(A) Excavation. The trench shall be excavated so that the house service line rests on good firm earth. If the excavation has been made deeper than necessary, the foundation shall be brought up to proper grade by the addition of well compacted sand or fine gravel. Where firm earth is not encountered at established grade, due to the presence of soft spongy material or other unsuitable soil, all such unstable material under the pipe shall be removed and replaced with well compacted sand or fine gravel to provide a firm foundation for the pipe. The width of the trench at the top of the pipe shall be sufficient to permit easy access to the joints and shall be of such depth that the house service line can be laid on a uniform grade of not less than one-eighth inch of fall per lineal foot of line.
(B) House service pipe.
(1) All house service lines shall be constructed of first quality vitrified clay six-inch sewer pipe, cast iron four-inch or six-inch sewer pipe, or asbestos cement four-inch sewer pipe, or PVC plastic four-inch or six-inch sewer pipe. The sewer pipe shall be of the bell and spigot type, straight, smooth and sound, thoroughly burned, well glazed, free from lumps or other imperfections and with the least possible variation from the specified dimensions and of true cylindrical shape. All straight pipe must be straight in the direction of the axis of the pipe, and the inner and outer surface of each pipe must be concentric. The curves, slants and “Y” junctions and other specials, where required, must conform to all the requirements with regard to quality, form and workmanship and the thickness shall be equal to that of pipes of the same caliber to which the special may be joined.
(2) The sewer tile used shall meet the standards of the American Society of Testing Material for standard strength pipe where the cut is over five feet and less than 12 feet. Where the cut is 12 feet or more, the sewer tile used shall meet the American Society of Testing Material’s standards for extra strength pipe. In no case shall pipe be used where excessive loads will be encountered which does not meet the ASTM standards for the anticipated loading.
(3) PVC plastic sewer pipe and fittings shall conform to the latest revised specification requirements of ASTM D 3033 or ASTM D 3034 for polyvinyl chloride (PVC) sewer pipe and fittings. Joints shall be either the solvent weld type conforming to the latest revised specification requirements of ASTM D 2564 and ASTM D 2855, or elastomeric gasket type conforming to the latest revised specification requirements of ASTM D 1869 and ASTM D 3212. Pipe and fittings shall be the products of one approved manufacturer only, and there shall not be any mixing of pipe and fittings of different manufacturers.
(4) PVC sewer pipe and fittings shall be installed in accordance with the latest revised recommended practice of ASTM D 2321 using either Class I or Class II embedment materials for bedding, haunching and initial backfill. The pipe shall be properly embedded to provide adequate side support so that the maximum deflection does not exceed 5% of the pipe’s original internal diameter.
(C) Pipe joints. A preformed polyvinyl joint, precast bituminous compound joints and joints for cast-iron pipe only may be used. Cement joints are not approved and shall not be used.
(1) Preformed polyvinyl joints. When a preformed polyvinyl joint is employed, it shall be a true mechanical joint made from plasticized resins of polyvinyl chloride. The joint shall be of the compression type and the surfaces of both the bell and spigot ends shall be in uniform compression permitting lateral movement without harm to either pipe or joint. The preformed polyvinyl joint shall be jointed to the vitrified clay pipe during manufacture.
(2) Joints for cast-iron soil pipe. Joints for cast-iron soil pipes shall be made by inserting a roll of hemp or jute and thoroughly caulking it into place and then following with pure molten lead well caulked not less than one inch deep. No paint, varnish or putty will be allowed in the joints until they have been tested.
(3) Precast bituminous compound joints. When a precast bituminous compound joint is employed, all joints shall be made in accordance with this procedure. Before a joint is made, each collar shall be brushed with a solvent recommended by the manufacturer of the joint material which will cause the surface to become plastic or adhesive. All collars will be inspected before being laid and any showing voids or injury will be rejected.
(D) Trenching and backfilling.
(1) All excavations shall be open trench work unless otherwise authorized by the City Engineer. The foundation in a trench shall be formed to prevent any subsequent settlement of the pipes. If the foundation is good, firm earth, the earth shall be pared or molded to give a full support to the lower quandrant of each pipe. Backfilling material shall be deposited in the trench in such manner as not to damage the sewer pipe or change its grade and alignment. Backfilling and tamping around the pipes shall be done by hand with suitable tools to six inches above the top of the pipe. Only the finest of the excavated soil shall be used for this purpose. The backfill shall be left with a smooth, even surface and a sufficient crown.
(2) Where the work passes under paved streets or driveways or sidewalks, all the backfill shall be well rammed, with suitable tools, in layers not exceeding six inches in depth, providing the ground is clay, stiff loam or of a tenacious nature. If the ground is sand or gravel, the backfill shall be puddled in such manner as directed. After being puddled or rammed to the required height, the pavement shall be reconstructed carefully and thoroughly with the same kind of material and in the same manner as when originally constructed and to the satisfaction of the city. Graveled streets and driveways are to be replaced to their original condition.
(E) Restoration of surface. Any person who excavates any earth, under or immediately adjacent to any street, avenue, alley, sidewalk, pavement or public ground shall comply with all other ordinances pertaining to such excavations and replace the earth by a mechanical method of compaction and compression adequate to prevent settling and shall restore such street, alley, avenue, sidewalk, pavement or public place to as good condition as it was before the making of such excavation. Where any surfaced street is excavated, it shall be backfilled only with pit run sand and gravel or crushed stone of a fine grade with maximum size of one inch.
(F) Size of sewer. No sewer from the property line to the main sewer shall be less than four inches in diameter.
(1974 Code, § 7-5-4) (Ord. 459, passed 11-9-1960; Ord. 609, passed 10-10-1978)