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26 September 2002 <br /> AGE-NC Project 02-0946 <br /> Page 3 of 5 <br /> SOIL EXCAVATION <br /> Debris and hydrocarbon-impacted soil will be excavated to a depth of approximately 15 feet bsg <br /> using a backhoe or excavator. The lateral extent will be determined by the extent of debris and <br /> petroleum hydrocarbon-impacted soil encountered during the excavation process; field and <br /> laboratory data to date suggest that the lateral extent of hydrocarbon-impacted soil appeared to be <br /> limited to the east by boring B-4,to the north by boring PB-3,the west by boring B-3 and trench T-3 <br /> and to the south by boring B-1 (see Figure 2). <br /> During excavation activities, soil will be screened for organic vapors (OVs)using a organic vapor <br /> meter(OVM).Excavated soil that appears visibly stained or has a petroleum hydrocarbon odor will <br /> be considered impacted. <br /> SOIL SAMPLE COLLECTION AND ANALYSIS <br /> Following State of California Regional Water Quality Board,Tri-Regional Board recommendations, <br /> soil samples will be collected from the base and each side wall of the excavation at a minimum <br /> interval of every 20 linear feet. Soil samples will be collected from the base of the excavation at a <br /> minimum of one sample for every 400 square feet of excavation area.Field procedures for collection <br /> of soil samples are presented below. <br /> Soil samples will also be collected from the stockpiled soil from the excavation. For soil disposal <br /> characterization, a 4:1 composite soil sample will be collected from every 100 cubic yards of soil <br /> excavated. <br /> Each soil sample will be analyzed by a DHS-certified laboratory for the following constituents: <br /> • Total petroleum hydrocarbons quantified as diesel and/or motor oil (TPH-d and TPH-mo) <br /> in accordance with EPA Method 8015 Modified and <br /> • Benzene, toluene, ethyl benzene and total xylene (BTEX) and methyl tert-butyl ether <br /> (MTBE) in accordance with EPA methods 8021. <br /> The laboratory report for soil analyses,testing methods,laboratory quality assurance/quality control <br /> (QA/QC) reports, and sample chain of custody documentation will be presented in a report with <br /> findings and recommendations. <br /> Advanced GeoEnvironmental,Inc. <br />