Historical PFAS Results

Per- and polyfluoroalkyl substances (PFAS) are thousands of different nonstick and water-resistant chemicals used in common household and commercial products since the 1940s. PFAS keep food from sticking to cookware and make clothes, carpets, and furniture water and stain resistant.

Drinking water is regularly tested for PFAS and other harmful or potentially harmful chemicals by law. As a result, you may hear more about PFAS in drinking water than in other sources. Many recent news articles and movies focus on PFAS in local drinking water. Other sources of PFAS exposure include things we eat, drink, and breathe. Understanding how PFAS can enter our environment, our homes, and our bodies helps us manage our exposure to these chemicals.

The manufacturing and use of products with PFAS release them into the environment. Many PFAS do not break down naturally, allowing the chemicals to build up and remain in the environment over time. They can travel far from their original use areas. This increases levels of PFAS in the natural resources we use from the environment, like water, food, and soil. Over time, PFAS may end up in drinking water supplies.

PFAS can enter the environment:

• When companies make products with PFAS and release PFAS-wastes directly into our water and air.
• When people and industry use products containing PFAS, such as firefighting foam like aqueous film forming foam (AFFF). 
• When we throw away products that have PFAS in landfills.
• When we wash household items that have PFAS down the drain (like laundry, dishes, and carpet cleaning wash-water).
• Through our own personal care products that have PFAS (like sunscreen and makeup products).

Most people in the United States and other industrialized countries have PFAS in their blood from these chemicals in everyday products. Humans can swallow PFAS when eating or drinking PFAS-impacted food. We can breathe in dust containing PFAS or rub it into our skin when using certain products. 

A person’s exposure to PFAS depends on many things, including: 

• The amount of PFAS in your local environment, 
• The amount of PFAS in food, water, or commercial products
• How much you eat, drink, or use products with PFAS in them 

Some PFAS can build up in the human body over time and scientists are still studying the health effects of elevated PFAS blood levels. The epidemiological evidence suggests that increases in exposure to (specific) PFAS are associated with certain health effects, including certain types of cancer (kidney and testicular), increases in cholesterol, and decreased antibody response to some vaccines. While blood tests can tell us how much PFAS we may have in our blood compared to population averages, these tests do not indicate if these PFAS concentrations will cause a future health effect or are linked to a current health effect. 

In 2000, the manufacturers 3M and Dupont voluntarily phased out production of two PFAS, perflurooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). After this phase out, the National Health and Nutrition Examination Survey (NHANES) found that the average blood levels of PFOA and PFOS dropped more than 70% and 85% respectively between 1999 and 2018. Despite this phase out, thousands of different PFAS chemical compounds are still in use that may also cause negative health effects. 

To learn more, visit the Centers for Disease Control and U.S. Environmental Protection Agency PFAS websites.

The United States EPA regulates PFAS at the federal level. Illinois has non-enforceable health advisories at the state level. Evanston’s drinking water meets the EPA’s PFAS standards.

The EPA released its first ever National Primary Drinking Water Regulation (NPDWR) for PFAS on April 10, 2024. This regulation established Maximum Contaminant Levels (MCLs) for six PFAS in drinking water. MCLs are the highest allowable level of chemical in drinking water. If the chemical is found at levels above the MCLs, EPA requires water unities to treat the water. The MCLs are:

• PFOA: 4.0 parts per trillion (ppt)
• PFOS: 4.0 ppt
• Perfluorohexane sulfonic acid (PFHxS): 10 ppt
• Perfluorononanoic acid (PFNA): 10 ppt
• GenX: 10 ppt
• Hazard Index for mixture of PFHxS, PFNA, GenX, and perfluorobutane sulfonic acid (PFBS): 1

Along with the individual MCLs for five PFAS, EPA’s regulation includes an MCL for mixtures of four PFAS, measured by a “Hazard Index.” Research shows that different PFAS may affect the same human organs, and thus, mixtures of different chemicals can increase the potential for health effects.

Along with the release of the MCLs, EPA also released Maximum Contaminant Level Goals (MCLGs) for each of these six PFAS. MCLGs are the level of a contaminant in drinking water below which there is no known or expected risk to health. They are lower than the MCLs because the MCLs consider health effects as well as best available treatment technology and cost. MCLGs allow for a margin of safety and are non-enforceable public health goals. The EPA does not require drinking water to have PFAS levels at or below the MCLGs.

In 2021, The Illinois Environmental Protection Agency (IEPA) set non-enforceable statewide health advisories for seven PFAS in drinking water. Six of these PFAS are now regulated by the EPA’s MCLs. The IEPA has an additional health advisory for perfluorohexanoic acid (PFHxA). The IEPA’s health advisory levels are:

• PFOA: 2 ppt
• PFOS: 14 ppt
• PFHxS: 140 ppt
• PFNA: 21 ppt
• GenX: 21ppt
• PFBS: 2,100 ppt
• PFHxA: 3,500 ppt

Trace amounts of PFAS are in drinking water sources across the U.S. This includes Lake Michigan, the source of the City of Evanston’s drinking water. The City of Evanston proactively and periodically has been monitoring PFAS levels in Lake Michigan water and our treated drinking water. The sampling to date found PFAS levels in the Lake Michigan water and Evanston’s drinking water below the EPA’s MCLs. Communities along the west shore of Lake Michigan have seen similar results. 

The table below summarizes the U.S. EPA’s regulations for drinking water and how the City of Evanston’s sampling results compare. Evanston’s drinking water meets the PFAS standards set by the EPA. All units are in ppt, except the hazard index, which is unitless. One ppt is about one drop of water in 20 Olympic-sized swimming pools.

Click here to see more PFAS testing results

Your health and the health of your household are our priority. That is why we tested our drinking water for PFAS starting in 2009, 15 years before EPA released its PFAS drinking water regulations. We will continue monitoring PFAS values through quarterly sampling.

While additional treatment is not needed to reduce PFAS levels in our drinking water to meet the EPA’s regulations, we are proactively studying potential future PFAS treatment systems. If the PFAS levels in the Lake Michigan increase in the future, the City will already know which treatment option is the best fit for our water system.

The treatment study is evaluating the following options:

1. Granular Activated Carbon (GAC) – Chemicals like PFAS stick to the small pieces of carbon as the water passes through.
2. Powdered Activated Carbon (PAC) – Powdered carbon is added to the water. The chemicals then stick to the powdered carbon as the water passes through.
3. Ion Exchange Resins – Small beads (called resins) work like magnets. The chemicals stick to the beads and are removed as the water passes through. 
4. Nanofiltration and reverse osmosis – Water is pushed through a membrane with small pores. The membrane acts like a wall to stop chemicals and particles from passing into drinking water.

If future sampling shows levels above the MCLs, you will receive notifications along with information on the next steps.

• Avoid buying non-stick cookware and stain-resistant furniture and carpeting containing PFAS. Look for 'fluoro' or 'perfluoro' in a list of ingredients or ask the manufacturer. For more information, visit the IEPA’s PFAS webpage.
• Limit eating foods packed in materials that use PFAS. Common food packaging that may have PFAS include microwave popcorn bags, fast food boxes (like french-fry containers and pizza boxes), and bakery bags.
• Reduce the dust in your home to limit PFAS particles in the air. You can do this by changing your home’s air filter on a regular basis and leaving your shoes at the door to avoid tracking in dirt and pollutants.
• Avoid using personal care products that contain PFAS. These include certain types of dental floss, nail polish, facial moisturizers, and cosmetics.
• Support companies that have taken steps to remove PFAS chemicals from their products. PFASCentral.org maintains a list of such manufacturers and retailers.