In the event that owners of property situated between the property of the petitioner and the point from which the sewer extension was made, desire to connect to the sewer as extended, they may make application to the City Engineer. The connection charge shall be on the basis established in Section 935.05. The City Engineer hereby has the authority to collect this connection charge and authority to make rebates of such collections to the original petitioner. However, in no event shall rebates be made to the petitioner of amounts necessary to cover his proportionate share of the final cost. (1964 Code §303.21)