Laserfiche WebLink
' Ms Mary Meays Page 2 <br /> April 14, 1991 g <br /> handling sampling equipment and sample bottles Bailer cord was <br /> replaced before sampling at each well location <br /> Lab= Anaj3MM <br /> Water samples collected ected at the site were transfered to Superior Analytical, <br /> Inc , Martinez, California under chain of custody This laboratory is <br /> ' different from the one which has been previously utilized for quarterly <br /> ground water monitoring activities At the laboratory, the samples were <br /> analyzed according to the following test procedures <br /> • Total Petroleum Hydrocarbons as Gasoline -- EPA Method 8015-M <br />' • Benzene, Toluene, Ethylbenzenes and Xylenes (BTE&X) -- EPA Method <br /> 8020, <br />' * Total Lead -- EPA Method 6010, <br /> • Organic Lead -- DHS Specified Method, and <br /> • Ethylenedibromide (EDB) -- DHS Specified Method <br /> The findings from the laboratory testing are summarized in Table 2 <br /> Laboratory reports and chain of custody are attached QA/QC procedures <br /> consisted of collecting a duplicate and field blank, and including a travel <br /> blank Analyses of the duplicate and sample blanks indicated that all <br />' constituents analyzed for were below detection limits At the laboratory, <br /> standard internal QA/QC procedures were followed <br />� indinga <br /> Plotting and contouring ground water level contours (Figure 1) indicate a <br /> trough centered at MW-5 and oriented towards the southeast Previously, <br /> flow directions were oriented in directions ranging between southwest and <br />' southeast The variability in flow direction is probably due to the influence <br /> of tidally induced water level changes in the adjacent Stockton deep water <br /> channel Tidal data for the Stockton area is provided in Table 3 <br />' The effect of tidal fluctuations on ground water level data was likely <br /> accentuated by the fact that ground water elevations were not obtained at <br />' the same time of day Instead, the time of measurement of ground water <br /> elevations differed by over seven hours For example, ground water <br /> elevation in MW-1 was measured at 9 30 AM, while MW-5 was measured at <br /> 2.54 PM During future quarterly monitoring activities, every effort will be <br /> made to minimize the time difference in obtaining groundwater elevation <br /> data <br />