(1) General. Unless otherwise recommended in the approved soils engineering report, fills shall conform to the provisions of this Chapter. In the absence of an approved soils engineering report, these provisions may be waived for minor fills not intended to support structures.
(2) Preparation of ground. Fill slopes shall not be constructed on natural slopes steeper than one (1) unit vertical in two (2) units horizontal (fifty percent (50%) slope). The ground surface shall be prepared to receive fill by removing vegetation, noncomplying fill, topsoil, and other unsuitable materials scarifying to provide a bond with the new fill and, where slopes are steeper than one (1) unit vertical in five (5) units horizontal (twenty percent (20%) slope) and the height is greater than five feet (5') (1524 mm), by benching into sound bedrock or other competent material as determined by the soils engineer. The bench under the toe of a fill on a slope steeper than one (1) unit vertical in five (5) units horizontal (twenty percent (20%) slope) shall be at least ten feet (10') (3048 mm) wide. The area beyond the toe of fill shall be sloped for sheet overflow or a paved drain shall be provided. When fill is to be placed over a cut, the bench under the toe of fill shall be at least ten feet (10') (3048 mm) wide but the cut shall be made before placing the fill and acceptance by the soils engineer or engineering geologist or both as a suitable foundation for fill.
(3) Fill material. Any amount of organic materials determined to be detrimental by a soils engineering shall not be permitted in fills. Except as permitted by the Building Official, no rock or similar irreducible material with a maximum dimension greater than twelve inches (12") (305 mm) shall be buried or placed in fills.
Exception: The Building Official may permit placement of larger rock when the soils engineer properly devises a method of placement, and continuously inspects its placement and approves the fill stability.
The following conditions shall also apply:
(a) Prior to issuance of the grading permit, potential rock disposal areas shall be delineated on the grading plan.
(b) Rock sizes greater than twelve inches (12") (305 mm) in maximum dimension shall be ten feet (10") (3048 mm) or more below grade, measured vertically.
(c) Rocks shall be placed so as to assure filling of all voids with well-graded soil.
(4) Compaction. All fills shall be compacted to a minimum of ninety percent (90%) of maximum density.
(5) Slope. The slope of fill surfaces shall be no steeper than is safe for the intended use. Fill slopes shall be no steeper than one (1) unit vertical in two (2) units horizontal (fifty percent (50%) slope).
Ord. No.97-35, Recodified, 6/19/1997
Ord. No. 03-31, Enacted, 9/4/2003