Developing New Use Sub-Categories for the Chicago Area Waterway System through the Use Attainability Analysis (UAA) Process

The Illinois Environmental Protection Agency (IEPA) is conducting a use attainability analysis (UAA) of the Chicago area waterway system (CAWS[EYC2]). The primary focus of the UAA is on the North Shore Channel, Chicago River system and Calumet River system waterway reaches currently classified by the Illinois Pollution Control Board (IPCB) as Secondary Contact and Indigenous Aquatic Life[EYC3]. The study area also includes three CAWS reaches that were upgraded relatively recently to General Use without undergoing the rigors of a UAA. The waterways have experienced significant improvements in water quality and increased recreational use. The current water quality standards may not be protective of the existing uses occurring in CAWS, and therefore, may have to be upgraded to protecting the existing and potential uses. Based upon the review and evaluation of the chemical, physical, biological, and waterway use data for CAWS, five use designation sub-categories are being proposed to protect aquatic life and recreational uses in CAWS. The recreational and aquatic life use sub-categories and the applicable water quality standards for CAWS include the following beneficial uses: general warm-water aquatic life, modified warm-water aquatic life, limited warm-water aquatic life, limited contact recreation and recreational navigation. These new sub-category use designations will be presented to the IPCB for review, approval, and adoption. Once these new use designations are in place, then appropriate management strategies for the waterways need to be implemented to protect the water quality and recreational uses. This will require modifications to existing wastewater reclamation plants, applying best available technology to improve instream water quality, applying new pretreatment standards for selected metals and interacting closely with governmental agencies, communities, and the public to achieve the water quality goals for the Chicago area waterways.