LARIMORE LAGOON Wastewater Treatment Plant, Grand Forks County, North Dakota

LARIMORE LAGOON is a wastewater treatment facility located in Grand Forks County, North Dakota, United States. The plant serves a small population of 1,346 residents, reflecting its role in a rural or small community setting. It operates as a lagoon system, a common treatment method for smaller agglomerations in the region. The plant provides secondary treatment, which is the standard level required under the US Clean Water Act for municipal wastewater. With a designed capacity of 416.39 m³/day and a current discharge volume of 378.54 m³/day, the facility operates below its capacity. As a US plant, it is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the state of North Dakota, ensuring compliance with effluent limits. The treated effluent is discharged into local surface waters, likely a nearby stream or river within the Red River Basin. This basin drains north into Lake Winnipeg in Canada, making the plant's operations relevant to transboundary water quality. The surrounding area is predominantly agricultural, so the plant helps protect downstream ecosystems from nutrient pollution.

The plant discharges into a waterway within the Red River Basin, which flows northward through North Dakota and Manitoba, Canada, eventually reaching Lake Winnipeg. Lake Winnipeg is a large, shallow lake prone to algal blooms due to nutrient loading from agricultural runoff and wastewater. The plant's secondary treatment helps reduce organic matter and nutrients, supporting the ecological health of the downstream river system and lake.