All operations in connection with excavations necessary for the laying of the water mains and the disposal of all surplus excavated material shall be made in accordance with requirements of the City Engineer.
All trenches, unless otherwise directed by the City Engineer, shall be excavated to a depth sufficient to allow a minimum of four and one-half feet cover over the pipe.
The earth backfill shall be placed in horizontal layers not over eight inches in thickness and each layer shall be thoroughly compacted by a mechanical tamper. Under favorable conditions, when allowed by the City Engineer, the earth backfill may be placed in the trench without being tamped in horizontal layers, but the trench shall be flooded with water and puddled so that a suitable settlement of the backfill materials may be obtained. The upper eighteen inches of the trench shall be backfilled with No. 6 or No. 7 limestone properly compacted, unless otherwise directed by the City Engineer.
Backfilling shall not be made in freezing weather except by permission of the City Engineer, nor shall it be made with frozen materials, nor when the material already in the trench is frozen. All materials used for backfilling shall be free from perishable and objectionable substances and shall contain no stones larger than three inches in diameter.
No slag, cinders, rubbish, rocks, boulders, shales or other objectionable material shall be used to backfill against the pipe or in any part of the trench where in the opinion of the City Engineer it will be injurious to the work. The owner shall maintain all excavations in good order so as not to hinder or injure the pipe laying or progress of the work.
Should the materials excavated from the trench be unsuitable for backfilling purposes to such an extent that the quantity of suitable materials is insufficient to complete the backfilling around and over the completed water main, the owner shall satisfactorily dispose of such unsuitable material and shall obtain suitable earth, gravel or stone, acceptable to the City Engineer, and use the same for backfilling to the lines and grades shown or given.
All waterline pipe and fittings shall be cement-lined ductile iron pipe with rubber gasket joints conforming to the following specifications of the American Water Works Association (AWWA) and of the American National Standards Institute (ANSI): AWWA-C-110, C-111, C- 104, C-150, C-151; ANSI-A21.10, A21.11, A21.4, A21.50, A21.51. All waterline pipe and fittings shall have a minimum six-inch inside diameter and shall be designed for a minimum water working pressure of 150 psi.
Other waterline shall not be used unless otherwise directed by the City Engineer.
All pipe shall be laid on a limestone bedding at least six inches in depth consisting of No. 6 or No. 9 limestone, unless otherwise ordered by the City Engineer and shall be backfilled to a depth of twelve inches over the top of the pipe with the same material. After laying, the pipe shall be chlorinated and tested for leakage to the full satisfaction of the Service Director or the City Engineer. (Ord. 1961-3. Passed 7-31-61.)