ARCHIVED REPORTS_1990 - Laserfiche WebLink

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KLEINFELDER 6 CONCLUSIONS The following conclusions are based on the activities and data presented in this report and are subject to the limitations described in Section 8. 6.1 DESCRIPTION OF HAZARDOUS MATERIALS The landfill has been accepting waste since 1965. Available historic information on waste disposal at the site has been reviewed from 1965 to the present. For most of the site history, the landfill was owned by Howard Lewis et al. and leased to Forward Sanitary Landfill, Inc. San Joaquin County took possession of the land in 1988,and allowed Foothill Sanitary Landfill, Inc. to continue operations. During its operations Foothill Landfill has received residential, industrial, commercial and bio-medical waste. The bio-medical waste quantities have accounted for less that one percent of the landfill gate volumes. 6.2 LEAKAGE OF HAZARDOUS MATERIALS This investigation produced no evidence that hazardous waste is leaking from the landfill into the soil or ground water under the site. No organic constituents were detected above the analytical laboratory reporting limits in the leachate, vadose zone, or ground water samples. In the leachate and soil pore fluid, iron and manganese were detected at higher concentrations than their respective secondary MCLs. Currently, there are not established hazardous concentrations for iron and manganese, the concentration of iron and _ manganese did not appear to be greater than background concentrations of these metals. It appears that boron concentrations may be elevated with respect to background in soil immediately under the older part of the landfill. Boron was also detected in the leachate is samples. However, there are not currently established hazardous concentrations for boron. Based on data collected in this investigation, concentrations of metals in the ground water do not appear to be increasing downgradient of the landfill. More metals and more FOOTHILL 35