ARCHIVED REPORTS XR0010226 - Laserfiche WebLink

Home Browse Search

------------------ Former Discovery Chevrolet June 5, 1998 Tracy,California Corrective Action Plan `` 2.3 Local Topography The city of Tracy is located in the northern portion of the San Joaquin Valley in western San Joaquin County, California. Tracy is situated with the Diablo Range to the west, and with most of the local land surface gently sloping to the north toward the inland delta that marks the confluence of the San Joaquin River with the Sacramento River. Much of the gently sloping, low-lying land around Tracy is still utilized for agricultural purposes. 2.4 Well Inventory Survey A review of California Department of Water Resources (DRW) well records was conducted by Horizon. Records were searched to identify wells within a one-half mile radius of the site. According to DWR records five wells, both public and private, were identified within this radius (historical Figure 4 and Table 4 in Appendix D). There were no recorded wells downgradient from this site. The nearest well, #1, is 700 feet north-northwest of the site and is completed to 427 feet bsg. tf-r During the Horizon February 19, 1998 site drilling, an apparent water well was discovered outside of the northwest corner of the service bay area (Figure 2). An approximately 6-inch diameter steel casing was noted with a 2-inch diameter galvanized pipe extending above ground level from inside the casing. The apparent well was measured with an electronic well sounder to a depth of approximately 145 feet bsg, where the sounder appeared to encounter soft sediments. 3.0 EVALUATION OF REGIONAL AND LOCAL HYDROGEOLOGY 3.1 Regional Geology The site is located in the central portion of the Great Valley geomorphic province of California. The Great Valley geomorphic province is a structural trough, known locally as r the Central Valley, and is bordered on the east by the Sierra Nevada Mountains and on the west by the Coast Ranges. The Sierra Nevada Mountains are a northwest-trending mountain 3001-21.cap 4 HORIZON ENVIRONMENTAL INC.