The Ontario Building Code | Classification of Systems
8.1.2.1. Classification of Systems
(1) All sewage systems shall be classed as one of the following:
(a) Class 1 — a chemical toilet, an incinerating toilet, a recirculating toilet, a self‑contained portable toilet and all forms of privy including a portable privy, an earth pit privy, a pail privy, a privy vault and a composting toilet system,
(b) Class 2 — a greywatersystem,
(c) Class 3 — a cesspool,
(d) Class 4 — a leachingbed system, or
(e) Class 5 — a system that requires or uses a holding tank for the retention of hauled sewage at the site where it is produced prior to its collection by a hauled sewage system.
In Plain Language
Private sewage systems are classified into different classes based on their design and treatment method, and this article sets out that classification system used throughout the rest of this Part.
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.