The following are standard conditions for surface mining operations, which shall apply to all surface mining operations unless specifically modified by the Planning Commission.
(A) Appearance. Surface mining shall be operated in a neat and orderly manner, free from junk, trash or unnecessary debris. Buildings shall be maintained in a sound condition, in good repair and appearance. Weeds shall be cut as frequently as necessary to eliminate fire hazards. Salvageable equipment stored in a non-operating condition shall be suitably screened or garaged.
(B) Setbacks.
(1) Cut slopes shall be a minimum of 25 feet distant from adjoining property lines, except where adjoining property is being mined, and a minimum of 40 feet from any right-of-way of any public street or official plan line or future width line of a public road. The Planning Commission may establish greater setbacks when it deems them to be appropriate, based on factors such as site conditions or proposed mining operations.
(2) When surface mining occurs in a canyon area which abuts an urban area, or the ridgeline is visible from the valley floor, the top of the uppermost cut area shall be as shown in an approved reclamation plan.
(C) Noise and vibration.
(1) Noise and ground vibration shall be reduced to a minimum. To achieve this, loading points shall not be located closer than 50 feet from any property line, unless otherwise permitted by the Planning Commission.
(2) Noise attenuation measures shall be installed where necessary to reduce noise levels in order to comply with noise standards of the county General Plan.
(3) Screening and rock crushing shall be noted in the permit application and subject to Planning Commission conditioning.
(D) Explosive use. Use of explosives in operations shall be noted in the permit application and subject to Planning Commission conditioning. When the Planning Commission finds that the use of explosives (blasting) is the only logical method of loosening natural material for the purpose of removal, the method shall be noted in the conditions of approval.
(E) Traffic safety.
(1) The site shall provide adequate space for the parking, queuing and loading of trucks, as well as packing of employee vehicles to minimize the traffic problem to residents on neighboring streets.
(2) Haul roads shall be designed where possible so as to stay away from property lines.
(3) The use permit shall specify the haul routes on public roads. Should any truck operating from a surface mining operation create a hazard to life or property, the Planning Director shall declare the surface mining operation a nuisance and set a revocation hearing before the Planning Commission.
(4) The use permit shall specify the number and location of access points, subject to approval by the Planning Commission. If required, acceleration and deceleration lanes which meet county standards shall be provided.
(5) The use permit shall specify an approved surface for the access road for a distance of not less than 100 feet from the pubic road right-of-way line into the area of operation in order to minimize the deposit of dirt and gravel from trucks onto the public roads. During hauling operations, the operator shall remove any spillage of materials on public roads promptly and completely.
(F) Dust control. Surface mining operations shall be conducted so as to reduce the occurrence of dust to a minimum in compliance with the regulations of the Monterey Bay Unified Air Pollution Control District currently in effect or subsequently adopted which are hereby incorporated by reference. Unless otherwise specified by the Planning Commission, operations shall be conducted in accordance with the following minimum standards.
(1) The operator shall maintain access roads in a reasonably dust-free condition by paving, oiling, watering or chemically treating the access roads from public thoroughfares to a point not less than 100 feet from the point at which haulage vehicles are being loaded.
(2) The operator shall maintain areas used for the movement of haulage vehicles and mobile equipment closer than 100 feet from the public road to the point at which haulage vehicles are being loaded by sprinkling the areas with oil or water or chemically treating such areas as frequently as necessary to reduce the stirring of dust to the minimum level possible.
(3) The operator shall conduct activities likely to raise dust, including but not limited to, dozing, digging, scraping and loading of excavated materials, in a manner which reduces dust to the minimum level possible. Sprinkling shall be done where necessary to comply with this standard.
(4) The operator shall sprinkle stockpiles and screen operations or any part of the facilities as necessary to reduce dust.
(G) Hours and days of operation.
(1) The use permit shall limit the hours of operation for the surface mining operation to daylight hours, excluding Sundays or holidays. However, the Planning Commission may alter this standard where conditions of density and proximity would warrant liberalization or restriction.
(2) In cases of public emergency, the Planning Director may temporarily waive restrictions regarding hours and days of operation. In cases of private emergency, the Planning Director may authorize reasonable and necessary repairs to the equipment and limited operations required to restore normal operations by issuing a temporary permit for periods up to and including 56 hours, but not to exceed one week total, allowing the temporary waiver of restrictions regarding hours and days of operation.
(H) Fencing and posting. The Planning Commission shall require for those portions of an excavation are where public safety requires fencing. The Planning Commission may require posting in other portions of the excavation area.
(1) Where excavation is authorized to proceed in stages, the operator may limit fencing to the area already excavated. The operator shall provide adequate fencing to exclude unauthorized dumping.
