Water Purification and Treatment Process

On an ordinary day, the human body loses about two litres of water through breathing, perspiration and excretion. It's important that we replace that lost fluid with clean, safe water. While the waterborne transmission of typhoid fever, diphtheria, cholera and several other intestinal diseases has decreased by over 98 percent in Canada during the last 50 years, our water still needs to be purified and treated before we drink it.

Constructed in 1874, Ottawa's original water supply system was located in the Fleet Street pumping station. This station used the hydraulic energy of the Ottawa River's Chaudiere Falls to pump untreated river water into the distribution system. In 1915, an electric motor-driven pumping station was constructed on Lemieux Island followed by a complete water purification plant in 1932. The Britannia water purification plant began operations in 1961. Today, these plants are part of a system that produces and distributes an average of 290 million litres of water a day.

The system draws water from the Ottawa River then, using the most effective processes and equipment available, treats it to remove colour, suspended particles, algae, vegetation, bacteria and viruses. Our water-purification processes are continuously monitored, ensuring that high-quality water is pumped out of the plants and maintained as it travels through the distribution system. The result is water that is sparkling clear, fresh tasting and safe to drink.

Water Purification Process Flow Chart

Click to enlarge

The City of Ottawa operates five ground water wells that supply drinking water to most residents in the communities of Vars, Richmond, Shadow Ridge, Munster Hamlet and Carp. The communal well water is disinfected using a process of continual chlorination; the Vars well is further treated using a grit removal and activated carbon filtration system.

City Water staff perform over 100,000 water quality tests per year covering over 350 different parameters to ensure safe and palatable drinking water for all users of the municipal distribution system. These tests cover a broad spectrum and provide information on the physical, inorganic, organic, microbiological and radiological characteristics of the water. The results are then analysed to confirm that quality is maintained as the water travels through the distribution system on its way to homes and workplaces in Ottawa we invite you to consult our Reports on Drinking Water Quality.

In addition to these process and distribution system tests, our water quality specialists are available to respond to customer inquiries and concerns. It's our job to investigate and resolve problems quickly and efficiently. Please feel free to contact us if you have any questions.