20230419 09381900 1.0 TRUE Archived - Total CSO Volume This layer group represents the total effluent volume in cubic meters (m3) deposited via a combined sewer overflow (CSO) point for each wastewater system. The results are presented on an annual basis, with one layer for each year. Environment and Climate Change Canada and ministère de l’Environnement et de la Lutte contre les changements climatiques du Québec