Wyoming DEQ

Total Maximum Daily Load (TMDL) Development Program

David Waterstreet

If you have any questions, please contact David Waterstreet at (307) 777-6709.

A Man Fishing in a River

What Is a Total Maximum Daily Load (TMDL) Project?

Basis of all TMDL projects: Section 303(d) of the Clean Water Act and the US EPA’s Water Quality Planning and Management Regulations (40 CFR Part 130) requires states to develop TMDLs for waterbodies which are not meeting applicable water quality standards.
Major components of a TMDL project: TMDL projects are based upon the calculation of the total allowable pollutant load for a surface water in order for it to meet the State’s Water Quality Standards (this is also referred to as the “assimilative capacity” of the waterbody). The TMDL project then allocates this allowable load between point sources (waste load allocations or WLAs) and nonpoint sources (load allocations or LAs) while incorporating a margin of safety.

What Does a TMDL Project Do?

Based on these waste load and load allocations (WLAs and LAs), point source permits are evaluated, and critical areas for implementation of best management practices for nonpoint sources are identified.
Local stakeholders and public participation are keys to a successful project. The TMDL program values and seeks out participation from stakeholders throughout the watershed to restore surface water so that it meets water quality standards and fully supports its designated uses. To achieve this, local stakeholders are asked to participate throughout the project so that assumptions, calculations, and restoration measures are reasonable and accurate. Public involvement and outreach are critical components for a TMDL project’s success.
Two People Testing Water

Click here to visit the EPA’s website for additional information on impaired surface waters and TMDLs.
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Find out which watershed you live in!

The 305(b) Integrated Report and the 303(d) List of Impaired Waterbodies

Section 303(d) of the Clean Water Act requires states to:
If a state does not comply with Section 303(d), the Environmental Protection Agency (EPA) is required to perform these activities.
Every two years, the state must evaluate its water quality data and submit an updated impaired waterbody list to the EPA for approval. This list is generated from the Statewide Water Quality Assessment (also known as the 305(b) Report), which must also be submitted every two years.

Excerpt from the Integrated Report – the 2012 303(d) List

Before and After of Drop Structure
Mountain Landscape

Wyoming's Nonpoint Source Program

In 1989, the State adopted a Nonpoint Source Management Plan to address nonpoint sources of pollution. Under this voluntary program, the state provides Clean Water Act Section 319 funds to local entities for projects which address nonpoint source pollution.

Completed TMDL Projects

Watershed-Based Plans

Page Last Updated: 6/10/2014