§ 54.08 BUILDING SEWERS.
   (A)   The building sewer shall be constructed of concrete, asbestos cement, or cast-iron pipe with rubber gaskets or lead caulked joints. Concrete grout joints shall under no circumstances be an acceptable joint. Fittings for angles, and the like, shall be pre-fabricated and standard. Mudding in angles will not be acceptable unless approved in writing and inspected by the Manager. Orangeburg, plastic, or fiber type pipe shall not be an approved type conduit.
   (B)   The size and slope of the building sewer shall be set to the approval of the Manager, but in no event shall the diameter be less than four inches. The slope of the four-inch pipe shall not be less than one-eighths-inch per foot, and the slope of larger diameter pipe shall conform to standard city specifications.
   (C)   Whenever possible the building sewer shall be brought to the building at an elevation below the basement floor. Cast-iron pipe shall not terminate less than five feet from the building, and a back water valve shall be at point of leaving building and a cleanout shall be placed in every building sewer at the junction with the soil pipe and at every change of alignment or grade exceeding and including a 45-degree bend. No building sewer shall be laid parallel to or within three feet of any bearing wall, which might thereby be weakened. The depth shall be sufficient to afford protection from frost, and shall be laid with a minimum cover of 18 inches within the property line or alley grade within street or alley right-of-way. The building sewer shall be laid at uniform grade and in straight alignment insofar as possible. Changes in direction shall be made only with properly curved pipe and fittings.
   (D)   In all buildings in which any building drain is too low to permit gravity flow to the public sewer, sewage carried by the drain shall be lifted by mechanical, electrical, or pneumatic means approved by the Engineer and discharged to the building sewer, and the property owner shall provide a back water valve to prevent back flow of sewage.
   (E)   The city shall not be liable for any damage caused by back flow.
   (F)   Whenever possible, all building drains and building sewers shall be installed not less than ten feet from a potable water supply. In the event that this provision cannot be complied with, the applicant will proceed only under special permit, and under the direction of the Manager. When circumstances force the installer to cross potable water lines with sewer lines, the sewer lines shall be installed under the water lines, and as near as possible to a 90-degree angle. Cast-iron pipe with caulked and leaded joints shall be used in crossing water mains unless the following requirements are met.
      (1)   The bottom of the water piping at all points shall be at least 18 inches above the top of the
sewer piping.
      (2)   The water piping shall rest on a solid shelf on both sides of the common trench crossing.
   (G)   All excavation required for the installation of a building sewer shall be open trench work. Pipe laying and backfill shall be performed in accordance with standard city specifications, except that no backfill shall be placed until the work has been inspected by the Manager.
(Ord. 240, passed 5-13-1975) Penalty, see § 54.99