View the most recent drinking water quality reports below:
2026
2025
Water Quality
The Ontario government has enacted a new drinking water regulation under the Safe Drinking Water Act, 2002. These changes were designed to safeguard the quality of Ontario's drinking water, while making the regulatory requirements more workable and affordable for owners and operators of municipal and non-municipal drinking water systems.
Ontario's Drinking Water Systems Regulation 170/03, made under the Safe Drinking Water Act, 2002, governs the operation of municipal drinking water systems. This regulation provides specific requirements that municipalities must adhere to in the operations of these systems, including:
- water system operational checks
- water quality sampling/testing and reporting
- corrective action requirements
Drinking Water systems
The City of Thorold owns and operates three drinking water systems that fall under this regulation:
- Thorold DeCew Distribution System (No. 220004313)
- Thorold Port Robinson System (No. 260049582)
- Thorold South End System (No. 260049621)
For procedures on how to flush the taps in your own home, please view the A Made in Niagara Guide to Flushing your Facility for more information.
Quarterly and Annual Reports
View our Annual Report and all drinking water sample results below:
- 2025 Annual Water Quality Report - Decew
- 2025 Annual Water Quality Report - Port Robinson
- 2025 Annual Water Quality Report - South End
- 2025 Operational Plan - Drinking Water Quality Management System - available upon request.
2020 - Financial Plans and Statements
- 2020 Water Financial Plan
- 2020 Drinking Water Supply System - Cash Flow Statement
- 2020 Drinking Water Supply System - Projected Statement of Financial Operations
- 2020 Drinking Water Supply System - Projected Financial Position Statement
Copies of these reports are also available for viewing at City Hall and the Thorold Public Library.
In accordance with Section 11 (1) of Ontario's regulation 170/03, the owner of a drinking water system shall ensure that an annual report is prepared in accordance with the requirements of Section 11.
The annual report must be:
- Given without charge to every person who requests a copy. Effective steps must be taken to advise users of the system that copies of the report are available and how they can be obtained.
- Posted to the municipality's web site if the drinking water system is a large municipal residential system serving more than 10,000 people.
- Given to the owner of any other drinking water system that is connected to and receiving all of its drinking water from the system that is the subject of the annual report.
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