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Water Quality Assessment Program and 305(b)/303(d) Integrated Reports

The Water Quality Assessment Program is responsible for providing information on the condition of Kentucky’s waterbodies (e.g. streams, rivers, lakes, reservoirs, springs, and wetlands).

All Kentucky waterbodies have assigned designated uses; an example being Primary Contact Recreation, a designated use that includes swimming. The Division of Water uses information collected by biologists and scientists to perform assessments on waterbodies to determine if that waterbody is meeting water quality standards and criteria, and therefore supporting its designated use (s).  A surface water assessment category is determined for each assessed waterbody based on the attainment decision and other considerations, such as 1) type of parameter (pollution vs. pollutant) and 2) if an action, such as TMDL, exists for that waterbody.  These assessment results are reported and published in the Integrated Report to Congress on the Condition of Water Resources in Kentucky (i.e. 305(b)/303(d) Integrated Report ).

Attainment

When water quality sampling occurs, specific information is gathered for each designated use. The data collected are compared to water quality standards to determine attainment, or support, of the designated use. 

For example, bacteria levels are examined when determining if the primary contact recreation (PCR) designated use is being supported, while water chemistry, habitat, and biological communities are examined when determining if aquatic life (WAH or CAH) designated use is being supported.

If water quality standards are being met, then the attainment of that designated use is Full Support (FS). If water quality standards are not being met, then the attainment of that designated use is Partial Support (PS) or Nonsupport (NS). Waterbodies classified as PS or NS for one or more of its designated uses due to either a pollution or a pollutant are considered impaired.

Surface Water Assessment Categories

The 305(b) list is a list of all waterbodies that have been assessed for one or more designated uses. Waterbodies on the 305(b) list are put into different categories depending upon the assessment decision made for that waterbody (Table 1). Impaired waterbodies on the 305(b) list will belong to category 4a, 4b, 4c or 5 (Table 1).

 

Table 1. Surface Water Assessment Categories

​Category ​Definition
​1​EPA​​All designated uses for waterbody are Fully Supporting
​2​EPA​​Assessed designated use(s) is/are Fully Supporting, but not all designated uses assessed
​2b​KY only​Segment currently supporting use(s), but 303(d) listed and proposed to EPA for delisting
​2c​KY only​​Segment with an EPA approved or established TMDL for use(s) now attaining Full Support
​3​EPA​Designated use(s) has/have not been assessed (insufficient or no data)
​4a​EPA​​Segment with an EPA approved or established TMDL for listed use(s) not attaining Full Support
​4b​EPA​​Nonsupport segment with an approved alternative pollution control plan (e.g. BMP) stringent enough to meet full support level of all uses within a specified time
​4c​KY only​Segment does not support designated use(s), but this is not attributable to a pollutant or combination of pollutants
​5​EPA​​Segment does not support designated use(s) and is impaired by a pollutant or combination of pollutants. A TMDL is required

 

Categories are assigned on multiple levels.

  • The parameter level
  • The designated use level
  • The  assesment unit level (or overall category)

A waterbody's overall assessment category is determined by the designated use category which is determined by the parameter level category (Figure 1).

Figure 1: Schematic diagram of how surface water assessment categories at the parameter and designated use level determine the overall surface water assessment category for a hypothetical waterbody in Kentucky

Figure 1 illustrates a hypothetical waterbody in Kentucky that has been assessed. This waterbody has been assessed for more than one designated use — primary contact recreation (PCR), warm water aquatic habitat (WAH), and secondary contact recreation (SCR). The designated use, domestic water supply (DWS), has not been assessed for this waterbody.

In Figure 1, the overall assessment category is category 5 because the waterbody is impaired by at least one pollutant where a TMDL has not yet been developed. The overall surface water assessment category is determined by the most impaired designated use scenario, which in Figure 1 is the WAH designated use, category 5-NS. This waterbody is not attaining (i.e. not supporting) the WAH designated use because it is impaired by two pollutants which still require a TMDL.

The designated use category determinations are based on the parameters assessed. If more than one parameter has been assessed for a designated use, the designated use assessment category is determined by the most impaired parameter scenario. In Figure 1, the WAH designated use has been assessed for Organic Enrichment (Sewage) Biological Indicators and Sedimentation/Siltation. Water quality standards are not being met for these parameters and a TMDL is required to address both pollutants. The most impaired parameter scenario is Sedimentation/Siltation, category 5-NS. Parameters classified as NS are more impaired than parameters classified as PS.

The other two assessed designated uses were assessed for only one parameter so the PCR designated use is determined by the E.coli parameter (category 4a-PS) and the SCR designated use is determined by the fecal coliform parameter (category 2-FS).

To find the surface water assessment categories assigned to assessed waterbodies in Kentucky, refer to the most recent 305(b) List.

