General PFAS Information

The Illinois Environmental Protection Agency (IEPA) recently tested our water system for 18 compounds known as Per- and Polyfluoroalkyl Substances (PFAS) as part of a statewide investigation of community water supplies. PFAS are a group of thousands of man-made substances that have been produced in the United States since the 1940s and utilized for a variety of applications ranging from stain/water-proofing to firefighting. Some PFAS have been phased out of production in the United States due to environmental and human health concerns, yet they persist in the environment and may contaminate surface and ground waters.

As of January 2021, neither the Illinois EPA nor the U.S. EPA have yet developed enforceable drinking water standards for PFAS. However, in the interim, Illinois EPA has developed health-based screening levels for the small number of PFAS for which there is appropriate information to do so. Screening levels are intended to be protective of all people consuming the water over a lifetime of exposure. Currently, there is not enough information available for scientists to develop health-based screening levels for all of the PFAS sampled, however some of the analytes do have health based screened levels associated with them.

While none of the analytes sampled were above the established health-based screening levels, Illinois EPA testing has determined that one or more PFAS were detected in our water system at levels greater than or equal to the lowest concentration the laboratory can reliably detect, shown as the Minimum Reporting Level in the table below. The levels are presented in units of nanogram per liter (ng/L) or parts per trillion (ppt).

More Resources on PFAS:

NPPWD Sample Results

PFAS AnalyteAcronymMinimum Reporting LevelAnalytical Result at TP03 (ppt)Analytical Result at TP04 (ppt)Analytical Result at TP02 (ppt)Analytical Result at TP01 (ppt)**
Perfluorobutanesulfonic acidPFBS22.4 - 3.42.7 - 3.53.5 - 3.82.8 - 6.9
Perfluorohexanesulfonic acidPFHxS22.5 - 34.8 - 5.311 - 153.2 - 200
Perfluoroheptanoic acidPFHpA2NDNDND8.5 - 11
Perfluorononanoic acidPFNA2NDNDND2.0 - 2.1
Perfluorooctanesulfonic acidPFOS24.1 - 5.04.2 - 5.22.6 - 3.04.1 - 90
Perfluorooctanoic acidPFOA22.1 - 32.6 - 3.13 - 4.32.4 - 42
Hexafluoropropylene oxide dimer acidHFPO-DA2NDNDNDND
Perfluorohexanoic acidPFHxA2NDND2.2 - 3.1<2 - 22
Perfluorodecanoic acidPFDA2NDNDNDND
N-ethyl perfluorooctanesulfonamidoacetic acidNEtFOSAA2NDNDNDND
N-methyl perfluorooctanesulfonamidoacetic acidNMeFOSAA2NDNDNDND
Perfluorododecanoic acidPFDoA2NDNDNDND
Perfluoroheptanoic acidPFHpA2NDNDNDND
Perfluorotetradecanoic acidPFTA2NDNDNDND
Perfluorotridecanoic acidPFTrDA2NDNDNDND
Perfluoroundecanoic acidPFUnA2NDNDNDND
11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid11Cl-PF3OUdS2NDNDNDND
9-chlorohexadecafluoro-3-oxanone-1-sulfonic acid9Cl-PF3ONS2NDNDNDND
4,8-dioxa-3H-perfluorononanoic acidADONA2NDNDNDND
**This well has not been used for primary production since 2013. To further remove this well from the system, NPPWD plans to take this well offline by June 2021.

What are PFAS?

Per- and poly-fluoroalkyl substances are a group of thousands of chemicals collectively known as PFAS. Since the 1940s, PFAS have been used in manufacturing, firefighting, water- and oil-resistant products, and many consumer products such as carpet, clothing, cosmetics, and food packaging. Two of the most common compounds within this class, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), stopped being produced in the United States (U.S.) in the early 2000s, but these compounds may still be present in imported goods.

PFAS are present in many consumer goods, including food packaging and personal care products, and scientists have found levels of PFAS in the blood of nearly all individuals tested. Exposure to high levels of PFAS over time may cause adverse health effects such as increased cholesterol levels, increased risk for thyroid disease, low infant birth weights, reduced response to vaccines, pregnancy-induced hypertension and increased risk of liver and kidney cancer as seen in studies of laboratory animals. Exposure to PFAS above the recommended screening levels does not mean that a person will get sick or an adverse health effect will occur, screening levels are conservative estimates. The possible health effects of PFAS are dependent on how much a person is exposed to and how long they are exposed to it. Exposure to PFAS above recommended screening levels for periods of time may mean that a person is at a greater risk of experiencing these adverse effects.

North Park Public Water District has taken measures to respond to the results of this testing. As a proactive measure(s) to protect our drinking water supply, we are working to:
• Monitor PFAS levels through quarterly sampling beginning in January 2021
• Evaluate treatment options
• Implement treatment options if required


The United States Environmental Protection Agency (U.S. EPA) evaluates the presence of emerging and unregulated contaminants in community water supplies on a national basis pursuant to the Unregulated Contaminant Monitoring Rule (UCMR). U.S. EPA uses the data collected from these sample results to establish new drinking water standards known as maximum contaminant levels or MCLs. Traditionally, U.S. EPA develops MCLs that are then adopted by the states and used to determine if additional actions are needed to respond to contaminant concerns in drinking water. U.S. EPA has started the regulatory process for listing MCLs for PFOA and PFOS. In 2016, U.S. EPA adopted a Lifetime Health Advisory for PFOA and PFOS of 70 parts per trillion (ppt), both individually and combined when both are present. This is a non-enforceable value intended to provide guidance for evaluating unregulated drinking water contaminants. Given the concern about these unregulated contaminants, Illinois EPA developed health-based screening levels for PFOA, PFOS, and three other PFAS, perfluorobutanesulfonic acid (PFBS), perfluorohexanesulfonic acid (PFHxS), and perfluorononanoic acid (PFNA) using the procedures from 35 Illinois Administrative Code 620. In 2020, Illinois EPA also initiated a statewide investigation of all community water systems to determine how commonly PFAS can be found in community drinking water supplies. Illinois EPA will compare the analytical results of this testing with the PFAS screening levels to help community water supplies evaluate future actions that may need to be taken. This data will also be used to aid in the development of future regulatory standards in Illinois.

What are the potential health concerns associated with PFAS exposure?

Studies indicate that exposures to high levels of PFAS contaminated water over time may cause certain adverse health effects. Exposure to PFAS above the recommended screening levels does not necessarily mean that a person will get sick or an adverse health effect will occur. Research on the health effects associated with PFAS is ongoing.

Scientific studies of laboratory animals, as well as studies on human populations exposed to PFOA and PFOS over periods of time, have shown that exposure to PFOA and PFOS above certain levels may result in adverse effects such as:

• increased cholesterol levels
• changes in liver enzymes
• decreased response to vaccines in children
• increased risk of high blood pressure or pre-eclampsia in pregnant women
• small decreases in infant birth weight
• increased risk of kidney or testicular cancer

If you have specific health concerns, please consult your health care professional.