Laserfiche WebLink
At the former waste oil tank, one boring will be drilled <br /> to a depth of 15 feet or 10 feet below the depth at which <br /> soil contamination is last detected in the field. Soil <br /> ` samples will be collected at five foot intervals starting <br /> at a depth of 10 feet below grade. <br /> As an indicator of potential groundwater contamination, <br /> the boring closest to the known area of contamination will <br /> be drilled first. If the boring is advanced to the point <br /> where saturated soils are encountered and soils remain <br /> contaminated based on field evidence, then it will be <br /> assumed that groundwater contamination exists. As such, <br /> additional soil borings around this tank would not <br /> immediately be drilled but would be included as part of a <br /> groundwater assessment proposal submitted separately. <br /> w. Drilling will be conducted by Osterberg and Stewart under <br /> C57 license 446670 using a hollow stem auger drill rig. <br /> Drill cuttings will be logged continuously for <br /> ` characterization of soil type utilizing the Unified Soil <br /> Classification System (Appendix I ) . Obvious soil <br /> discoloration and hydrocarbon odors will be utilized to <br /> determine soil contamination in the field. Descriptions <br /> of the soils encountered will be recorded on boring logs <br /> and included within the assessment report. All excavated <br /> soils will remain on-site, covered with plastic sheet, <br /> pending return of laboratory results. <br /> 2. 8 . 2 WaterWork anticipates beginning the activities described <br /> ` in this workplan within 14 days of approval by the SJLHD. <br /> The soil borings should be completed within one and a half <br /> days of mobilization to the site. This time estimate is <br /> dependent upon the exact number of borings required, the <br /> availability of a qualified drilling rig, the occurrence <br /> of good weather, and other factors including client needs <br /> and site specific conditions. <br /> 2. 6.3 The soil samples collected from the site will be handled <br /> in accordance with WaterWork ' s Soil Sampling Protocol <br /> ` (Appendix II ) . The drive samples collected from the <br /> former tank pit areas will be analyzed for BTX ( EPA 8020) , <br /> TPH as gasoline (DOHS method) and tetra ethyl lead (DOHS <br /> method) . Drive samples collected from soil borings near <br /> the former 5, 000 gallon gasoline tank pit fronting Aurora <br /> Street (Figure 2) will also be analyzed for chlorinated <br /> hydrocarbons (EPA 8010) since u/g paint thinner storage <br /> tanks are located next door, adjacent to the De Rollo <br /> property. Composite soil samples will also be collected <br /> from material formerly excavated from the fuel tank pits. <br /> ` The composite samples will be analyzed for BTX and TPH for <br /> the purpose of obtaining an aeration permit for the site. <br /> These sample results will be submitted to the San Joaquin <br /> Local Air Pollution Control District. Soil samples <br /> 5 <br />