Laserfiche WebLink
2.0 GROUNDWATER MONITORING, SAMPLING AND ANALYSIS <br /> On March 15 2006 to comply with quarterlygroundwater monitoring requirements and to monitor <br /> the plume of impacted groundwater, Ramage Environmental monitored and sampled the seven <br /> on-site monitoring wells In addition, Ramage Environmental continued monthly free product <br /> removal from MW-1 <br /> 21 Groundwater Monitoring <br /> Depth-to-groundwater was measured to within 0 01 foot in each of the wells using a water level <br /> indicator The depth to static groundwater across the site ranged from 44 45 feet bgs in MW-7 to <br /> 46 42 feet bgs in MW-2 The corresponding groundwater surface elevation ranged from a high of <br /> 26 40 feet below mean sea level (msl) at MW-7 to a low of 27 29 feet below msl at MW-4 The <br /> groundwater table surface appears as a plane dipping toward the east-southeast at a gradient of <br /> approximately 0 0017 foot/foot A groundwater surface depression at MW-1 does not fit within the <br /> regional trend A groundwater surface contour map is included as Figure 4 The well construction <br />' details and groundwater monitoring data are summarized in Table 1 <br /> 22 Groundwater Sampling and Analysis <br /> Following the groundwater level measurements, all wells except MW-1 were purged and sampled <br />' Due to the presence of a free product sheen, MW-1 was not sampled The wells were purged <br /> using a pump and dedicated disposable tubing, until at least three well casing volumes were <br /> extracted, and/or after groundwater temperature, pH and electrical conductivity values had <br /> stabilized Fallowing well purging and recharge, groundwater was sampled from the wells using <br /> dedicated disposable bailers and laboratory-supplied containers <br /> Each sample container was transported in an iced cooler with chain-of-custody documentation to <br /> Excelchem Environmental Labs (Excelchem), a state of California certified hazardous waste <br />' testing laboratory (Certification #2119) Excelchem analyzed each of the groundwater samples <br /> for TPH-as-gasoline and BTEX by EPA Method 8021 B/801 5M, and for methyl tertiary butyl ether <br /> (MTBE), di-isopropyl ether (DIPS), ethyl tertiary butyl ether (ETRE), tertiary amyl methyl ether <br /> (TAME), tertiary butanol (TBA), 1,2-dichloroethane (1,2-DCA), and 1,2-dibromoethane (EDB) by <br /> EPA Method 82606 <br /> 5 <br /> i <br /> M <br />