The Ontario Building Code | Water Distribution Systems
7.1.5.3. water Distribution Systems
(1) Except as provided in Sentence (2), every water distribution system shall be connected,
(a) to a watermain that is part of a municipal drinking water system, or
(b) to a drinking water system, if a watermain described in Clause (a) is not available.
(2) Storm sewage or greywater that is free of solids and treated to conform to Article 7.7.4.1. is permitted to be used as a water supply for,
(a) water closets,
(b) urinals,
(c) sub-surface irrigation, or
(d) the priming of traps.
(3) Rainwater that is free of solids and treated to conform to Article 7.7.4.1. is permitted to be used as a water supply for,
(a) clothes washers,
(b) laundry trays,
(c) mop sinks,
(d) bedpan washers,
(e) water closets,
(f) urinals,
(g) hose bibbs,
(h) sub-surface irrigation, or
(i) the priming of traps.
(4) Piping conveying the non-potable water described in Sentence (2) shall be installed in conformance with Section 7.7.
In Plain Language
Except in a specific case, every water distribution system must be connected to a water main that's part of a municipal drinking water system, ensuring buildings generally draw from an approved, regulated water supply.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.