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' Petrig Seed Company Monitoring Well Installation ' Page 3 lis n ted o the Chain of Custody but was not analyzed because the sample did not contain contaminants All sampling equipment including the pump, bailer, and cables, used by sampling t personnel, was disassembled, and steam-cleaned prior to commencement of sampling De- ionized or organic-free water was then introduced into the pump or bailer as a final stage of cleaning This water was then pumped or gently poured into sample vials to be used as pump or bailer blank This blank was not tested because the corresponding sample did not contain contaminants ' Immediately pnor to sampling, water levels and well depth measurements were taken in all wells at the site Each well was evacuated using a stainless steel bladder pump, which does not introduce air into the water column, or a Teflon bailer The pH, temperature, ' and electrical conductivity of the water was monitored as the well was evacuated These parameters were noted on a field log Instruments calibrated to known standards were ' used to monitor these parameters At Ieast five well volumes were evacuated from each well, and more, if necessary, until the above parameters were stabilized The sample was carefully poured from a Teflon bailer into clean glass vials with Teflon- lined screw caps provided by the laboratory Care was taken to ensure that no air space existed in the vials by inverting to check for bubbles and re-sampling if necessary The ' sample was analyzed or extracted within 14 days according to its EPA method The water sample collected for analysis was analyzed by EPA method 602 for BTEX compounds, and method 5030/LUFT for gasoline range hydrocarbons Analysis was conducted by Geo-Monitor Laboratories, a California State certified laboratory 5.0 GEOLOGY/HYDROLOGY OF SITE The subsurface geology of the Petng Seed site is characterized by an upper unit composed of silty clay clayey silt This unit extends from the surface down to a depth of approximately thirteen feet A thin aquifer, composed of clayey sand extended from thirteen to eighteen feet Below the aquifer, the boring again penetrated into a silty and clayey unit down to the bottom of the hole at twenty five feet Water was first encountered in the boring at fifteen feet, rising to a depth of fourteen feet after the well was completed 6.0 CONCLUSIONS AND RECOMMENDATIONS No soil or ground water contamination was encountered in the monitoring well, despite ! the proximity to soil boring B-3, which had soil contamination near the ground water