ARCHIVED REPORTS_XR0005839 - Laserfiche WebLink

Home Browse Search

' 16 December 2005 . AGE-NC Project No. 04-1214 Page"6 of 8 EPA Method 8260B. ' Chlorinated Pesticides and Herbicides in accordance with EPA 8141 and EPA 8151. • Ammonia, nitrate and pH in accordance with EPA Methods 350.2, 300 and 150.1. 3.3. WELL ELEVATION SURVEY On 29 November 2005, a California state-licensed surveying engineer from Baumbach& Piazza, Inc.of Lodi,California surveyed the elevation of monitoring wells MW-101 through MW-104.The elevation at the top of the well casing was surveyed to the nearest 0.1-foot. The elevations of wells MW-101 through MW-104 were determined to be 60.80 feet, 60.72 feet, 57.11 feet and 57.95 feet ' above mean sea level (MSL), respectively. The results of the monitoring well survey are recorded in Table 1. The survey report(Baumbach& Piazza, Inc.) is presented in Appendix C. 4.4. FINDINGS Ground water elevation, flow direction, and gradient were determined from field data collected on 17 October 2005; the contaminant impact to ground water was quantified from laboratory data. 4.1. STRATIGRAPHY ' The soil borings advanced for wells MW-101 through MW-104 were comprised of fine-grained sediments and a ground water table within coarse sands.Generally brown silty sand was encountered from surface grade to approximately 30 feet bsg.A coarse poorly graded sand was present in the soil borings at a depth of 35 feet bsg to 40 feet bsg.A silt layer was encountered from approximately 10 to 15 feet bsg in the eastern monitoring well pilot borings. Saturated soil was encountered at 30 feet ' bsg.No VOC or chemical odor or staining or unusual soil coloration were detected in any of the soil samples taken. The soil boring logs are provided in Appendix A. 4.2. GROUNDWATER GRADIENT AND FLOW DIRECTION ' Depths to ground water during the October 2005 monitoring event ranged from 22.94 feet(MW-103) to 2 6.5 6 feet(MW-102)below the tops of the well casings. The calculated ground water elevations ' ranged from 34.16 feet (MW-102) to 34.29 feet (MW-101) above MSL. The ground water flow direction was inferred to be north to northeast,at a ground water gradient of 0.0008 foot/foot(ft/ft) • north of well MW-101'. The ground water flow direction and gradient are depicted in Figure 3. '. Advanced GeoEnvironmentnl,Inc.