The connection of the building sewer into the public sewer shall conform to the requirements of the Building and Plumbing Codes, or other applicable rules and regulations of the City, or the procedures set forth in appropriate specifications of the American Society of Testing Materials, Water Pollution Control Federation Manual of Practice No. 9 and Chapter 12, Iowa Standards for Sewer Systems. All such connections shall be made gastight and watertight. Any deviation from the prescribed procedures and materials must be approved by the authorized City representative before installation.