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The mine waste material shall be put in place in lifts that optimally should be <br /> between 12-18 inches and in no case shall exceed 24 inches. The density of <br /> each lift should meet state regulations, which require that waste material be <br /> compacted to at leask 90% of the maximum dry density. <br /> A Proctor Test was run on soil samples from the existing waste pile to <br /> determine the maximum dry density and the optimum moisture content of that <br /> material. The tests conformed to the required AASHTO T99-74 standard <br /> procedure. The maximum dry density was 91.0 pcf and the optimum moisture <br /> content was12%. <br /> Ongoing Density Measurements: <br /> As construction of the pile progresses, periodic density measurements of the <br /> compacted fill material shall be pertormed. The following guidelines should be <br /> used. <br /> 1. The density of all waste material placed on the pile shall be at least 90% of <br /> the maximum dry density. <br /> 2. A Standard Proctor Test (AAS HTO T99-74) shall be pertormetl near the <br /> beginning of construction to establish baseline parameters. Subsequent test <br /> can be pertormed using a nuclear density gage. <br /> 3. A random test shall be pertormetl during each of the first five years of <br /> construction and at least every other year after that. <br /> 4. If at any point during the construction of the waste pile, the consistency of the <br /> waste material changes, another Standard Proctor Test shall be pertormed to <br /> verify the validity of the current baseline parameters. <br /> 5. If the results of a rantlom density test fail Ito meet the required 90% <br /> compaction one or more follow up tests shall be pertortned until the site <br /> engineer is confident that compaction standartls are being met. <br /> 6. The site engineer shall determine the number of measurements and location <br /> of tests. Both of these will vary as the waste pile increases in size. <br /> Topsoil and Fill Cover Material: <br /> Final reclamation of the waste pile requires that there be 3.5 feet of cover and <br /> 6 inches of topsoil on top of the waste pile. The fill material may consist of <br /> naturally occurring soil and rock removed from the site and stockpiled in <br /> preparation of placement of waste fill. All vegetative material should be removed <br /> prior to stockpiling the cover material. Material appropriate for topsoil should be <br /> kept in a separate pile. Cover material stockpiles should be located near the five, <br /> tan and fifteen year estimated elevations of the waste pile (or at other logical <br /> intervals which will reduce the transport cost during fill placement). <br /> The unit weight and composition (percent topsoil, rock, other soil etc.) of <br /> cover material should be periodically estimated during the clearing process. This <br /> January 1998 <br />