(A) Size and slope. The size and slope of the building sewer and service connection shall be subject to the approval of the secretary, but in no event shall the diameter be less than four inches. The slope of such four-inch pipe shall not be less than one-fourth inch per foot, unless otherwise approved by the secretary and in no case will slopes less than one-eighth inch per foot be approved.
(B) Excavation and backfill.
(1) All excavations required for the installation of a building sewer and service connection shall be open trench work unless otherwise approved by the secretary. No backfill shall be placed until the work has been inspected by the Secretary. Minimum cover shall be 1/16” above the top of the pipe unless otherwise approved by the secretary.
(2) All excavations for building sewer and service connection installation shall be adequately guarded with barricades and lights so as to protect the public from hazard. Streets, sidewalks, parkways, and other public property disturbed in the course of the work shall be restored in a manner satisfactory to the secretary.
(C) Building sewer inspection.
(1) Building sewer pipe shall be installed in accordance with ASTM C12 and the recommendations of the manufacturer. The joints shall be water-tight. The pipe shall be laid at a uniform grade and in straight alignment insofar as possible. Changes in direction shall be made with no greater than 45-degree radius bends. All pipe shall be laid on a minimum four-inch pipe base placed for the full width of the trench. Backfill around the pipe to a point six inches above and for the full width of the trench shall be the same material, hand-placed, and tamped.
(2) Building sewer connections shall be made on the building side of the existing septic tanks. When connecting cast iron soil pipe or PVC pipe to asbestos-cement, clay, or concrete pipe, a special approved adaptor shall be used. An approved adaptor shall also be used when connecting the building sewer to the service connection.
(D) Testing fitting. A tee or wye fitting shall be the first fitting at the junction of the building drain and the building sewer. The fitting shall be of the same material as the service connection pipe and shall be furnished by the owner. A riser of the same material as the service connection pipe shall extend to finished ground surface and shall be sealed with an approved cap or plug. This riser shall be used for inserting a test plug for water testing the building sewer and as an auxiliary cleanout. Backfilling around the riser shall be done in such a manner so as not to damage the pipe and provide firm support for the riser.
(E) Building sewer and service connection inspection and testing.
(1) The applicant for building sewer and service connection permit shall notify the city when the building sewer and service connection has been laid, connected to the service connection, but not backfilled or connected to the building drain. After inspection and approval by the secretary, the building sewer and service connection trench shall be backfilled except at the point of connection to the building drain. The building sewer and service connection shall be constructed so they are gas- and water-tight. Any sanitary building sewer, in which water infiltration or exfiltration is evident, shall be reconstructed or repaired so that they are gas- and water-tight.
(2) Any sewer which is tested, either before or after the backfill is completed, and found by such test to be defective, shall be repaired and re-tested to assure that the said sewer is gas- and water-tight. If, for cause, an inspector has reason to believe that a building sewer and service connection does not conform to the requirements of these rules, he or she may require that said sewer be tested according to the provisions of this section and that all leaks be repaired.
(3) Building sewer and service connection installations or pipe which is made for gravity flow sewers shall be capable of withstanding a pressure test consisting of water under static pressure with at least eight-foot average head of water applied internally to all parts of the sewer being tested; or compressed air with at least three and one-half pounds per square inch gauge pressure applied inside all parts of the sewer being tested and held for at least three minutes after the pressure in the sewer has been stabilized and the source of air pressure disconnected; or other effective test which is in accordance with good engineering practice and accepted by the Department of Commerce, Building Codes Division.
(4) After the building sewer and service connection has successfully passed inspection, or if deemed necessary by the secretary, has successfully passed the sewer pressure test, the city will authorize connection of the building sewer in an approved manner to the building drain.
(Ord. 46, passed 4-8-1975; Ord. 216, passed 4-11-1995)