ARCHIVED REPORTS_XR0007992 - Laserfiche WebLink

Home Browse Search

Mr Chuck Carmel March 9, 1994 Page 2 for total petroleum hydrocarbons as gasoline (TPH-G), and for benzene, toluene, ethylbenzene, and xylenes (BTEX) by U S Environmental Protection Agency (EPA) Method 5030/8020/DHS LUFT Field data sheets and the chain-of-custody form are included in Exhibit A Results The general groundwater flow beneath the site on October 27, 1993, was to the north- northeast under an average hydraulic gradient of 0 003 (Figure 1) A summary of depth-to- water measurements and calculated groundwater elevations is presented in Table 1 Table 2 lists past and present groundwater flow directions and hydraulic gradients for this site Analytical results of groundwater samples are summarized in Table 3 The complete laboratory report for the sampling event is presented in Exhibit A Figure 2 shows TPH-G and BTEX concentrations for the October 27, 1993, sampling event Benzene concentrations ranged from nondetectable in several wells to 620 micrograms per Iiter (pg/1) in ATR-8 TPH-G concentrations ranged from nondetectable in several wells to 52,000 pg/l in well ATR-8 The detection limits for the BTEX constituents and for TPH-G are 0 5 and 50 pg/l, respectively Approximately 0 01 feet of free product was measured in ATR-3, and a sheen was present in ATR-8 Discussion Not including well ATR-8, water level elevations decreased an average of 0 06 feet across the site since August 30-31, 1993 The water level in ATR-8 rose 1 13 feet since August 30, 1993 The northerly groundwater flow direction and the hydraulic gradient (0 003) are consistent with previously reported data Concentrations of hydrocarbon constituents were nondetectable in samples collected from on- site monitoring wells ATR-1, ATR-2, and ATR-6 and off-site monitoring wells ATR-10 through ATR-12 BTEX and TPH-G concentrations in well ATR-4 are within the range of previously reported values The benzene, toluene, ethylbenzene, and TPH-G concentrations were nondetected and the xylene concentration increased slightly from the previous sampling event in wells ATR-7 and ATR-9 Well ATR-5 had nondetected BTEX concentrations and a lower TPH-G concentration than the previous sampling The BTEX and TPH-G Use or disclosure of data conrarned on [Iris sheet is subject to the restriction specified at the beginning of this • docwnent 7 QTRY.Pr