ELI’s report, The Role of Aquatic Invasive Species in State Listing of Impaired Waters and the TMDL Program, examines how seven states representing a range of geography, number of aquatic invasive species, water quality standards, 303(d) listings for invasive species, and aquatic invasive species management programs have addressed the effects of aquatic invasive species on the waters of their respective states through the federal Clean Water Act. The report finds that most of the case study states have identified invasive species as a cause of water quality impairment within the past decade, that some states consider invasive species to be “pollution” while another identifies them as ”pollutants,” but that all case study states have water quality standards that could be used to assess impairments due to invasive species. The report concludes that there is little consistency between states in how they use the structures of the Clean Water Act, if at all, to identify and solve water quality problems associated with aquatic invasive species.