Perfluoroalkyls & Water

What are PFAS and where do they come from?

PFAS is an abbreviation to describe Per- and Polyfluoroalky, a family of chemicals that include the two most notable compounds perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Starting in the 1940s, these human-made chemicals were used in manufacturing and industrial uses due to their oil and water-resistant properties in nonstick cookware, water replant clothing, and stain proof carpeting. Their widespread use resulted in PFAS being released into the air, water and soil. Even though PFAS have been phased out of production in the US, they’re considered “forever chemicals” because they persist in the environment.

Scientists are studying the impacts of these compounds on the environment and people. Though typically found in miniscule amounts, PFAS are found nearly everywhere from people to animals, food to water.

Source: Illinois Environmental Protection Agency: Per- and Polyfluoroalkyl Substances (PFAS)

Are PFAS levels regulated?

The US EPA regulates drinking water standards by setting Maximum Contaminant Levels (MCLs) for more than 90 contaminants. MCLs are numeric enforceable drinking water standards set as close as feasible to health-based benchmark levels, using the best available analytical and water treatment technologies while taking into consideration costs for treatment. Importantly, the US EPA has not set MCLs for any PFAS chemicals. In 2016, US EPA did set Lifetime Health Advisory Levels for PFOA and PFOS at 70 parts per trillion (ppt) combined. A Health Advisory Level is a non-enforceable value provided as guidance for evaluating the prevalence and occurrence of unregulated drinking water contaminants.

Illinois EPA is conducting a statewide investigation into the prevalence and occurrence of per- and polyfluoroalkyl substances (PFAS) in finished drinking water at all 1,749 community water supplies in Illinois.

Data gathered as part of this investigation will aid in the possible development of future state-only MCL regulatory standards. In the interim, the Illinois EPA developed health-based guidance levels intended to be protective of all people consuming water over a lifetime of exposure. It is important to understand health-based guidance levels are not regulatory limits for drinking water. Rather, the health-based guidance levels are benchmarks against which sampling results are compared to determine if additional investigation or response is necessary.

Source: Illinois Environmental Protection Agency: Per- and Polyfluoroalkyl Substances (PFAS)

Are there PFAS in the City's drinking water?

As a “forever chemical,” trace amounts of PFAS are often detected in drinking water. Illinois EPA testing has determined that one or more PFAS were detected in the City’s drinking water at values greater than or equal to the State of Illinois EPA health-based guidance levels.

Based on the evolving science for these compounds, the levels detected in water are well below the EPA published levels of health concerns which is 70 parts per trillion (ppt).
When testing water, many compounds are measured in parts per billion (ppb); however, the concentration of PFAS is so small that it’s measured in parts per trillion (ppt). As a frame of reference, one part per trillion is roughly the equivalent of one drop in 20 Olympic-sized swimming pools.

Are there health effects related to PFAS exposure?

Researchers continue working to fully understand the effects of PFAS on human health. PFAS are present in many consumer goods, including food packaging and personal care products, as well as in the soil, air and water. PFAS are bioaccumulative, meaning they build up in the body over time. They are hard to break down and take several years to be eliminated from the body. Exposure does not necessarily mean that a person will get sick or experience an adverse health effect. While research on the effects of PFAS exposure on human health is ongoing, current scientific studies have identified possible adverse health effects to high exposure levels such as increased cholesterol levels, increased risk for thyroid disease, low infant birth weights, reduced response to vaccines, liver and kidney toxicity, and pregnancy-induced hypertension. 

Source: Illinois Environmental Protection Agency: Per- and Polyfluoroalkyl Substances (PFAS) Health Effects
What is the City of Lake Forest doing?

The City is following guidance from the Illinois EPA and closely monitoring the latest health-based guidance. We will continue monitoring PFAS values through quarterly sampling. The most recent test results will be added to the above chart on this web page.

We are also investigating the difference between low levels of PFAS in raw and finished water in order to review the removal effectiveness of the current filtration system. The City will continue to closely monitor the situation and ensure information is communicated with residents.

Where can I find more information?

If you have questions for the City of Lake Forest, please contact John Gulledge, Chief Water Plant Operator, at or 847.810.4650. The 2020 Annual Water Quality Report contains additional information about the City’s water quality.

The US Environmental Protection Agency and the Illinois Environmental Protection Agency are great resources for latest research and information about PFAS. The City is following the issue closely and will continue following guidance from the Illinois EPA and US EPA.

Stay Informed!