FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

Mr. Mike Higgins 2 December 5, 1991 rFollowing separator removal, underlying soils were examined by the IT field representative. No product stain P p , petroleum odor or groundwater were encountered in the excavation. One ' soil sample (112191SS-1) was collected from the excavation bottom, at an approximate depth of 8.0 feet below grade. Since the excavation could not be entered safely, the backhoe bucket was used to bring soils, from the desired sampling location, to the ground surface. The sample was collected from the backhoe bucket using a decontaminated brass sleeve, inserted in a split spoon sampler. The sampler was driven into the soil by using a detachable slide hammer. Upon sample extraction, sample tube ends were immediately ediately sealed with teflon lined plastic end caps to prevent the loss of volatile compounds. The sample was placed in a zip-loc bag, stored in a refrigerated ice chest and transported under chain of custody control to Precision Analytical Laboratory for analysis. The sample was analyzed for Total Petroleum Hydrocarbons (TPH) as gasoline and diesel, oil and grease, benzene, toluene, ethyl benzene and xylene (BTEX), PCB's, metals, acid/base neutrals and purgeable halocarbons by EPA methods 5030, DHS-luft, 9071, 8020, 8080, 6010, 8270 and 8010 respectively. Analytical Results Analytical results revealed the presence of oil and grease only (90 ppm). Although detectable concentrations of metals were encountered, none were greater than the California Title 22 TTLC's and only one (1.8 ppm cadmium) was greater than the STLC's (1.0 ppm for cadmium). Based on the concentration of oil and grease encountered, limited over excavation was recommended by San Joaquin County representatives. The over excavation was conducted November 26, 1991 by Paradiso Construction. Verification samples were collected by an IT Corporation representative following the stockpiling of excavated soils. Soil samples were collected from the excavation comers (112691SS1, 112691SS2, 112691SS3 and 112691SS4), at a depth of 8.5 feet below grade. Two soil samples were collected from the soil stockpile generated on November 21 and 26, 1991. A subsequent soil sample from the pit bottom (120291SS1) was collected on December 2, 1991. Soil samples, collected after over excavation was completed,p d, were analyzed by Precision Analytical Laboratory for oil and grease and metals only, since these were the only contaminants encountered in the original sample. Analytical results revealed oil and grease concentrations ranging from 50 - 90 ppm. No metals were detected above Title 22 STLC values. Analysis of the soil sample collected from the pit bottom (following over excavation revealed the presence of 55 ppm oil and grease. No metals were detected above Title 22 STLC values.