Sombra Lagoons Wastewater Treatment Plant, St. Clair, Ontario

Sombra Lagoons is a municipal wastewater treatment facility located in the community of Sombra, within the municipality of St. Clair in Lambton County, Ontario, Canada. The plant serves a population of about 6,876 residents and operates under Ontario's regulatory framework for wastewater treatment. As a lagoon-based system, the plant provides natural treatment through settling and biological processes, which is typical for smaller communities in Ontario. The designed capacity is 1.00 million gallons per day, and the plant is classified as a small-to-medium agglomeration under provincial guidelines. The treated effluent is discharged into the St. Clair River, which flows into Lake St. Clair and ultimately into the Great Lakes system. The plant plays a key role in protecting the water quality of the St. Clair River, a vital waterway that supports diverse aquatic life and provides drinking water for downstream communities.

The plant discharges into the St. Clair River, part of the Great Lakes Basin. The river connects Lake Huron to Lake St. Clair and supports a variety of fish species, including walleye and perch. The downstream environment includes Lake St. Clair, an ecologically important lake that provides habitat for migratory birds and aquatic life. Protecting water quality in this watershed is critical for maintaining the health of the Great Lakes ecosystem.