Every connection made with any public sewer shall be made in the following manner, utilizing the materials specified:
A. All pipe shall be first-class, vitrified, salt-glazed, socket pipe four or six inches in internal diameter, and in pieces of two feet in length as specified in each permit.
B. Proper bends shall be used in connecting the pipe leading to the house with the Y. Every such bend shall have an internal diameter of four or six inches, as may be so specified.
C. The material used shall be equal in quality and the manner of laying shall be the same as required by the specifications for public sewers in the City.
D. The grade shall be straight from the property line to the public sewer and shall have a fall of not less than one foot in fifty feet, unless otherwise permitted by the Division of Public Works.
E. The pipe must be at least three and one-half feet (3½') below the established grade of the street where such pipe crosses the property line. In all cases the line of pipe must be straight from the property line to the bend of the Y.
F. Where Y's cannot be found, a new Y provided with a sleeve or collar of proper dimensions shall be inserted and carefully connected with the pipe sewer by means of Oakum and cement or other material approved by the Division of Public Works, where the diameter of such sewer does not exceed ten inches. All work herein mentioned shall be done to the satisfaction of the Division of Public Works, and all excavations and back-filling shall be as required by the specifications for public sewers in the City.
('65 Code, § 29-2)