Laserfiche WebLink
Mr. Michael Collins <br /> Page 2 <br /> August 19, 1993 <br /> SF031604.P3 <br /> shallow groundwater. The shallow groundwater surface was found to exist at <br /> approximately 75 feet below ground surface within fine sandy silts, clayey silts and sand. <br /> Groundwater was observed to flow northwesterly at a gradient between 0.0005 and 0.0013. <br /> As reported in the RI/FS, benzene was found to exceed the hazardous waste Toxicity <br /> Characteristic Leaching Procedure (TCLP) level for benzene of 500 14g11 in Monitoring <br /> Wells MW-DIS-1 and -2. Benzene concentrations in Monitoring Wells MW-DIS-1, -2, -3, <br /> and -71) have exceeded the California Maximum Contaminant Level (MCL) for benzene of <br /> 1 µg11 <br /> A schedule of groundwater monitoring and remedial activities planned at Del Monte Plant <br /> 33 was submitted to Mr. Steven Schneider of San Joaquin County Public Health Services <br /> on May 14, 1992. Del Monte is currently proceeding with the activities outlined in this <br /> letter. <br /> GROUNDWATER MONITORINGIQUALITY <br /> The quarterly monitoring event conducted on July 20, 1993 consisted of water level <br /> measurements and groundwater sampling. Water level depths were measured in monitoring <br /> wells MW-DIS-1 through MW-DIS-7S and MW-DIS-7D. Monitoring well locations and <br /> groundwater elevation contours are shown on Figure 1. Water level elevations from this <br /> quarter and previous monitoring events are summarized on Table 1. <br /> Monitoring wells MW-DIS-1, -2, -3, -4, -6, -7S, and -7D were sampled on July 20, 1993 <br /> as part of the quarterly groundwater quality monitoring program. The groundwater <br /> samples were analyzed by the CH2M HILL Analytical Laboratory for total petroleum <br /> hydrocarbons (TPH) as gasoline; benzene, toluene, ethylbenzene, and xylenes (BTEX) <br /> (EPA method 801518020); and soluble lead. The sample collected from monitoring well <br /> MW-6 was not analyzed for TPH as gasoline or BTEX due to the presence of air bubbles <br /> in the sample vials. Results of the July 20, 1993 sampling event and results from previous <br /> sampling events are summarized on Table 2. The laboratory report from the July 20, 1993 <br /> sampling event is also attached. <br /> I <br /> I <br /> i <br /> quarterly.rep <br />