For Consideration in Preparing the 2020 Integrated Report on Illinois Water Quality, including the List of Clean Water Act Section 303(d) Impaired Waters


The Illinois Environmental Protection Agency (Illinois EPA) is in the process of considering all applicable surface-water data (biological, chemical and physical) and information to help identify:

  • Waters that are attaining (i.e., in "good" condition) all of their designated uses, such as Aquatic Life Use, Primary Contact Use, or Fish Consumption Use;
  • Waters that are not attaining (i.e., "fair" or "poor" condition) all of their designated uses (collectively called "impaired waters"); and
  • Potential causes and sources of impairment (e.g., excessive nutrients, sediment, or heavy-metal concentrations; habitat alteration).

This information will be considered in preparing the 2020 Section 305(b) and 303(d) reports on Illinois water quality (due April 1, 2020), as required by the federal Clean Water Act. Section 305(b) of the Clean Water Act requires states to prepare a water quality inventory of its surface waters every two years. Section 303(d) requires states to prepare a list of impaired surface waters for which comprehensive water quality studies (i.e., Total Maximum Daily Load studies) must be prepared to help guide restoration and other management efforts. This list, commonly called the "303(d) List," represents a subset of all impaired waters, as some impaired waters do not require a Total Maximum Daily Load study.

Illinois EPA is interested in surface-water quality data or other information, regardless of whether it suggests that the water body is in "good", "fair", or "poor" condition. This guidance provides information on how and when surface-water data/information can be submitted to Illinois EPA for consideration.

What To Submit

Data packages will be accepted through October 15, 2018. Data packages submitted after this date will be considered in the preparation of similar reports subsequent to the 2020 report.

Quality assurance and quality control considerations are especially important; knowing the quality of the data/information helps minimize the potential for errors in distinguishing "good" waters from impaired waters. To be considered by Illinois EPA, submitted data/information must meet the following requirements:

  1. Data/information packages must include an electronic copy of a Quality Assurance Project Plan approved by your project manager and quality-assurance officer. The plan must be prepared in accordance with the U.S. Environmental Protection Agency's document EPA QA/R-5, EPA Requirements for Quality Assurance Project Plans, March 2001. This document can be viewed and downloaded from the USEPA web site.
  2. All environmental sampling that generated the data/information — including replicate and blank samples — must be prepared/collected according to the submitted Quality Assurance Project Plan.
  3. All laboratory analyses related to generation of the data/information must be performed by a laboratory that is State-certified or accredited by the National Environmental Laboratory Accreditation Program (NELAP).
  4. Analytical testing methods should be in accordance with Title 40 Code of Federal Regulations Part 136, Guidelines for Establishing Test Procedures for Analysis under the Clean Water Act or with the latest edition of Standard Methods for the Examination of Water and Wastewater.

Data packages sent to the Illinois EPA must include:

  1. An electronic copy of a Quality Assurance Project Plan approved by your project manager and quality-assurance officer.
  2. An electronic file of data/information formatted according to the  Data-Submission Template. This electronic file should include all water quality data from January 2015 through December 2017 in one worksheet. Even if some of this data (e.g. 2014 and 2015) were submitted for the previous Integrated Report, it needs to be included with this submittal because quite often these previous data are in different formats and may not be compatible with the more recent data format. Data qualifiers must be entered into a separate qualifier column and not included within the result column (see Data-Submission Template).
  3. A document (preferably as a Microsoft Word file) that summarizes the submitted data/information. This Data Quality Assessment Summary should include information that aids data interpretation such as a description of any deviations from the Quality Assurance Project Plan or other problems encountered during sample collection or analytical processes that could affect data quality.

How To Send Data Packages

Send electronic files by e-mail to Michelle Rousey or by regular mail to Michelle Rousey, Quality Assurance Officer, Illinois Environmental Protection Agency, Bureau of Water, P.O. Box 19276, Springfield, Illinois, 62794-9276.


For questions regarding this guidance document, please contact Michelle Rousey, Bureau of Water Quality Assurance Officer, or Gregg Good, Manager, Surface Water Section, Bureau of Water at (217) 782-3362.