(A)   The building sewer used to connect single-family dwellings shall have a minimum diameter of four inches and the building sewer used to connect multiple-family dwellings and commercial buildings with the public sanitary sewer shall have a minimum diameter of six inches, and shall be laid on a uniform grade of not less than one-eighth of an inch per foot.
   (B)   All joints shall be made gas-tight and water- tight and joining material and the methods for sealing joints shall meet the approval of the Superintendent.
   (C)   All service sewer pipe shall be laid in a straight line whenever possible and, where deflection from a straight line of more than three inches per foot is necessary, curved pipe shall be used.
   (D)   All new buildings sewers shall be constructed of one of the following types of materials:
      (1)   Vitrified clay sewer pipe and fittings, extra-strength clay pipe, A.S.T.M. designated C-20065T with factory-applied coupling meeting A.S.T.M. specifications C-425-66T, Type I or II;
      (2)   Extra-heavy, cast-iron soil pipe having joints of caulked oakum and molten lead; building plumbing drains shall be connected with a sealed connection to the building sewer; no open jointed field tile shall be used for a connection to the public sanitary sewer; and
      (3)   Rigid PVC sewer pipe having a rubber gasket or solvent weld joint, and meeting PSP SDR 41 (except four-inch size shall be SDR 33.5). The A.S.T.M. designation is D3033.
(Prior Code, § 13.20.190)