PFAS Mitigation Efforts

What are PFAS?

Per- and polyfluoroalkyl substances (PFAS) are man-made chemicals contained in many commonly used household products. PFAS are also sometimes found in the air we breathe, in some foods, in drinking water, and even in rainfall.

The Environmental Protection Agency (EPA) has enacted a new regulation that will require drinking water from public utilities like the City of Asheville Water Resources Department not to exceed new Maximum Contaminant Levels (MCLs). The EPA will begin enforcement of the MCLs in 2029.


What is an MCL?

The Maximum Contaminant Level (MCL) is the maximum level allowed for a contaminant in water that is delivered to any user of a public water system. The EPA sets the MCL, prioritizing public health while considering technical and financial barriers.


Can PFAS be removed from water?

Completely removing PFAS from drinking water will be impossible until the substances are no longer manufactured. They remain in the environment for a very long time, earning them their nickname “forever chemicals.”


Which items contain PFAS?

PFAS are often found in everyday products such as toilet paper and personal electronic devices. The diagram below lists a few of the items that contain PFAS.

Image source: Getty Images


PFAS have been around longer than 50 years, and were originally included in products to help with waterproofing, and to resist heat, oil, stains and grease.

Manufacturers use thousands of different types of PFAS in consumer and industrial products, some common examples of which are:

  • Coatings on some food packaging, especially microwave popcorn bags and fast food wrappers
  • Non-stick cookware
  • Shampoo
  • Some cosmetics
  • Components of fire-fighting foam
  • Many industrial applications such as synthetic fiber and plastic manufacturers


Does the City of Asheville Water Resources Department test for PFAS?

Yes! Laboratory methods have greatly improved since 2015, when the City of Asheville Water Resources Department first tested for PFAS. These advancements have allowed for increased accuracy and consistency in detection levels. For example, detectable levels of PFAS in drinking water have gone from being measured in parts per billion (ppb) to parts per trillion (ppt). As a result, water utilities that previously recorded no detectable levels of PFAS are now reporting extremely small amounts in source water and treated water. It is important to note that these very low detectable levels are well below the EPA’s required limits. For example, one part per trillion is the equivalent of one drop of water in an Olympic-sized swimming pool, whose average capacity is almost 700,000 gallons.

In 2019, the City of Asheville Water Resources Department participated in a PFAS detection study conducted by Duke University and the University of North Carolina. Very low concentrations – again, well under the required EPA limits – were found in the source water at Mills River, French Broad River and Bee Tree Reservoir. Upon receiving these results, The City of Asheville Water Resources Department proactively started annual measuring for PFAS at city-owned water infrastructure. That testing, done on source water and treated water, began in 2022.


City of Asheville Water Resources Department PFAS Test Results


How does the EPA calculate contaminant limits?

When a chemical or contaminant of concern is discovered in drinking water and needs to be regulated, EPA reviews the health effects data by looking at sensitive sub-populations (eg: infants, elderly) and sets a Maximum Contaminant Level Goal (MCLG) for the chemical. The MCLG is the maximum level of a contaminant in drinking water at which no known or anticipated adverse effect on the health of persons would occur, allowing an adequate margin of safety. The EPA sets MCLs as close as possible to the MCLG. EPA understands that staying within the limits of MCLGs is not always possible, due to environmental circumstances and cost of water treatment. Because of these constraints, EPA does not enforce MCLGs.

The EPA also uses a Hazard Index, which is a formula-based tool that is used to set an allowable limit for a mixture of chemicals based on each chemical’s Health-Based Water Concentration (HBWC). The four PFAS chemicals (PFBA, PFHxS, PFNS, HFPO-DA(GenX) were chosen because these chemicals were most commonly found across the U.S.


What are the MCLs and Hazard Index for PFAS?

EPA regulates the PFAS chemicals listed below for drinking water because testing revealed they’re the most common.


PFOA – 4 ppt

PFOS – 4 ppt

PFNA- 10 ppt

PFHxS- 10 ppt

HFPO- DA- (GenX chemicals)- 10 ppt

Hazard Index- mixture of PFAS compounds
PFBA, PFHxS, PFNA, HFPO-DA(GenX) – 1.0 (unitless)

The EPA set the MCLs for these contaminants by considering both the health risks of sensitive populations and the lowest feasible level based on the ability to reliably measure and remove these contaminants from drinking water. Again, 1 ppt is equivalent to one drop of water in an Olympic-sized swimming pool.

The hazard index will be used to determine if any mixture of these compounds are a health risk. As stated above, the 1.0 index is based on health-based water concentration.


Calculation for hazard index
Hazard Index calculation


Does the City of Asheville drinking water meet the new PFAS MCLs?

The City of Asheville’s drinking is currently below the PFOA, PFOS, PFBA, PFHxS, PFNS, and HFPO-DA (GenX) maximum contaminant levels (MCLs) and the hazard index for this EPA regulation. All drinking water utilities will have five years to comply with the regulations.

The EPA PFAS regulation requires that the treated water that is delivered to users be tested quarterly. Compliance with EPA regulations will be determined by calculating the average detectable levels of the quarterly samples collected during a calendar year.  Although EPA does not require it, the City of Asheville Water Resources Department will continue to test source water on an annual basis as a proactive measure. 


What’s next?

The City of Asheville Water Resources Department is currently working with an engineering firm to develop best practices for the removal of as much PFAS as possible. There is not a “one size fits all” treatment process. Implementing a new treatment technique requires multi-phased testing at each treatment facility. System implementation, construction and waste disposal costs will all be part of the calculation.


What can I do as a customer?

While the City of Asheville’s drinking water already meets the EPA’s proposed requirements, there are additional steps customers can take:

  • Consider a point-of-use or whole-house filter

It is recommended to use reverse osmosis or activated carbon filters that are certified by NSF International to lower levels of PFAS in drinking water. Water for consumption can be filtered for drinking, cooking, and other household consumption. It is important to follow the manufacturer’s maintenance and replacement recommendations.

  • If you consider bottled water

PFAS have been found in some brands of bottled water. The Food and Drug Administration (FDA) regulates bottled water, and they have not put enforceable limits in place yet. Bottled water distributors that are members of the International Bottled Water Association (IBWA) are required to test for PFAS annually. Not all bottled water distributors are members of the organization. You can check IBWA membership at Consumers should not purchase bottled water or any other product that contains PFAS.

  • Boiling water does NOT remove PFAS


Additional Information

Glossary of Terms

Health Information

EPA Article for PFAS Chemicals

EPA 2023 Proposed Rule for Regulating PFAS in Drinking Water

NC Department of Health and Human Services Presentation

EPA Ground Water and Drinking Water

EPA Health Advisories

NC DEQ Health-Related Resources About GenX, PFOA and PFAS

Per-and Polyfluoroalkyl Substances (PFAS) and Your Health


Contact Information

Brenna Cook, Compliance Manager