In an April 24, 2013 decision letter, US EPA has approved Iowa’s 2012 list of impaired waters requiring Total Maximum Daily Load (TMDL) calculations. The Iowa Department Natural Resources (IDNR) submitted its impaired waters list to EPA on April 1, 2013, for review and approval as required by the Clean Water Act.
In its decision, EPA approved the removal of 73 water bodies and the addition of 78 water bodies to the Iowa list of impaired waters. The action brings the total number of impaired waters on the state’s list to 479.
As background, a water body is placed on the impaired waters list when monitoring finds that pollutant levels prevent the lake, river, or stream from attaining its beneficial uses. A water body can be removed from the list if it meets its beneficial uses or if a pollution reduction plan (TMDL) for a water body is approved by EPA. Beneficial uses in Iowa include human recreation, water supply, and maintaining healthy aquatic life.