ST MARY WWTP - St. Mary, Missouri Wastewater Treatment Plant

ST MARY WWTP is a municipal wastewater treatment facility located in St. Mary, Missouri, a small community in Ste. Genevieve County. The plant serves a population of 360 and is part of the region's wastewater infrastructure, handling domestic sewage from the area. As a secondary treatment plant, it provides biological treatment to reduce organic pollutants and suspended solids before discharge. The plant operates under the US Clean Water Act, which requires NPDES permits for all point source discharges. For small communities like St. Mary, secondary treatment is the standard requirement, ensuring effluent meets federal water quality standards. The plant's designed capacity is 370.97 volume units, with a current discharge volume of 162.77, indicating it operates below capacity. The treated effluent from ST MARY WWTP is discharged into local streams that drain into the Mississippi River system. This watershed supports diverse aquatic life and provides drinking water for downstream communities. The plant's location inland, away from coastal areas, reduces direct marine impact, but its discharge contributes to the overall water quality of the Mississippi River basin.

ST MARY WWTP discharges into local tributaries of the Mississippi River, which flows into the Gulf of Mexico. The Mississippi River basin is a major ecological corridor, supporting fish, migratory birds, and other wildlife. The plant's secondary treatment helps protect water quality in this sensitive watershed, reducing nutrient loads that can contribute to hypoxia in the Gulf.