All acts or parts of laws in conflict herewith are hereby repealed, including, but not limited to, Act 99-255, 1999 Regular Session, Act 94-478, 1994 Regular Session, as amended by Act 98-242, 1998 Regular Session and Act 91-609, 1991 Regular Session. Notwithstanding the foregoing, the tax levied pursuant to this article shall not be operative in any county in which, on October 1, 2004, there is a local law which levies a severance tax on natural material in an amount of twenty-five cents ($.25) or more per ton of severed material. This article provides the only method and manner to tax the severance of severed materials subject to the tax levied herein. This article shall preempt all local acts, now or in the future, except as provided herein, regarding the taxation of the severance of the severed material subject to the tax levied herein. Provided, however, that notwithstanding any other provision of this article, the Legislature shall be allowed and shall have the power to tax, by local act or local law applicable to a single county, the severance of materials and/or any use thereof which is not subject to the tax levied by this article or which is otherwise excepted or exempted from the tax levied herein.