The following minimum requirements shall apply to all excavation operations:
A. Outer Limits: Outer limits of excavation shall be determined by the following:
1. In zoning districts where commercial excavation is not a permitted use, but allowed by conditional use permit, the outer limit or edge of any excavation shall not be closer than one hundred feet (100') to any abutting property line.
2. In the Commercial Excavation District, I-3, no excavation outer limit or edge shall be closer than one hundred feet (100') to any property abutting a zoning district where excavation is not a permitted use.
B. Slopes:
1. Finished slopes of any edge contiguous to property owned by others shall not be less than a ratio of four feet (4') horizontal to one foot (1') vertical for sand and gravel operations.
2. The slope of banks during the excavation of material shall be kept in such a condition so as not to be dangerous because of overhangs, sliding or caving banks. Such dangerous conditions shall be declared to be a nuisance, and the City may give notice to the operator or owner to abate the same.
C. Removal of Materials:
1. All excavated materials shall be removed from the premises only upon and along such highways, streets or other public ways as the City Council shall order and direct.
2. All trees, stumps and debris must be disposed of within thirty (30) days by removal or, if allowed, by burning. Rocks which are not crushed, and which are one-third (1/3) yard or larger in size shall be buried after termination of excavation operations.
D. Depth: The depth of excavation may be restricted in areas programmed for future public utilities. This restriction may be necessary to ensure adequate utility service and routing. The City Engineer shall determine the maximum depth of excavation allowed in these areas. No excavation shall be allowed below grade closer than one hundred feet (100') to the right-of-way line of any existing street, road or highway; except, that excavating may be conducted within such limits in order to reduce the elevation thereof in conformity to the existing or proposed street grades.
E. Berms: In order to prevent contamination of freshwater lakes created as a result of mining, infiltration of flood water and storm water shall be prevented by the use of an earthen berm where necessary. No berm will be required where it can be shown that the natural topography will prevent such infiltration. When a berm is necessary, such berm may not be constructed in the required setback. Berms shall be constructed at least to the height of the City’s official flood protection elevation.
F. Water Bodies:
1. The operator shall replace any public or private well or water body which goes dry or is contaminated as a result of the mining operation.
2. In order to prevent erosion and to preserve shore land aesthetics, mining within a strip two hundred feet (200') from a lake shore, river or stream shall be prohibited. This zone shall be measured inland from the normal high water mark as determined by the point where the natural vegetation changes predominantly aquatic to predominantly terrestrial.
3. Excavations resulting in the accumulation of substantial water areas after rehabilitation must meet the following requirements:
a. All banks shall be sloped to the water line at a slope which shall not be steeper than four feet (4') horizontal to one foot (1') vertical.
b. All banks shall be sodded or surfaced with soil of a quality at least equal to the topsoil of land areas immediately surrounding and to a depth of at least three inches (3").
c. Such topsoil as required in subsection F.3.b. of this Section shall be planted with trees, shrubs, legumes or grasses upon the parts of such area where re-vegetation is possible.
d. In the event that a development plan is submitted which anticipates a lake about which lots will be platted, such lake must be planned for at least a fifteen-foot (15') depth. Any development plan indicating a lake development shall provide a means for level control or computations which prove that the lake can contain drainage directly to it by free board storage utilizing a one hundred (100) year storm. It is understood that the water table in the area in question is unstable, and any problems arising regarding the depth of the lake created shall be referred to the City Engineer.
e. The bottom of a reclaimed lake shall be sloped to a grade not to exceed three feet (3') horizontal to one foot (1') vertical for a distance of thirty feet (30') from the water’s edge.
f. Swimming beaches and access areas shall have a minimum frontage of at least one hundred feet (100'). Water depth in swimming beach areas shall not be in excess of ten feet (10') within one hundred feet (100') of the shore.
4. Excavations not resulting in water areas after rehabilitation, but which must be graded or backfilled, shall meet the following requirements:
a. The graded or backfilled area shall not collect or permit stagnant water to remain therein.
b. The peaks and depressions of the area shall be reduced to a gently rolling topography in substantial conformity to the land area immediately surrounding and which will minimize erosion due to rainfall.
c. Such graded or backfilled area shall be surfaced with soil of a quality at least equal to the topsoil of land areas immediately surrounding, and to a depth of at least three inches (3").
d. Such topsoil as required by subsection F.4.c. of this Section shall be planted with trees, shrubs, legumes, or grasses upon the parts of such area where revegetation is possible.
e. New slopes on boundary areas shall not be steeper than four feet (4') horizontal to one foot (1') vertical.
G. Noise and Air Pollution; Vibrations:
1. The operator shall maintain and operate all equipment in such a manner as to minimize noise and air pollution. Any emission which can cause any damage to health, animals or vegetation or other forms of property or which can cause any excessive soiling at any point or any emission of any solid or liquid particles in concentrations exceeding State Pollution Control Agency air quality regulations shall be prohibited. No noise resulting from the excavation shall exceed the most current state pollution agency noise control regulations or Title 4, Chapter 7 of this Code, whichever is the more restrictive. These regulations shall not apply to incidental traffic or maintenance operations.
2. Dust shall be controlled by watering as necessary.
3. Any vibration resulting in any combination of amplitude and frequencies beyond the “safe” range of the most current standards of the United States Bureau of Mines for any structure shall be prohibited.
H. Hours of Operation: Hours of operation shall be as follows:
1. Excavation and processing may be conducted only between the hours of six o’clock (6:00) A.M. and ten o’clock (10:00) P.M. in areas zoned I-3 commercial excavation district or as otherwise allowed by the City Council of a license, application or permit approval. In all other districts, hours of operation shall be limited to the hours in Section 4-7-8 of this Code.
2. Loading of barges, maintenance and repair of plants and equipment may be conducted twenty-four (24) hours a day in areas zoned I-3 commercial excavation district. In all other districts, such activities shall be limited to the hours in Section 4-7-8 of this Code.
3. Operation of trucks may be conducted only between the hours of seven o’clock (7:00) A.M. and six o’clock (6:00) P.M. weekdays. No truck loading is permitted on Saturdays, Sundays and legal holidays unless otherwise allowed by the City Council of a license, application or permit approval.
4. Hauling by truck of excavation materials from mines located in the City may be conducted only between the hours of seven o’clock (7:00) A.M. and six o’clock (6:00) P.M. weekdays. No truck hauling on public roads within the City is permitted on Saturdays, Sundays or legal holidays unless otherwise allowed by the City Council of a license, application or permit approval.
5. The foregoing hours and days of operation may be modified by the City Administrator in case of public emergency upon request of the permit operator or as allowed by City Council of a license, application or permit approval.
I. Traffic Hazards: Flag persons may be required where a traffic hazard may exist as a condition of the annual mining permit.
J. Restoration of Excavated Area: Upon termination of the operation, any pit or excavation created shall be regraded or modified according to the reclamation plan.
K. Termination or Abandonment of Operation: Within a period of three (3) months after the termination of a sand and gravel operation, or within three (3) months after abandonment of such operation, or within three (3) months after the expiration of a sand and gravel permit, the operator or owner shall dismantle or remove buildings and structures incidental to such operation and shall grade the site to the specifications of the final grade plan as well as complete all reclamation on the site as proposed by the reclamation plan.