If a majority of the voters of said metropolitan area approve the issuance of bonds as provided in Section 240-22, the Authority shall have power to levy and collect annually a sum sufficient to pay for the annual principal and interest charges on such bonds; provided, that such tax levy shall be reduced by a sum equal to such grants or matching grants as the Authority shall receive, in any year, for this purpose.
     Such taxes proposed by the Authority to be levied upon the taxable property within the metropolitan area shall be levied by ordinance. After the ordinance has been adopted it shall, within 10 days after its passage, be published once in a newspaper published and having a general circulation within the metropolitan area. A certified copy of such levy ordinance shall be filed with the county clerk no later than the 3rd Tuesday in September in each year. Thereupon the county clerk shall extend such tax; provided the aggregate amount of taxes levied for any one year shall not exceed the rate of .0005% of the full fair cash value, as equalized or assessed by the Department of Revenue.