Treatment types of the wastewater systems in Canada subject to the Wastewater Systems Effluent Regulations

The Wastewater Systems Effluent Regulations (WSER), developed under the Fisheries Act, came into force in 2012 to manage wastewater releases by systems that collect an average daily influent volume of 100 cubic metres or more. The WSER also does not apply to any wastewater system located in the Northwest Territories, Nunavut and north of the 54th parallel in the provinces of Quebec and Newfoundland and Labrador. The WSER set national baseline effluent quality standards that are achievable through secondary wastewater treatment.

The map below presents the wastewater system locations in Canada and the type of treatment they utilize (mechanical, lagoon or no treatment). The data is based on the information submitted to Environment and Climate Change Canada as of November 2022. Note that this layer does not represent the level of wastewater treatment or whether the system complies with the WSER.

The map is available in both ESRI REST (to use with ARC GIS) and WMS (open source) formats. For more information about the individual reporting wastewater systems, datasets are available in either Excel or CSV formats at the resource listed below: “Wastewater Systems Effluent Regulations Reported Data”.

Data from Quebec and Yukon

The data for Quebec municipalities (after 2017) is provided to the department separately through the equivalency agreement that was finalized in October 2018. Beginning in 2015, the data reported for the Yukon is provided to the department separately through an equivalency agreement finalized in 2014.

More information on the wastewater sector including the regulations, agreements, contacts and resource documents is available at: https://www.canada.ca/wastewater

Data and Resources

Additional Info

Field Value
Last Updated April 17, 2026, 18:08 (UTC)
Created April 17, 2026, 18:08 (UTC)
contact_email ec.eaux-usees-wastewater.ec@canada.ca
contact_person {"fr": "Gouvernement du Canada; Environnement et Changement climatique Canada,ec.enviroinfo.ec@canada.ca", "en": "Government of Canada; Environment and Climate Change Canada,1-800-668-6767,ec.enviroinfo.ec@canada.ca"}
criticality_level []
data_dictionary ["environment"]
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open_canada_date_published 2022-02-25 00:00:00
open_canada_keywords {"fr": ["Test réglementaire", "eaux usées", "eau", "rejet", "effluent", "eaux-vannes", "SIRRE", "RESAEU", "DBOC", "demande biochimique en oxygène de la partie carbonée", "matières en suspension", "ammoniac non ionisé", "chlore résiduel total", "létalité aiguë", "surverses des égouts unitaires", "surveillance", "rapports", "traitement", "Loi sur les pêches", "substances nocives", "pollution de l'eau", "qualité de l'eau", "Eaux usées", "Règlements", "Évaluer la toxicité de la présence dans l'environnement des substances et des déchets dangereux; les gérer et les surveiller", "Planifier et mettre en œuvre l'infrastructure de surveillance dans le but d'évaluer la présence et les niveaux de substances préoccupantes", "National (CA)", "Direction générale de l'intendance environnementale", "Direction des secteurs industriels", "3.1.2 Gestion des effluents", "Non Classifié"], "en": ["Statutory Instrument", "wastewater", "water", "discharge", "effluent", "sewage", "ERRIS", "WSER", "CBOD", "carbonaceous biochemical oxygen demand", "suspended solids", "un-ionized ammonia", "total residual chlorine", "acute lethality", "combined sewer overflow", "monitoring", "reporting", "treatment", "Fisheries Act", "deleterious substances", "water pollution", "water quality", "Waste water", "Regulations", "Assess Toxicity; Manage and Monitor for Environmental Presence of Hazardous Substances and Waste", "Plan and Implement Monitoring Infrastructure to Assess Presence and Levels of Substances of Concern", "National (CA)", "Environmental Stewardship Branch", "Industrial Sectors Directorate", "3.1.2. Effluent Management", "Unclassified"]}
open_canada_subject ["nature_and_environment"]
sensitivity_level unrestricted
title_fr Types de traitement des systèmes d’assainissement des eaux usées au Canada assujettis au Règlement sur les effluents des systèmes d’assainissement des eaux usées
update_frequency P1Y