ARCHIVED REPORTS_XR0012728 - Laserfiche WebLink

Home Browse Search

Woodward-Clyde Gansultants B820011STI CON 1.2 Site Description The site is located along the U.S. Hwy 99 East Frontage Road approximately 800 feet north of Morada Lane in Stockton, California. It is bordered on the north, east, and south by a mobile home park, and on the west by the Hwy 99 east Frontage Road. At the time of-this investigation, the service station had been demolished and removed from the site, and a fence had been constructed around the property. p Structures existing when the service station was in operation included: �'. (1) three 10,000 gallon subsurface tanks in one complex which stored regular, unleaded, and supreme unleaded gasoline, (2) two 1,000 gallon subsurface tanks in separate excavations which stored fuel oil and waste oil, (3) one service building, (4) three pump islands and (5) one } groundwater well. According to Gettler-Ryan Inc., the underground storage # tanks were removed in June 1986. 2.0 HYDROGEOLOGIC SETTING The site is located in the Eastern San Joaquin County groundwater basin, 7 which lies in the central part of the Great Central 'Dalley (California Department of Mater Resources, 1980). Wagner, et al (1981) have mapped the surficial material at the site as Quaternary aged alluvium in the upper member of the Modesto Formation. The California Department of Water Resources (1950 indicates that the surficial deposits in the vicinity of the site are composed of Holocene to Pleistocene aged, stream deposited gravel, sand, silt, and clay of the Victor Formation. The Victor Formation has a maximum thickness of 150 feet and grades from coarser sand and gravel in eastern San Joaquin County to sand, silt, and clay in the center of the county. The surficial deposits are underlain by the Pleistocene to Pliocene aged Laguna Formation and the Pliocene to Miocene aged Mehrten Formation, which is the oldest of the fresh groundwater-bearing aquifers in the study area.