A river is reborn--Use Attainability Analysis for the Lower Des Plaines River, Illinois

The goal of the Use Attainability Analysis (UAA) of the Lower Des Plaines River was to upgrade the designated "Secondary Contact Recreation and Indigenous Aquatic Life Use" to a higher use that would be commensurate with the goals of the Clean Water Act (CWA). In Illinois, the water body use in compliance with the goals of the CWA is named "General Use". The river has been extensively modified and receives most point-source and urban runoff discharges from the Chicago metropolitan area (9.5 million inhabitants). The study included an extensive assessment of the physical, chemical, biological, and bacteriological integrity status of the water body and sediments. The UAA found that the water quality situation of the river has improved significantly since the 1970s, when the Illinois Pollution Control Board defined and assigned the Secondary Contact Recreation and Indigenous Aquatic Life Use designation to the Lower Des Plaines River. The study defined and suggested a "Modified Impounded Use" for one highly modified reach, with adjusted standards for dissolved oxygen and recreation. The study also recommended adoption of the General Use standards, some of them in a modified form, for other water quality parameters. Standards for limited recreation were also developed. The UAA also outlines a suggested action plan that will bring UAA segments of the Lower Des Plaines River in compliance with UAA goals.