The Ontario Building Code | Non-Potable Connection
7.7.1.1. Non-Potable Connection
(1) Except as permitted by Sentences (2) and (3), a non-potable water system shall not be connected to a potable water system.
(2) Make-up water may be supplied to the non-potable water system by,
(a) a reduced pressure backflow preventer, or
(b) an air gap.
(3) Where a clothes washer is supplied by a rainwatersystem and a potable water system, the potable water system shall be protected by dual check valve backflow preventers conforming to CSA B64.6, "Dual Check Valve (DuC) backflow Preventers" for,
(b) premise isolation.
7.7.2. Identification
In Plain Language
Non-potable water systems, such as those using reclaimed or reused water, can't be cross-connected with the potable water supply, protecting drinking water from contamination.
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.