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ASSOCIATE S INC Effluent samples were collected in the VOA vials, liter amber bottles without preservative and 500 milliliter plastic bottles without preservative The samples were analyzed for TPHg, BTEX, MTBE, volatile and semi-volatile compounds (VOC and SVOC), metals cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni) and zinc (Zn) in accordance with EPA Method 200 Modified, and pH Dissolved hydrocarbon concentrations detected from groundwater samples collected at the influent end of the treatment system generally declined over the quarter The concentration of benzene detected in the influent treatment samples was reduced by an average of 70% during the remediation period ' Groundwater Treatment ' Between April 15 and September 19, 2003, the groundwater extraction and treatment system Semis processed approximately 302,703 gallons of water The total volume of groundwater treated as of September 30, 2003 is approximately 2,459,704 gallons, and estimated that approximately T ? ' 5,700 gallons of water was discharged per day during this time Cumulative totals of 5 69 t� )Jc- pounds (lbs) of benzene and 140 lbs of TPHg are estimated to have been extracted since groundwater treatment began on April 2, 2002 A summary of historical analytical results for soil samples is presented in Table 1, historical analytical results for groundwater are presented in Tables 2 and 3 4.0 EXISTING CONDITIONS ' 4.1 Soil Conditions ' 41 1 Site Geology Geologic materials encountered beneath the site during previous drilling activities consisted of ' clays and silty clays (CL), clayey and sandy silts (ML), elastic silts (MH), silty sands and silt/sand mixtures (SM), fine to medium-grained poorly-graded sands (SP), and fine to medium- grained well-graded sands (SW) ' Soil boring logs indicate that there is a layer of fine-grained material extending from the surface to depths of 6 to over 35 feet that extends over most of the site area This layer is composed of lean clay, silty clay, elastic silt, clayey silt, and sandy silt This layer is stratigraphically underlain by a layer of sandy material beneath most of the site area The sand layer is composed of silty fine sands, well-graded fine to coarse sands, and poor-graded fine to coarse sands with ' silt The sand layer ranges in thickness from 4 feet to over 31 feet extending to ground surface at some locations and is underlain by clays and silts at some locations is w 1271411,,port\d,,u,doc 11