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 Drinking Water Quality 

Discoloured Water

Niagara Region is doing scheduled maintenance work on several watermains in St. Catharines. Work started March 17 and will last for three to four weeks.

This maintenance work may cause slight tap water discolouration. If your tap water appears discoloured, please run your taps until the water runs clear.

Your tap water remains safe and reliable to drink.

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 Treatment

The Decew Water Treatment plant is a conventional surface treatment plant which incorporates zebra mussel control, screening, chemically assisted flocculation, coagulation, sedimentation, filtration and disinfection using sodium hypochlorite and ultraviolet light.

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 905-688-5601 ext. 2197 or email the Environmental Services Division.

Email Environmental Services regarding Drinking Water Testing.

Drinking Water Quality Management System (DWQMS)

As part of the Ministry of the Environment's Municipal Drinking Water Licencing 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% of the earth's water is salt water and 2% is frozen in ice, making only 1% of water available for drinking.

  • Every year, more than 3000 drinking water samples are taken and analyzed.

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

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

Public Information Factsheets

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

Download the Drinking Water Frequently Asked Questions factsheet

Download the Seasonal Taste and Odour Issues in Drinking Water factsheet

Click here to Download the Lead and Drinking Water factsheet

Download the Lead Exceedances in Drinking Water factsheet

Additional information

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

Email the Environmental Services Department.

The Niagara Region has additional information concerning the drinking water supply available on their website. 

Visit the Niagara Region website.

The Niagara Region's Public Health Department also has additional information on water quality. 

Visit the Niagara Region Public Heath Departmart website.

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