WASHINGTON STP 2 Wastewater Treatment Plant, Washington, Illinois

WASHINGTON STP 2 is a municipal wastewater treatment plant located at 898 Ernest Street in Washington, Tazewell County, Illinois. The facility serves a population of about 13,325 people, classifying it as a medium-sized agglomeration under U.S. regulatory standards. As a U.S. plant, WASHINGTON STP 2 operates under the Clean Water Act, administered by the Illinois Environmental Protection Agency (IEPA). Facilities of this scale typically require secondary treatment as a minimum, with permits specifying effluent limits for biochemical oxygen demand, total suspended solids, and other pollutants. The regulatory framework ensures compliance with state and federal standards. The plant discharges treated wastewater into a local water body that ultimately drains into the Illinois River, a major tributary of the Mississippi River. This river system supports diverse aquatic life and provides drinking water for downstream communities. The plant's operations contribute to protecting water quality in this ecologically significant watershed.

The treated effluent from WASHINGTON STP 2 enters a local stream that flows into the Illinois River, which joins the Mississippi River near Grafton, Illinois. The Illinois River watershed supports a variety of fish species, migratory birds, and other wildlife. The plant's discharge must meet state water quality standards to protect aquatic habitats and downstream uses, including recreation and drinking water supply.