Chapter 17.20
SPECIFICATIONS FOR BUILDING SEWERS
Sections:
17.20.010 General requirements.
17.20.030 Location – Direction of flow.
17.20.010 General requirements.
The building sewer shall meet the requirements of the Uniform Plumbing Code (UPC) in accordance with Chapter 21.01 RMC. [Ord. 77; Ord. 07-04; Ord. 39-09 § 1.02; amended during 2011 recodification].
17.20.020 Size – Slope.
The size and slope of the building sewer shall be as required in the UPC, but in no event shall the diameter be less than four inches or the slope less than one-eighth inch per foot. Variances to these requirements shall be approved by the city engineer. [Ord. 77; Ord. 07-04; Ord. 39-09 § 1.02].
17.20.030 Location – Direction of flow.
Whenever possible, the building sewer shall be brought to the building at an elevation below the basement floor. 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 or freezing. 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. [Ord. 77; Ord. 07-04; Ord. 39-09 § 1.02].
17.20.040 Backwater valve.
If the lowest drain in the building is less than three feet above the top of the sewer main, an approved backwater valve shall be installed in the building sewer in an accessible location. [Ord. 77; Ord. 07-04; Ord. 39-09 § 1.02].
17.20.050 Artificial lifts.
In all buildings in which any building drain is too low to permit gravity flow to the public sewer, sewage carried by such a drain shall be lifted by artificial means and discharged into the building sewer. The connection between this building sewer and the public sewer shall be accomplished by a gravity-flow section of sewer pipe. The artificial means of lifting shall meet the requirements of the Uniform Plumbing Code (UPC). [Ord. 77; Ord. 39-09 § 1.02].