What must a pool's main drain be certified by?

A pool's main drain must be certified by a Professional Engineer because this ensures that the drain system is designed and constructed according to specific safety and engineering standards. A Professional Engineer possesses the necessary education, training, and licensing to evaluate the hydraulic and structural components of the pool's main drain, ensuring it meets regulatory requirements and safe operational standards. This certification is crucial in preventing any safety hazards associated with main drain malfunctions, such as entrapments or insufficient water circulation, which can pose risks to swimmers.