ARCHIVED REPORTS XR0012563 - Laserfiche WebLink

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.,� .,,., - - s -,•'�g,,,;�;;�. r M � _ :- 'g '3�'A�'>�'-$ .gip ->.y-�,-1�- �' � �y=y< .0 ww 2 3 Ms. Diane Hinson - March 6, 1990 Page 6 Ground water analytical reports indicate that water samples collected from monitoring wells MW-1, MW-5, and MW-6,did not contain detectable coarentrations of benzene- Water samples collected from MW-3 and MW4 contained benzene at concentrations of 0.030 ppm, 0.(.'25 ppm. respectively. TPH(g) was present in samples collected from MW-3 (2.2 ppm), M.W--i (2.5 ppm), and MW-5 (1 ppm). TPH(g) was not found in the water samp:es collected from MW-1 and MW-6. A ground water sample collectcd on December I8, 1989 from monitoring well MW-I was submitted for lzboratory analysis of fecal coliform. Monitoring well MW-I is located approximately 13 feet north of a sanitary sewer Iine. Analytical results indicate that bacteria is present in the water sample collected from MW-1 at a cor.:entration 240 (most probable number/100 m1). As indicated on the laboratory data sheet in Enclosure E,laboratory results indicate the bacteria identified in this+yellis not of fecal origin. Ground Wuter Depths, Flow Direction, and !Hydraulic Gradlen� Depth to ground water was measured in each existing monitoring well on December 18, 1989. Ground water was present at depths ranging from 28.27 to 30.97 feet below grade. Ground water level measurements are compiled in Table 4. Water level measurements indicate an inferred direction of ground water flow toward the north, as indicated in Figure. 6. Based on ground water measurements recorded in December and January, the ground water gradient beneath the site is calculated to be approximately 0.019-foot per foot. TABLE 4 Ground Water Elevations Monitoring Top of Riser Depth to Ground Water Comments/ Well Date Elevation (Feel Ground Water (feet) Elevation (feet) Ohcervations MW-1 12/1889 38.80 28.27 60.53 No odor 01/10/90 28.28 6053 No odor MW-2 12/18/89 89.85 FP --- 4.43 feet Ft' 01/10/90 FP --- 4.45 fix t FP MW-3 12!1889 90.35 29.83 60.52 No odor 01/10/90 29.85 60.50 No odor MW-4 12/1889 89.75 30.96 58.79 No odor 01/10/90 30.97 58.78 No odor MW-5 01/10/90 NM 30.40 --- No odor MW-6 12/13/89 90.00 28.94 61.06 No Odor 01/10190 28.97 MW-7 01/10/90 NM FP --- 0.71 feet F? f NOTES: "Elevation relative to top of casing of monitoring well MW-6, assumed elevation 90.00 feet. NM = Not Measured. FP = Free Product.