(A) The minimum cover over the top of a sewer shall be four feet, unless the City Engineer, in writing, approves a lesser minimum. Such approval may be made contingent upon the satisfaction of such terms and conditions as are set out by the City Engineer in his or her written approval. It is the intent of this section that the discretion granted the City Engineer is to be exercised in those cases where strict adherence to a four-foot minimum would be physically impossible, or would be contrary to accepted engineering practices.
(B) Backfill material shall be grade “B” borrow or approved bank run sand or gravel and shall be placed as backfill in six-inch layers equally on both sides of the pipe mechanically compacted to a point 12 inches above the top of the sewer pipe. The placement of this backfill material must be equally placed so as not to disalign the sewer pipe. The top of the granular backfill material shall be uniform so as to assure that the compacted backfill material will provide the necessary proper support to the sewer pipe. Backfill material to be placed between the area which is one foot above the top of the pipe and the surface of the ground shall be installed in a good workmanlike manner, and shall either be compacted with mechanical compaction equipment or by the use of water jetting. If water jetting is selected, the spacing of each jetting hole shall not exceed ten feet. The area immediately below the ground surface shall be replaced with a minimum of four inches of top soil. The top soil layer shall be seeded.
(C) Backfilling for areas which are under hard surfaces, such as sidewalks, drives, alleys, streets, and parking lots, shall be performed with granular backfill which shall be either mechanically compacted or water jetted between the area of one foot above the top of the pipe to the bottom of the sub base required for the various types of hard surface. The type of material and thickness of the sub base and the actual street material shall be determined from the thoroughfare cross section as listed in the City Plan Commission Master Plan Ordinance, unless the City Engineer requires a design of additional thickness due to either existing street or alley conditions or anticipated conditions for the area. The repair of the actual street surface shall be in compliance with the most current Indiana State Highway Department specifications.
(Ord. 6619, passed 1-28-13)