FIELD DOCUMENTS_CASE 2 - Laserfiche WebLink

Home Browse Search

_ 16 March 2000 AGE-NC Project No. 99-0683 Page 2 of 5 During the UST removal, a total of four soil samples from the floor of the UST excavation and three composite soil samples from the stockpiled soil were collected. Total petroleum hydrocarbons quantified as diesel (TPI-I-d) was reported in two soil samples collected from the east end of the excavation floor at concentrations of 13,000 milligrams per kilogram(mg/kg)and 230 mg/kg. TPH-d was also reported in all three composite stockpiled soil samples at concentrations as high as 3,000 mg/ko. Toluene was reported in soil sample T2E, collected from the east end of the excavation, at a concentration of 0.005 mg/kg. No benzene, ethylbenzene, xylenes or methyl tertiary butyl ether (MTBE) were reported in any of the soil samples submitted for analysis. A summary of soil analytical results are presented in Table 1. 2.3. REGIONAL GEOLOGIC SETTING The property is situated within the Great Valley Geomorphic Province of California. a large, elongate, northwest trending, asymmetric structural trough. The Great Valley Province has been filled with thick sequences of sediment ranging in age from Jurassic to Recent, creating a nearly flat- lying alluvial plain, extending from the Tehachapi Mountains in the south to the Klamath Mountains in the north. The western and eastern boundaries of this province are comprised of the California Coast Range and the Sierra Nevada, respectively. Rocks composing the basement complex of the province have not been completely defined but are believed to be metamorphic and igneous in origin. The northern and southern portions of the Great Valley Province have been designated the _ Sacramento and San Joaquin Valleys, respectively. The Modesto. Riverbank, Turlock Lake Formations and overlying recent alluvium are the principal _ source of domestic ground water in the 13,500 square-mile San Joaquin Valley Ground Water Basin (Basin 5-22). This basin is drained primarily by the San Joaquin River. 25. GROUND WATER DEPTH AND GRADIENT Based on review of the Lines of Eclual Depth to Groundivater Fall 1997 map published by the San Joaquin County Flood Control District and Water Conservation District(FCD&WCD),the estimated depth to ground water at the site is between 50 to 60 feet below surface grade (bsg). Based on the map Lines of Equal Elevation of Groundwater Fall 1997(FCD&WCD),AGE interprets the regional ground water flow- direction to be towards the east. Advanced GeoEnvironmental,Inc,