1988-04-29_PERMIT FILE - C1981008A (54)

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Additional ahead-of-mining soil sampling by or under the supervision of a soil scientist will be completed for Map Unit D70B to acquire premine fertility data and to define individual areas where one- versus two-lift topsoil salvage techniques will be utilized. Sampling sites will be located around existing data points by utilizing a 60 degree slant grid system with 150-foot centers. The upper five feet of soil will be sampled with a hydraulic soil sampler, a bucket auger, or other suitable equipment and described by horizon. The upper 1.5 feet of soil from each pedon will be utilized to determine the premine fertility status for the three components of Map Unit D70B. The vertical sampling increment and compositing method will typically vary by horizon thickness, field descriptions, and anticipated first-lift salvage depth for each sample site. Soil color, rooting characteristics, structure, consistence, and effervescence will be the primary field properties utilized to evaluate whether one- or two-lift topsoil salvage should be utilized. The soil scientist will also visually inspect and describe the surface soil and vegetation characteristics between grid points to distinguish any obvious differences between sample sites. A representative number of soil samples will be analyzed for the following parameters to confirm or revise the initial one- or two-lift field predictions: pH, salinity, organic matter content, and calcium carbonate percentage. The following • parameters shall also be utilized to determine the premine fertility status: nitrogen, phosphorous, and potassium. Replacement depths of topsoil and subsoil will be documented and recorded for each reclamation block. Topsoil depth measurements will be recorded on a 300-foot sample grid. This soil replacement depth information will be utilized in the annual topsoil balance and for bond release purposes. Topsoil replacement areas are defined on Exhibit 21-3, Postmine Soil Replacement Depths - Nucla East. A detailed annual Topsoil Balance/Spoil Quality Report will be completed and submitted to CMLRD by April 15 of each year to reconfirm topsoil volumes and, if necessary, readjust topsoil salvage depths through the life-of-mine operation. Replaced topsoil will be sampled, tested, and evaluated for fertility to ensure optimum germination, seedling emergence, and root growth conditions. Replaced topsoil shall meet the suitability criteria listed in Tab 9, Table 9-5-2. A 300-foot sampling grid will be utilized whereby every four or five samples per reclamation block are composited. First lift and second lift topsoil will be sampled separately wherever this method is utilized. At a minimum, the samples will be analyzed for pH, salinity, calcium carbonate, particle size, organic matter, nitrate, and ammonium nitrogen, and phosphorous utilizing standard 21-32 Revised 08/19/88