Laserfiche WebLink
1 - <br /> operation. The highest concentration detected in any individual well was TPHg detected in <br /> VW5 at 280 mg/m3 Extraction rates have been less than 1 4 pounds per day Even if <br /> 1 petroleum hydrocarbons remain in soil, groundwater monitoring data suggest that it is unlikely <br /> that the integrity of groundwater beneath the site will be affected in the future Historical <br /> groundwater data indicates that the highest groundwater elevation on-site was 67 23 feet bgs <br /> 1 and soil contamination was limited to depths between 10 and 45 feet bgs Benzene has never <br /> been detected in any wells and TPHg was only detected in one well, MW1, during the first <br /> sampling event on March 4, 1992 Toluene, ethylbenzene, and xylenes have only been <br /> detected two wells at concentrations well below their respective maximum contaminant levels <br /> or action levels TPHd has been detected at low levels once or twice in each well <br /> 1 6_3 Site Specific Information Summa <br /> o Nine groundwater supply wells are known to exist within 2,000 feet of the site, based <br /> 1 upon information provided by the Department of Water Resources (DWR) The <br /> information provided by DWR did not provide accurate locations of any of the nearby <br /> wells The nearest municipal well was located visually and is approximately 100 feet <br /> 1 northeast of the project site <br /> 1 o Depicted on enclosed figures are the site location and nearby surface waters (Figure 1), <br /> the site to scale and former tank locations (Figures 2 and 4), well and boring locations <br /> (Figures 2 and 4), most recent groundwater gradient contours (Figure 3), the former <br /> area of impaction in the soil (Figure 6), and the site plan of the remediation system <br /> (Figure 5) <br />' o Water level data are presented in Table 1 During the investigative history of the site, <br /> depth to groundwater has ranged from 67 23 to 70 14 feet below grade <br />' o Table 4 presents the sod analytical results and Table 2 presents the groundwater <br /> analytical results <br />' o Soil remediation methodology is described in Section 4 4 Remedial Actions A vapor <br /> extraction system was used to remove petroleum hydrocarbons from the soil on-site <br /> 1 o No subsurface groundwater remediation system has been recommended or installed <br /> Histoncally, groundwater had not been significantly impacted by the former petroleum <br /> hydrocarbon impacted soil Historical analytical results indicated TPHg and BTEX <br /> 1 were below detection limits, MCLS, or ALs for the last nine quarters of groundwater <br /> monitoring <br /> 1 <br /> wW141*anIyl4gr-1993&c 10 <br /> • <br /> s�N <br /> 1 <br />