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<br />1 <br /> <br /> <br /> <br /> <br /> <br />LJ <br /> <br /> <br /> <br />San Luis Projoct Phase 0 Raue 1 expansion - Pinal ConaWction Report <br />significant layering or material segregation did not occur during placement in acres I through 23 <br />(prior to the use of the screening plant). These tests, results of which are included in Appendrz <br />C.2,indicate a generallack of layering and relatively consistent material over the full depth placed. <br />Initial material Type 2 placement near the south abutment of the raise, Acre 1, proved difficult on <br />the steep slopes and required pushing numerous loads of material up the slope. This resulted in <br />poor blending and some layering as evidenced by the test results. This area was investigated and <br />found to be beneath the south abutment of the embankment raise and not subjlect to the tailings <br />dewatering process. <br />Field permeability tests in the Type 2 material in azeas of high equipment traffic were requested by <br />the Engineer to demonstrate the affect of excessive trafficking to the Contractor. These tests <br />indicate that azeas receiving heavy equipment traffic exhibit permeabilities which are approximately <br />2x lower than those areas receiving minimal traffic. Areas which have received minimal traffic have <br />exhibited field permeability values which range from 1.7 to 3.6 z 10~ cm/sec and averaged 2.6 x <br />10~ cm/sec (7 tests). laboratory permeability testing of material Type 2 prepared at the field <br />density was conducted. Results of these laboratory tests, conducted in accordance with ASTM <br />procedures, indicate permeabilities ranging from 1.5 x 1173 to 2.5 z 1t7' cm/sec, averaging 7 x 1t75 <br />cm/sec (10 tests) and included samples prepared at densities in excess of those observed in the field. <br />These permeability test resulu are contained in Appendix C.2. <br />' The difference in field to laboratory permeability testing is interpreted to be mainly due to the <br />equipment used for the insitu tests. Ths equipment is the BAT insitu permeability apparatus <br />' manufactured by BAT Envitech AB of Danderyd, Sweden, which is ideally suited to measurement <br />of the lower permeabilities of the soil liner at the site. At higher permeabilities some error exists <br />for this type of equipment due to inwmplete saturation of the material surrounding the test probe. <br />' A higher degree of confidence is therefore given to the laboratory permeability values for the liner <br />cover material. Comparison of the BAT field permeability test results with laboratory permeability <br />' values for the lower permeability clay liner layer indicate excellent agreement for this material as <br />discussed in the following section. <br />' Conformance sampling of the drainage blanket was conducted at a frequency of 1 sample per every <br />half acre in areas where the drainage blanket material was placed prior to the Contractor's use of <br />' the screening plant (Acres 1 through 23). Figure 1 depicts the drainage blanket conformance sample <br />locations. In areas where out of specification material was located or suspected, the sampling <br />ar ra r~r o. __ <br /> <br />