Tennessee Code Title 13. Public Planning and Housing § 13-20-405

(a) The boundaries of such authority shall include the city and the area within ten (10) miles from the territorial boundaries of the city, but in no event shall it include the whole or a part of any other city nor any area included within the boundaries of another authority.

(b) In case an area lies within ten (10) miles of the boundaries of more than one (1) city, such area shall be deemed to be within the boundaries of the authority embracing such area which was first established, all priorities to be determined on the basis of the time of the issuance of the aforementioned certificates by the secretary of state.

(c) After the creation of an authority, the subsequent existence within its territorial boundaries of more than one (1) city shall in no way affect the territorial boundaries of such authority.