A total maximum daily load (TMDL) is the calculation of the maximum amount of a specific pollutant that a water body can absorb and still meet water quality standards. Missouri’s water quality standards establish pollutant limits to protect drinking water supply, fishing, swimming, aquatic life and other designated uses. When waterbodies fail to meet the water quality standards, they are considered impaired waters. The federal Clean Water Act requires states to develop TMDLs for all waters on the 303(d) List of Impaired Waters. The calculated TMDL is allocated among the various pollutant sources in the watershed and becomes the goal to restore water quality. For more information, review the department's What are TMDLs? - PUB2090 fact sheet or visit the U.S. Environmental Protection Agency's Overview of Total Maximum Daily Loads (TMDLs) website.
In Missouri, the Missouri Department of Natural Resources develops TMDLs. Each TMDL document includes allocations of the acceptable load for all pollutant sources. It also includes an implementation plan to identify how the load will be reduced to a level that will protect water quality. All draft TMDLs are made available for review and comment during a 45-day public comment period. Email public comments or questions about TMDLs to email@example.com.
TMDL Development Prioritization and Scheduling
Water body impairments are ranked as high, medium or low priority for TMDL development. For impairments ranked as high priority, a specific year is given for when a TMDL may be developed. All priority rankings and development schedules are reevaluated with each new 303(d) List.
- Prioritization Framework for Development of Total Maximum Daily Loads
- TMDL Alternative - Category 5-alt Components
The department's Impaired Waters and TMDL Map Viewer is an online ArcGIS map. A user can access information about an impaired water body or lake by clicking on the line or polygon segments on the map. Included on the water body information is a link to the final TMDL document, approved by the U.S. Environmental Protection Agency after public notice and comment. Although the department compiled the map information, no warranty, expressed or implied, is made by the department as to the accuracy of the data and related materials.
Water Body Identification Number and Name
||Low Dissolved Oxygen||
A revised TMDL was submitted to EPA for approval Sept. 16, 2020. The department revised the underlying model used for calculating the TMDL as a result of comments from EPA. The updated revised TMDL and implementation strategies documents are available for public review and comment from Oct. 22, 2021 to Dec. 6, 2021. For more information, please review the Spring Creek Public Notice.
A draft TMDL was submitted to EPA for approval Oct. 21, 2021.
TMDL under development
||Low Dissolved Oxygen||Revised draft TMDL under development|
||Low Dissolved Oxygen||TMDL under development|
||Low Dissolved Oxygen||Revised TMDL planned|
A draft TMDL was submitted to EPA for approval Oct. 20, 2021.
A revised TMDL was submitted to EPA for approval Nov. 10, 2020.
Draft TMDL and implementation strategies documents are available for public review and comment from Oct. 8, 2021 to Nov. 22, 2021. For more information, please review the South Grand River Public Notice.
||E. coli||Revised draft TMDL under development|
||Low Dissolved Oxygen||
A revised TMDL was submitted to EPA for approval Jan. 30, 2020. As a result of EPA comments, an updated revised TMDL document was available for public review and comment until Oct. 5, 2021. The department currently is reviewing all submitted comments.
Draft TMDL and implementation strategies documents were available for public review and comment until Aug. 30, 2021. The department currently is reviewing all submitted comments.