A tax of not more than 0.03% or the rate limit in effect on July 1, 1967, whichever is greater, of the value, as equalized or assessed by the Department of Revenue, of all taxable property within each township that has established a public comfort station shall be assessed, levied, and collected by the township in the manner provided for the assessment, levy, and collection of other taxes for corporate purposes. The proceeds of this tax shall be kept in a separate fund and shall be used for the establishment, equipment, and maintenance of public comfort stations and for no other purpose. The foregoing limitations upon tax rates may, however, be increased under the referendum provisions of the General Revenue Law of Illinois.