127(3)If, for the purpose of affording an outlet for a domestic sewer, a sewer main is constructed along a street or through land in which it would not in the opinion of the council have been constructed except as a means of affording an outlet as aforesaid, the lots or parcels of land abutting on such street and such land may be exempted from the payment of any special frontage assessment in respect of the domestic sewer system and sewer main either for the whole or a part of the term of the special frontage assessment imposed in respect of the said domestic sewer system served by the outlet, or from the payment of the whole or a part of the proportionate cost thereof as appears to the council to be just under the circumstances.