(2) The Planning Commission may require the enclosure of all or a portion of an excavation by an approved fence either along the property line or the periphery of the excavation where deemed necessary for public safety by the Planning Commission. The fence shall not be closer than ten feet to the top edge of any cut slope. All fences shall have suitable gates at access points, which shall be securely locked during hours and days of non-operation.
(3) Fencing shall be a four-strand barbed-wire unless otherwise provided by the Planning Commission.
(4) The operator shall post signs conspicuously along the periphery of the property in such a manner and at such intervals as will give reasonable notice to passers-by of the matter contained in such notice. The signs shall state by letters no less than four inches tall “WARNING: COMMERCIAL SURFACE MINING OPERATION CONDUCTED ON THESE LANDS” both in English and Spanish.
(I) Screening.
(1) Operators shall provide screening for surface mining operations to secure the use and enjoyment of nearby properties.
(2) Acceptable methods of screening shall include, but not be limited to, installation of berms, fences, plantings of suitable shrubs and trees, which shall be placed and maintained in order to minimize visibility of cut slopes, mining operations and equipment from public view.
(3) Operators may place and maintain screening along the streets and exterior property lines or the perimeter of the visible portions of the site being operated, so long as the screening satisfies the objectives of this division.
(J) Health and sanitation. The operator shall maintain any body of water created during operations within the mining operation in such a manner as to provide for mosquito control and to prevent the creation of health hazards or public nuisances.
(K) Protection of streams and water bearing aquifers.
(1) Operators shall conduct surface mining in a manner so as to keep adjacent streams, percolation ponds or water bearing strata free from undesirable obstruction, silting, contamination or pollution of any kind. The objective is to prevent discharges, which would result in higher concentrations of silt than existed in off-site water prior to mining operation. The regulations of the Regional Quality Control Board currently in effect or subsequently adopted are incorporated by reference.
(2) The operator will minimize the removal of vegetation and overburden in advance of surface mining.
(3) The operator shall manage stockpiles of overburden and minerals to minimize water and wind erosion. Stockpiling in the river channel is forbidden.
(4) The operator shall construct and manage erosion control facilities including, but not limited to detention basins, settling ponds (desilting and energy dissipaters), ditches, streambank stabilizers and dikes so as to control erosion.
(5) Where operations are in stream channels or are located in areas that are sufficiently proximate to stream channels so as to allow such operations to directly affect stream channels, all operations shall conform to the operation plan approved by the Planning Commission. The operation plan shall require the operator to do the following:
(a) Maintain the location of the approved channel;
(b) Avoid increasing the gradient of the stream;
(c) Finish side slope of the lawful channel no later than October of each year;
(d) Remove all debris and vegetation growth from the center channel by October 1 of each year;
(e) Mitigate erosion adjacent to the mining operation both upstream and downstream of the mining operation (e.g., by installing blocking walls, riprap and the like); and
(f) Maintain, wherever practicable, a filter strip of an appropriate width and consisting of undisturbed soil, with riparian vegetation, or its equivalent, between areas significantly disturbed by surface mining operations and any watercourse, lake, bay, estuary, marsh or other water body.
(6) The county may adopt from time to time plans to mitigate the effects of mining on the river. The operator shall comply with such plans.
(L) Permits. Applicants shall comply with applicable laws.
(M) Silt prevention. The Planning Commission may restrict mining operations in the natural or artificially enlarged channel of any river, creek, stream or natural or artificial drainage channel when the mining may result in the deposit of silt therein.
(N) Groundwater protection. The operator shall ensure that surface mining operations which may penetrate near or into usable water-bearing strata including, without limitation, wells, shall not reduce the transmissivity or area through which water may flow, unless the operator first provides approved equivalent transmissivity or area elsewhere, and shall not subject the groundwater basin or sub-basin to significant pollution or contamination.
(O) Staging. The operator may conduct reclamation in stages compatible with continuing operations, or on completion of all excavation, removal or fill as approved by the Planning Commission. The operator may reclaim the land for agricultural, residential, commercial, industrial, open space and recreational or any other appropriate use.
(P) Overburden. The salvage of existing topsoil is an important factor in revegetation and thus is a crucial part of the reclamation process. Topsoil is a valuable asset and the operator shall segregate it for future use in revegetation. The Planning Commission may require the operator to conduct soil survey to allow the Planning Commission to determine the appropriate use of top soil in post-mining rehabilitation and to determine whether the types of vegetation being proposed in the reclamation plan are appropriate.
(Q) Final slope gradient.