For more information about Kentucky's assessment and listing methodology including information clarifying the distinction between partial support and nonsupport, refer to the Consolidated Assessment and Listing Methodology (CALM).

Re-categorization

A waterbody that has been assessed and assigned to a surface water assessment category can be re-categorized. Find out more in this Re-categorization Example [PDF, 232 KB].

303(d) List -- Category 5 Only

The 303(d) list is a subset of the 305(b) list and only includes those waterbodies in category 5, which require a TMDL.

The waterbodies on the 303(d) list:

  • Have been identified as having one or more parameters that are not meeting water quality standards, which impairs the designated use
  • The parameter of impairment is a pollutant (not pollution)
  • Require the development of a TMDL

Each row on the 303(d) list is called a pollutant-waterbody combination (PWC). Each PWC consists of a waterbody that is not meeting water quality standards for a specific parameter (identified as a pollutant), which results in the impairment of one or more designated uses.. A waterbody will have one entry on the 303(d) list for each parameter causing an impairment.


305(b)/303(d) Integrated Report

The 305(b)/303(d) Integrated Report provides waterbody-specific information on whether waterbodies are or are not meeting water quality standards and supporting designated uses, statewide water quality assessment summaries, and a schedule for restoring impaired waters.
 

The Integrated Report is published every two years and submitted to the Environmental Protection Agency (EPA). This report includes two lists, the 305(b) list and 303(d) list, which satisfy the U.S. Clean Water Act requirements for:

  • Section 305(b) - to produce biennial reports on the general condition of all assessed waterbodies in the state
  • Section 303(d) - to produce a list of all assessed waterbodies in the state identified as being impaired by one or more pollutants, which require a TMDL.
     

The Integrated Report format has varied throughout the years. Beginning in 2006, the 303(d) and 305(b) reports were published in two volumes. For 2016 and beyond, the two volumes will be published as one report. The EPA periodically issues Integrated Reporting Guidance under CWA Sections 303(d), 305(b) and 314.

Download Kentucky's Integrated Reports.

The 305(b) list is a list of all Kentucky waterbodies that have been assessed for one or more  designated uses.
 

On the 305(b) list you will find information such as:

  • The general location of the waterbody
  • The waterbody type
  • The length of the stream/segment or area of the lake/reservoir
  • All assigned designated uses for the waterbody (An unassessed designated use will be listed as category 3. If the designated use does not apply, it will be marked as N/A.)
  • The surface water assessment category assigned to each designated use
  • The overall surface water assessment category for the entire waterbody
  • Parameter(s) (pollutant or pollution) associated with the watebody and its attainment status (impaired or meeting water quality standards)

​The 303(d) list is a subset of the 305(b) list and only includes those waterbodies with parameters in category 5, which require a TMDL.

Pollutants (e.g. bacteria) and pollution (e.g. habitat degradation) can both contribute to an impaired waterbody. The 303(d) list is a list of waterbodies impaired by a pollutant. Waterbodies impaired by pollution are in category 4c.

Each entry on the 303(d) list is called a pollutant-waterbody combination (PWC). Each PWC consists of a waterbody that is not meeting water quality standards for a specific parameter (identified as a pollutant), which results in the impairment of one or more designated uses. A waterbody can have multiple entries on the 303(d) list if impaired by more than one pollutant. A TMDL calculation is developed for each PWC.

In some circumstances, waterbodies on the 303(d) list could be suitable for a TMDL Alternative Approach.

On the 303(d) list you will find information such as:

  • The location of the impaired watebody
  • The length of the impaired stream or area of the impaired lake/reservoir
  • The designated use(s) that are impaired for that waterbody
  • Parameter(s) (pollutant only) associated with impaired attainment (e.g. not meeting water quality standards)
  • Priority status for TMDL developemnt
  • Suspected sources that are likely causing or contributing to the impairment.

The 303(d) list must be reviewed and approved by the EPA. Integrated Reports including 303(d) lists are available on the Download Page.

Waterbodies are listed on the 303(d) list as pollutant-waterbody combinations (PWCs); therefore, waterbodies are removed from the 303(d) list by PWC.

Conditions that would allow an individual PWC to be removed from the 303(d) list (i.e. delisted) include:

  1. The state determines water quality standards are being met
  2. A TMDL report has been approved by the EPA (Category 4a)
  3. Other pollution controls are expected to meet the water quality standards (Category 4b)
  4. An EPA-accepted TMDL alternative plan has resulted in water quality standards being met
  5. The impairment is due to a condition other than a pollutant, e.g., a natural environmental condition or a condition not addressed by the TMDL process (Category 4c)
  6. There was a flaw in the original 303(d) listing
  7. The waterbody is not within the state's jurisdiction
  8. Change in water quality standards
  9. Change is assessment methodology
  10. Other reasons that are defined as needed.

When certain conditions are met as determined by the state, a request can be made to EPA to delist an entire waterbody. Please contact the assessment coordinator for more information.