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Jim Tjosvold Page 5 July 3 , 1987 addition, aquifer testing requires that high-quality semi-undisturbed samples of confining beds be collected for determining storage coefficients. 21. The State will not allow pumping of the E zone at this time. We believe that the potential of drawing contamination down into this clean zone is too great. We are already aware that the conductivity in this zone is much greater than in the overlying zones. Soils Assessment 22 . Background sampling will determine natural concentrations of metals in the area. The locations for sampling are adequate for having no influence from McCormick and Baxter. The amount of samples (60 samples) to be analyzed are excessive for determining background. There needs to be only 3 samples from each of the two zones at each location. All 60 samples may be collected and additional testing (metals hold time is 60 days) may be performed at a later time if data warrants such action. 23 . As stated above regarding water samples, all soil samples in all locations must be confirmed where positive results are obtained by GC. Therefore, second column or GC/MS confirmation is required for EPA methods 8040 and 8100. Therefore, analysis of only one sample by GC/MS for confirmation is not adequate. Confirmation of samples is not required if there are no positive results. 24 . All analyses by EPA method 8040 shall. include all chlorophenols and not be restricted to only pentachlorophenol. Analytes and detection limits must be specified. 25 . No information on hexavalent chromium has been provided to describe the deionized water extraction, method of analysis, or sample hold time and preservation. This information should be included in the workplan. 26. The State does not recognize any significance in comparing lead samples at I-5 or Washington Street to contamination on-site. Samples from on-site locations should not be used as background. If lead background samples are necessary, they can be analyzed from the samples taken from off-site locations. 27 . To determine if further characterization is needed at the off-site pole storage area, we request that soil results for two consecutive depths show no sign of contamination. Therefore, at a minimum, the surface sample and next depth sample must be analyzed.