Arthur Lagoon Wastewater Treatment Plant, Arthur, North Dakota

Arthur Lagoon is a municipal wastewater treatment facility located in Arthur, North Dakota, a small town in Cass County. The plant serves a population of approximately 337 residents, classifying it as a small-scale treatment facility under US EPA regulations. It operates under the Clean Water Act, which requires secondary treatment for municipal discharges to protect water quality. The plant employs secondary treatment, a standard biological process that removes organic matter and suspended solids. With a designed capacity of 113.56 million gallons per day and a discharge volume matching that figure, the facility is operating at full capacity. As a small community plant, it is subject to state-level NPDES permitting through the North Dakota Department of Environmental Quality, ensuring compliance with effluent limits. The treated effluent from Arthur Lagoon ultimately drains into the Red River Basin, which flows north into Canada and empties into Lake Winnipeg. This watershed supports diverse aquatic life and is an important migratory corridor for birds. The plant's discharge contributes to the overall water quality in the basin, requiring careful management to prevent nutrient loading and protect downstream ecosystems.

Arthur Lagoon discharges into local tributaries of the Red River, which flows northward through North Dakota and Manitoba into Lake Winnipeg. The Red River Basin is a flat, agricultural region prone to seasonal flooding, and its waters support fish species such as walleye and northern pike. Nutrient runoff from agriculture and wastewater can contribute to algal blooms in Lake Winnipeg, making effective treatment at plants like Arthur Lagoon critical for downstream water quality.