Section 303(d) List of Impaired Waters

The IDEM Office of Water Quality (OWQ) develops Indiana's 303(d) List of Impaired Waters as part of the state's Integrated Water Monitoring and Assessment Report (IR), which is submitted to the U.S. EPA every two years in accordance with Sections 305(b) and 303(d) of the Clean Water Act (CWA). CWA Section 305(b) requires states to make water quality assessments and provide water quality reports to the U.S. EPA, and CWA Section 303(d) requires states to identify waters through their Section 305(b) water quality assessments, that do not or are not expected to meet applicable state water quality standards with federal technology based standards alone. Under CWA Section 303(d), states are also required to develop a priority ranking for these waters taking into account the severity of the pollution and the designated uses of the waters. Once this listing and ranking of impaired waters is completed, states are required to develop Total Maximum Daily Loads (TMDLs) for these waters in order to achieve compliance with the water quality standards.

These requirements were met for the 2008 cycle by the submission of Indiana's 2008 IR to the U.S. EPA and the subsequent approval of Indiana's 2008 303(d) list by that agency.

On May 8, 2013, U.S. EPA issued a partial approval of Indiana's 2010 303(d) list. More information pertaining to IDEM's 2010 cycle submittal and U.S. EPA's decision can be found 2010 Section 303(d) List of Impaired Waters page.

Since U.S. EPA’s partial approval of Indiana’s 2010 303(d) list in 2013, IDEM has submitted updated 303(d) lists for the 2012, 2014, and 2016 cycles: 

  • IDEM submitted its 2012 303(d) List of Impaired Waters to the U.S. EPA on April 1, 2012 and submitted an updated 303(d) list on December 28, 2012 as part of an addendum to the 2012 IR.
  • IDEM submitted its 2014 303(d) List of Impaired Waters to U.S. EPA on April 1, 2014 and submitted and updated 303(d) list on September 25, 2015 as part of an addendum to the 2014 IR.
  • IDEM submitted its 2016 303(d) List of Impaired Waters to U.S. EPA on April 1, 2016 and submitted an updated 303(d) list on February 23, 2017 as part of an addendum to the 2016 IR.

To date, U.S. EPA has not issued any decisions regarding Indiana’s 303(d) List of Impaired Waters submitted for the 2012, 2014, or 2016 integrated reporting cycles.

IDEM published the notice of public comment period for its draft 2018 303(d) List of Impaired Waters, in the Indiana Register on April 11, 2018, formally opening the 90-day public comment period. IDEM received no comments on the draft 2018 303(d) list or the Consolidated Assessment and Listing Methodology (CALM) used to develop prior to the close of the public comment period on July 10, 2018.

General information on the 303(d) list is available on the Section 303(d) List Frequently Asked Questions page. You may also contact the Integrated Report Coordinator with any questions you have regarding the 303(d) list.

2018 Finalized 303(d) List of Impaired Waters

IDEM submitted its 2018 finalized 303(d) List of Impaired Waters to U.S. EPA on August 17, 2018 as Appendix I of the 2018 Integrated Report. Appendix I includes the 303(d) List (Category 5 of Indiana’s Consolidated List) and Category 4 waters, which are those that are impaired but do not require a Total Maximum Daily Load. Combined, these categories include all known impairments to Indiana waters.

2018 Draft 303(d) List of Impaired Waters

Presentation of Indiana’s Draft 2018 303(d) List of Impaired Waters to Indiana’s Environmental Rules Board on April 11, 2018 [PDF]

Notice of Comment (NOC) Period for Indiana’s Draft 2018 303(d) List - NOC Narrative [PDF]

Appendices 3-6 and 8-10 are provided in a spreadsheet format to facilitate sorting and searching of the information they contain (Appendix 7 is not included because, while it is sorted alphabetically, it cannot be effectively sorted in a spreadsheet format).

General information on the 303(d) list is available on the Section 303(d) List Frequently Asked Questions page. You may also contact the Integrated Report Coordinator with any questions you have regarding the 303(d) list.