SU0004149 - Laserfiche WebLink

Home Browse Search

V f in the preceding three (3) years) when site specific geologic and engineering analysis demonstrate through a slope stability analysis that the proposed saturated slopes will have ' a minimum slope stability factor as required in Section 9- 1415.2(k)(4). The final fill slopes proposed for the project would have a gradient of one and one half(1.5) horizontal to one (1) vertical. Although steeper than the general requirement of this standard; the slope stability analysis prepared for the project indicates that the factors of safety for the slopes meet the requirements of Section 9-1415.3(k)(4). The proposed project does not include excavation of mining pits to below the expected groundwater level at the project site. Sec. 9-1415.3(k)(7) Fill Slopes. Fill slopes shall be constructed consistent with recommendation from a qualified civil/geotechnical engineer based on site-specific geologic conditions. The proposed project slopes were designed by a registered civil engineer. In addition, the i slope stability analysis was performed by a registered civil engineer and registered �• geotechnical engineer. These professionals have specific experience in the design, construction, and monitoring of constructed slopes. The project, if constructed consistent with the proposed design (as modified by any condition of approval for the project), would appear to be in compliance with this standard. Potential impacts associated with unstable -- slopes are addressed in Mitigation Measures 4.2-2a, 4.2-2b, and 4.2-2c and potential erosion of slopes is addressed in-Mitigation Measures 4.2-3a and 4.2-3b. Sec. 9-1415.3(n) Ponding. All water utilized in the plant operation shall be disposed of behind a closed dike unless an alternative method is approved by the Review Authority. The reclamation plan proposes to discharge all plant process to a settling pond that is excavated below existing grade. During the Phase 1 mining period, the processing water would be stored in a pond excavated within the Phase IV mining area in the northwest corner of the project site and adjacent to the processing plant site. Following excavation of other mining areas, the processing water would be directed into the completed mining areas. The design capacity of the preliminary processing water pond has not been defined in the reclamation plan. The pond is shown on design drawings in the plan. The area of the pond (shown as including the cells) is approximately 7 acres. The depth and slopes of the pond are not specified. The excavated pond does not meet general requirement of a "closed dike." The potential impacts related to the design and operation of the pond are addressed by Mitigation Measures 4.2-4a and 4.2-7a. Sec. 9-1415.3(q) Annual Inspection Reports. The applicant shall pay a fee to the County of San Joaquin to cover the cost of annual inspections of the excavation to ensure compliance with the conditions of the permit and reclamation plan. The County may use professional services.... Draft Environmental Impact Report 8 ER-96-3