(a) The authority is declared to be performing a public function in behalf of each county or municipality with respect to which it is organized and to be a public instrumentality of such county, counties, municipality or municipalities. Accordingly, the authority and all properties at any time owned by it and the income therefrom and all bonds issued by it and the income therefrom shall be exempt from all taxation in the state of Tennessee.(b) For purposes of the Tennessee Securities Act of 1980, compiled in title 48, chapter 1, part 1, bonds issued by the authority shall be deemed to be securities issued by a public instrumentality or a political subdivision of the state of Tennessee.Acts 1991, ch. 451, § 71; T.C.A., § 68-31-914.