§ 51.09  BUILDING SEWERS.
   (A)   The building sewer shall be constructed of cast iron, or PVC pipe, with rubber gasket joints. Any other material approved by the state’s Plumbing Code for building sewers, shall be an approved material under this chapter. Concrete grout joints shall under no circumstances be an acceptable joint. Fittings for angles and the like shall be prefabricated and standard. Mudding-in angles will not be acceptable unless approved in writing and inspected by the inspector. Orangeburg and 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 inspector, but in no event shall be diameter be less than four inches. The slope of such four-inch pipe shall not be less than one-fourth inch per foot, and the slope of pipe of larger diameter shall conform to state’s Plumbing Code.
   (C)   Where the users cannot enter directly to the public sewer and have to enter an existing four-inch line of another user, from the point of connection, the building sewer pipe to the public sewer shall not be less than six inches including Wye connection.
   (D)   Whenever possible the building sewer shall be brought to the building at an elevation below the basement floor. Cast iron pipe or other approved pipe as herein specified shall not terminate less than five feet from the building, and a cleanout shall be placed in every building sewer and at every change of alignment or grade extending and including a 45-degree bend. No building sewer shall be laid parallel to or within feet of any bearing wall, which might thereby be weakened.
   (E)   The department shall be sufficient to afford protection from frost, and shall be laid with a minimum cover of 18 inches within the property or street or alley right-of-way. Any line with less than 30-inch cover in an alley or street shall be cast iron. The building sewer shall be laid at uniform grade and in straight alignment wherever possible. Changes in direction shall be made only with properly curved pipe and fittings.
   (F)   In all buildings in which any building drain is too low to permit gravity flow to the public sewer, sewage carried by such drain shall be lifted by mechanical, electrical or pneumatic means approved by the inspector, and discharged to the building sewer, and the user shall provide a back water valve to prevent back flow of sewage.
   (G)   The city shall not be liable for any damage caused by backflow.
   (H)   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, applicant will proceed only under special permit, and under the direction of the inspector. 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 approved gasketed joints shall be used in crossing water mains unless the following requirements are met. Caulked and leaded joints will not be allowed.
      (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.
   (I)   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 good construction practices, using granular bedding free from large amounts of silts and clays. No backfill shall be placed until the work has been inspected by the inspector.
(Ord. 97-02, passed 6-3-1997)