The notices provided for in this chapter may be served personally by the superintendent of streets or by any citizen of the United States over the age of twenty one (21) years; or they may be served if the person upon whom service is to be made resides outside of the city, by the superintendent by mail, by depositing the same in the United States post office in a sealed envelope, with the postage thereon prepaid, and directed to the person sought to be served, at his last known address or place of residence; and the certificate of the superintendent of personal service or the affidavit of any other person as hereinbefore provided or in case of service by mail, the affidavit of the superintendent as to the necessary facts as herein required, shall constitute prima facie evidence of service of the notice. In case the owner is a nonresident of the city, then the occupant of the property, if there is one, must also be served with a duplicate of the notice served by mail on the owner. (Ord. 507, 8-9-1901)