ARCHIVED REPORTS XR0009151 - Laserfiche WebLink

Home Browse Search

i 23 March 2001 AGE-NC Project No 97-0301 ' Page 4 of I 1 surveyed a reference point on the casing tops of wells MW-5, MW-6 and MW-7 to the nearest 0 01-foot relative to the San Joaquin County Bench Mark Datum BM # 117 The results of the monitoring well survey are contained in Table 3 A copy of the surveying report (Baumbach & Piazza Job No 9797) is in Appendix B 26 WELL DEVELOPMENT ACTIVITIES On 07 December 2000, monitoring wells MW-5 and MW-6 were developed utilizing a two-stage l i submersible pump, monitoring well MW-7 was developed on 28 December 2000 Prior to well development, total depth measurements were collected utilizing a Solinst water level ' indicator to measure the quantity of sediment settled at the bottom at each well Thereafter, ground water was purged from the bottom of each monitoring well utilizing a submersible pump until ground water was visually sediment free, approximately 25 to 40 gallons of water were removed from each of monitoring wells MW-5,MW-6 and MW-7 during development Purged ground water was containerized at the site in properly labeled DOT-approved model 17H 55-gallon drams Copies of monitoring well field logs for development activities are in Appendix C 3.0 WELL INSTALLATION RESULTS Soil descriptions were utilized to construct geologic cross sections of the site, field data was utilized ' to select soil samples for laboratory analysis Petroleum hydrocarbon-impact to saturated and unsaturated soil was assessed and quantified by laboratory analysis Laboratory analysis of soil samples detected TPH-g, TPH-d, TPH-k, 1,2-DCA or BTEX compounds to nine soil samples 3 1 STRATIGRAPHY RESULTS Generally,pale brown/gray,damp to moist, fine sandy silt was encountered at depths of 15, 30 and 35 feet bsg Pale brown/gray, damp to moist, silty fine sand was encountered at depths of 20, 25 and 40 feet bsg, some gravel and medium sand were observed at 40 feet bsg At depths between 45 and 100 feet bsg, a dark gray/blue, moist to saturated, sandy silt was encountered ' Saturated soil was observed in soil sample duplicates at 45 feet bsg in boring MW-5, at 35 feet in boring MW-6 and at 40 feet bsg in boring MW-7, ground water levels were measured from MW-5, MW-6 and MW-7 at approximately 29 feet bsg utilizing a Solmst water level meter during well ' installation activities Boring logs are included in Appendix A General lithology beneath the site is depicted in cross-sectional views A-A', B-B' and C-C'in Figures 3, 4 and 5, respectively Advanced GeoEnvironmental,Inc i