Etangs aeres Sainte Marie - Sainte-Marie, Quebec Wastewater Treatment Plant

Etangs aeres Sainte Marie is a wastewater treatment plant located in Sainte-Marie, Quebec, Canada. The facility serves a population of approximately 8,804 residents in the Chaudière-Appalaches region. It is situated inland, more than 50 km from the coast, and treats municipal wastewater from the community. As an aerated lagoon system, the plant provides secondary-level treatment, which is typical for small to medium-sized agglomerations in Canada. Under Canadian federal and provincial regulations, such facilities are required to meet effluent quality standards set by Environment Canada and the Quebec Ministry of the Environment. The plant has a designed capacity of 1.00 million cubic meters per year, indicating it is sized appropriately for the population served. The treated effluent from the plant is discharged into local waterways that ultimately drain into the St. Lawrence River via the Chaudière River basin. This watershed supports diverse aquatic life and is an important ecological corridor in southern Quebec. Proper treatment helps protect downstream water quality and the St. Lawrence River ecosystem.

The plant discharges into the Chaudière River watershed, which flows northward into the St. Lawrence River near Quebec City. The St. Lawrence River is a major waterway that supports diverse fish populations, including Atlantic sturgeon and American eel, and serves as a critical migratory route for birds. The region's agricultural and urban runoff can impact water quality, making effective wastewater treatment essential for maintaining the ecological health of the river system.