40.250.020 Surface Mining Overlay District (S)

A.    Purpose.

    It is the intent of this overlay district to ensure the continued use of rock, stone, gravel, sand, earth and minerals without disrupting or endangering adjacent land uses, while safeguarding life, property and the public welfare. Provisions of Chapter 78.44 RCW and Chapter 332-18 WAC applicable to Clark County pertaining to surface mining are adopted by reference. No surface mining use shall be established until the responsible official issues site plan approval.

B.    Uses.

    The following uses are permitted outright or by conditional use permit within this district:

1.    Permitted.

a.    All uses allowed in the zone district with which this district is combined.

b.    Extractions from deposits of rock, stone, gravel, sand, earth and minerals.

2.    Conditional.

a.    Asphalt mixing.

b.    Concrete batching.

c.    Clay bulking.

d.    Rock crushing.

(Amended: Ord. 2009-03-02)

C.    Accessory Uses.

    On-site hazardous waste treatment and storage facilities, subject to state siting criteria (RCW 70.105.210) are permitted as an accessory use in this district.

D.    Special Standards or Requirements.

1.    Site Area. When the activity includes both extraction and any one (1) of the uses listed in Section 40.250.020(B)(2), the total site area shall be a minimum of twenty (20) acres. Activities which are limited to extractions only shall not have a minimum site size.

2.    Lot Width. There shall be a minimum lot width of sixty (60) feet for all activities included in Section 40.250.020(B)(2).

3.    Fencing. The periphery of all sites within the gross site area being actively mined or reclaimed shall be fenced according to the Department of Natural Resources’ standards.

4.    Setbacks. The tops and toes of cut and fill slopes shall be set back from property boundaries according to the Department of Natural Resources’ standards for safety of the adjacent properties, and to prevent damage resulting from water runoff or erosion of slopes.

5.    Maximum Permissible Noise Levels. Maximum permissible noise levels shall be according to the provisions of the Chapter 173-60 WAC.

6.    Hours of Operation. Hours of operation, unless otherwise approved by the responsible official, shall be between 6:00 a.m. and 8:00 p.m.

7.    Erosion Control. All disturbed areas, including faces of cuts and fill slopes, shall be prepared and maintained to control erosion. This control may consist of planting sufficient in amount or type to stabilize the slope (as approved by the responsible official).

8.    Drainage. Provisions shall be made to:

a.    Prevent any surface water or seepage from damaging the cut face of any excavations or the sloping face of a hill.

b.    Prevent sediment from leaving the site in a manner which violates RCW 90.48.080 and WAC 173-201-100.

9.    Bench/Terrace. Benches shall be backsloped, and shall be established at not more than forty (40) foot vertical intervals, to control surface drainage and debris. Swales or ditches on benches shall have a maximum gradient of five percent (5%).

10.    Access Roads Maintenance. Access roads to mining and quarrying sites shall be maintained and located to the satisfaction of the director of public works, to minimize problems of dust, mud and traffic circulation.

11.    Overburden. Overburden shall only be removed to accommodate aggregate and related activities of this section.

(Amended: Ord. 2009-03-02)

E.    Plan Approval.

1.    For those uses permitted under Section 40.250.020(B)(1), the responsible official shall review and approve plans and specifications and other supporting data through a Type II site plan review process.

2.    Conditional uses under Section 40.250.020(B)(2) shall be reviewed through a Type III conditional use review process.

F.    Special Notice Requirements. Notice shall be sent to owners of property within a radius of one-half (1/2) mile of the property that is the subject of a Type II or Type III application.

G.    Information on Plans and in Specifications.

    Plans shall be drawn to an engineer’s scale and shall be of sufficient clarity to indicate the nature and extent of the work proposed, and show in detail that they will conform to the provisions of this section and all other relevant laws, ordinances, rules and regulations. The first sheet of each set of plans shall give the location of the work, and the names and addresses of the owner and the person by whom they were prepared. The plans shall include the following minimum information:

1.    General vicinity maps of the proposed site.

2.    Property boundaries and accurate contours of existing ground, details of terrain, and details of area drainage.

3.    Dimensions of area to be mined, elevations or finished contours to be achieved by the grading, proposed drainage channels and related construction.

4.    Detailed plans of all surface and subsurface drainage devices, walls, cribbing, dams, berms, settling ponds and other protective devices to be constructed with or as a part of the proposed work, together with the maps showing the drainage area and the estimated runoff of the area served by any drains.

5.    Location of any buildings or structures on the property where the work is to be performed, and the location of any buildings or structures on land of adjacent property owners which are within fifty (50) feet of the property, or which may be affected by the proposed operation.

6.    Landscape and rehabilitation plan, as required by Section 40.250.020(H).

H.    Land Restoration.

1.    Upon the exhaustion of minerals or materials, or upon the permanent abandonment of the quarrying or mining operation, all buildings, structures, apparatus or appurtenance accessory to the quarrying and mining operation which are nonconforming to the underlying district shall be removed or otherwise dismantled to the satisfaction of the responsible official.

2.    Unless approved as a sanitary landfill, grading or backfilling shall be made with non-noxious, nonflammable, noncombustible and nonputrescible solids.

3.    Such graded or backfilled areas, except for roads, shall be sodded or surfaced with soil of a quality at least equal to the topsoil of the land areas immediately surrounding, and to a depth of at least four (4) inches, or a depth of that of the topsoil of land areas immediately surrounding, if less than four (4) inches.

4.    Such topsoil as required by Section 40.250.020(H)(3) shall be planted with trees, shrubs or grasses. If the site is within an AG or FR district, the topsoil shall be of a similar type to the surrounding area.

5.    Graded or backfilled areas shall be reclaimed in a manner which will not permit stagnant water to remain. Suitable drainage systems approved by the responsible official shall be constructed or installed if natural drainage is not possible.

6.    Waste or soil piles shall be leveled and the area treated, as required in Sections 40.250.020(H)(3) and (H)(4).

I.    Applicability to Pre-Existing Operations. Notwithstanding Section 40.530.050, the provisions of the surface mining overlay district shall apply to surface mining operations commenced prior to, and in continued operation, as of December 30, 1997.

(Amended: Ord. 2009-03-02)