Old Monroe WWTP - Secondary Treatment Plant in Old Monroe, Missouri

Old Monroe WWTP is a municipal wastewater treatment plant located in Old Monroe, Lincoln County, Missouri, United States. The facility serves a small population of 250 residents and operates under the regulatory framework of the US Clean Water Act, which requires secondary treatment for municipal plants discharging to surface waters. The plant provides secondary treatment, a standard biological process that removes organic matter and suspended solids. With a designed capacity of 253.62 megaliters per year and an actual discharge volume of 113.56 megaliters per year, the plant operates well below its capacity, indicating room for future growth. The treated effluent is discharged to a local water body, likely a tributary of the Mississippi River, which ultimately drains to the Gulf of Mexico. The plant plays a role in protecting downstream water quality in the Mississippi River basin, a major ecological and economic corridor.

The plant discharges into a local water body within the Mississippi River basin, which flows into the Gulf of Mexico. The Mississippi River supports diverse aquatic life and is a critical migratory corridor for birds and fish. The plant's secondary treatment helps reduce nutrient loads that could contribute to the Gulf of Mexico hypoxic zone.