Illinois EPA issues health advisories for per-and polyfluoroalkyl substances (PFAS) in accordance with Illinois groundwater regulations


SPRINGFIELD – Illinois Environmental Protection Agency Director John J. Kim today announced the issuance of health advisories for four chemicals in accordance with Illinois groundwater regulations. Health advisories are issued when there is detection of a chemical substance(s) harmful to human health for which no numeric groundwater standard(s) exists, and resampling confirms the presence in a community water supply well (35 Ill. Adm. Code 620.605).

The four chemicals specified in the health advisories are compounds included in the family of per- and polyfluoroalkyl substances (PFAS), often referred to as “forever chemicals” because of their persistence over time in surface water and groundwater. Each health advisory contains a general description of the chemical, information on carcinogenicity and potential adverse health effects, and a guidance level. The below chart provides the heath advisory guidance level for each chemical identified.

Chemical Abstract Services Registry Number (CASRN)

Substance Name

Substance Acronym

HA Guidance Level in milligrams per liter (mg/L)

HA Guidance Level in nanograms per liter (ng/L)


Perfluorobutanesulfonic Acid





Perfluorohexanesulfonic Acid





Perfluorohexanoic Acid





Perfluorooctanoic Acid




The health advisories will be published in the Environmental Register, a publication of the Illinois Pollution Control Board, and placed on the website: The health advisories are also available on the Illinois EPA website at:

“This action is part of the Illinois EPA’s statewide PFAS investigation intended to determine the prevalence of PFAS chemicals in our community water supplies. This information is critical to future efforts to set drinking water standards for PFAS compounds,” said Director Kim. “Illinois EPA will work with affected community water supplies to ensure measures are taken to protect drinking water.”

The guidance levels contained in the health advisories are not enforceable groundwater or drinking water standards. The Illinois EPA will use the health advisory guidance levels and data gathered from the statewide drinking water investigation in the development of enforceable drinking water standards for PFAS known as Maximum Contaminant Levels, or MCLs.

The statewide PFAS investigation, which began in September 2020, is expected to be completed in the fall of 2021. The Illinois EPA is sampling drinking water at every Community Water Supply in Illinois. If PFAS chemicals are confirmed at concentrations above laboratory minimum reporting levels (MRLs), the Illinois EPA will work directly with those community water supplies to ensure residents are informed and to determine next steps for reducing exposure. To date, Illinois EPA has 442 samples from community water supplies in Illinois. An additional 1,012 samples will be collected as the investigation continues. A complete listing of sample results to date is available on the interactive map established by Illinois EPA at:

For additional information, please visit the Statewide PFAS Investigation Network webpage at:

Myradiolink, 28 January 2021