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• feet for irrigated pasture, and 1.0 feet for dry pasture over regraded spoil at Nucla East <br /> will be beneficial to establishing a good seedbed and rooting medium. This conclusion is <br /> supported by the above referenced literature, premine soil survey (Tab 9), and vegetation <br /> inventories (Tab 10), as well as on-site data from Nucla Mine. The anticipated loamy <br /> textured topsoil will likely have favorable infiltration and water holding <br /> characteristics. Also, the spoil medium immediately below the topsoil will typically have <br /> desirable chemical and physical characteristics for plant growth including a loamy <br /> texture, low sodicity, moderately low salinity, and moderately low saturation percentage <br /> for acceptable water holding characteristics, and no minor element toxicity problems (see <br /> Tab 6, Attachment 6-1, Geology and Overburden Assessment). <br /> Maintenance and Testing Procedures. Prior to distribution of topsoil, all graded mined <br /> areas (on which topsoil is to be applied) will be sampled to confirm spoil suitability <br /> (see Overburden/Spoil Handling Plan for more details). The density and physical <br /> characteristics of the replaced topsoil and upper spoil will be observed. Past experience <br /> has shown that ripping and chisel plowing will correct any excessive compaction problems. <br /> • A topsoil resource quality control program will be implemented to insure that topsoil is <br /> salvaged and replaced as recommended. The optimum soil salvage depth for each soil map <br /> unit will routinely be evaluated on-site by an individual qualified to evaluate field <br /> observation tests including soil color, rooting depth, coarse fragment content, <br /> horizonation, and effervescence. Periodic field inspections will also be made by a soil <br /> scientist. Field staking will be utilized, when required, to assist in delineating soil <br /> map unit boundaries. Soil samples will be collected to correlate field procedures with <br /> laboratory data. Topsoil depths will be recorded on a 1" = 400' aerial photograph for <br /> each soil map unit while the salvage operation is occurring to document the actual mean <br /> thickness of topsoil recovered. A small, undisturbed topsoil island or pedestal will be <br /> left at each sample point. This will enable Division inspectors to observe that topsoil <br /> has indeed been salvaged to the extent possible and then allow overburden stripping and <br /> mining of that area after measurements have been taken. Color photographs of the soil <br /> profile and landscape at each sample point will also be taken to verify topsoil salvage <br /> depths. The minimum sampling intensity shall be one hole per map unit or five acres, <br /> whichever is less. This topsoil salvage depth information will be kept on file at the <br /> mine office and will be submitted with the annual Topsoil Balance/Spoil Quality Report. <br /> Topsoil recovery depths will be adjusted if warranted by the aforementioned quality <br /> control program. <br /> 21-31 Revised 08/19/88 <br />