The plans and specifications for the improvement and the proposed assessment roll shall be filed with the city or county clerk and shall be open for public inspection. Such clerk shall thereupon, at the direction of the governing body of the city or county, publish notice that the governing body will conduct a hearing to consider the proposed improvement and proposed assessments. Such notice shall be published in a newspaper of general circulation at least once, not more than twenty days and not less than ten days before the hearing, and shall state the project name for the improvement, the date, time and place of such hearing, the general nature of the improvement, the revised estimated cost or, if available, the final cost of the improvement, the boundaries of the sewage or storm water facility improvement district to be assessed, and that written or oral objections will be considered at the hearing. At the same time, the city or county clerk shall mail to the owners of record of the property made liable to pay the assessments, at their last known post-office address, a notice of the hearing and a statement of the cost proposed to be assessed against the property so owned and assessed. The failure of any owner to receive such notice shall not invalidate the proceedings.