(a) Except as provided in subsection (b) of this section, a lifeguard shall not be required for a Class C, semi-public swimming pool that is: (1) Open for use only to persons who hold membership or other paid association in the facility where the swimming pool is located; (2) Open for use only to persons who are permanent or temporary residents or guests of residents at the facility where the swimming pool is located; (3) Open for use to persons who are lodging for a fee at the facility where the swimming pool is located; or (4) A spa pool or sauna. (b) A lifeguard shall be required for a Class C, semi-public swimming pool that has: (1) A diving board; (2) A depth greater than 5 feet; provided, that the swimming pool is constructed after June 30, 2018; or (3) An expected bather population that is 50 % or more children under 15 years of age.