At least fifteen days before the date fixed for hearing, notice thereof shall be mailed to the owner or reputed owner of the property whose name appears on the assessment roll, at the address shown on the tax rolls of the county treasurer for each item of property described on the list. In addition thereto the notice shall be published at least once a week for two consecutive weeks in the official newspaper of the city or town, the last publication to be at least fifteen days before the date fixed for hearing.