Drinking Water Quality

Discover how the City of Cornwall works every day to maintain and protect your drinking water. Even water that looks clean can contain invisible germs like bacteria and viruses. To keep you safe, we thoroughly treat and continuously test every drop of water that enters our system, ensuring your tap water is clean and healthy to drink. We operate our water systems under Ontario’s Safe Drinking Water Act of 2002, which guarantees your right to safe water through strict treatment, testing and controls. 

Water treatment system

The City of Cornwall owns and operates our local drinking water system. We draw water from the St. Lawrence River and treat it to the highest provincial standards before delivering it to your home or business.

Key facts about our system:

• We pump over 11 million cubic metres of clean water each year through more than 270 kilometres of water pipes.
• Our treatment process uses filtration, chlorine, and ultraviolet light to ensure the water is safe.
• The system is rigorously inspected and has consistently earned a 100% compliance rating from the Ministry of the Environment.

To understand how we fund our systems, you can view our most recent Water and Wastewater Financial Plan.

Drinking Water Quality Management System

We are committed to providing safe, high-quality drinking water to our community. To ensure we consistently meet this goal, we have created and use a certified Drinking Water Quality Management System (DWQMS) that follows all provincial regulations.

As part of our DWQMS, we are committed to providing you with safe, clean drinking water. Our promise includes:

• Meeting all provincial safety laws and regulations
• Continuously maintaining and improving our water system
• Promptly resolving any water quality issues
• Regularly investing in our water infrastructure

For more information on our DWQMS, you can view the Ministry of the Environment, Conservation and Parks' Drinking Water Quality Management Standard and our DWQMS Operational Plan.

Drinking water quality reports

As required by the Province of Ontario, we publish Drinking Water Quality Reports once a year:

• 2025 Drinking Water Quality Report
• 2024 Drinking Water Quality Report
• 2023 Drinking Water Quality Report

Our Drinking Water Quality Reports confirm that we provided a safe and clean water supply throughout the year. These reports give you a detailed look at our water system, including:

• All testing results and water quality measurements
• Updates on our water treatment and distribution systems
• The status of our safety management program and water meter installation

Source water protection

Our drinking water comes from the St. Lawrence River. To keep this source water clean, we follow a plan required by Ontario's Clean Water Act.

Our protection plan

The Raisin-South Nation Source Protection Committee developed an Assessment Report and a Source Water Protection Plan for us. The Assessment Report maps our Source Protection Area and identifies activities that could threaten our water. It also establishes two Intake Protection Zones around our water intake, based on how quickly contaminated water could travel to it.

We also created a Source Water Protection Implementation Guide to ensure we have the tools to meet all obligations of the Clean Water Act. Protecting our source water is a vital step in delivering safe drinking water and keeping our river environment healthy.