Granville Lagoon Wastewater Treatment Plant, Granville, North Dakota

Granville Lagoon is a municipal wastewater treatment facility located in Granville, McHenry County, North Dakota. It serves a small population of 241 residents, reflecting the rural character of the area. The plant operates as a lagoon system, a common treatment approach for small communities in the northern Great Plains. The plant provides secondary treatment, which meets the minimum federal standard under the U.S. Clean Water Act for municipal wastewater. With a designed capacity of 113.56 megaliters and an annual discharge volume of 75.71 megaliters, the facility operates below its capacity, indicating adequate headroom for current demand. As a small system, it is regulated under the National Pollutant Discharge Elimination System (NPDES) permit program, administered by the North Dakota Department of Environmental Quality. The treated effluent is discharged to local surface waters, likely a nearby stream or wetland that drains into the Souris River basin. The Souris River flows north into Canada, eventually reaching Hudson Bay. The plant's location in a semi-arid region means that maintaining water quality in receiving waters is important for downstream ecosystems and agricultural uses.

The plant discharges into a local watercourse that is part of the Souris River watershed, which flows northward through North Dakota into Manitoba, Canada, and ultimately drains into Hudson Bay. The receiving waters support aquatic life and are used for irrigation and livestock watering. The semi-arid climate means that stream flows are highly variable, and the plant's nutrient load could affect downstream water quality, particularly during low-flow periods. The region is also part of the Prairie Pothole Region, an ecologically sensitive area for migratory waterfowl.