ARMSTRONG WWTP - Emmet County, Iowa Wastewater Treatment Plant

ARMSTRONG WWTP is a municipal wastewater treatment facility located on State Highway 15 in Emmet County, Iowa. It serves a small community of approximately 1,025 residents, reflecting the rural character of the region. The plant is situated in the northern part of Iowa, near the Minnesota border, within the Des Moines River basin. The plant provides secondary treatment, which is the standard level required by the U.S. Clean Water Act for municipal facilities of this scale. Secondary treatment uses biological processes to reduce organic matter and suspended solids. The plant has a designed capacity of 757.08 volume units and currently discharges an average of 412.61 volume units, indicating it operates below its design capacity. As a U.S. facility, it operates under a National Pollutant Discharge Elimination System (NPDES) permit issued by the Iowa Department of Natural Resources, which sets effluent limits to protect water quality. The treated effluent from ARMSTRONG WWTP is discharged to a local receiving water body, which ultimately drains into the Des Moines River and then to the Mississippi River. This watershed supports diverse aquatic life and provides drinking water for downstream communities. The plant's secondary treatment helps reduce nutrient loads that could contribute to algal blooms in the Mississippi River and the Gulf of Mexico hypoxic zone.

The ARMSTRONG WWTP discharges into a tributary of the Des Moines River, which flows southeast to the Mississippi River. The Des Moines River basin is a major agricultural region, and nutrient runoff from both point and non-point sources can impact water quality. The plant's secondary treatment helps mitigate local pollution, but downstream ecosystems, including the Mississippi River and the Gulf of Mexico, benefit from reduced nutrient loads. The area supports diverse fish and wildlife, including migratory birds along the Mississippi Flyway.