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c- Lift thicknesses should not be greater than 12 inches followed by compaction <br /> using surface equipment. Compaction testing will then follow and this will show <br /> if a greater lift thickness is possible. Frequency of testing is discussed in Item 5. <br /> d- No compaction of tailings and waste rock can take place if the air temperature is <br /> below 3o degrees F. Tailings from the mill that are produced under these <br /> conditions are to be handled as described in Section 6.Proper compaction cannot <br /> take place in frozen conditions and the material must be temporarily stockpiled <br /> until conditions allow proper compaction. <br /> 5. Measuring and Documenting Proper Compaction of Tailings and <br /> Waste Rock <br /> Since compaction testing will occur on an ongoing basis, it is required that a nuclear <br /> density Gauge be kept on site and utilized by a designated qualified person at the mine. <br /> The machine selected for this process is a Troxler 344o Gauge which has been widely <br /> accepted by the civil engineering community as an excellent on site device that can <br /> accurately record compaction quickly. The tailings and waste rock mixture must attain a <br /> compaction of 94% maximum dry density according to ASTM Standard D698. <br /> Rules: <br /> a- When conditions allow good compaction, (more than 3o degrees F), once a 12 <br /> inch thick lift is compacted over an area of approximately 3000 square feet, a <br /> nuclear Gauge compaction test is required. The Operation Manual for the Troxler <br /> Gauge is included in Appendix B. This Gauge will be calibrated on site to report <br /> the % dry density of the material, which will then be compared to the 94% <br /> required for good compaction. This Gauge has radioactive material(cesium and <br /> americium)which require a special license for the purchase and operation of the <br /> instrument. The Gauge will also report the % moisture of the test material. The <br /> 2 <br />