Degrilleur Wastewater Treatment Plant, Saint-Irénée, Québec

Degrilleur is a municipal wastewater treatment plant located at 537 Chemin des Bains in Saint-Irénée, a small community in the Charlevoix-Est region of Québec, Canada. The plant serves a population of 478 and operates under secondary treatment, meeting Canadian federal and provincial standards for wastewater management. As a secondary treatment facility, Degrilleur employs biological processes to reduce organic matter and suspended solids, ensuring effluent quality aligns with the Wastewater Systems Effluent Regulations (WSER) under the Canadian Environmental Protection Act. For small agglomerations like Saint-Irénée, secondary treatment is the standard requirement to protect receiving waters. The plant discharges 450 m³/day of treated wastewater into a local watercourse that flows into the St. Lawrence River, a major waterway and ecologically significant estuary. The St. Lawrence River supports diverse aquatic life, including fish species such as Atlantic salmon and sturgeon, and is a critical migratory corridor for birds. The plant's coastal location within 10 km of the river underscores the importance of effective treatment to minimize nutrient and contaminant loads.

The treated effluent from Degrilleur enters a small stream that drains into the St. Lawrence River, one of the largest rivers in North America. The St. Lawrence River estuary is a dynamic ecosystem that supports rich biodiversity, including fish, marine mammals, and migratory birds. The plant's proximity to the coast means that any nutrient or pollutant discharge could affect downstream water quality and the health of the estuary, which is a vital habitat for species like the beluga whale and various waterfowl.