Springfield, IL – November 24, 2025 – The Illinois Environmental Protection Agency has issued a new health advisory for a “forever chemical” found in community water supplies across the state, the eighth such advisory since 2021.
New Chemical Identified
Acting Director James Jennings announced the health advisory for 6:2 Fluorotelomer Sulfonic Acid (6:2 FTS), a member of the per- and polyfluoroalkyl substances (PFAS) family. The chemical was identified through the agency’s ongoing statewide sampling program of community water supplies.
EPA has set a guidance level for 6:2 FTS at 0.00077 milligrams per liter (770 nanograms per liter), although this is not an enforceable drinking water standard.
What Are Health Advisories?
Health advisories are issued when harmful chemicals are detected in water supplies, but for which no official numeric groundwater standards have been established. An advisory is issued if resampling confirms the presence of the substance in community water supply wells.
“Through Illinois EPA’s proactive statewide sampling of PFAS chemicals, we have identified chemicals that present potential public health impacts,” said Jennings. “Health advisories ensure the public has clear, science-driven information about potential exposures and associated risks.”
Understanding PFAS
Because PFAS chemicals persist in surface water and groundwater over a great deal of time, they are commonly called “forever chemicals.” They are synthetically manufactured industrial compounds that have been used in many industrial applications and consumer products for decades.
The Illinois EPA has now issued health advisories for eight PFAS chemicals, with some advisories recently updated to reflect new scientific data. In April 2025, the agency revised guidance levels for perfluorobutanoic acid (PFBA) and perfluorohexanoic acid (PFHxA).
From Advisories to Standards
Five PFAS chemicals that previously had health advisories now have enforceable groundwater quality standards following regulatory amendments adopted by the Illinois Pollution Control Board. These include:
- Perfluorobutanesulfonic acid (PFBS)
a) Perfluorohexanesulfonic acid (PFHxS)
Perfluorononanoic acid – PFNA - Perfluorooctanesulfonic acid (PFOS)
- Perfluorooctanoic acid (PFOA)
A standard was also set for hexafluoropropylene oxide dimer acid, commercially known as GenX.
Comprehensive State Testing Program
The Illinois EPA completed a comprehensive statewide investigation in 2021 by sampling drinking water at every community water supply in Illinois. When PFAS chemicals were confirmed above laboratory reporting levels, the agency worked directly with water suppliers to inform residents and reduce exposure.
Many community water suppliers continue voluntary PFAS testing which resulted in the recent 6:2 FTS detections. The U.S. EPA is also conducting PFAS testing in Illinois from 2023-2025 as part of the fifth Unregulated Contaminant Monitoring Rule (UCMR 5).
Public Information
Health advisories are published in the Environmental Register and are available at both the Illinois Pollution Control Board website and the Illinois EPA website. The agency maintains an interactive map showing sample results from the statewide investigation.
These health advisory guidance levels provide information to Illinois EPA’s regulatory programs in developing cleanup and action objectives for groundwater.
Mainly- For more information, contact Kim Biggs, Illinois EPA, at 217-558-1536 or [email protected]
