Tenn. Code Ann. § 5-16-111

A county may not extend any public facilities, as provided for in this chapter, within five (5) miles of any part of the boundary of an incorporated city or town unless such incorporated city or town has failed to take appropriate action to provide a specified public facility or facilities in a specified area or areas for a period of ninety (90) days after having been petitioned to do so by resolution of the county legislative body or other governing body. The resolution shall contain a plan of service, and shall be accompanied by a preliminary engineering report and a financial feasibility report, and shall set out the type, standard and schedule of installation of public facilities and the specified area or areas proposed to be served by the county. The resolution, plan of service and reports shall have been previously submitted to the local planning commission for review as provided for in § 5-16-112.