3136B.2 Perimeter Overflow Systems

A perimeter overflow system shall be required in pools whose water surface area equals or exceeds 5,000 square feet (464.52 m²). Perimeter overflow systems shall be designed by an engineer or architect who has experience working on public pools and shall comply with the following provisions:

1. Location. The overflow system shall be integrated with the pool structure and extend completely around the pool parallel to the pool deck except where an entry or exit may require interruption; and
2. Channel detail. The overflow channel shall be not less than 3 inches (76 mm) deep, the section shall not diverge with depth of the channel, and the width of the bottom shall be not less than 3 inches (76 mm). The opening beneath the coping into the overflow system shall be a minimum of 4 inches (102 mm) beneath the coping in any direction measured radially from the inner edge of the overflow channel lip; and
3. Channel lip. The overflow channel lip shall be not more than 12 inches (305 mm) below the level of the coping or deck. The lip edge shall be rounded and shall be not thicker than 2¹/₂ inches (64 mm) or thinner than 1 inch (25 mm) for the top 2 inches (51 mm); and
4. Channel covering. Covered overflow channels shall be permitted provided the openings do not exceed ¹/₂ inch in the smaller dimension; and
5. Channel outlets. Channel outlet spacing and channel bottom slope shall be hydraulically designed by an engineer or architect who has experience working on public pools; and
6. Channel outlet covers. Overflow channel outlet covers shall be accessible for cleaning and maintenance. Openings of the channel outlet covers shall not pass a ¹/₂ inch (13 mm) sphere in the smaller dimension; and
7. Channel drain piping. Channel drain piping shall provide drainage of the overflow system, carry overflow water to a surge basin and return to skimming within 10 minutes after being flooded by a sudden displacement of the pool water by pool users; and
8. Surge storage capacity. A perimeter overflow system shall be provided with a minimum surge storage capacity of not less than 1 gallon per square foot (40.75 L/m²) of pool water surface area. Surge storage shall be permitted in the surge basin, perimeter overflow channel and in the channel drain piping returning to the surge basin.