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May 6, 1996 <br /> , Page e 3 <br /> � <br /> • <br /> FINDINGS <br /> Subsurface Conditions <br /> Soils encountered dunng drilling consisted predominantly of silt Sand and silty sands <br /> interbeds in the silt are common, ranging in thickness from less than one foot to eight <br /> feet Encountered stratigraphically beneath the silt unit was a poorly sorted sand, this <br /> unit was noted consistently at approximately 30 feet below ground surface (bgs) <br /> Groundwater occurred in the sand 1n the boring for MW-1, alight brow-rush clay was <br /> encountered from approximately 36-1/2 to the total depth explored of 40 feet bgs <br /> Groundwater was encountered and stabilized at a depth of approximately 30 to <br /> 32-1/2 feet bgs during dulling Groundwater elevation data, calculated from data <br /> collected on February 12, 1996, indicate that groundwater flow beneath the site is <br /> towards the southwest at an approximate gradient of 0 001 foot per foot A ground- <br /> water ridge is present at the site The southwesterly groundwater flow direction <br /> observed in the southern portion of the site is consistent with groundwater flow at <br /> nearby sites Groundwater elevation, flow direction, and gradient data are shown on <br /> Figure 2 <br /> Soil Analytical Results <br /> TPPH-g, BTEX compounds, TEPH-d, and MTBE were not detected in any soil samples <br /> collected from the bonngs and wells with three exceptions TEPH-d was detected at <br /> concentrations of 1 0 and 1 3 parts per nuliion (ppm) at 11 and 16 feet bgs for the <br /> borings for B-2 and MW-4, respectively This unidentified hydrocarbon, although within <br /> the diesel range, could not be positively identified by the laboratory as petroleum <br /> hydrocarbons and may be a result of other organic matter occumng in the soils The <br /> detection limit for TEPH-d is 10 ppm MTBE was detected at a concentration of <br /> 0 I8 (ppm) at 11 feet bgs for Boring B-1 Soil analytical results are presented in <br /> Table 1 The laboratory's certified analytical report is presented in Attachment B <br /> Groundwater Analytical Results <br /> Results of groundwater analyses indicate that groundwater samples collected from <br /> Wells MW-I through MW-4 were non-detected for all analytical parameters <br /> Groundwater elevation and analytical data are presented in Table 2 The laboratory's <br /> certified analytical report is presented in Attachment B <br /> 320 i 591 AaEPORT <br />