Spencerville Lagoons Wastewater Treatment Plant - Edwardsburgh/Cardinal, Ontario

Spencerville Lagoons is a wastewater treatment plant located in Edwardsburgh/Cardinal, Ontario, Canada. It serves a small population of 1,204 residents in the rural community of Spencerville, within the Leeds and Grenville Counties region. The plant is situated near County Road 21 in Shanly, part of Eastern Ontario. As a lagoon-based system, the plant provides natural treatment through settling and biological processes, typical for small communities in Ontario. The facility has a designed capacity of 1.00 million liters per day, which aligns with the population served. Under Ontario's regulatory framework, such plants operate under the Ontario Water Resources Act and are subject to Environmental Compliance Approvals (ECAs) that govern discharge quality. The treated effluent from Spencerville Lagoons is discharged into a local watercourse that eventually drains into the St. Lawrence River, a major waterway connecting the Great Lakes to the Atlantic Ocean. The plant plays a key role in protecting downstream aquatic ecosystems, including fish habitats and recreational waters in the St. Lawrence River basin.

The plant discharges into a local tributary of the St. Lawrence River, which flows from Lake Ontario to the Atlantic Ocean. The St. Lawrence River supports diverse aquatic life, including fish species such as walleye and bass, and is an important migratory corridor. The watershed is ecologically sensitive due to its role in the Great Lakes system, and the plant's treatment helps maintain water quality in this downstream environment.