Arkansas Total Maximum Daily Loads (TMDL)
Some of the state’s impaired waterways on the 303(d) list are tapped for corrective action to improve their water quality. Some require the development of a TMDL – Total Maximum Daily Load.
A TMDL is a calculation developed for some waters that are not meeting or are at risk of not attaining water quality standards. The TMDL calculates the maximum amount of a constituent a waterbody can receive and still meet the standards.
A TMDL accounts for both point source and nonpoint source discharges.
Calculations are performed by various models that predict safe levels of contaminants based on worst-case conditions and providing a margin of safety. The calculated safe amounts then may be allocated to point source discharges as a wasteload allocation and to nonpoint sources as a load allocation. This constitutes a TMDL. Permit limits are set according to a stream’s TMDL.
The Arkansas Department of Environmental Quality (DEQ) created a "Long-Term Vision for Assessment, Restoration, and Protection under the Clean Water Act (CWA) 303(d) Program" (4/17/2015) in accordance with the new measures set forth by the United States Environmental Protection Agency (EPA).
DEQ has been working in conjunction with the Arkansas Natural Resources Commission (ANRC) to target resources for water quality improvements within the state. The ANRC is responsible for developing and implementing Arkansas’ Nonpoint Source Pollution Management Program. ANRC prioritized ten basins in Arkansas using stakeholder involvement coupled with a science-based process. For TMDL prioritization, nine of the ten ANRC basins were chosen because they have impairments that carry from DEQ’s 2008 303(d) list to the Draft 2014 303(d) list. DEQ plans to work towards TMDL or alternative plan development for the currently selected basins by 2022.
Arkansas Total Maximum Daily Loads (TMDLs)
Draft TMDLs at Public Notice
Review the draft document and find the dates marking the beginning and end of each draft’s public comment period.
Below is a list of final TMDLs issued by DEQ.
DEQ's draft TMDL calculations must be approved by EPA for implementation.
|Water Body||TMDL Date||Pollutant(s)||Planning Segment|
|Bayou Bartholomew||12/18/2002||Mercury in Fish Tissue||2B|
|Bayou Bartholomew||3/31/2008||Total Dissolved Solids (TDS)||2B|
|Bayou Dorcheat||12/10/2002||Mercury in Fish Tissue||1A|
|Bear Creek Lake||1/16/2007||Nutrient||5B|
|Beech Creek||9/27/2012||Dissolved Oxygen||1A|
|Big Cornie Creek||8/01/2011||Sulfate||2E|
|Big Creek||9/27/2012||Total Dissolved Solids (TDS)||1A|
|Big Creek near Sheridan||1/16/2007||Dissolved Oxygen||2C|
|Big Creek near Sheridan||3/21/2008||Turbidity||2C|
|Big Johnson Lake||5/25/2004||Mercury in Fish Tissue||2D|
|Boeuf River||3/03/2005||Total Dissolved Solids (TDS)||2A|
|Bull Shoals (White River) Tailwaters||5/01/2009||Dissolved Oxygen||4I|
|Champagnolle Creek||12/18/2002||Mercury in Fish Tissue||2D|
|Cove Creek Lake||12/10/2002||Mercury in Fish Tissue||3H|