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Attachment <br /> Review of May 6, 1985 <br /> "Geochemical Program Final Report" <br /> prepared by Roman Z. Pyrih & Associates <br /> 1. Replication of subsurface conditions <br /> The soil sample preparation, and testing methods used in the <br /> leaching and precipitation experiments fail to replicate <br /> subsurface conditions at the facility. <br /> o The soil samples used in the column test were <br /> created from air-dried composites of boring <br /> samples. Apparently the samples were not <br /> consolidated prior to their placement in the <br /> columns. This assumption is borne out by <br /> calculating dry densities from the data presented <br /> in Table 7 ; the calculated densities are <br /> suspiciously low for the samples obtained from the <br /> greater depths. <br /> o The applied pressures used in the testing do not <br /> correspond to in-situ horizontal and vertical <br /> stresses at the points where samples were <br /> collected. <br /> o In-situ microstructure was destroyed by remolding <br /> the samples. No information is given on curing of <br /> the remolded samples. Remolding and curing create <br /> major changes in results from permeability and <br /> dispersion tests. <br /> o Even laboratory permeability tests performed with <br /> correctly consolidated samples which are <br /> representative of subsurface conditions typically <br /> err in estimating in-situ permeabilities by at <br /> least an order of magnitude. <br /> o Small diameter (1-inch) columns were used for the <br /> test. The combination of highly disturbed samples <br /> and side-wall effects from a small-diameter <br /> permeameter render the resulting data very <br /> unreliable. <br /> o The testing was performed on samples in a <br /> saturated, undrained condition. Actual conditions <br /> in the vadose zone, even under a regime of <br /> injection of treatment solution, are not likely to <br /> approach saturation throughout the soil mass. <br />