Illinois EPA Completes Statewide Sampling for Investigation into the Prevalence of PFAS in Drinking Water
Data Collected Will Aid in Future Development of Drinking Water Standards

 

[March 17, 2022] 

Illinois Environmental Protection Agency Director John J. Kim announced the completion of statewide sampling to investigate the prevalence and occurrence of per- and polyfluoroalkyl substances (PFAS) in finished drinking water at all community water systems (CWSs) in Illinois. Illinois EPA began the investigation in the fall of 2020 and completed sampling for 18 PFAS compounds in early 2022. Illinois EPA sampled the finished drinking water at the distribution system entry points at 1,017 CWS, at 1,428 sample locations. This represents all operational sources of water for the entirety of CWS in the state. Data gathered as part of this investigation will aid in the development of future Maximum Contaminant Level (MCL) drinking water quality standards for PFAS.

“The completion of this sampling exercise marks a significant step in our goal to establish state-specific drinking water standards for PFAS in Illinois. More importantly, it has enabled Illinois EPA to notify community water systems when PFAS chemicals were detected and confirmed. Based on the results of confirmation sampling, additional evaluations and actions were and continue to be undertaken by community water systems that are necessary to protect human health and the environment,” said Director Kim. “Illinois EPA is working directly with affected systems to ensure residents are informed and to determine appropriate actions to reduce exposure to PFAS contaminants.”
 

With the completion of sampling, Illinois PFAS detections were found to be similar to other Midwest states. Of the 1,017 CWSs sampled, 126 (or 12.4%) had confirmed PFAS detections. Of those 126 systems with detections, 120 systems had detections for Perfluorooctanoic Acid (PFOA) and/or Perflurooctanesulfonic acid (PFOS). In addition, of the 126 systems that had confirmed PFAS detections, 68 (or 53.9%) of the systems’ detections are below health advisory guidance levels issued by Illinois EPA. During the sampling, two locations were found to have levels that exceeded the United States Environmental Protection Agency’s (U.S. EPA) Lifetime Health Advisory levels, and those sources were taken out of service. Illinois EPA has entered into an agreement with the United States Geological Survey (USGS) to review the analytical data and provide a report that evaluates the prevalence and occurrence of PFAS in CWS-supplied drinking water in Illinois.

During the investigation, and in accordance with Illinois groundwater regulations, Illinois EPA also issued Health Advisories for six PFAS chemicals. Heath Advisories are issued when there is a 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). Health advisory guidance levels are informal, non-enforceable standards used to help guide responses to these detections.

To inform residents and interested parties, Illinois EPA established and maintains a comprehensive webpage to inform the public about Illinois EPA’s Statewide PFAS Investigation, including background, exposures, health effects, minimum reporting levels for each of the 18 PFAS chemicals and regulatory status of these emerging contaminants. Community-specific data is also available on an interactive dashboard and map.  (CLICK ON DOTS ON MAP TO SEE INDIVIDUAL RESULTS)

PFAS chemicals are human-made and do not occur naturally in the environment. They have been used in a wide range of consumer products, industrial processes, and in some fire-fighting foams (called aqueous film-forming foam or AFFF). Due to their persistence, historic and ongoing use, and mobility, PFAS chemicals have been found widely in the environment, including in unpopulated areas. U.S. EPA established a federal Health Advisory for PFAS of 70 ppt in 2016 but has taken no formal action to set drinking water standards.

Prior to proposing Illinois-specific MCLs for PFAS, additional work must be completed. In addition to the final report by USGS on the prevalence and occurrence of PFAS in Illinois, technical feasibility and economic reasonableness documents and studies must be completed. Illinois EPA will also coordinate with the Illinois Department of Public Health to review and develop necessary risk assessment and health effects data in support of any proposed state MCLs. Illinois EPA will conduct outreach with stakeholders on proposed PFAS MCLs prior to submitting a formal proposal to the Illinois Pollution Control Board (Board). Illinois EPA will then initiate the proposed rulemaking process as prescribed by the Illinois Environmental Protection Act and Board Procedural Rules.

[Illinois Office of Communication and Information] 

The below chart provides the heath advisory guidance level for each chemical identified:

Chemical Abstract Services Registry Number (CASRN)	PFAS Analyte	Acronym	HA Guidance Level in nanograms per liter* (ng/L or ppt)	Date Heath Advisory Issued/Revised
375-95-1	Perfluorononanoic acid	PFNA	21	7/27/21
1763-23-1	Perflurooctanesulfonic acid	PFOS	14	4/16/21
375-73-5	Perfluorobutanesulfonic Acid	PFBS	2,100**	4/16/21
355-46-4	Perfluorohexanesulfonic Acid	PFHxS	140	1/28/21
307-24-4	Perfluorohexanoic Acid	PFHxA	560,000	1/28/21
335-67-1	Perfluorooctanoic Acid	PFOA	2	1/28/21

* The levels are presented in nanograms per liter (ng/L), equal to parts per trillion (ppt).  For reference: 1 milligram per liter (mg/L) or part per million (ppm) = 1,000 micrograms per liter (µg/L) or parts per billion (ppb) = 1,000,000 nanograms per liter (ng/L) or parts per trillion (ppt).
**Health-Based Guidance Level per April 16, 2021 PFBS Heath Advisory Update.