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EPA Additions to Illinois' 2024 Impaired Waters List

Summary

Public Notice of EPA Additions to Illinois’ 2024 Impaired Waters List

This notice announces EPA solicitation of public comment on its identification of 19 water quality limited segments impaired by total phosphorus (Appendix 3) to be included on Illinois’ 2024 List of Impaired Waters under Section 303(d) of the Clean Water Act. The 45-day Public Comment Period starts December 17, 2024, and ends January 31, 2025. The EPA will consider any comments received, make appropriate revisions based on the comments and transmit the final list of WQLS to Illinois.

Background

Section 303(d)(2) of the CWA requires each state to identify waters for which existing required pollution controls are insufficient to meet state water quality standards. States are required to develop a list of impaired water bodies requiring total maximum daily load calculations (the 303(d) list) and submit the list to the EPA for review and approval or disapproval every two years [see 40 CFR Section 130.7(d)(1)]. If the EPA disapproves any portion of the state’s 303(d) list, the EPA must identify the WQLS that should be included on the state’s 303(d) list and issue a public notice seeking comment on the EPA’s listing decision no later than 30 days after the date of such disapproval. After considering public comments and making appropriate revisions, the EPA is to transmit the final list of WQLS to the state for inclusion on the state’s 303(d) list [see 40 CFR Section 130.7(d)(2)].

Illinois submitted its 2024 Section 303(d) list to the EPA on October 2, 2024, with additional information submitted on October 30, 2024. The EPA evaluated the state’s submission and determined that it was not fully consistent with the requirements of Section 303(d) of the CWA and the EPA’s implementing regulations. On December 11, 2024, the EPA partially approved and partially disapproved Illinois’ 2024 303(d) list submission. Specifically, the EPA approved Illinois’ listing of certain WQLS and associated pollutants (Appendix 1). The EPA disapproved Illinois’ decision not to list WQLS for total phosphorus, because Illinois’ submission did not demonstrate that it satisfied its obligation to assemble and evaluate all existing and readily available water quality-related data and information. The EPA believes that the existing and readily available data and information indicate total phosphorus impairments on the WQLS identified in Appendix 3 and meet the federal requirements for listing under Section 303(d). For additional information on the EPA’s partial disapproval decision for Illinois’ 2024 303(d) list, refer to Section 2.D.iv of the Decision Document.

Documents related to the EPA’s decision on Illinois’ 2024 list of impaired waters

  • Transmittal Letter for EPA Action on Illinois' 2024 Section 303(d) List (pdf) (415.86 KB, 12/11/2024)
  • EPA Decision Document for Illinois’ 2024 Section 303(d) List (pdf) (381.9 KB, 12/11/2024)
  • Appendix 1 (pdf) (1.62 MB, December 2024)  EPA Approved Illinois 2024 303(d) List of Impaired Waters Needing TMDLs.
  • Appendix 2 (pdf) (297.77 KB, December 2024)  Water Quality Limited Segments Removed from the Illinois’ Approved 2020/2022 303(d) List.
  • Appendix 3 (pdf) (152.62 KB, December 2024)  Water Quality Limited Segments the EPA is Adding to the Illinois’ 2024 303(d) List for Total Phosphorus.
  • Appendix 4 (pdf) (335.41 KB, December 2024)  Illinois Environmental Protection Agency. Illinois 2024 Integrated Report Appendix E—Responsiveness Summary.
  • Appendix 5: Illinois Algae and Total Phosphorus Data for Waters with Algae Impairments in Category 4C Without a Pollutant in Category 5
    • Appendix 5 - Table 1 (pdf) (131.68 KB, December 2024)  Algae Data.
    • Appendix 5 - Table 2 (pdf) (106.96 KB, December 2024)  Total Phosphorus Data.
  • Appendix 6 (pdf) (729.16 KB, December 2024)  Illinois Cyanotoxin Data, 2017-2021.

The EPA requests that any written comments be sent by email to drake.wendy@epa.gov on or before January 31, 2025.

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