Tennessee Code Title 68. Health, Safety and Environmental Protection § 68-14-402

(a) Notwithstanding any rule or regulation of the department of health to the contrary, if a public owned swimming pool, owned by a public entity, is more than thirty thousand square feet (30,000 sq. ft.) in size, the owner or operator of the pool shall install one (1) lifeguard station for each six thousand square feet (6,000 sq. ft.), or major portion thereof, that is available for public use, and shall staff each such station at all times the area covered by such station or major portion thereof is open.

(b) The commissioner of health may, in the commissioner's discretion, increase the amount of pool square footage that may lawfully be covered by a single lifeguard station.

(c) This section does not apply in counties having a metropolitan form of government and a population of not less than four hundred seventy thousand (470,000) nor more than five hundred thousand (500,000), according to the 1980 federal census or any subsequent federal census.