Laserfiche WebLink
10 2.0 GROUNDWATER MONITORING, SAMPLING AND ANALYSIS <br /> On February 19, 2003, to comply with quarterly groundwater monitoring requirements, Ramage <br /> Environmental monitored and sampled the seven monitoring wells <br /> 21 Groundwater Monitoring <br />' Upon arrival at the site, each of the wellheads was inspected, unlocked and opened Depth-to- <br /> groundwater was measured in each of the wells using a water level indicator capable of <br /> measuring groundwater to within 0 01 foot <br /> The static depth-to-groundwater ranged from 41 73 feet bgs in MW-7 to 43 24 feet bgs in MW-1 <br /> The corresponding groundwater surface elevations ranged from a high of 23 71 feet below mean <br /> sea level (msl) at MW-6 to a low of 24 39 feet below msl at MW-2 The resulting groundwater <br /> surface appears as an irregular plane dipping to the east-southeast at a gradient of approximately <br /> 0 0022 foot/foot As shown on the groundwater surface contour map (Figure 4), a groundwater <br /> depression observed at MW-2 is not consistent with the regional groundwater surface The <br /> groundwater monitoring data are summarized in Table 1 <br /> 10 22 Groundwater Sampling and Analysis <br /> Ramage Environmental purged and sampled all seven monitoring wells The wells were purged <br /> using a pump and disposable tubing until at least three well casing volumes were removed and/or <br /> after groundwater temperature, pH and electrical conductivity had stabilized <br /> Following well purging, groundwater was sampled from the wells using dedicated disposable <br /> bailers and laboratory-supplied containers, which were transported in an iced cooler with chain-of- <br /> custody documentation to Kiff Analytical, LLC (Kiff), a state of California certified hazardous waste <br /> testing laboratory (Certification #2236) Kiff analyzed the groundwater samples for TPH-as- <br /> gasoline, BTEX, MTBE, di-isopropyl ether (DIPS), ethyl tertiary butyl ether (ETBE), tertiary amyl <br /> methyl ether (TAME), tertiary butanol (TBA), and 1,2-DCA by EPA Method 82608 _ <br /> ' Gasoline compounds were only detected in on-site wells MW-2 and MW-3 MTBE was not <br /> detected in any of the groundwater samples The groundwater sample analytical results are <br /> summarized in Table 2, the approximate lateral extent of impacted groundwater at the water table <br /> is shown on Figure 5, and the laboratory reports are included in Appendix A <br /> 7 <br />