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Site Investigation and No Further Action Request Report <br /> R&L Diesel Services, Project#051111 Tabw <br /> Slate 1954 <br /> with sand and silt. The thickness of these undifferentiated formations ranges to 150 feet. <br /> These deposits are moderately to highly permeable. <br /> Tertiary deposits incorporate the Pliocene-recent flood basin deposits, the Pliocene- <br /> Pleistocene Laguna Formation and the Miocene-PliOCE ne Mehrten Formation. The Pliocene- <br /> recent flood basin deposits are exposed in the delta area of the San Joaquin Valley. They are <br /> essentially fine-grained transported versions of the LaC una, Riverbank, and Modesto <br /> Formations and recent deposits. This unit's thickness anges from 0 to 1,400 feet and has low <br /> permeability. The Pliocene-Pleistocene Laguna Forma ion consists of discontinuous stream-laid <br /> sand and silt with minor amounts of clay and gravel. The thickness ranges from 400-1000 feet, <br /> and permeability ranges from moderate-high. The Mio ene-Pliocene Mehrten Formation is <br /> F-1 composed of moderately-well indurated andesitic sand and sandstone with conglomerate <br /> interbeds. The thickness ranges from 400-600 feet in he Stockton area. <br /> F-1 Site-specific geology consists of silt and sand with some clay overlying a well graded <br /> fine-to medium-grained sand at approximately 53 feet bgs overlying sand and silt to a total <br /> explored depth of 65 feet bgs. Previous direct-push site investigations have encountered a <br /> tight, hard clay layer at approximately 40 feet below grade which caused refusal for the <br /> geoprobe being used to advance the borings. <br /> These data are consistent with the American Forest Products site located approximately <br /> 0.2 miles north on the west side of West Lane and the 3acific Pride site located approximately <br /> 0.5 miles north on the east side of West Lane. Advancad Geo Enviromental, Inc. (AGO, the <br /> environmental consulting company working on the Pac frc Pride site, has installed five <br /> monitoring wells while logging borehole lithology. Collaboratively summarizing the five logs <br /> reveals a profile of clayey silt to 5 feet bgs, sandy silt to 10 feet bgs, silty sand to 20 feet bgs, <br /> clayey sandy silt and silty sand to 55 feet bgs, sand to 35 feet bgs and sandy silt to 80 feet bgs. <br /> 2.2.2 Hydro_geology <br /> The eastern San Joaquin Valley is the southernmost section of the Great Valley <br /> Geomorphic Province, a broad basin bordered by the E ierra Nevada on the east and Coast <br /> Range Complex to the west. The San Joaquin Subbas in is composed of unconsolidated and <br /> semiconsolidated sedimentary deposits, bordered by t e Modesto, Delta-Mendota, and Tracy <br /> Subbasins to the south, southwest and west, respectively. The San Joaquin Subbasin is drained <br /> F by the San Joaquin River and its tributaries northward and discharges into the San Francisco <br /> Bay. Annual precipitation ranges from 11 inches in the southwest to 25 inches in the northeast. <br /> F-1 <br /> The aquifer system consists of the late Tertiary o Quaternary-aged continental deposits <br /> detailed previously in the Geology section, with the upper Quaternary deposits being moderately <br /> Fto highly permeable and the lower Tertiary deposits ra ging in permeability from low to high. <br /> f,� <br /> Again, these data area consistent with AGI's data for the Pacific Pride site, reporting <br /> depth to water in their February 16, 2009 Quarterly Report, First Quarter 2009, MW-5R at 56.22 <br /> Fj feet bgs. URS, the environmental consulting company working on the American Forest <br /> F3 <br /> y <br /> M_� <br />