On direction from the Board of Directors, OOWA struck a task group to review the proposed 2026 Ontario Building Code Part 8 changes related to Combined Treatment and Dispersal Systems. The task group brought together a cross-section of member perspectives from across the onsite wastewater industry, with a focus on helping ensure the proposed code language is clear, practical, and consistently understood by designers, installers, regulators, and other code users.
OOWA generally supports the proposed direction to incorporate Combined Treatment and Dispersal Systems into the Ontario Building Code. At the same time, our review identified several areas where the current draft language may create ambiguity or lead to inconsistent interpretation in the field. In particular, OOWA’s comments emphasize the need for clearer terminology, more precise requirements for sand depth and vertical separation, consistent expectations for even distribution, clearer detection provisions, and additional guidance on practical implementation details such as venting, sampling locations, and product-specific installation requirements.
The intent of OOWA’s submission is to support a code framework that can be applied reliably across Ontario while recognizing the technical realities of these systems. Clearer requirements will help reduce uncertainty during design, permit review, installation, inspection, and long-term system management.
Members and interested stakeholders are encouraged to review OOWA’s full submission, linked below, for the detailed recommendations provided in response to ERO number 026-0577.
