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NYS Section 303(d) List of Impaired/TMDL Waters

The New York State Section 303(d) List of Impaired/TMDL Waters identifies those waters that do not support appropriate uses and that may require development of a Total Maximum Daily Load (TMDL). The Section 303(d) List is updated every two years. The current List in effect is the Final 2014 New York State Section 303(d) List of Impaired/TMDL Waters (PDF, 261 KB) (September 2014).

The process to update the Section 303(d) List for 2016 is currently underway. A DRAFT 2016 Section 303(d) List (PDF, 311 KB) was made available for a 45-day public comment period that ended March 4, 2016. More information regarding this effort can be found below.

The 2014 NYS Section 303(d) List

The Final NYS 2014 Section 303(d) List was "partially approved and partially disapproved" by USEPA on January 13, 2015. In its letter of partial approval/partial disapproval (PDF, 915 KB), USEPA stated that it approved New York State's listing of all waterbody segments and associated pollutants included in its Proposed Final 2014 Section 303(d) List. However EPA also noted that it was disapproving the State's decision not to list the Jones Inlet/Jones Bay on the South Shore of Long Island for nitrogen.

Pursuant to its partial disapproval, USEPA opened a public comment period to receive comments on its recommendation to add Jones Inlet/Jones Bay to the State's 2014 Section 303(d) List. After examining comment received during this period (NYSDEC submitted the only comment), USEPA made a final determination (PDF, 386 KB) to include a listing of Jones Inlet/Jones Bay for nitrogen.

Prior to the USEPA partial approval/partial disapproval, a Draft 2014 Section 303(d) List was made available for public comment for a 45 day period that ended March 14, 2014. After considering comments received from the public, a Proposed Final List was submitted to USEPA prior to the April 1, 2014, date for State submittal of 2014 Lists. Additional discussion during the USEPA review of the List led to other revisions and the re-submittal of a Final List to USEPA in September 2014. Except for the decision to not include Jones Inlet/Jones Bay, this version of the List was found by USEPA to meet the requirements of Section 303(d) of the Clean Water Act and was approved in January 2015. Public comments received during the public notice of the Draft List and other issues raised by USEPA during their review of the List are addressed in a response summary (PDF, 228 KB).


The Federal Clean Water Act requires states to periodically assess and report on the quality of waters in their state. Section 303(d) of the Act also requires states to identify impaired waters, where designated uses are not fully supported. For these impaired waters/pollutants, states must consider the development of a Total Maximum Daily Load (TMDL) or other strategy to reduce the input of the specific pollutant(s) restricting waterbody uses, in order to restore and protect such uses.

The waterbody/pollutant listings in the Section 303(d) List are segmented into a number of categories. The various categories, or Parts, of the list include:

  • Part 1 - Individual Waterbodies with Impairment Requiring a TMDL
  • Part 2 - Multiple Segment/Categorical Impaired Waterbodies - Includes Acid Rain Waters, Fish Consumption Waters, and Shellfishing Waters
  • Part 3 - Waterbodies for which TMDL Development May Be Deferred - Includes Waters Requiring Verification of Impairment, Waters Requiring Verification of Cause/Pollutant, and Waters Where Implementation/Evaluation of Other Restoration Measures is Pending

Impaired Waters NOT Included on the NYS 2014 Section 303(d) List

Not all impaired waters of the state are included on the Section 303(d) List. By definition, the List is limited to impaired waters that require development of a Total Maximum Daily Load (TMDL). A list of Other Impaired Waterbody Segments Not Listed (PDF, 115 KB) on the 303(d) List Because Development of a TMDL is Not Necessary is also available. The purpose of this supplemental list is to provide a more comprehensive inventory of waters that do not fully support designated uses and that are considered to be impaired.

There are three (3) categories of justification for not including an impaired waterbody on the Section 303(d) List:

  • Category 4a Waters - TMDL development is not necessary because a TMDL has already been established for the segment/pollutant.
  • Category 4b Waters - A TMDL is not necessary because other required control measures are expected to result in restoration in a reasonable period of time.
  • Category 4c Waters - A TMDL is not appropriate because the impairment is the result of pollution, rather than a pollutant that can be allocated through a TMDL.

