The Total Maximum Daily Load (TMDL) Section of the Water Quality Branch is responsible for tracking impaired surface waters, developing plans to address water quality impairments and working cooperatively to achieve and maintain water quality standards for the streams and lakes of the commonwealth of Kentucky.
All surface waters are assessed based on a five-year rotating watershed basin cycle. Waters are categorized according to water quality indicators based on water chemistry, biological community structure and physical habitat components. Assessment data and narrative explanations are compiled into a biannual report submitted to Congress titled "Kentucky Report to Congress on Water Quality" or the 305(b) report. Additional information is available on the assessment process by accessing the following Web pages:
Monitoring and Assessment
305(b) Reports to Congress
A subset of the 305(b) report is the "List of Waters for Kentucky" or the 303(d) report. The 303(d) report identifies all waters assessed as impaired for one or more designated uses and as not meeting one or more water quality standards.
Both the 305(b) and the 303(d) reports are requirements of the federal Water Pollution Control Act Amendments of 1972, commonly known as the Clean Water Act.
The abbreviation "TMDL" stands for Total Maximum Daily Load. It is associated with water pollution planning and can refer to several related concepts:
- A TMDL is a calculation of the maximum amount of a pollutant (examples are sediment, phosphorus and bacteria) that a stream or lake can receive and still meet water quality standards.
- A TMDL may also refer to a written report, which includes detailed assessment information of site-specific impaired waters, watershed information, mathematical modeling and the calculated number of a pollutant load.
The 303(d) List of Waters for Kentucky
Reports on impaired waters are available in electronic format from 1990, 1992, 1994, 1996, 1998, 2002, 2004, 2006 and 2008. You may view and download copies of reports at the 303(d) List Web page. Information on impaired waters prior to 1992 may be obtained by contacting the Water Quality Branch.
From 1992 to 2004, 303(d) reports were compiled as separate documents. In 2006, the Environmental Protection Agency (EPA) recommended states prepare the 305(b) and 303(d) as one document incorporating the concept of integrated reporting on all waters. The final approved integrated report is also available at the 303(d) List link, accessed by the link above.
TMDLs Under Development
A TMDL is considered under development in several different situations, as in the following examples:
- A project is being planned for an impaired water on the 303(d) list.
- Water and/or biological monitoring is occurring.
- Monitoring is completed and computer modeling is occurring.
- The TMDL is completed and being reviewed by the public or EPA.
Approved TMDLs
This refers to the list of impaired waters with completed TMDLs that have received official EPA approval.
Waters Delisted
In order for a stream or lake to be delisted from the 303(d) list, the impaired water must go through a formal delisting review process by EPA.
