The Ontario Building Code | Separate Systems
7.4.6.1. Separate Systems
(1) No vertical soil or waste pipe shall conduct both sanitary sewage and storm sewage.
(2) There shall be no unused open ends in a drainage system and dead ends shall be so graded that water will not collect in them.
In Plain Language
No vertical soil or waste pipe may carry both sanitary sewage and storm sewage, and the drainage system can't have unused open ends, keeping the two systems separate and fully connected.
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.