Designated Use Impairments
Illinois River Watershed Impairments
The States of Arkansas and Oklahoma develop their respective 303d lists every two years under provisions of Section 303(d) of the Federal Clean Water Act. The Departments of Environmental Quality for each State assesses water quality monitoring data from numerous locations and utilizes a comprehensive assessment methodology to determine which waters are not meeting their designated uses or water quality standards.
The Illinois River Watershed has many designated (or beneficial) uses as determined by the Arkansas Department of Environmental Quality and the Oklahoma Water Resources Board. In Arkansas, those uses include propagation of fish and wildlife, water supply for domestic, agricultural, and industrial uses, and primary contact recreation. In Oklahoma, the Watershed has the same uses plus an additional aesthetic provision.
Arkansas Impairments
According to the 2018 impairment listing created by Arkansas Department of Environmental Quality, there are eight stream reaches currently considered impaired. These include:
Impairments for Arkansas tributaries of the Illinois River.
Oklahoma Impairments
According to the 2018 impairment listing created by Oklahoma Department of Environmental Quality, there are 20 stream reaches currently considered impaired. Two impairments occur on Tenkiller Ferry Lake. These include:
Impairments for Oklahoma tributaries of the Illinois River.