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CLEARWATER <br /> G R O U P I N C <br />' additional vapor extraction wells in the vicinity of the former gasoline dispenser <br /> island The vapor extraction wells were installed in late 1994 and the soil vapor <br /> extraction system was installed in February 1995 <br /> 3.0 QUARTERLY FIELD ACTIVITIES <br />' All work completed this quarter was performed in accordance with Clearwater Field <br /> Procedures which have been previously submitted and under the directives and <br />' guidelines established by the PHS/EHD and the Regional Water Quality Control <br /> Board <br /> The monitoring wells were sampled on March 22, 1995 Prior to sampling, all wells <br /> were gauged to the nearest hundredth of a foot and then purged of a minimum of <br /> three saturated well volumes Temperature, pH and conductivity parameters were <br />' monitored to ensure collection of a representative groundwater sample. All purged <br /> water was stored on site in labeled drums pending future disposal <br />' Groundwater samples were collected from the monitoring wells using dedicated <br /> polyethylene bailers and placed in appropriate sample containers Samples were <br /> labeled, documented on a chain-of-custody form, and stored in a cooler for transport <br /> to PACE, Inc (PACE), a state-certified laboratory located in Novato, California Well <br /> gauging, purging and sampling data is presented in Appendix A All groundwater <br />' samples were analyzed for total petroleum hydrocarbons as gasoline (TPHg) by EPA <br /> Method 8015 (CA LUFT), and for benzene, toluene, ethylbenzene and total xylenes _ <br /> (BTEX) by EPA Method 8020 (CA LUFT) <br /> 4.0 QUARTERLY MONITORING RESULTS <br />' 4.1 Water Level Monitoring Data <br /> On March 22, 1995, the depth to ground water in each of the wells ranged from 68 10 <br /> to 68 60 feet below top of casing Groundwater flow was determined to be variable <br /> due to a groundwater depression in the vicinity of MW-1. In the eastern portion of <br /> the site, groundwater flow was toward the west at an approximate gradient of 0 50% <br /> (0 005 feet/foot). In the western portion of the site, groundwater flow was toward <br /> the southeast at an approximate gradient of 0 11% (0 0011 feet/foot) Depth to water <br /> measurements and wellhead elevation data were used to calculate groundwater <br /> Ielevation contours (Figure 3) <br /> D-102 IQ95 2 May 14, 1995 <br />