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The actual maximum acceptable salt level, measured by Electrical Conductivity, will depend on <br />the plant species proposed in the revegetation plan and the potential for upward salt movement. <br />As pointed out in the report in Attachment 2.05.4(2)(d) -1, Dave Dearstyne of the NRCS said <br />that a level of 6.0 in the subsoil would not be detrimental to grasses or alfalfa. A study done by <br />Curtis Swift, PhD, of Colorado State University (Attachment 2.05.4(2)(d) -2), titled Salt <br />Tolerance of Various Temperate Zone Ornamental Plants, shows that alfalfa handles a soil <br />conductivity of 4 -8 mmhos /cm. The specific species cited is Medicago Sativa, which is exactly <br />the same as that prescribed in the revegetation plan for irrigated cropland. Also, this reference <br />does not differentiate between topsoil and subsoil. Based on this data, and NRCS <br />recommendations, the limits for Electrical Conductivity are shown in Table 2.05.4(2)(d) -1 and 2, <br />for the various topsoil and subsoil types. The averages will be reported for each landowner in <br />the Soil Sampling Report. <br />Specific level depends upon clay mineralogy, soil texture, and saturation percentage according <br />to Dollhopf et al., 1983. <br />The specific percentage of clay or sand allowed will depend upon clay mineralogy, organic <br />matter content, consistence, soil lift, spoil characteristics, and size of sand fraction. <br />These values may vary depending upon the plant species proposed for revegetation in specific <br />locations (e.g., a soil with a high coarse fragment content throughout its profile may be <br />completely salvaged if used for rangeland versus cropland postmine land use). Prime farmland <br />Lift A Topsoil will not have >10% cobbles and boulders (3 inches mean diameter and greater) <br />and 15% coarse fraction (caught in a 2 millimeter sieve) by volume. The cobbles and boulders <br />% is estimated visually (by volume) using standard charts while looking at the replaced soil <br />profile or a sample of the material in the profile <br />The prime farmland Lift B Topsoil criteria and single lift criteria were developed in conjunction <br />with Dave Dearstyne of the NRCS. <br />Revised PR 06 June 10 2.05.4(2)(d) -9 <br />