ARCHIVED REPORTS_1993_1 - Laserfiche WebLink

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1 The proposed new fill slopes are flatter than 2:1. Most of the existing cut and fill slopes in the reclaimed quarry are also flatter than 2:1. The exception is in the northwest corner of the former pit, where slopes as steep as about 1.5:1 are present. The current site development plan indicates that wood storage and composting (both currently proposed and future) is planned in the area where slopes steeper than 2:1 occur. Mitigation 4.4-2 Proper construction practices, according to the geotechnical engineer's recommendations (RGH, 1993), shall be followed for all new cuts and fills. It must be demonstrated that any reclaimed fills in areas near the proposed facilities were constructed according to RGH recommendations, or at least demonstrated that soils properties of these fills are in accordance with those assumed during the slope stability analyses. In areas where slopes are steeper than 2:1, or where old fill soils properties are questionable, mitigation shall be performed. Mitigation options include: • Regrade slopes to 2:1 or flatter; • Set back all improvements at least 30 feet from the top and bottom of the slopes; and/or • Erect landslide debris barriers. The impact after mitigation is considered to be less -than -significant. Impact 4.4-3 Existing surface soils are Inadequate to support foundations for the proposed project facilities. Weak, porous surface soils were described in the geotechnical report (RGH, 1993). These soils are considered inadequate to support the loads of fills, foundations, slabs and pavement when their moisture content approaches saturation. Mitigation 4.4-3 Construction of fills, foundations, slabs and roadways shall be in accordance with RGH (1993) recommendations. The impact after mitigation is considered to be less -than -significant. Im .� 4.4-4 Construction of the proposed project facilities would restrict the recovery of valuable mineral resources. The project site has previously been mined of its valuable gravel resources. No gravel resources remain. The proposed TMRTF will have no impact on the gravel operations which occur to the west and north of the project area. Mitigation 4.4-4 No mitigation is required or recommended. ER -93-1 4 IK. -?Z (9-27-93)