Drinking Water Quality

Stagnant Drinking Water

In buildings where the plumbing has remained out of use for more than a week, such as businesses temporarily closed due to COVID-19, drinking water left sitting in pipes can become stagnant. Stagnant water can contain harmful bacteria, and unwanted chemicals.

Occupants of buildings where the plumbing has been out of use should flush their system before use by running all their taps and faucets until the water runs cold and clear.

For more information check out our Stagnant Drinking Water Guide.

Community Lead Testing Program

The City of St. Catharines is looking for volunteers for our Community Lead Testing Program to test for lead in the drinking water of private residences and businesses.

Who can participate?

Anyone with a municipal water connection.

How does the process work?

The process is non-intrusive, and involves City staff collecting water samples from within a home or business, and sent to a third party accredited laboratory for testing. 

Want to participate?

Please contact Citizen First at 905-688-5600 for more information.

Drinking Water Monitoring Program

The City of St. Catharines water distribution system is classified by the Ministry of the Environment (MOE) as a Class II system. The City's waterworks consists of over 600 kilometres of watermains serving the local street network. This watermain network is one of several municipal networks supplied by the Decew Water Treatment Plant operated by the Regional Municipality of Niagara. The source of water for this plant is surface water, from Lake Erie via an intake from the Welland Canal located approximately six kilometres from the treatment plant, near Allanburg. The water is diverted to Decew's supply channel which flows by gravity directly to the treatment plant.

Water Sampling

The treated water enters the City's distribution system where it gets sampled daily for microbiological parameters and free chlorine residual.  A variety of additional parameters including lead, pH, alkalinity, trihalomethanes (disinfection by-products), iron, copper, magnesium, calcium, and sodium, are sampled on a regular basis as well.  Each year, thousands of samples are collected and analyzed.

The City of St. Catharines drinking water continually meets the Drinking Water Quality Standards set out by the Province of Ontario, proving that the City of St. Catharines drinking water is of excellent quality.

Free Drinking Water Testing

The City of St. Catharines offers free in-home drinking water testing to all residents on municipally treated water.  A licensed water quality technician will come to your home and collect a drinking water sample. 

For more information please call 905-688-5600 or email the Environmental Services Department.

Drinking Water Quality Management System (DWQMS)

As part of the Ministry of the Environment's Municipal Drinking Water Licensing Program, the City of St. Catharines is required to implement a Quality Management System.  The DWQMS is a "made in Ontario" management standard developed specifically for municipal drinking water systems.

Download the Drinking Water Quality Management System factsheet which includes the City's Quality Policy.

Did You Know?

  • 97 per cent of the earth's water is salt water and 2% is frozen in ice, making only 1 per cent of water available for drinking.

  • Every year, more than 3,000 drinking water samples are taken and analyzed.

  • There are 3,500 fire hydrants in the City of St. Catharines.

  • 28 per cent of our water is used for flushing toilets, while 27 per cent is used for showers. 

Public Information Fact Sheets

For frequently asked questions and concerns please refer to the fact sheets provided below.

Download the Drinking Water Frequently Asked Questions fact sheet

Download the Seasonal Taste and Odour Issues in Drinking Water fact sheet

Click here to Download the Lead and Drinking Water fact sheet

Additional information

For more information on the City's Drinking Water Monitoring Program  please call 905-688-5601 ext. 2197 or email the Environmental Services Department.

Additional information concerning the drinking water supply is also available on the Niagara Region's website.

Copyright © 2014 The Corporation of the City of St. Catharines