PFAS is an acronym that describes an extensive list of man-made chemicals that consist of a long chain of carbon and fluorine atoms.
PFAS stands for per and polyfluoroalkyl substances and represents a group of chemicals estimated to contain over 5,000 individual formulations. PFAS are used in many applications because of their unique physical properties that include resistance to high and low temperatures, resistance to degradation, and nonstick characteristics. The resistance to degradation is why PFAS have often been referred to as “forever chemicals”.
PFAS compounds have been widely used in manufacturing many consumer goods, non-stick coatings, carpets, textiles, firefighting foams, cosmetics and various industrial processes. Although there are thousands of PFAS compounds, the EPA has prioritized research on a small number of these compounds that may have health effects at very low concentrations. Two of these are Perfluorooctanoic acid (PFOA) and Perfluorooctane Sulfonate (PFOS).
For the most part, PFOA and PFOS were voluntarily phased out of production in the mid-2000s by manufacturers. However, PFOA and PFOS can still be imported to the U.S. in consumer goods and manufacturers have developed numerous other PFAS chemicals (e.g., hexafluoropropylene oxide dimer acid [HFPO-DA; GenX]) to replace these long-chain PFAS.
Drinking water health advisories (HAs) are intended to provide an estimate of the minimum concentration of a compound that may result in adverse health effects over a lifetime. EPA’s health advisories are not regulatory levels and are not a federally enforceable health-based limit. Health advisories are issued as a result of ongoing research conducted as part of the rule-making process.
In 2016, the EPA first set the health advisory levels for PFOA and PFOS (individually or combined) at 70 parts per trillion (ppt). On June 15, 2022, the EPA set new health advisory levels for four PFAS compounds that are much lower than the previous levels established in 2016. The new Health Advisory levels are provided below:
These new health advisories for PFOA and PFOS represent incredibly small concentrations. For illustration, one part per trillion (1 ppt) is approximately equal to one grain of sand in an Olympic-size swimming pool.
It is important to note that levels contained in the health advisory are many times lower than can be detected by current EPA-approved laboratory analytical methods.
On March 14, 2023, the EPA announced its proposed national drinking water standards – also known as Maximum Contaminant Levels (MCLs) – for PFOA, PFOS, and four other compounds (PFNA, PFHxS, PFBS and GenX). Maximum Contaminant Level Goals (MCLGs) were also announced. It is important to note the difference between an MCL and an MCLG. An MCL is an enforceable drinking water standard. An MCLG is NOT a drinking water standard; it is a public health goal. The EPA defines an MCLG as the maximum level of a contaminant in drinking water at which no known or anticipated adverse effect on the health of persons would occur.
The proposed standards announced on March 14, 2023 are as follows:
EPA is proposing to regulate four PFAS – PFHxS, GenX Chemicals, PFNA, and PFBS – as a mixture, using an approach called a hazard index. The Hazard Index is a tool used to evaluate health risks from simultaneous exposure to mixtures of certain chemicals. Many PFAS are found together and in different levels and combinations. To determine the Hazard Index for these four PFAS, the amount of each PFAS in drinking water is compared to its associated Health-Based Water Concentration (HBWC), which is the level at which no health effects are expected for that PFAS. The comparison values for each PFAS contained within the mixture are then added (The EPA is working to develop a calculator that can be easily utilized by each utility to determine the Hazard Index.). If the value is greater than 1.0, it would be an exceedance of the proposed Hazard Index MCL for these four PFAS compounds.
In addition to establishing MCLs and MCLGs, the proposed regulation would require water systems to take the following steps:
• Monitor. The EPA is proposing requirements for monitoring for the six PFAS that build upon the EPA’s long-established monitoring frameworks under which monitoring frequency depends on previous results. The March 14, 2023 proposal also includes flexibilities allowing systems to use some previously collected data to satisfy initial monitoring requirements.
• Notify consumers. Public water systems would be required to notify the public if monitoring detects these PFAS at levels that exceed the proposed regulatory standards.
• Treat to achieve the MCLs. Public water systems would be required to take actions to reduce the levels of these PFAS in drinking water if they exceed the proposed regulatory standards. This could include removing these chemicals through various types of treatment or switching to an alternative water supply that meets the standard.
The Proposed PFAS National Drinking Water Regulation announced on March 14, 2023 along with fact sheets and reference information can be found on the EPA’s website below:
The announcement prompts the next phase in the process, which consists of public comment and review. Please keep in mind that until this process is complete, the EPA’s final drinking water standards may differ from the proposed MCLs initially announced on March 14, 2023.
The EPA is expected to issue the final MCLs by early 2024. It is anticipated that water utilities will have a three-year period thereafter to comply with the final rule.
Paducah Water has a strong commitment to preserving public health. Our water is reliable, high quality and meets or exceeds all regulatory standards. Paducah Water has voluntarily begun monitoring PFAS monthly, and our most current monitoring results can be found at the link below:
Based on the proposed regulatory levels for PFOA and PFOS of 4.0 ppt, it is possible that PW’s water may exceed the proposed regulatory MCLs. Like many water utilities across the nation, PW is following the proposed rule closely and continues to examine its potential impacts. And it will be challenging.
That said, here are several steps that PW is taking:
Avoiding all exposures to all sources of PFAS may not be possible due to the wide use of PFAS in many consumer products, and most people in the United States have PFAS compounds in their blood. PFAS can accumulate and remain in the human body for long periods of time. However, the recommendations below can help reduce your PFAS exposure.
Paducah Water operates a “conventional” surface water treatment plant. That means PW pumps water from the Ohio River and treats the water through a process that includes coagulation, sedimentation, filtration and disinfection. This approach has been an industry standard for water treatment for many decades.
Although this treatment process has been very effective at meeting all current regulatory requirements for drinking water, it does not effectively remove PFAS compounds. Therefore, PFAS compounds in the source water move through the treatment process largely unaffected and into the distribution system.
Paducah Water also has the ability to feed Powdered Activated Carbon (PAC), which is utilized as part of the treatment process to address with taste, odor and organics resulting from the source water. PAC also has been shown to be somewhat effective in the removal of PFAS at lower concentrations. One area of focus for PW is to re-evaluate the application and dosage of PAC in our treatment process to determine if a modification in either can assist with reducing PFAS levels in PW’s tap water.
If our existing treatment process cannot be modified to sufficiently remove PFAS, PW may need add a new treatment technology. Current treatment methods for removing PFAS compounds include Granular Activated Carbon (GAC), Ion Exchange (IX) and Reverse Osmosis (RO). An expansion of the current treatment plant to include any one of these technologies will likely cost tens of millions of dollars and will take years to complete. Annual operational costs for PW will increase by hundreds of thousands of dollars per year. Further, each treatment process generates a waste stream that has concentrated levels of PFAS that must then be disposed of appropriately.
The American Water Works Association (AWWA) estimates that more than 5,000 water utilities across the nation will be in a similar situation as PW with an annual cost of more than $3.8 billion. As you can see, PFAS is a complicated, costly and challenging matter to address as a public utility, and many drinking water providers across the nation are confronting the same challenges.
Regardless of the challenges, Paducah Water is committed to providing safe, reliable drinking water in a way that protects public health. We will continue to make sound, fiscally-responsible decisions that put public health first, and it may require time and substantial investment to do so.