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Carol Pahlke <br />December 23, 1980 <br />Page 9 <br />growth medium. Specifically, according to USDA <br />Handbook 60, Saline and Alkali Soils are classed <br />into four major categories based upon pH, E.C. and <br />SAR values as indicated below. <br /> E.C. SAR ~H <br />Normal Soils < 4 <13 S 8.4 <br />Saline Soils 1 4 < 13 < 8.4 <br />Sodic Soils <4 ~ 13 > 8.4 <br />Saline-Sodic Soils ~4 X13 y 8.4 <br />Topsoils (see Table 42a) to be used for revegetation <br />purposes in Pit pl, according to this standard, are <br />all classified as normal soils with respect to salt <br />content. Similarly, the spoil materials in Pit #1 <br />which were sampled for chemical analysis (Map 13a, <br />Geological Cross-Section G and Table 76, Texture <br />Analysis of Overburden Raw Data), demonstrate a <br />weighted pH of 7.7, a weighted E.C. of 1.4, and a <br />weighted SAR of 6.7. According to the standards <br />presented above, this material would be classified <br />as a normal agricultural soil with respect to salt <br />hazard. In fact, Tables 42a and 76 reveal no pH, <br />E.C. or SAR values for topsoil or spoil which are <br />outside the normal soils category defined above. <br />Potential problems of permeability and infiltra- <br />tion, likewise, are greatly exaggerated. While no <br />site-specific infiltration data for this site are <br />available, the SCS has published infiltration rates <br />for the soils found in Pit #1. According to the <br />existing soil survey.for this area, infiltration <br />rates for these soils range from 0.06 to 0.2 inches <br />per hour. According to Handbook 60 the exact limi- <br />tations on infiltration rates are unknown. Specifi- <br />cally, Handbook 60 indicates that: "It is difficult <br />to specify a boundary limit between satisfactory and <br />unsatisfactory infiltration rates at the low end of <br />the range, because so many factors are involved... <br />However, if the infiltration rate is less than 0.25 <br />cm/hr (0.1 in/hr) special water-management problems <br />are involved that may make irrigation enterprises <br />unprofitable for average operators." Clearly, the <br />requirements of intensively managed irrigated farm <br />lands are much higher than those for native plant <br />communities such as Kerr Coal has proposed for the <br />