Water Quality & Treatment

All water distributed in the Regional Municipality of Waterloo system must meet high levels of quality legislated by the Ontario Ministry of Environment.

About 80 per cent of water used throughout the Region comes from wells. The remainder comes from the Grand River. Water treatment facilities, water storage reservoirs, and pumping stations located throughout the Region distribute treated water to consumers.

Grand River water is treated at the Mannheim Water Treatment Plant. To see a description and schematic of the treatment process use the links below:

Raw and treated water from both sources is required to be tested by an accredited lab for more than 120 water quality characteristics, such as physical and chemical, organic/inorganic and microbiological parameters. Legislation requires that all these tests be done on a predetermined schedule.

The Environmental Enforcement Laboratory at 100 Maple Grove Rd. in Cambridge is an accredited lab for the Region. It is responsible for all testing and enforcement of the Sewer Use Bylaw and responds in the event of spills.


Municipal Drinking Water Licensing Program (MDWLP)

Based on the Walkerton Inquiry recommendations, the Ministry of the Environment implemented the Municipal Drinking Water Licensing Program (MDWLP) through regulation, O. Reg. 188/07.

Upon successfully meeting the following criteria, the Region of Waterloo was issued its first Municipal Drinking Water Licenses (MDWLs) and Drinking Water Works Permits (DWWPs) by the Ministry of the Environment in May 2011:

  1. A Drinking Water Works Permit (DWWP), replaces Certificate of Approval (C of A),
  2. A Permit to Take Water (PTTW), already existing,
  3. An MOE accepted Operational Plan, based on the Drinking Water Quality Management Standard (DWQMS),
  4. An Accredited Operating Authority, achieved by passing a third party audit of the DWQMS, and
  5.  A Financial Plan, as required by regulation O. Reg. 453/07.


Quality Management System (QMS)

The QMS is based on 21 elements of the Drinking Water Quality Management Standard (DWQMS).  The DWQMS was adopted from principals and standards of ISO systems requiring a PLAN, DO, CHECK and IMPROVE components in controlling quality.  The QMS establishes policies and procedures in the management of the Region's drinking water systems and focuses on the following:

  • A proactive approach to identify and mange risks to public health
  • Establishes and documents management procedures
  • Continual improvement of the QMS

The Region of Waterloo received "Full Scope - Entire DWQMS" accreditation  in March 2013, following a successful third party audit.  The Region will continue to maintain and improve the Quality Management System.


To view the policy, click on Quality Management System Policy.

To view the Distribution Financial Plan, click on Region of Waterloo Water Services Distribution Financial Plan.

To view the Water Supply Financial Plan, click on Region of Waterloo Water Services Water Supply Financial Plan.

For more information about the Quality Management system, please contact the Call Centre at 519-575-4400 or by email waterops@regionofwaterloo.ca.

Annual Water Quality Reports

As required by the Ministry of Environment, the Region completes annual Water Quality Reports for Consumers and Summary Reports. The reports confirm that drinking water supplied by the Region and area municipalities is safe and has met all health-related Ontario Drinking Water Standards. The Province of Ontario sets the level of quality that is to be maintained for all Drinking Water in Ontario and the quality standards are defined in the legislation O. Reg.169/03

Use the links below to view a report or see our Glossary of Commonly Used Terms included in the Reports. The Safe Drinking Water Act requires that both the Region of Waterloo as well as the Cities and Townships produce Annual Water Quality and Summary Reports. See links to the Cities' and Townships websites at the bottom of the page to access these reports.

Annual Water Quality Reports



Annual Summary Reports



Copies of earlier reports are available by calling 519-575-4400.

Questions or comments?   

If you need more information or have questions or comments about the Region's water quality or supply, refer to Water Quality Frequently Asked Questions, contact the Call Centre at 519-575-4400, or contact Water Operations & Maintenance by email at waterops@regionofwaterloo.ca.