(1) When designing the proposed steepness and treatment of the mined lands’ final slopes, the operator consider the physical properties of the slope material, landscaping requirements and other factors. The maximum stable slope angle might range from 90 degrees in a sound limestone, igneous rock or similar hardrock to less than 20 degrees in highly expansive clay. In all cases, reclamation plans shall specify slope angles flatter than the critical gradient for the type of material involved.
(2) The operator shall eliminate dangerous contours caused by operations from the land surface of the excavated area and shall fill mine shaft openings or otherwise secure them in a manner so as to eliminate dangerous conditions.
(3) The operator shall ensure that the slopes of excavations made to a water-producing depth shall not be steeper than one and one-half feet horizontal to one foot vertical for areas from five feet above the water line to the bottom of the excavation below the water line, unless otherwise specifically permitted.
(4) The operator shall prepare an engineering analysis of slope stability whenever final slopes approach the critical gradient for the type of material involved. The analysis shall place special emphasis on slope stability and design when final slope gradient may affect public safety or adjacent property.
(5) Based upon the maximum stable slope angle of the material involved, the Planning Commission may, at the time of approval or modification of the reclamation plan, specify the slope of the reclaimed land surface, require grading or backfilling, and require the elimination of unnatural steps or benches. The Planning Commission shall take into account the environmental and/or technological feasibility of any such requirement or specification, but such considerations may be overridden when the Planning Commission determines that the public health, safety or welfare require.
(R) Erosion and drainage. The operator shall design grading and revegetation to prevent excessive erosion and to convey surface runoff to natural drainage courses or interior basins designed for water storage. The operator may create lakes, ponds, streams or other bodies of water within an excavation only when authorized by the approved reclamation plan approved. The operator shall treat final surfaces so as to prevent erosion unless otherwise specifically permitted by the Planning Commission.
(S) Resoiling.
(1) When the reclamation plan calls for resoiling, the operator shall level coarse hard mine waste and cover it with a layer of finer material or weathered waste and place a soil layer on this prepared surface. The operator shall remove toxic material. Operators of surface mines that did not salvage soil during their initial operations shall attempt, where feasible, to upgrade remaining native materials. The operator shall use soil conditioners, mulches or imported topsoil where revegetation is part of the reclamation plan and where such measures appear necessary to ensure successful revegetation. The operator shall not denude adjacent areas of soil for purposes of reclaiming areas disturbed by surface mining operations for any such denuded area must in turn be reclaimed.
(2) The operator shall address reclamation of any area mined to produce additional materials for backfilling and grading in the reclamation plan.
(3) The operator shall address settlement of filled areas in the reclamation plan. Where probable ultimate site uses include roads, building sites or other improvements sensitive to settlement, the reclamation plan shall provide for compaction of the fill materials in conformance with good engineering practice to avoid excessive settlement.
(T) Replanting.
(1) Within six months after surfaces have been graded to their final contours, or within such other time period as is approved by the Planning Commission, the operator shall take suitable measures to establish vegetation capable of stabilizing the soil on areas where revegetation is possible and rock is not exposed. The Planning Commission shall approve vegetation types and the operator shall maintain the vegetation until the soil is adequately stabilized to withstand the elements and shall provide irrigation when necessary.
(2) When the operator proposes to conduct surface mining operations in stages of a series of benches, the Planning Commission may require the operator to landscape each bench or group of benches upon completion of excavation on the particular bench or benches.
(3) The operator shall use available research regarding revegetation methods, the selection of species having good survival characteristics and the climate of this area. The operator shall use native species wherever practicable and may use screens and roadside plantings at mines currently in operation, where the screens and plantings are practicable and desirable.
(U) Removal of structures; equipment and stockpiles.
(1) The operator shall remove all structures, equipment and stockpiles, except required fences, from areas disturbed by surface mining operations excavations six months after termination of operations, or such other time period as determined by the Planning Commission.
(2) Within the same period, the operator shall remove individual sewage disposal systems in accordance with the county Health Department’s recommendations.
(V) Additional standards. The Planning Commission may impose additional performance standards developed either during environmental review of individual projects or through the formulation and adoption of countywide performance standards.
(W) Time frame. The operator shall initiate reclamation activities on those portions of the mined lands that will not be subject to further disturbance at the earliest possible time. The county may require the operator to conduct interim reclamation of mined lands that have been disturbed and that may be disturbed again in future operations. The operator may conduct reclamation 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:
(1) The beginning and expected ending dates for each phase;
(2) All reclamation activities required;
(3) Criteria for measuring completion of specific reclamation activities; and
(4) Estimated costs for completion of each phase of reclamation.
(1966 Code, § 6C-10) (Ord. 722, § 2(part))