Statistics Canada has released a report on municipal wastewater systems in Canada from 2013 to 2017.
According to the study, just over 5 900 million cubic metres of sewage flowed through municipal wastewater systems in Canada that processed 100 cubic metres per day or more of sewage in 2017, equivalent to the volume of water that flows over Niagara Falls over a 24-day period.
An additional 164 million cubic metres were discharged from combined sewer overflows in 2017. Combined sewer systems convey both storm water and sewage to wastewater treatment plants.
In 2017, 1 535 million cubic metres were discharged from primary treatment systems, which removes a portion of suspended solids and organic matter by physical and/or chemical processes.
Secondary treatment systems, which remove biodegradable organic matter and suspended solids using biological treatment processes and secondary settlement, processed 2 827 million cubic metres.
Tertiary systems, which further remove residual suspended solids, nutrients and/or other contaminants using various physical, chemical or biological processes, released 1 442 million cubic metres.
Systems that provide no treatment discharged 106 million cubic metres of wastewater back into the environment.
In 2017, just over 30 million people were served by municipal wastewater systems that have daily flows that process 100 cubic metres per day or more. Primary treatment systems served 4.8 million people, secondary treatment systems processed wastewater for 15.1 million people, while 9.8 million Canadians were served by tertiary treatment systems.
Monthly volumes of wastewater collected and discharged from municipal wastewater systems increased during spring snow melt from 2013 to 2017.
Read the whole report here.