ARCHIVED REPORTS XR0003742 - Laserfiche WebLink

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The elevations of the newly installed wells have been surveyed by a licensed surveyor relative to the existing site wells The top of casing and top of vault box elevations for each of the new wells were surveyed to the nearest 0 01 foot A survey marker on the was placed on the pier in the Smith Canal located at the 2468 Country Club Boulevard property This survey marker will be used for measuring the water level in the Smith Canal during regular quarterly ground water monitoring events On December 22, 1997, Blaine Tech Services (Blaine) of San Jose, California developed Wells MW-12, MW-13, and MW-14 by surging and purging the wells Findings Geology and Hydrogeology Lrthology encountered during the drilling of the exploratory soil borings consisted of clay, silt, clayey sand, silty sand, to a maximum depth of approximately 86 5 fbg Clay and silt was encountered in each well from the surface to depths of 12 fbg in MW-13 to 28 fbg in MW-12 Beneath the silt and clay is a water bearing zone consisting of a clean sand in MW- 12, silty sand and clayey sand in MW-13 and silty sand to MW-14 The thickness of this water bearing zone ranges from 10 to 30 feet Fine grained sediments consisting of clay and silt were encountered beneath the water bearing zones at thicknesses of 20 to 34 feet thick and extended to approximate depths of 63 to 69 fbg These fine grained sediments contained notably less water than the first water bearing unit The boring logs note these soils as "moist" not "wet" The second water bearing zone was encountered at approximately 69 fbg in MW-12 and MW-14 and at approximately 63 fbg in MW-13 This second water bearing zone consisted of silty sand in each of the three borings These findings are consistent with the findings of the hthologic interpretation done by the CPT survey First encountered ground water occurred in the borings at depths of 10 5 to 15 fbg In the deeper water bearing zone, ground water was encountered at depths between 69 and 70 fbg Ground water in the wells later stabilized at approximately 13 3 to 14 8 fbg Soil Chemical Analytical Data Soil samples collected from Borings MW-12, MW-13, and MW-14 were analyzed for TPPH, BTEX and MTBE Soil chemical analytical data are presented in Table 2 and shown on Plate 4 Certified analytical reports for soils are contained in Appendix C A summary of the analytical findings for each well are presented below Soil samples were collected from MW-12 at the depths of 6 5, 11 5, 31, 56, 66 5, 71 5, and 86 5 fbg The soil sample from 6 5 fbg contained 2 1 ppm TPPH, 0 04 ppm benzene, and 0 055 ppm MTBE The soil sample from 31 fbg contained 0 34 ppm MTBE TPPH, BTEX and MTBE were not detected in any of the other sample intervals analyzed from this boring i 240-0783 14