Notice of Study Completion: Municipal Class Environmental Assessment Study - Mid-Halton Wastewater Treatment Plant Expansion

About the study

Halton Region has undertaken a Municipal Class Environmental Assessment (MCEA) for the expansion of the Mid-Halton Wastewater Treatment Plant, as identified in the 2011 Sustainable Halton Water and Wastewater Master Plan.

The recommended solution is to expand the Plant’s wastewater treatment capacity from 125 million litres per day (ML/d) to 195 ML/d by 2031 to meet future demands and support growth. The expansion will take place within the existing plant boundary and will be achieved using treatment process technologies similar to those currently in use at the Plant.

Process and consultation

The study was completed in accordance with Schedule C of the MCEA process (October 2000, as amended 2007, 2011, 2015, 2023 and 2024), which is an approved process under the Ontario Environmental Assessment Act. A key component of the MCEA process is consultation with the public, review agencies, Indigenous Communities, First Nations and Métis Communities, and other interested parties. Two Public Information Centres were held throughout the study to obtain input on the project. An Environmental Study Report has been prepared, which documents the planning, public consultation, and decision-making process for this study.

Comments and more information

By this Notice, the Environmental Study Report is being placed on the public record for a 30-day review period starting March 2, 2026 and ending March 31, 2026, in accordance with the requirements of the MCEA process. Subject to comments received as a result of this Notice, and the receipt of necessary approvals, Halton Region intends to proceed with the detailed design and expansion of the Mid-Halton Wastewater Treatment Plant.

The Environmental Study Report is available online for public review through the MCEA Study page on halton.ca. We invite you to review the Report and provide any comments or questions on or before March 31, 2026. To submit your comments, or if you wish to review the report in hard copy or require an alternative format to meet accessibility needs, please contact one of the project team members below.

In addition, a request to the Minister of the Environment, Conservation and Parks for an order imposing additional conditions or requiring an individual environmental assessment may be made on the grounds that the requested order may prevent, mitigate, or remedy adverse impacts on constitutionally protected Indigenous and treaty rights. Requests should include your full name and contact information.

Requests should specify what kind of order is being requested (additional conditions or a comprehensive environmental assessment), explain how an order may prevent, mitigate, or remedy potential adverse impacts, and include any supporting information. The request should be sent in writing or by email to:

Requests should also be copied to the Halton Region’s Project Manager, Erica Wilson, P.Eng.

Information provided in response to this notice will be collected in accordance with the Municipal Freedom of Information and Protection of Privacy Act. With the exception of personal information, all comments will become part of the public record.

This Notice was first issued on March 2, 2026.