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k'9 KLEINFELDER 5.0 CONCLUSIONS & RECOMMENDATIONS Based on the results of Kleinfelder's limited soil and groundwater assessment, the following conclusions can be made 1 Total lead concentrations detected in soil were found to be below the TTLC and ten times ' the STLC regulated levels as expressed in California Code of Regulations 22CCR§66261 24 and/or Residential and U S EPA Region IX Preliminary Remediation Goals (PRGs), dated October 1, 2002 as summarized in Section 4 The total lead ' concentrations in soil in Kleinfelder's opinion are representative of naturally occurring background concentrations Please note, the client should contact the signatories of this report for additional consultation prior to any off site disposal Many disposal facilities ' have gate acceptance criteria, which must be satisfied prior to transportation and disposal Therefore, additional analysis may be required prior to full waste classification and disposal t2 Groundwater was encountered at depths ranging from 9%2 to 13 feet bgs in the Mission Site Area and at depths ranging from 13%2 to 15 feet bgs in the Pershing Site Area ' Groundwater flow direction based on assessments of adjacent sites from the Pershing Site Area are generally to the north/northeast Based on this information and groundwater flow directions noted in the Franklin Site Area (also noted to be north/northeast) the groundwater flow direction in the Mission Site Area is also assumed to be to the north/northeast The static groundwater depth in these two areas of the project is ' estimated at 10 to 12 feet bgs Please note local pumping and tidal fluctuations can affect the depth to groundwater ' 3 Some groundwater contaminants detected exceed either State and Federal MCLS or the City's acceptance criteria for discharge to the samtary sewer Significantly elevated concentrations of two of the four groundwater contaminants (benzene and MTBE) appear ' to be located primarily in proximity to GP-12 in the Mission Site Area Kleinfelder estimates groundwater approximately 150 linear feet along the proposed pipeline routing along Country Club Boulevard near the intersection of Mission Road As part of the ' same area, affected groundwater is estimated beneath approximately 100 linear feet of pipeline routing trending south on Mission Road from Country Club Boulevard These estimates are based on the nearest sampling points to GP-12 extrapolating between trace ' or non-detected concentrations of requested petroleum analytes in groundwater sampling points to the east, west and south of GP-12 One of the four contaminants exceeding the City's limit (DIPE) was detected in the Pershing Area at 1 5 µg/1 This concentration of D1PE detected appears to be a trace value, but may also be an indication of the edge of an existing groundwater contaminant plume (potentially from a former Shell Station, 1267 Country Club Boulevard) 28699 P.01 /5T03R793 Page 13 of 16 ' Copynght 2003,Klemfelder,Inc July 21,2003