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Mpj <br /> G" Working To Restore Nature <br /> Phase I of a subsurface investigation was conducted on October 17 and 18, 1989 by WaterWork <br /> Corp. Six soil borings (SB-1, SB-2, MW-1, MW-2, MW-3, MW-4) were drilled at the subject <br /> site to depths ranging from 16 to 36 feet below grade. Four of these borings were completed <br /> as two-inch diameter groundwater monitoring wells (MW-1 to MW-4). Soil boring locations <br /> a are shown on Figure 2. Soil samples collected during drilling activities were analyzed for the <br /> presence of benzene, toluene, ethylbenzene, and xylenes (BTEX) and TPHd. Field observations <br /> and laboratory analyses of soils collected from the soil borings (Table 1) indicated that soil had <br /> been impacted by the release of petroleum hydrocarbons to the subsurface. TPHd was detected <br /> in all borings with the exception of MW-1, at depths varying from 10 to 15 feet below grade. <br /> Groundwater was initially encountered at approximately 11.5 feet below grade. Hydrocarbon <br /> constituents were detected in groundwater samples from monitoring wells MW-3 and MW-4 <br /> subsequent to development (Table 2). <br /> A more detailed description of work performed prior to 1991 is included in WaterWork <br /> Corp./RESNA Industries Inc. (RESNA) December 5, 1990 "Preliminary Report - Assessment <br /> of Potential Soil and Groundwater Contamination". <br /> I :1 <br /> �...� On February 28, 1992, the 5,000-gallon u/g diesel tank was removed from the site by Falcon <br /> Energy Associates. RESNA was present in an advisory capacity. A soil sample collected from <br /> beneath the center of the tank indicated 340 ppm diesel contamination was present at 18 feet <br /> below ground surface. Free petroleum product was noted floating on groundwater within the <br /> excavation. A report summarizing the tank removal and sampling is included in Appendix I. <br /> During the first quarter of 1992, RESNA was retained by the City to conduct quarterly <br /> groundwater monitoring and sampling of the site monitoring wells (MW-1 - MW-4). Neither <br /> TPHd nor BTEX have been detected to date in groundwater samples from either MW-1 or MW- <br /> 2. TPHd was detected at 66 parts per billion (ppb) in well MW-3 during the fourth quarter of <br /> I :I <br /> 1992 (December 9, 1992) and at 55 ppb during the second quarter of 1993 (June 9, 1993). <br /> REPORTSIPAR1093.FNL 2 <br />