ARCHIVED REPORTS_XR0003233 - Laserfiche WebLink

Home Browse Search

S 2 0 GROUNDWATER MONITORING, SAMPLING AND ANALYSIS On June 18, and August 19, 2004, to comply with quarterly groundwater monitoring requirements, Ramage Environmental monitored and sampled the four existing groundwater monitoring wells 21 Groundwater Monitoring Depth-to-groundwater was monitored using a water level indicator capable of measurements to within 0 01 foot On June 18, 2004, the static depth to the groundwater table, as measured in the four groundwater monitoring wells, ranged from 24 28 feet bgs in MW-1 to 25 55 feet bgs in MW- 3 The groundwater surface elevation in the four wells ranged from a high of 13 15 feet below mean sea level (msl) at MW-1 to a low of 13 92 feet below msl at MW-4 On August 19, 2004, the depth to groundwater ranged from 24 77 feet bgs in MW-1 to 26 13 feet bgs in MW-3 The groundwater surface elevation in the four wells ranged from a high of 13 64 feet below msl at MW- 1 to a low of 14 36 feet below msl at MW-3 r The groundwater surface appears as an irregular plane dipping to the east-southeast On June 18, 2004, the groundwater gradient was approximately 0 0263 foottfoot A groundwater surface contour map is included as Figure 4, and the groundwater monitoring data are summarized in Table 3 The sample information field sheets are included as Appendix A 22 Groundwater Sampling and Analysis Fallowing groundwater level measurements, the wells were purged and sampled The wells were purged with a pump and dedicated disposable tubing until at least three well casing volumes had been removed and/or after groundwater temperature, pH and electrical conductivity values had stabilized Groundwater was sampled from the wells using disposable polyethylene bailers and laboratory-supplied containers Each sample container was transported in an iced cooler with chain-of-custody documentation to Excelchem Environmental Labs (Excelchem), a state of California-certified hazardous waste testing laboratory (Certification #2119) Excelchem analyzed each of the samples for TPH-as-kerosene, TPI -as-gasoline and BTEX by EPA Method 8020/8015M, and for MTBE, di-isopropyl ether (DIPE), ethyl tertiary butyl ether (ETBE), tertiary amyl methyl ether (TAME), and tertiary butanol (TBA) and 1,2-dichloroethane (1,2-DCA) by EPA Method 8260B 7