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ID ~-689-3254 JUL 227 18 ~ 06 No .012 P .03 <br />retained on the 1` screen and may not have been larger than 1'h inches -then: was no 1'h inch <br />screen in use at the time.). <br />To demonstrate the effect of the oversize material in the soil liner fill on permeability, liner test <br />fills were constructed and in-situ permeability tests were performed. The perm:ability tests were <br />performed using a sealed single ring infiltrometer (`SSRI"). The SSRI, as you know, is <br />commonly used to measure in-situ permeability. Three test fills were consWcted using the same <br />equipment that will be used during full scale construction of the soil liner at tte leach pad. The <br />first test fill was constructed with a combination of material that had been processed through the <br />pug mill and borrowed from the unprocessed stockpile. The pug mill was the first attempt to <br />process the tailing which proved unsuccessful. The pug has since been demobilized from the <br />site and replaced with a screening plant. The second and third pads were constructed with <br />material that had been processed through the screening plant. The third pad was wnstructed <br />because the second pad had been consumed by attempts to successfully seat the SSRI. <br />The coefficients of permeability for the five tests are summarized in Table 1.:Four "acceptable` <br />permeability tests were performed on the three test fills. The results of perm~:ability Tests No. <br />1,2,3, and 5 give a range of permeability values that ar+e consistent (Table 1). However, the <br />coefticient of permeability ("k") calculated from data collected during Test Nu. 4 indicated that <br />"k' was two orders of magnitude higher than any other test result. The soils technician who <br />performed the test believes the SSRI may have been leaking around the base. (Four additional <br />SSRI tests were attempted on the three pads but were unsuccessful as the seal between the soil <br />and the bottom of the ring failed during the test.) <br />TABLE 1. Coefficients of Permeability <br />TEST NO. COEFFICIENT OF <br />PERMEABILITY <br />(k) cm/sec <br />1 1.9 x 10'' <br />2 7.8 x l0A <br />3 1.4 x 10'~ <br />4' 2.4 x 10s <br />5 1.1 z 10' <br />'Test data not used because SSRI appeared to be leaking around base. <br />The geometric mean of the four "acceptable" tests is 1.2 x 30-` cm/sec. T to subject permit <br />requires that the Ironclad soil liner must be constructed from materiels that acttleve a coefficient <br />of permeability of less than 1 x IOd cm/sec. Thus the tests demonstrate aln'ost two orders of <br />magnitude lower permeability than required by the approved specifications. The data wllection <br />