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Tennessee's Total Maximum Daily Load (TMDL) Program


Section 303(d) of the Clean Water Act requires states to develop TMDLs for those waterbodies not attaining water quality standards. The objective of a TMDL is to allocate loads among all of the known pollutants sources throughout a watershed so that appropriate control measures can be implemented and water quality standards can be achieved.

The TMDL process quantifies the amount of a pollutant that can be assimilated in a waterbody, identifies the sources of the pollutant, and recommends regulatory or other actions to be taken to achieve compliance with applicable water quality standards based on the relationship between pollution sources and instream water quality conditions. A TMDL can be expressed as the sum of all point source loads (waste load allocations), nonpoint source loads (load allocations) and an appropriate margin of safety, and is represented by this relationship:

TMDL = Sum of Point Sources + Sum of Nonpoint Sources + Margin of Safety

More information is available on the EPA web site.

Proposed TMDLs

9/17/19 - Announcement is hereby given of the availability of Tennessee’s proposed Total Maximum Daily Load (TMDL) for E. coli in the South Fork Obion River watershed, located in west Tennessee. 

Persons wishing to comment on the proposed TMDL are invited to submit their comments in writing through October 22, 2019. Details can be found in the public notice document above. 

Comments may also be submitted directly via our web form.

February 2019- Please note, in an effort to move to a more environmentally friendly, paperless workflow, all notifications of TMDL public notices will be done electronically.  If you would like to receive notification when a TMDL is placed on public notice, please e-mail to be added to our e-mail distribution list.

Proposed Final TMDLs

The following is a list of proposed TMDLs that have completed public notice and have been submitted to EPA for final approval.

EPA Approved TMDLs

Search for EPA reviewed and approved TMDLs.  


David Duhl

Watershed Planning Unit Manager