Crosby Lagoon Wastewater Treatment Plant, Crosby, North Dakota

Crosby Lagoon is a municipal wastewater treatment facility located near State Highway 5 in Crosby, Divide County, North Dakota. The plant serves a small population of 1,070 residents and operates with secondary treatment, which is the standard for communities of this size in the United States. The plant has a designed capacity of 1,514.16 m³/day and currently discharges an average of 946.35 m³/day of treated effluent. As a secondary treatment facility, it meets the minimum requirements under the U.S. Clean Water Act for removing organic matter and suspended solids before discharge. The treated effluent from Crosby Lagoon flows into the surrounding watershed, which is part of the Missouri River basin. The plant's inland location, far from coastal waters, reduces direct marine impact. The local environment includes prairie streams and agricultural land, where the treated water supports downstream aquatic habitats and irrigation needs.

Crosby Lagoon discharges into local streams that drain into the Missouri River system, ultimately reaching the Gulf of Mexico. The plant's inland location in the Great Plains means its effluent contributes to base flow in small prairie waterways, supporting fish and wildlife in a semi-arid region. The secondary treatment process helps protect downstream water quality from nutrient and organic pollution.