A loaded canoe on the shore of the Big River

Missouri’s water resources play a critical and valuable role in providing our families, friends and visitors with the ability to enjoy numerous outdoor recreational opportunities. Ensuring our Missouri waters are safe to enjoy today, as well as ensure the same for future generations, is the essence of the department's mission.

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. Those waters that fail to meet the standards are listed as impaired.

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." The department is required to report the status of Missouri's waters to the U.S. Environmental Protection Agency (EPA). More information about Missouri's monitoring and assessment program and links to our reports to EPA are provided in the tabs below.


Missouri's Monitoring and Assessment Program

Under Section 106(e)(1) of the Clean Water Act, EPA provides monitoring support to eligible state monitoring programs. EPA's elements of a state water monitoring and assessment program guidance recommends 10 basic elements of a state water monitoring and assessment program. These elements, in addition to Missouri's proposed monitoring strategy, are described in the department's A Proposal for a Water Quality Monitoring Strategy for Missouri report. 

Missouri's 303(d) Streams and Lakes

Water quality standards protect the beneficial uses of water, including whole body contact (such as swimming), maintaining fish and other aquatic life, and providing drinking water for people, livestock and wildlife. Section 303(d) of the federal Clean Water Act requires that each state identify waters not meeting water quality standards and for which adequate water pollution controls have not been required. The 303(d) list helps state and federal agencies 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 in the table in the Reports and Data tab above.

Missouri Water Quality 305(b) Report

Under Section 303(d), 305(b) and 314 of the Clean Water Act, each state is required to report the status of their state waters to EPA on April 1 every even-numbered year. Missouri's 305(b) integrated report provides an overview of the status of Missouri's waters. The report summarizes water quality issues and assesses the degree of progress Missouri has made toward meeting federal Clean Water Act goals. The report also includes the list of impaired waters included in the 303(d) list and maps showing what waters in the state are impaired, what pollutants affect them and the sources of those pollutants. The department must provide EPA with written methodology describing its approach for considering and evaluating existing and readily available data and information used to develop its 303(d) list of impaired waterbodies. The water quality assessments made in this report help direct future water quality management efforts to those waters most in need of restoration or protection. Links to Missouri's 305(b) report submittals are available in the table in the Reports and Data tab above.

National Water Quality Inventory Report

EPA combines the information provided by each state in their 305(b) integrated report into one National Water Quality Inventory Report to Congress. The EPA report and other information reported by states is available online at the electronic reporting database, Assessment, Total Maximum Daily Load (TMDL) Tracking and Implementation System (ATTAINS). This is the main way EPA reports the general status of water quality conditions to Congress and the public. 

Upcoming Meetings

Video Attendance Available!
Lewis and Clark State Office Building
Gasconade Camp Conference Room
1101 Riverside Drive
Jefferson City, Missouri

More Info:
Join the Dec. 13 meeting using Webex
Public Hearing - Jan. 11, 2023

Past Meetings

Public Comment Periods

Notice Areas of Focus Topic Meeting/ Hearing Info
Proposed 2022 Section 303(d) Impaired Waters List Public Comment Period, Oct. 13, 2022 to Jan. 18, 2023
Water Protection Program
Water » Impaired Waters-303d list 303(d) Impaired Waters List
Impaired Waters
Public Hearing - Jan. 11, 2023

Reports and Data

This table includes 303(d) and 305(b) reporting and listing methodology information, organized by reporting year. Additional information is also available about Water Quality Data, TMDLs, and Biological Assessment Reports.

305(b) Integrated Report Listing Methodology Document EPA Approval Memo EPA Approved 303(d) List EPA Approved 303(d) Delist
2022 2022 PNP 2022 PNP
2020 2020 2020 2020 2020
2018 2018 2018 2018 2018
2016 2016 2016 2016 2016