Laserfiche WebLink
3.0 GEOLOGY AND HYDROGEOLOGY <br /> Based on a review of the United States Geological Survey (USGS) Stockton West, CA Quadrangle <br /> topographic map, the Site is situated at an elevation approximately 15 feet above mean sea level, <br /> and the local topography is sloping gently to the east-southeast. <br /> The Site is located within the Great Valley geomorphic province of northern California. The Great <br /> Valley is an alluvial plain about 50 miles wide and 400 miles long in the central part of California. <br /> Its northern part is the Sacramento Valley, drained by the Sacramento River and its southern part <br /> is the San Joaquin Valley drained by the San Joaquin River. The Great Valley is a trough in which <br /> sediments have been deposited almost continuously since the Jurassic (about 160 million years <br /> ago). In the Sacramento Valley, the Sutter Buttes, the remnants of an isolated Pliocene volcano, <br /> rise above the valley floor. <br /> Based on borings advanced during the previous Phase II and Additional Subsurface Investigation, <br /> the underlying subsurface consisted predominantly of silt and silty clay from the ground surface <br /> to approximately 10 feet bgs. From 10 feet bgs to approximately 30 feet bgs, the subsurface <br /> consisted predominately of silty sand and sand. Static groundwater was encountered during the <br /> previous investigations between approximately 24 and 27 feet bgs. <br /> According to groundwater monitoring reports from a LUST site located approximately 750 feet <br /> east of the Site (641 East Charter Way, CVRWQCB Case # 391007) and a LUST site located <br /> approximately 2,000 feet northwest of the Site (1201 South Center Street, CVRWQCB Case # <br /> 390865) the groundwater flow direction was generally to the north-northwest. <br /> Additional Site Assessment Work Plan <br /> Heliostockton Property <br /> 434 Dr.Martin Luther King Jr.Boulevard <br /> Stockton,California <br /> Partner Project Number SM17-191672 <br /> RWQCB Case#:392004 <br /> January 9,2018 <br /> Page 7 <br />