Irondale WWTP - Secondary Treatment Facility in Irondale, Missouri

Irondale WWTP is a municipal wastewater treatment facility located in Irondale, Missouri, United States. The plant serves a small population of 445 residents, reflecting its role in a rural community within Washington County. The facility provides secondary treatment, which is the standard level required by the U.S. Clean Water Act for municipal plants discharging to surface waters. With a designed capacity of 227.12 megaliters per year and an annual discharge volume of 151.42 megaliters, the plant operates below its capacity, indicating room for future growth. The treated effluent is discharged into a local waterway, ultimately contributing to the Meramec River basin and the Mississippi River watershed. This downstream system supports diverse aquatic life and provides recreational and drinking water resources for communities along its course.

The plant discharges into a tributary of the Meramec River, which flows into the Mississippi River and eventually the Gulf of Mexico. The Meramec River basin is ecologically significant, supporting species such as the Ozark hellbender and various freshwater mussels. The plant's secondary treatment helps protect water quality in this sensitive watershed.