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CRYSTAL PIT <br />• As a rule, slopes will be maintained to not steeper than 2: 1, <br />except where the original slope was steeper than 2:1 Ca rare <br />occurrence). In those instances, the increase will depend upon the <br />mining configuration. However, in no instance will a slope be <br />produced which is steeper than 1.75:1 <br />Fine grading is probably more important in many respects than the <br />gross configuration. The gross configuration and slope gradients will <br />change little from the pre-existing condition, but if the fine grading <br />is not done properly, irrespective of the slope gradient, the <br />potential for erosion is rather high. Therefore, in the fine grading <br />process, the surface will be striated with small ridges from 1 to 3 <br />inches high in a direction which is nearly parallel to the contours. <br />In decomposed granite the production of this surface roughness is very <br />important to the control of erosion. These small ridges tend to act <br />as tiny catchment basins thereby reducing the velocity of runoff and <br />helping to control rill and gully erosion which can be a significant <br />problem in this type of material. <br />• Because the micro striations on the slopes cannot control all the <br />runoff, a larger and similar pattern will be produced in the bottom of <br />the valley drainage course. By producing small rises and catchments <br />which tend to blend into one another in the bottom of the valley, the <br />larger runoff events can be largely controlled. Of course, preventing <br />all erosion is only possible if the land is made perfectly flat, but <br />by introducing numerous and frequent areas where the water will slow <br />or even temporarily stop, much of the erosion damage can be prevented. <br />TDPSOIL REPLACEMENT: As discussed in Exhibit B, the soil resources <br />on the sites are limited at best. Therefore a prioritization process <br />must be used to utilize the soil where it is most effective. <br />The highest priority for soil placement will be the valley <br />bottom. This currently is the area where the soil is the deepest and <br />its effectiveness in controlling erosion is considerable. By having <br />the best and most soil in the valley bottom the most dense vegetation <br />• can be produced to aid in the control of runoff. <br />16 <br />