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​A TMDL Alternative Approach is a near-term water quality restoration plan that achieves water quality standards more quickly than a TMDL Report.

Kentucky communities taking the initiative to develop and implement water quality restoration plans to clean up their impaired waters may defer or even bypass the need for a TMDL. TMDL alternative approaches are developed and carried out by the local community, which allows for flexibility in the water quality restoration process.

Two types of TMDL Alternative Approaches are TMDL Alternative plans and Category 4b plans.

TMDL Alternative Plans

 A TMDL Alternative plan is a near-term water quality restoration plan with a schedule of actions and milestones that are more immediately beneficial or practicable to achieving water quality standards than a TMDL.

TMDL alternative plans are accepted by the EPA. The impaired waters in a TMDL alternative plan will remain in category 5 on the 303(d) list, but will be assigned a lower priority for TMDL development. If water quality standards are not achieved, a TMDL is still required.

To learn more about TMDL alternative plans, read the Clean Water Act Section 303(d) Program Vision, a new collaborative framework developed in 2011 by the Environmental Protection Agency and state TMDL program managers.

The EPA-accepted TMDL Alternative plans for Kentucky may be downloaded from the table below. 

The EPA recommends that states interested in pursuing alternative restoration approaches for waterbodies on the 303(d) list consider the following factors to determine if the approach would expedite the achievement of water quality standards more quickly than a TMDL:

  1. States should evaluate whether there are unique local circumstances such as watershed groups already working in the area, support from stakeholders and the local community to make sure timely progress can be made, and available funding to implement the plan
  2. States should evaluate whether the approach is more cost-effective
  3. States should evaluate whether the initial review of the parameter of impairment shows that specific and singular point or non-point sources are responsible for the impairment with clear mechanisms to address all sources (e.g. watershed plans, straight to implementation approaches, etc)

For more information about your watershed or available funding, contact your Division of Water Basin Coordinator. For more information about TMDL alternative plans, email the TMDL Program at or call (502) 782-6987.


The components of a TMDL Alternative plan will be case-specific due to the complex nature of addressing impaired waterbodies.

Early and ongoing communication with the Division of Water TMDL Program is key to developing a successful plan.

These are not requirements but a list of components to consider including in a TMDL alternative plan to ensure water quality standards can be achieved. Many of the components are similar to those needed to develop a nine element watershed management plan.

  1. Identification of the impaired water segments, pollutants, and sources contributing to the impairment
  2. Implementation plan that includes actions to address all point and nonpoint sources, an analysis or explanation as to why those actions are expected to achieve water quality standards, and clear milestones and dates to achieve those actions
  3. Identification of available funding opportunities for implementation
  4. Identification of all parties committed (and needed) to achieve implementation and meet water quality standards
  5. Estimate of when water quality standards will be met
  6. Plans for effectiveness monitoring following implementation to demonstrate progress and identify where adaptive management is needed
  7. Commitment to periodically evaluate whether the plan is on track for achieving water quality standards more quickly than a TMDL


Additional Resources
303(d) list of impaired waters
Basin Coordination
Watershed Planning Guidebook
EPA’s Watershed Planning Module

Category 4b Plans

A Category 4b plan is a plan with other pollution control requirements stringent enough to achieve water quality standards within a reasonable period of time.

Category 4b plans are approved by the EPA and will be submitted by the state with the 305(b)/303(d) Integrated Report as a stand-alone document. The impaired waters in a Category 4b plan are removed from the 303(d) list and do not require a TMDL.

Kentucky does not currently have any approved Category 4b plans.

Background on Category 4b

Section 303(d) of the Clean Water Act and supporting regulations require states to develop lists of “impaired waters” which are not meeting water quality standards. These 303(d)-listed waters require states to develop Total Maximum Daily Loads (TMDLs) which establish pollution reduction goals and loading allocations for impaired waterbodies to attain water quality standards.

The U.S. Environmental Protection Agency (EPA) regulations also acknowledge other pollution control requirements that may obviate the need for a TMDL, including technology-based effluent limitations, more stringent effluent limitations, or other pollution control requirements (e.g. best management practices) that are stringent enough to achieve water quality standards within a reasonable period of time.

These impaired waters where a TMDL is not required because they are expected to meet water quality standards due to other pollution control requirements are commonly referred to as “Category 4b” waters, as described in the 2008 EPA Integrated Reporting (IR) guidance.

Category 4b Requirements

Category 4b plans will be evaluated on a case-by-case basis.

Early and ongoing communication with the Division of Water TMDL Program is key to developing a successful plan.

The six requirements are:

  1. Identification of impaired segment(s) and a statement of the problem causing the impairment(s)
  2. Description of the pollution controls and how they will achieve water quality standards; including a description of the pollutant loads needed to meet water quality standards and a description of the requirements under which the controls will be implemented
  3. Provide an estimate of when water quality standards will be met based on the implementation of existing control requirements
  4. Provide a schedule for implementing pollution controls
  5. Provide a monitoring plan to track effectiveness of pollution controls
  6. Commitment to revise pollution controls (as necessary) if progress is not shown

To view the EPA’s recommended format and content for a Category 4b submittal, read Category 4b—Current National Status and Trends.

To learn more about Category 4b and “pollution control requirements,” please refer to the following EPA guidance documents:

Guidance for 2006 Assessment, Listing and Reporting Requirements Pursuant to Sections 303(d), 305(b) and 314 of the Clean Water Act and

Information Concerning 2008 Clean Water Act Sections 303(d), 305(b), and 314 Integrated Reporting and Listing Decisions.

For more information, email the TMDL program at or call 502-782-6987.

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TMDL and Program Support Section
Division of Water
300 Sower Blvd., 3rd floor
Frankfort, KY 40601

EPA-Accepted TMDL Alternative Plans for Kentucky
WaterbodyDocumentsParametersNumber of Pollutant-Waterbody CombinationsAcceptance YearCountyBasin
Gunpowder CreekE. coli, Fecal Coliform, Sediment, Nutrients, Organic Enrichment, Cause Unknown172018BooneLicking
Sulphur Creek

Sulphur Creek TMDL Alternative [PDF, 4017 KB]

Cover Letter - DOW​ [PDF, 275 KB]​

E. coli, Nutrients, Sediment122023Anderson, Mercer, WashingtonSalt
Threemile CreekPathogens12022CampbellLicking
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