Deadline UpdateLiveReporting Deadline
Illinois establishes PFAS drinking water MCL compliance timeline
35 Illinois Administrative Code Part 620 (Groundwater Quality)Illinois Environmental Protection AgencyIllinois
Announced
May 21, 2026
Effective
Apr 26, 2029
Implementation
Apr 25, 2027
Description
Illinois EPA has established specific compliance timelines for the PFAS drinking water Maximum Contaminant Levels (MCLs) under the amended Part 620 groundwater quality regulations. Community water supplies must complete initial monitoring by April 25, 2027, begin ongoing compliance monitoring on April 26, 2027, and achieve compliance with MCLs by April 26, 2029. The standards cover PFOA (4 ppt), PFOS (4 ppt), PFHxS (10 ppt), PFNA (10 ppt), HFPO-DA/GenX (10 ppt), and PFBS (part of Hazard Index mixture).
Key Findings
Illinois establishes PFAS drinking water MCL compliance timeline
May 21, 2026 Kim Biggs, Illinois EPA FOR IMMEDIATE RELEASE 217-558-1536 kim.biggs@illinois.gov Illinois EPA Issues Statement on Trump Administration’s Rollback of PFAS Requirements for Drinking Water State Drinking Water Standards Remain in Place for PFAS Springfield – Illinois Environmental Protection Agency’s (Illinois EPA) Director James Jennings issued a statement following the U.S. EPA’s announcement to roll bac