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Results of the statistical calculations are provided in Appendix E. <br /> The 90%UCL was calculated for total lead data and are presented below and in Appendix D. <br /> Mean Concentration 90%UCL <br /> Sample Population (mg/kg) (mglkg) <br /> All Samples 36.0 44.8 <br /> Pearson (product moment) correlation coefficients (Pearson values)were obtained from <br /> regression analysis for regression lines forced through the origin (Appendix E). Correlation <br /> coefficients for total/WET and total/DIWET lead data for samples were 0.7 and 0.9, respectively. <br /> The correlation coefficient for the WET data is outside the desired correlation value of 0.8,per <br /> Caltrans contract 43A0012. This is likely caused by the variability of the soil conditions <br /> affecting lead solubility. <br /> An expected soluble lead concentration was obtained from regression analysis (model forced <br /> through the origin) developed from the total/WET and total/DIWET soluble lead data. The <br /> coefficient for the dependant variable (slope of regression lines) used in the regression analysis <br /> and the total lead versus soluble lead concentration plot is presented in Appendix E. The soluble <br /> lead concentration for WET data corresponding to the total lead 90%UCL is 0.899 mg/l. The <br /> soluble lead concentration for DIWET data corresponding to the total lead 90%UCL is <br /> 0.128 mg/l. <br /> To compare with predicted soluble lead concentrations, 90%UCL concentrations for the WET <br /> and DIWET data set were calculated. The 90%UCL value for the WET and DIWET data are <br /> 5.11 and 0.463 mg/l, respectively(Appendix E). These calculations were conducted on data that <br /> are skewed to higher values by the sample selection criteria and therefore result in higher <br /> concentration values than the predicted soluble lead concentrations. <br /> 4.1.3 Summary <br /> Soil in specific locations may be considered a California-hazardous waste based on the soluble <br /> concentrations of lead reported in certain soil samples. Management of the soil within the DTSC <br /> variance may be possible. However, soil containing greater than 350 mg/kg total lead would be <br /> excluded from this option. <br /> SacDP-N:IrancjpllProjectsl8218212641Reportll2O Austin report.doc 4-4 <br /> 5/21/01 <br />