Surface mining operations shall be conducted and the site maintained in accordance with the following requirements:

    A.    Slopes.

    1.    Finished slopes shall conform to the requirements of Section 6.80.240E.

    2.    Temporary slopes steeper than the finished slopes, in areas where finished slopes are to occur, shall be constructed and maintained in accordance with the recommendations, as approved by the planning director, of a soil engineer or a civil engineer registered in the state or an engineering geologist registered and certified in the state. Temporary slopes shall not be created or maintained in a manner that will interfere with the construction of finished slopes conforming to subsection (A)(1) of this section, and the soil engineer or engineering geologist shall make specific recommendations for the conversion of such temporary slopes to finished slopes.

    B.    Benches. Benches shall be provided where necessary to control drainage on slopes or to provide for access or public safety.

    C.    Setbacks.

    1.    Surface mining excavations shall not be conducted closer than:

    a.    Twenty-five (25) feet of the common property line of any parcel, except where the adjacent property is being mined in the same manner with respect to such line;

    b.    Fifty (50) feet of the right-of-way or future width line of any street.

    2.    Mining excavations shall be set back from water courses, flood control channels, reservoirs and water conservation facilities a distance as may be determined by the planning commission on recommendation of Alameda County flood control and water conservation district or public works agency to be sufficient to protect existing or planned facilities.

    D.    Screening of Operations. Where the planning commission determines that mining operations may conflict with visual qualities that should be maintained for adjacent areas, such operations shall be screened by the operator by the construction of appropriate landforms and planting and maintenance of appropriate landscape materials.

    E.    Fencing. Fencing for surface mines shall be designed and installed in order to preserve the health, safety and welfare of the public, including pedestrians, motor vehicles on public and private ways, and all persons and uses on adjacent lands. In areas where surface mine operations are located within wildlife movement corridors, fences shall be designed to permit passage of wildlife with minimal hazard. Fences may be of any reasonable description that fit these criteria. The fence type proposed for the surface mine shall be submitted with the mining plan for review and approval by the planning commission. Gates, the same height and type as the approved fence, shall be installed at all points of vehicular or pedestrian ingress and egress, and shall be kept locked when not in regular use.

    F.    Use of Explosives. No explosives shall be used except as authorized by the surface mining permit. When authorized, the specific times of use shall be approved by the director of public works.

    G.    Drainage— Water Quality and Conservation.

    1.    Provision shall be made to protect mining operations from overflow from adjacent streams or from slope failures caused by infiltration and seepage from surface water bodies by the construction of levees or other devices to prevent flooding. No obstruction shall be placed in stream channels without obtaining a permit allowing such obstruction from the county flood control and water conservation district.

    2.    Grades in areas being mined shall be maintained so as to avoid accumulations of water that could serve as breeding areas for mosquitoes.

    3.    Excavations that may penetrate near or into usable water bearing strata shall not reduce the transmissivity or area through which water may flow unless approved equivalent transmissivity or area has been provided elsewhere, nor subject such groundwater basin or subbasin to pollution or contamination.

    4.    Nothing in this chapter shall be construed to prevent the use of mined lands for the conservation or storage of water, or for the control of flood or storm waters, by a public agency duly authorized to engage in such work, provided that any such use will not conflict with nor prevent reclamation required under an approved reclamation plan, and provided such use is approved by the county flood control and water conservation district and/or public works agency.

    5.    Any waters discharged from the site to adjacent lands, streams, or bodies of water or to any groundwater body shall meet all applicable water quality standards of the regional water quality control board and any other agency with authority over such discharges. Records of any water quality monitoring conducted in conjunction with the requirements of such agency or agencies shall be made available to the planning director and the director of public works on request. Discharges of water to designated on-site settling ponds or desilting basins shall not be deemed to be in violation of this chapter solely on the basis of sediment content.

    H.    Erosion, Sedimentation and Pollutant Discharge.

    1.    During the period mining operations are being conducted, and prior to final reclamation of mined lands, the operator shall take measures to prevent erosion of adjacent lands from water discharged from the site of mining operations and the off-site discharge of sediment. Such measures may include the construction of properly designed retarding basins, settling ponds and other water treatment facilities, ditches, diking and revegetation of slopes. No discharge of sediment to off-site bodies of water shall be permitted that will result in higher concentrations of silt than existed in off-site waters prior to mining operations.

    2.    Stockpiles of overburden and minerals shall be managed to minimize water and wind erosion.

    3.    The removal of vegetation and overburden in advance of surface mining shall be kept to a minimum.

    I.    Control of Noise, Dust and Bright Lights. All activities of mining and processing minerals shall be conducted in a manner that noise, dust and bright lights do not exceed levels compatible with the uses of adjacent lands as determined by the planning commission in the issuance of the surface mining permit or as a result of its periodic review of any permit.

    J.    Salvage of Topsoil. Topsoil suitable for use in revegetation shall be stockpiled at the site of mining operations in an amount up to that necessary for future reclamation.

    K.    Hours of Operation. Hours during which mining operations and processing of minerals may be conducted shall be established by the planning commission in approving any permit. Such hours of operation shall be set to minimize conflict between the operations and other uses conducted in the immediate area.

    L.    Boundary Markers. The property approved for mining operations shall be prominently and permanently

marked. Where property lines cannot otherwise be determined, their location shall be established by survey by a registered civil engineer or licensed surveyor. The requirement for boundary markers may be waived by the planning commission where excavation will not occur within one thousand (1,000) feet of the property boundary.

    M.    Groundwater Use. All groundwater lost by pond evaporation and by export with the product in the mining operation and related activities shall be determined with reasonable accuracy and recorded annually. Said information shall be made available to the planning director and the director of public works if required. (Ord. 2003-61 (part); Ord. 99-60 (part): prior gen. code § 8-119.0)