ARCHIVED REPORTS - OZONE PILOT TEST & SEMI-ANNUAL GROUNDWATER MONITORING REPORT - THIRD QUARTER 2014

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20 March 2015 AGE Project No. 00-0769 ' Page 6 of 19 AUGUST 2014 On 04 and 05 August 2014, a progress-pilot test monthly monitoring and sampling event ' was performed utilizing wells MW-1, MW-2A, MW-3A, MW-5A, MW-6B, MW-7B, MW- 8A, MW-9A, and MW-10 as required by the MRP; depth to groundwater was measured; pH, EC, and temperature were measured during well purging and final values after ' purging was complete were utilized; DO and ORP were measured down-hole prior to purging in non-CMT wells and from purge water during the initial purge volume in CMT wells; and groundwater samples were collected in each of the above-mentioned wells. ' Groundwater samples were analyzed for the constituents required in the MRP (Appendix B). ' • Depths to groundwater ranged between 20.15 feet (MW-8A) below the tops of the well casings (btoc) and 22.37 feet (MW-1) btoc (Table 1). Groundwater elevations at the site ranged between 8.58 feet (MW-10) below North American ' Vertical Datum 88 (NAVD88) and 11.71 feet (MW-1) below NAVD88. • TPH-g were detected in groundwater samples collected from wells MW-1, MW-2A, MW-3A, MW-5A, MW-6B, MW-7B, and MW-10 at concentrations ' ranging from of 1,000 pg/I in MW-5A to 230,000 pg/I in MW-1. BTEX were detected in groundwater samples collected from the same wells at maximum ' concentrations of 44,000 pg/l benzene, 59,000 pg/l toluene, 4,600 fag/I ethylbenzene, and 37,000 pg/I total xylenes (Table 2). • pH was measured between 6.89 and 7.43; EC was measured between 581 and 1,231 pS/cm; temperature was measured between 20.4 and 23.1 degrees Celsius; DO was measured between 0.19 and 2.25 mg/1; and ORP was measured between -111.6 and 67.4 mV. Results of YSI Multi-Parameter Meter ' data is presented in Table 3. • Various dissolved metals (Ba, B, Al, Ca, Fe, K, Mg, Mn, Na, and Zn) were detected in groundwater samples collected in August 2014. Concentrations of Ba detected in samples collected from wells MW-1, MW-2A, and MW-5A were above the State of California Primary MCL for Ba in drinking water; ' concentrations of Ba detected in the remaining samples were below the MCL; and concentrations of Fe and Mn detected were significantly above the State of California Secondary MCLs for drinking water. Concentrations of Ca, B, Mg, Na, ' K, and Zn all appear to be within normal background levels. Analytical results of metals are summarized in Table 4. • Hexavalent chromium was not detected above the laboratory reporting limit ' (0.2 pg/1) in groundwater samples collected in August 2014 (Table 4). • Bromide was detected at concentrations ranging between 1.71 mg/I (MW-3A) ' and 8.74 mg/I (MW-1). • Bromate was detected at concentrations ranging between 1.06 mg/I (MW-3A) ' and 6.71 mg/l (MW-1); Bromate concentrations were significantly above the State Advanced CeoEnvironmental Inc.