Click on the image to access online locational data for impaired water bodies or lakes.
The goal of the federal Clean Water Act, found in U.S. Code 33 U.S.C. §1251 et seq., is "to restore and maintain the chemical, physical, and biological integrity of the Nation's waters." Many organizations throughout Missouri monitor bodies of water across the state. The department combines this data with department-collected data and then determines if the waters meet state water quality standards, which protect the beneficial uses of water. Those waters that fail to meet the standards are listed as impaired.
Under section 303(d) of the Clean Water Act, each state is required to identify waters not meeting water quality standards and for which adequate water pollution controls have not been required. The resulting 303(d) list helps the state keep track of impaired waters not addressed by normal water pollution control programs. Links to Missouri's current and previous 303(d) lists are available below.
Under Code of Federal Regulations 40 C.F.R. 130.7, states are required to submit to the U.S. Environmental Protection Agency (EPA), a written methodology document describing the states approach in considering and evaluating existing readily available data and information used to develop its 303(d) list of impaired waterbodies. The department invites the public to review and submit written comments on the draft listing methodology document, before submitting it to the Missouri Clean Water Commission for approval. While EPA does not approve or disapprove the listing methodology document, the department must provide the methodology used during its review of the state’s 303(d) impaired waters list and its determination to list or not to list waters.
Under 40 C.F.R. 130.7, each state is also required to report the status of their impaired and threatened waters still needing a Total Maximum Daily Load by April 1 of every even-numbered year. Following approval by the Missouri Clean Water Commission, the Section 303(d) list, the 305(b) report and the assessment data on the remaining waters of the state is submitted to EPA as part of Missouri's Section 305(b) Integrated Water Quality Report.
Notice
NEW The department currently is preparing for the 2024-2026 Integrated Water Quality Monitoring and Assessment Report, also known as the 305(b) report and the 303(d) list. The department is requesting readily available and qualified water quality data collected through Oct. 31, 2024. For more information, please review the Request for Water Quality Data.
Water Protection Program
Section 305(b) Integrated Water Quality Report