On January 28, the Illinois Environmental Protection Agency (Illinois EPA) announced the issuance of health advisories for four (4) per- and polyfluoroalkyl substances (PFAS) compounds in accordance with the Illinois Part 620 groundwater regulations (35 Ill. Adm. Code Part 620). 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 (35 Ill. Adm. Code 620.605). The four (4) PFAS compounds for which Illinois health advisories were issued are PFBS, PFHxS, PFHxA, and PFOA.

These four (4) PFAS compounds were identified during the course of Illinois’ statewide PFAS groundwater investigation. This ongoing investigation, which commenced in September 2020, is assessing finished drinking water in all 1,749 community water supplies (CWS) in Illinois for 18 different PFAS compounds. The statewide assessment is expected to be completed in the fall of 2021. A complete listing of sample results to date from Illinois’ statewide PFAS groundwater investigation is available on the interactive map established by Illinois EPA at https://illinois-epa.maps.arcgis.com/apps/opsdashboard/index.html#/d304b513b53941c4bc1be2c2730e75cf.

As required by the Part 620 regulations, each health advisory contains 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 below chart provides the health advisory guidance level for each of the PFAS compounds.

Chemical Abstract Services Registry Number (CASRN) Substance Name Substance Acronym HA Guidance Level in milligrams per liter (mg/L) or ppm

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

or ppt

375-73-5 Perfluorobutanesulfonic Acid PFBS 0.14 140,000
355-46-4 Perfluorohexanesulfonic Acid PFHxS 0.00014 140
307-24-4 Perfluorohexanoic Acid PFHxA 0.56 560,000
335-67-1 Perfluorooctanoic Acid PFOA 0.000002 2

The guidance levels contained in the Illinois health advisories are not enforceable groundwater or drinking water standards; rather, 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. In addition, the Illinois health advisory levels can be used to establish groundwater cleanup or action levels (35 Ill. Adm. Code 620.601).

The Illinois health advisories will be published in the Environmental Register (a publication of the Illinois Pollution Control Board) and placed at the website https://pcb.illinois.gov/Resources/News.

In addition, the health advisories will be available on Illinois EPA’s website at https://www2.illinois.gov/epa/topics/water-quality/pfas/Pages/pfas-healthadvisory.aspx.

USEPA PFAS Health Advisories

At the federal level, there are currently no MCLs established for PFAS chemicals. However, in 2016, the U.S. Environmental Protection Agency (USEPA) established drinking water health advisories for two of the most common PFAS compounds: PFOA, for which Illinois is likewise establishing a health advisory, and PFOS (perfluorooctane sulfonate), for which no Illinois health advisory is being established. The federal health advisories are similarly non-enforceable and nonregulatory, but rather are intended to provide technical information to states agencies and other public health officials on health effects, analytical methodologies, and treatment technologies associated with drinking water contamination. USEPA’s health advisory levels for PFOA and PFOS are set at a level of 70 ppt, or .00007 ppm, which is intended to offer a margin of protection for all persons, including the most sensitive populations, from adverse health effects resulting from exposure to PFOA and PFOS in drinking water over a lifetime of exposure. Despite this, the Illinois health advisory level for PFOA is an order of magnitude more stringent than the federal health advisory. In contrast, as indicated, no Illinois health advisory is being set for PFOS. These differences highlight the continuing patchwork nature and variability among PFAS regulations across the country.

USEPA is continuing to collect and evaluate data on PFAS chemicals in drinking water, which may lead to the establishment of additional health advisories or enforceable MCLs. Under the Safe Drinking Water Act (SDWA), once every five years, USEPA is required to issue a new list of unregulated contaminants to be monitored by public water systems. The third Unregulated Contaminant Monitoring Rule (UCMR3), published May 2, 2012, addressed six PFAS compounds, including:

  • perfluorooctanesulfonic acid (PFOS) (now subject to a federal health advisory)
  • perfluorooctanoic acid (PFOA) (now subject to federal and Illinois health advisories)
  • perfluorononanoic acid (PFNA)
  • perfluorohexanesulfonic acid (PFHxS) (now subject to an Illinois health advisory)
  • perfluoroheptanoic acid (PFHpA)
  • perfluorobutanesulfonic acid (PFBS) (now subject to an Illinois health advisory)

The proposed Fifth Unregulated Contaminant Monitoring Rule (UCMR5), signed on January 14, 2021, proposes to expand the list of monitored PFAS compounds to 29.[i] The data collected under UCMR3 and UCMR 5 will undoubtedly be used to establish additional PFAS standards and regulatory limits going forward.

Troutman Pepper attorneys have been at the forefront of PFAS and emerging contaminant issues for years. During the past year, PFAS has been the subject of our six-part webinar series. The most recent webinar in the series covered technical issues and chemistry. To read more about the firm’s PFAS capabilities, click here.

[i] The 29 PFAS compounds proposed for evaluation in the UCMR5 are: 11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS); 9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS); 4,8-dioxa-3H-perfluorononanoic acid (ADONA); hexafluoropropylene oxide dimer acid (HFPO‑DA); nonafluoro-3,6-dioxaheptanoic acid (NFDHA); perfluorobutanoic acid (PFBA); perfluorobutanesulfonic acid (PFBS);

1H,1H, 2H, 2H-perfluorodecane sulfonic acid (8:2FTS); perfluorodecanoic acid (PFDA); perfluorododecanoic acid (PFDoA); perfluoro(2-ethoxyethane)sulfonic acid (PFEESA); perfluoroheptanesulfonic acid (PFHpS); perfluoroheptanoic acid (PFHpA); 1H,1H, 2H, 2H-perfluorohexane sulfonic acid (4:2FTS); perfluorohexanesulfonic acid (PFHxS); perfluorohexanoic acid (PFHxA); perfluoro-3-methoxypropanoic acid (PFMPA); perfluoro-4-methoxybutanoic acid (PFMBA); perfluorononanoic acid (PFNA); 1H,1H, 2H, 2H-perfluorooctane sulfonic acid (6:2FTS); perfluorooctanesulfonic acid (PFOS); perfluorooctanoic acid (PFOA); perfluoropentanoic acid (PFPeA);

perfluoropentanesulfonic acid (PFPeS); perfluoroundecanoic acid (PFUnA); N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA); N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA); perfluorotetradecanoic acid (PFTA); and perfluorotridecanoic acid (PFTrDA).