A.    General Requirements. All reclamation plans shall comply with the provisions of SMARA (§ 2772 and § 2773 as may be amended), state regulations (CCR § 3500-3505 as may be amended) and the requirements of this chapter. Reclamation plans approved after January 15, 1993, reclamation plans for proposed new mining operations, and any substantial amendments to previously approved reclamation plans, shall also comply with the requirements for reclamation performance standards (CCR § 3700-3713 as may be amended). Reclamation of mined lands shall be carried out in accordance with the requirements of this chapter, the approved reclamation plan and state policy. The operator shall guarantee all reclamation work accomplished for any period as may be determined necessary by the planning commission to assure the permanency of any or all physical reclamation features and standards.

    B.    Progressive and Interim Reclamation. Reclamation of mined lands shall take place as soon as practical following completion of mining operations at successive locations within the mining site as specified by the planning commission in the approval of the reclamation plan. Interim reclamation may also be required for mined lands that have been disturbed and that may be disturbed again in future operations. Reclamation may be done on an annual basis, in stages compatible with continuing operations, or on completion of all excavation, removal, or fill, as approved by the county. Each phase of reclamation shall be specifically described in the reclamation plan and shall include (a) the beginning and expected ending dates for each phase; (b) all reclamation activities required; (c) criteria for measuring completion of specific reclamation activities; and (d) estimated costs for completion of each phase of reclamation.

    C.    Disposal of Overburden and Mining Waste.

    1.    Permanent piles or dumps of overburden and waste rock placed on the land surface shall be made stable, shall not block natural drainage without provision for diversion, shall have an overall smooth or even profile and, where practical, shall be placed in the least visible location. Old equipment and similar inert mining wastes shall be removed or buried. Toxic materials shall be removed or protected to prevent leaching.

    2.    Overburden and mining waste placed below the existing or potential groundwater level shall not reduce the transmissivity or area through which water may flow unless approved equivalent transmissivity or area has been provided elsewhere.

    D.    Drainage, Erosion and Sediment Control.

    1.    Any temporary stream or watershed diversion shall be restored in final reclamation unless determined unnecessary by the planning commission based on recommendation of the county flood control and water conservation district and/or public works agency.

    2.    Regrading and revegetation shall be designed and carried out to minimize erosion, provide for drainage to natural outlets or interior basins designed for water storage, and to eliminate potholes and similar catchments that could serve as breeding areas for mosquitoes.

    3.    Silt basins which will store water during periods of surface runoff shall be equipped with sediment control and removal facilities and protected spillways designed to minimize erosion when such basins have outlet to lower ground.

    4.    Final grading and drainage shall be designed in a manner to prevent discharge of sediment above natural levels existent prior to mining operations.

    5.    Upon reclamation, no condition shall remain that will or could lead to the degradation of water quality below applicable standards of the regional water quality control board or any other agency with authority over water quality.

    E.    Final Slope Gradient. Final slopes shall be of such gradient as necessary to provide for slope stability, maintenance of required vegetation, public safety, and the control of drainage, as may be determined by engineering analysis of soils and geologic conditions and by taking into account probable future uses of the site. Final slopes shall not be steeper than two feet horizontal to one foot vertical (2:1) unless the applicant can demonstrate to the satisfaction of the planning commission that any such steeper slope will not:

    1.    Be incompatible with the alternate future uses approved for the site;

    2.    Be hazardous to persons that may utilize the site under the alternate future uses approved for the site; and

    3.    Reduce the effectiveness of revegetation and erosion control measures where such are necessary.

    In no event shall the steepness of slopes exceed the critical gradient as determined by an engineering analysis of the slope stability.

    F.    Backfilling and Grading. Backfilled and graded areas shall be compacted to avoid excessive settlement and to the degree necessary to accommodate anticipated future uses. If future use of the site contemplates structures for human occupancy, fill placement shall conform to the Uniform Building Code except that alternate methods of backfilling and grading may be utilized when incorporated in the approved reclamation plan. Material used in refilling shall be of a quality suitable to prevent contamination and pollution of groundwater.

    G.    Resoiling. Resoiling shall be accomplished in the following manner: coarse, hard material shall be graded and covered with a layer of finer material or weathered waste and a soil layer then placed on this prepared surface. Where quantities of available soils are inadequate to provide cover, native materials should be upgraded to the extent feasible for this purpose.

    H.    Revegetation. All permanently exposed lands that have been denuded by mining operations shall be revegetated unless any such revegetation is determined by the planning commission to be technically infeasible or not beneficial with respect to the intent of this chapter. Revegetation methods and plant materials utilized shall be appropriate for the topographical, soil and eliminate conditions present at the site. Native species shall be used wherever practical.

    I.    Ponds, lakes or bodies of water created as a feature of the reclamation plan shall be approved by the county flood control and water conservation district, the health care services agency and the mosquito abatement district.

    J.    Additional Requirements. The county may impose additional performance standards as developed either in review of individual projects, as warranted, or through the formulation and adoption of county-wide performance standards. (Ord. 2003-61 (part); Ord. 99-60 (part): prior gen. code § 8-119.3)