The size, slope, alignment, materials of construction of a building sewer and the methods to be used in excavating, placing of the pipe, jointing, testing and backfilling the trench shall all conform to the requirements of the appropriate specifications of the ASTM or WPCF Manual of Practice No. 9, all installation to be subject to the expressed written approval of the city and in no case shall the size of pipe installed be less than four (4) inches in nominal diameter for gravity sewer and two (2) inches for force mains.
(Ord. passed 10-14-1985)