(a)   Engineering Rules and Regulations. In all cases not specifically covered by these Subdivision Regulations and appendices thereto, the appropriate sections of the existing County Engineering Rules and Regulations, as amended, shall remain in effect. However, all amendments to the County Engineering Rules and Regulations taking effect after the passage of these Subdivision Regulations (Ordinance 22-1979, passed September 11, 1979) shall not be binding, unless approved by the Planning Commission and adopted by Council.
   The requirements for backfilling of trenches set forth in division (b) hereof are an exception to this division.
   (b)   Backfill Requirements. Excavations for any purpose under street pavements, sidewalks or areas to be paved shall be backfilled with granular material meeting the requirements for 310 material as per the State Construction and Material Specifications. No paving operation shall be permitted until all excavations have been backfilled, compacted, inspected and approved.
   All trenches made in the subgrade of the proposed roadbed or sidewalk area, and all trenches parallel to the roadway where the edge of the trench is nearer than one foot to the edge of the proposed pavement or the proposed curb, shall be backfilled with granular material. All transverse trenches shall be backfilled two feet outside the limits of the proposed roadbed of the pavement.
   Granular material used for bedding and backfilling shall be compacted, with mechanical tampers, under and around the conduit and to the top of the trench in layers not to exceed four inches in thickness. Granular material may be compacted with water if satisfactory drainage is provided for the free water. When compacting with water, the granular material may be deposited in ponded water, or it may be placed in layers not to exceed twelve inches loose depth and each layer thoroughly saturated with water. The material shall be filled and compacted to the final grade, line and cross-section of the subgrade as shown on the improvement plan. The granular material shall be compacted to 95 percent of its maximum laboratory dry weight.
   Trenches in areas in the unimproved portion of the right-of-way shall be backfilled with suitable soil placed in layers not to exceed four inches in thickness and compacted with mechanical tampers. The soil shall be compacted to 95 percent of its maximum laboratory dry weight. Granular material may be used in backfilling such trenches. The granular material shall be placed and compacted as mentioned in this division.
(Ord. 22-1979, passed 9-11-1979)