2014 Waterbody/Pollutant Delistings

A separate list of waterbody/pollutant combinations that were included on the previous (2012) Section 303(d) List, but that are NOT included on the 2014 List is also available. This list of 2014 Water/Pollutant Delistings (PDF, 16 KB) provides some linkage and continuity between the previous and current Lists. The specific reason why a waterbody/pollutant was removed from the List (i.e., delisting action, reassessment, re-segmentation, etc.) is included in this document. Some of these waterbodies/pollutants (specifically, those that have been delisted but that remain impaired) also appear on the list of Other Impaired Waterbody Segments Not Listed Because Development of a TMDL is Not Necessary.

All Impaired Waters

A searchable, sortable spreadsheet of all impaired waters/pollutants is also available. The All Impaired Waters List (Excel, 322 KB) includes both Section 303(d) List waters, as well as Category 4a, 4b and 4c waters that are impaired but not included on the Section 303(d) List.

The 2016 CWA Section 303(d) List

As noted above, Section 303(d) of the Federal Clean Water Act (CWA) requires states to compile periodically (every two years) a list of impaired waters that do not meet water quality standards and where designated uses are not fully supported and where a Total Maximum Daily Load (TMDL) plan is necessary to address the impairment. States are scheduled to submit their next Section 303(d) Lists to USEPA by April 1, 2016 and the process to update the New York State List is currently underway. A Draft New York State 2016 Section 303(d) List of Impaired/TMDL Waters was made available for public review and comment for a 45-day period that ended March 4, 2016. NYSDEC is currently developing a Proposed Final 2016 List for USEPA review and approval.

Additionally, the state is required to maintain a Consolidated Assessment and Listing Methodology (CALM) to outline its process for monitoring and assessing the quality of New York State waters, and developing the Section 303(d) List. The CALM consists of three parts:

Public Solicitation of Data/Information

As part of the process for developing the 2016 Section 303(d) List, the public was solicited to provide water quality data and information (by October 2015) for NYSDEC's consideration. Such data/information was received for a number of waterbodies from a number of organizations and individuals. In most instances, these submittals did not result in an addition to, or delisting from, the Section 303(d) List. In most cases the reasons for this are 1) the submitted data was limited (either spatially or temporally) and needs to be verified, or 2) the water quality issue of concern is already reflected in a current listing and/or the corresponding assessment of the waterbody in question, or 3) the water quality impact does not rise to the level of an impairment, or 4) the cause of the impact/impairment is not a specific pollutant for which a TMDL would be able to address, and therefore that particular impact is not appropriate for inclusion on the Section 303(d) List of Impaired/TMDL Waters. Specifically data/information was submitted for waters:

  • with occurrences of harmful algal blooms (HABs) that were not accompanied by unusually high nutrient levels (such waters are assessed as having uses impaired by HABs, but are not appropriate to include on the List),
  • with elevated levels of a constituent (such as enterococcus) for which NYSDEC has not currently adopted a water quality standard, or where the standard does not apply to the specific waterbody of concern (such waters will have the issue of concern reflected in the appropriate waterbody assessments and will be identified as a priority for follow-up investigation by NYSDEC), and

  • with occurrences of low dissolved oxygen where the where the impact/impairment is more appropriately listed for the pollutant that is causing the oxygen demand - e.g., phosphorus, nitrogen - rather than for dissolved oxygen (such water will be listed for the more appropriate pollutant that is the cause of low dissolved oxygen).

Much of the solicited and other more recent data/information reviewed during the development of the 2016 Section 303(d) List is reflected in updated Waterbody Inventory/Priority Waterbodies List (WI/PWL) assessment fact sheets. The updated WI/PWL fact sheets (PDF, 1.17 MB) include information considered during the development of the List, whether that data resulted in a listing or not.

Section 303(d) List Update Schedule

A schedule for updating the list is as follows.

June thru September 2015 - Solicitation of the public for existing water quality data and information that may be useful in compiling the 2016 Section 303(d) List.

October thru December 2015 - Review of water quality data and information and development of the Draft 2016 Section 303(d) List for Public Comment.

Mid-January thru February 2016 - Public Notice and Comment Period for the Draft 2016 Section 303(d) List.

March 2016 - Review of Public Comments and preparation of Proposed Final 2016 Section 303(d) List.

April 1, 2016 - Submittal of Proposed Final 2016 Section 303(d) List of USEPA.

April thru May 2016 - USEPA review of Proposed Final 2016 Section 303(d) List and NYSDEC response to public comments.

June 2016 - USEPA approval of Final NYS 2016 Section 303(d) List.

Additional information regarding the NYSDEC Water Quality Assessment Program, including the Waterbody Inventory/Priority Waterbodies List assessments and Section 305 (b) water quality reporting can also be found on the NYSDEC website.