Guidance

How to Submit Water Quality Data to Illinois Environmental Protection Agency for Consideration in Preparing the 2026 Integrated Report on Illinois Water Quality

Submitted data for the 2026 Integrated Report must include all available data from January 2021 through December 2023.

Section 305(b) of the federal Clean Water Act requires each state to monitor, assess, and submit a report on the quality of the state's surface waters to the U.S. Environmental Protection Agency every two years.

The Illinois Environmental Protection Agency (Illinois EPA) solicits all applicable surface-water data (biological, chemical, and physical) and information to help identify:

• Waters attaining all designated uses (e.g., Aquatic Life Use, Primary Contact Use, Aesthetic Quality Use, Fish Consumption Use);
• Waters not attaining one or more designated uses (collectively called "impaired waters"); and
• Potential causes of impairment (e.g., excessive pollutant concentrations, habitat alteration).

Illinois EPA will accept surface-water-quality data or other information and consider the submitted data and information when preparing the 2026 Integrated Report.

 Illinois EPA will accept data packages, as defined below, through November 15, 2024.

Illinois EPA requires submitted data and information for consideration in preparing the 2026 Integrated Report be obtained using a documented quality assurance and quality control plan.  This ensures that all data are of known and documented quality and can be used with a reasonable degree of certainty to support specific decisions or actions.

     1. Quality Assurance Project Plan (QAPP)

• Must be prepared according to the U.S. Environmental Protection Agency's document EPA QA/R‐5, EPA Requirements for Quality Assurance Project Plans (March 2001, reissued May 2006), available at USEPA website
• Must be approved in writing by the submitting entity’s project manager and quality assurance officer.
• Must contain all environmental sampling, analysis, and quality-control procedures that were used to obtain data and information.
• Must contain the analytical test methods used to prepare and analyze the environmental samples. Analytical test methods must comply with Title 40 Code of Federal Regulations Part 136, “Guidelines for Establishing Test Procedures for Analysis under the Clean Water Act” or the latest edition of Standard Methods for the Examination of Water and Wastewater.
• Must contain the analytical laboratory’s name and location. The laboratory must be a state-certified laboratory or hold National Environmental Laboratory Accreditation Program accreditation for the analyses performed.

    2. Electronic file of data and information

• Must be configured and formatted according to the Data Submission Template.
• Must include all data collected between January 2021 through December 2023 in one worksheet.

     3. Data-Quality Summary

• Must include a summary that describes and aids interpretation of submitted data and information. 
• Must include a description of any deviations from the Quality Assurance Project Plan or other problems with sample collection or analytical processes that could affect data quality. 

How To Send Data Packages

E-mail the QAPP, completed Data Submission Template, and data-quality summary to Michelle Rousey (Michelle.Rousey@illinois.gov) or mail to Michelle Rousey, Quality Assurance Officer, Illinois Environmental Protection Agency, Bureau of Water, Mail Code #15, 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 Nicole Vidales, Manager, Surface Water Section, Bureau of Water at (217) 782-3362.