The size, slope, alignment, materials of construction of a building sewer, and the methods to be used in excavating, placing of the pipe, joining, testing and backfilling the trench shall all conform to the requirements of the Building Code and Plumbing Code or other applicable rules and regulations of the village. In no event shall the diameter of the pipe be less than six inches. The slope of such six inch pipe shall not be less than one-eighth inch per foot. In the absence of code provisions or in amplification thereof, the materials and procedures set forth in appropriate specifications of the Standard Specifications for Water and Sewer Main Construction in Illinois, published by the Standard Specification Committee of the Illinois Society of Professional Engineers and other similar organizations, third edition, shall apply.