Illinois has joined a growing list of states seeking to regulate per- and polyfluoroalkyl substances (PFAS) and compounds. On January 28, 2021, the Illinois Environmental Protection Agency announced four “health advisories” in accordance with the Illinois Part 620 groundwater regulations (35 Ill. Adm. Code Part 620). Specifically, the four PFAS compounds Illinois issued health advisories on are PFBS, PFHxS, PFHxA, and PFOA.

Pursuant to the Illinois Administrative Code, 35 Ill. Adm. Code 620.605, health advisories are issued when a chemical substance that is harmful to human health, and for which no numeric groundwater standard exists, is detected and confirmed in a community water supply well. The four PFAS compounds were identified during the course of an Illinois’ statewide PFAS groundwater investigation, which began in September 2020. The investigation’s goal was to assess finished drinking water in all 1,749 community water supplies in Illinois for 18 different PFAS compounds. The statewide assessment is expected to be completed in the fall of 2021.

As required by the Illinois Part 620 groundwater regulations, each of the four health advisories contain a general description of the chemical, provides information on carcinogenicity and potential adverse health effects, and establishes a guidance level (35 Ill. Adm. Code 620.605(b)). The guidance levels contained in the four Illinois health advisories are not enforceable groundwater or drinking water standards. However, the health advisory guidance levels and other data gathered from the statewide drinking water investigation will be used by Illinois EPA in the development of maximum contaminant levels (MCLs) for PFAS, which are enforceable drinking water standards. The Illinois health advisory levels can additionally be used to establish groundwater cleanup or action levels pursuant to 35 Ill. Adm. Code 620.601.

Additional information concerning the health advisories are available on the Illinois EPA’s website.

On the federal level, there are currently no MCLs established for PFAS. However, in 2016, the U.S. Environmental Protection Agency established drinking water health advisories for two of the most common PFAS compounds: PFOA, for which Illinois is likely to establish a health advisory, and PFOS (perfluorooctane sulfonate), for which no Illinois health advisory has been established to date. Like in Illinois, the federal health advisories are similarly non-enforceable and nonregulatory, but only intended to provide technical information to state agencies and other public health officials on health effects, analytical methodologies, and treatment technologies associated with drinking water contamination.