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OBC DIVISION B · PART 3 · SECTION 3.11 — PUBLIC POOLS

What are the drain and suction entrapment safety rules for public pools in Ontario?

Section 3.11 requires suction outlets to be designed to prevent entrapment: protective anti-entrapment fittings or grates on drains, limits on suction so a bather cannot be held against an outlet, and system layouts that avoid a single point of dangerous suction.

Code reference
Public pool recirculation and drainage systems must be arranged so bathers cannot be entrapped by suction. Outlets require secure protective covers or gratings sized and designed to prevent hair, limb and body entrapment, and the suction system must be configured, including through outlet sizing and arrangement, so that blocking an outlet does not create a hazardous holding force.
OBC Division B, Section 3.11 (Public Pools)

Paraphrased for clarity — open this provision in the BUILDAiD Library for the exact wording.

What this means in practice

Entrapment provisions respond to real drownings and are enforced strictly. The mechanical designer, not just the architect, owns much of this: drain cover selection to recognized anti-entrapment standards, flow velocities through grates, and the arrangement of multiple outlets or vacuum-relief measures so no single blocked drain becomes lethal. Common pitfalls include reusing old single-main-drain details on renovations and installing covers not certified for the actual flow. On pool renovations, upgrading legacy drains is often the most safety-critical scope item and should be priced early.

Plain language

Pool drains create powerful suction that has trapped and drowned swimmers, especially children. Ontario requires public pool drains to have special safety covers and plumbing designed so that even if someone sits on a drain, they cannot be held underwater.

Related questions

What counts as a public pool under the Ontario Building Code?What are the deck requirements for a public pool in Ontario?Where do water depth markings have to go on a public pool in Ontario?

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This page is provided for general information. Building code requirements depend on your specific project, occupancy and municipality, and code editions change. Always verify requirements against the current Ontario Building Code and confirm with your local building department.