WORK PLANS - Laserfiche WebLink

Home Browse Search

03 August 2001. AGE-NC Project No. 99-0641 Page 2 of 6 toluene, ethylbenzene, and total xylenes (BTEX), halogenated volatile organic compounds, fuel oxygenates and selected metals(cadmium,chromium,hexavalent chromium,lead,nickel and zinc). TPH-g, TPH-d, TPH-mo, hexavalent chromium, BTEX compounds and the five fuel oxygenates were not detected at or above laboratory reporting limits in the soil samples analyzed. Cadmium, chromium, lead, nickel and zinc were detected in all four soil samples at concentrations as high as 1.3 milligrams per kilogram (mg/kg), 27 mg/kg, 20 mg/kg, 21 mg/kg and 1,540 mg/kg, respectively. Metals concentrations do not exceed the EPA Region IX Preliminary Remediation Goal's. PCE was detected in the four soil samples collected at concentrations as high as 48 micrograms per kilogram(µg/kg). The analytical soil results are summarized in Tables 1 and 2. 2.3. REGIONAL GEOLOGIC/HYDROGEOLOGIC 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 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 of metamorphic and igneous origins. The northern and southern portions of the Great Valley Province nave been designated ilte Sauiainuido quid Sari Joaquin Valleys, respectively. The Modesto, Riverbank and 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. The nearest surface water feature in the vicinity of the property is the Moklumne River approximately one-half mile north of the subject property. 2.4. GROUND WATER DEPTH AND FLOW DIRECTION Based on data acquired from a previous investigation at the site,the estimated depth to ground water in the vicinity of the site is 20 to 30 feet below surface grade (bsg). Based upon data obtained from nearby sites, the prevailing ground water flow direction in the vicinity of the site is estimated to be south to southwest.However,flow direction may be both locally and seasonably variable. Advanced GeoEnvironmental,Inc.