control (QA/QC) reports and chain of custody form are included in Appendix C GeoTracker confirmation pages of the submitted laboratory electronic deliverable format files are included in Appendix D 4.0. SUMMARY AND CONCLUSIONS The findings of the Fourth Quarter 2005 site investigation include the following • At the time of the November 2005 ground water monitoring event, ground water elevations at the site ranged from 10 92 feet to 11 71 feet below MSL The shallow ground water was inferred to flow generally towards the southeast,at a gradient of 0 005 ft/ft,while the deeper ground water zone was inferred to flow generally toward the southeast,at a gradients ranging from 0 002 ft/ft to 0 006 ft/ft • 0 TPH-g was detected in ground water samples collected from four ofthe fifteen wells sampled at the site at concentrations as high as 79,000 µg/1 TPH-g-impacted shallow ground water has been defined (Figure 5) However, the TPH-g-impact to the deeper ground water zone has not been defined toward the east and to a lesser degree south and north (Figure 5) • Various BTEX constituents were detected in five of the fifteen sampled ground water wells The benzene concentrations detected in the wells exceeded the DHS' Maximum Contaminant Level (MCL) for benzene in drinking water The concentrations of toluene, ethylbenzene and total xylenes were also significantly above their respective MCLs in EX-1 • 1,2-DCA was detected in ground water samples collected from eight of the fifteen sampled wells at the site, at concentrations as high as 180 µg/l (EX-1) The detected concentrations of 1,2-DCA were above the MCL of 0 5 µg/1 1,2-DCA-impacted shallow ground water has ' been fully defined, but the 1,2-DCA-impacted deeper ground water zone has not been defined toward the south, east and north A map illustrating the approximate extent of 1,2-DCA in shallow and deep ground water is presented on Figure 6 • EDB was detected in ground water sample EX-1 at a concentration of 53 µg/1 EDB has been detected intermittently in well EX-1, located near the former UST location ' 0 Additional site assessments(soil borings and/or monitoring wells)are necessary to determine whether commingling is occurring with the contamination plume detected at the adjacent ' Lopez property (also managed by AGE) to the northeast of site ' Advanced GcoEnvnronmental,Inc