Municipal wastewater is one of the largest sources of pollution discharged in Canada’s lakes, rivers and oceans. Through the Canada-wide Strategy for the Management of Municipal Wastewater Effluent (the Strategy) governments have developed a consistent approach to managing wastewater across Canada.
Under the Strategy, all wastewater facilities should eventually achieve a minimum of secondary level treatment. Facilities must regularly monitor and report on the quality of the effluent being discharged.
Newfoundland and Labrador, Québec and Nunavut agree with the environmental and public health objectives of the Strategy, but they have not endorsed it. Newfoundland and Labrador and Québec have voluntarily agreed to participate in this report on progress.
Municipal wastewater consists of sanitary sewage from homes, businesses, industries and institutions as well as the rain and melted snow that drain into sanitary sewers. Municipal wastewater typically contains human and other organic waste, nutrients, pathogens, microorganisms, suspended solids and household and industrial chemicals. Treating wastewater before it is released into lakes and rivers reduces the risks posed to human health and the environment.
National Performance Standards are the minimum requirements for effluent quality from all municipal wastewater facilities that discharge into lakes, rivers and oceans. The National Performance Standards do not apply to sanitary or combined sewer overflows or to facilities located in geographic areas where extreme climatic conditions impede treatment, such as Canada’s Far North.
While all municipal wastewater facilities are required to meet the National Performance Standards immediately, provisions for staggered deadlines to the end of 2020, 2030 and 2040 were offered to existing facilities that needed upgrades. This was put in place to give the necessary time to plan, finance and construct new infrastructure, while ensuring that improvements are made to the highest risk wastewater facilities first. The National Performance Standards form the basis of the federal government’s Wastewater Systems Effluent Regulations.
Carbonaceous Biochemical Oxygen Demand (CBOD5)
The National Performance Standard for carbonaceous biochemical oxygen demand is 25 mg/L.
CBOD5 is the amount of dissolved oxygen required by microorganisms to break down organic carbon and inorganic material in a wastewater sample. When wastewater with a high CBOD5 value is returned to a natural water body, it poses a greater risk of depleting oxygen, harming aquatic organisms and disrupting ecological processes.
Total Suspended Solids (TSS)
The National Performance Standard for TSS is 25 mg/L.
Total suspended solids refers to silt, clay, metals, and other organic and inorganic materials that are undissolved in wastewater. Suspended matter not only decreases water clarity, but harmful bacteria, viruses and heavy metals may attach to the particles and spread through waterways.
Total Residual Chlorine (TRC)
The National Performance Standard for TRC is 0.02 mg/L.
Some wastewater treatment facilities use chlorine as a disinfectant. Chlorine is toxic to aquatic organisms so it must be removed from wastewater before it is discharged to lakes, rivers and oceans. Since the implementation of the Strategy, governments have moved away from using chlorine in favour of other methods of disinfection.
Most wastewater facilities meet the National Performance Standards. Federal, provincial, territorial and municipal governments, as well as private companies continue to upgrade and improve wastewater treatment facilities so that by the end of 2040, all wastewater treatment facilities should meet the National Performance Standards. Wastewater treatment facilities that currently do not meet the National Performance Standards may still comply with regulations if they have been approved for one of the staggered deadlines.
Data
Data include wastewater facilities owned by municipalities, communities, provincial and federal governments, private companies, and facilities on Indigenous lands.
Only facilities that process over 100 cubic metres per day of influent have been included. Wastewater facilities from Northwest Territories and Nunavut are not included because the National Performance Standards do not apply in Canada’s Far North.
Data for CBOD5 and TSS were obtained from the Government of Canada’s Effluent Regulatory Reporting Information System (ERRIS), which contains the data reported under the Wastewater Systems Effluent Regulations and through equivalency agreements with provinces and territories.
There is no standardized reporting for TRC, therefore federal, provincial and territorial governments provided their own reports on achievement, which may not match the quality or consistency of data from ERRIS. Facilities achieving the National Performance Standard for TRC include those that do not use chlorination for disinfection as well as those that have functioning dechlorination systems in place.
Newfoundland and Labrador did not endorse the Strategy because of the disproportionate costs associated with its implementation, especially for small communities. Approximately 97% of municipal wastewater facilities in Newfoundland and Labrador are considered small or very small.
Progress can also be visualized by the volume of municipal wastewater effluent that achieves the National Performance Standards. While there are many very small facilities that are not yet achieving the National Performance Standards, their contribution to the overall volume is small. Conversely, there are a small number of very large wastewater treatment facilities that will need to be upgraded before Canada as a whole meets the 2040 target.
Data include wastewater facilities owned by municipalities, communities, provincial and federal governments, private companies, and facilities on Indigenous lands. Only facilities that process over 100 cubic metres per day of influent have been included. Wastewater facilities from Northwest Territories and Nunavut are not included because the National Performance Standards do not apply in Canada’s Far North.
Data were obtained from ERRIS, which contains the data reported under the Wastewater Systems Effluent Regulations and through equivalency agreements with provinces and territories. There is no standardized reporting for TRC, therefore volumetric data are not available.
Wastewater facilities can achieve the National Performance Standards through secondary level wastewater treatment. By volume, most wastewater released into the environment is treated to a secondary level. Governments are directing resources to address the remaining 25% of undertreated or untreated wastewater effluent by 2040.
No treatment means wastewater is not treated or has limited screening or grit removal before being released into the environment.
Primary treatment involves the removal of a portion of suspended solids and organic matter by physical and/or chemical processes.
Secondary treatment involves further removal of suspended solids and organic matter using biological treatment processes.
Data were obtained from ERRIS based on data reported under the Wastewater Systems Effluent Regulations and through equivalency agreements with provinces and territories.
The map shows the total investment in wastewater infrastructure upgrades by federal, provincial, territorial and municipal governments through cost-sharing agreements since 2002, as reported by Infrastructure Canada in September 2023. Investments include upgrades to pumping stations, sewer systems and wastewater treatment facilities. There have been upgrades and investments by provincial, territorial and municipal governments outside of cost-sharing agreements that are not reported here.
Amount invested: Over $14 Billion
Number of Projects: More than 3,700
Select a province or territory below to learn more