PFAS (per- and polyfluoroalkyl substances) have been around for a long time. The man-made chemicals have been used in many everyday products and applications for decades. Further, when in the environment, the chemicals break down very slowly over time.
But now, water and wastewater utilities finally face a very real timeline to assess the potential presence of PFAS in water and the environment and eventually get rid of the “forever chemicals.”
The Biden-Harris Administration has issued the first-ever national, legally enforceable drinking water standard to protect communities from exposure to PFAS. According to the rule, all public water systems have three years to complete their initial monitoring for PFAS and must inform the public of the level of PFAS measured in their water. Where PFAS is found at levels that exceed the new rule’s standards, the drinking water systems must implement solutions to reduce PFAS in their drinking water within five years.
In announcing the new rule, EPA estimated that 6% to 10% of the 66,000 public drinking water systems may have to take action to reduce PFAS to meet these new standards. However, a study released in mid-2023 by the U.S. Geological Survey indicates the potential for 45% of U.S. utility tap water systems to be contaminated with PFAS. Researchers couldn’t test for all types of PFAS, instead looking at only 32 of the compounds.
The problem is large scale, complicated and, like PFAS themselves, persistent. Removing the compounds requires advanced technology, and to destroy them requires technology even more advanced, says Steven Greseth, Kiewit’s Director of Wastewater and Biosolids Technologies.
For those impacted by PFAS, solutions will also require near-term corrective actions and funding.
And it all starts with data.
What’s Data Got to Do With It?
While some states and water utilities have tested for PFAS, many utilities hadn’t begun testing for the chemicals while the new regulation remained unfinalized, said Jim Scholl, Kiewit’s Director of Drinking Water Technologies. In many cases, the initial data is typically two years old and is very limited. With the finalization of the new rule, additional testing will be needed to confirm current conditions. Having this knowledge from testing is foundational to the full process, from sorting out a near-term plan to tackle contamination to positioning for funding and ultimately deploying treatment technologies. Testing and data collection can help to answer:
- Is PFAS present in the source water? If so, what is the level of contamination?
- Based on the changing criteria and proposed regulations, where does the utility stand with its water?
- Can the utility determine the source of the PFAS contamination?
- How does the system handle PFAS in terms of the finished water that is produced?
- What near-term corrective actions need to be taken?
- What longer-term changes should be considered for future regulatory compliance?
How Is Contamination Measured?
The testing protocol involves using an officially adopted EPA procedure through a certified testing lab. Three methods – Method 533, Method 537 and Method 537.1 have been developed, validated and published by the EPA for testing and analysis of 29 PFAS in water. The process looks for presence of PFOS (perfluorooctane sulfonic acid) and PFOA (perfluorooctanoic acid) – two types that are the most prevalent and widely studied – among six basic categories that are part of all testing.
Fueled by settlement funding opportunities, the demand for testing has risen sharply, and accordingly, lab capacity has also increased. However, capacity can still be limited, sample testing is not cheap, and completing the data collection process can take some time, Scholl notes.
The EPA recommends utilities contact their state regulators for certified labs available for PFAS testing and analytical protocols.
PFOS and PFOA are no longer used in commercial products, but, due to the chemical compounds’ environmental persistence, they can still be found in the environment and older products as well as potentially from other countries that still manufacture and use them, according to the Agency for Toxic Substances and Disease Registry. Because studies have found associations between PFOS and PFOA exposure and several types of health effects, the EPA has proposed listing the two as hazardous substances under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), otherwise known as Superfund.
Interim health advisories established by the EPA in 2022 for PFOS and PFOA were exceeded in every sample in which they were detected in the USGS drinking water study.
What Is It Measured Against?
The new rule sets maximum contaminant limits (MCL) for five individual PFAS: PFOA and PFOS in addition to PFNA (perfluorononanoic acid), PFHxS (perfluorohexane sulfonate) and HFPO-DA (hexafluoropropylene oxide dimer acid and its ammonium salt), also known as “GenX Chemicals.” The rule also sets a limit for mixtures of any two or more of PFNA, PFHxS, PFBS (perfluorobutane sulfonate) and GenX Chemicals.
For PFOA and PFOS, the final MCL is a miniscule 4 parts per trillion (ppt). For perspective, 1 ppt is roughly equal to one drop of ink in the volume of water contained in 20 Olympic-sized swimming pools, according to information from the Missouri Department of Natural Resources.
The final MCL is 10 ppt for PFHxS, PFNA and GenX Chemicals.
For the portion of the rule limiting mixtures of any two or more of the four listed, water systems will use a hazard index calculation to determine if the combined levels pose a potential risk.
Additionally, EPA has proposed a new rule under the Resource Conservation and Recovery Act (RCRA) to define nine PFAS compounds as hazardous substances, subject to the regulations for containment and removal from the environment. This proposed rule will affect how wastes containing any hazardous substances are documented, managed and disposed.
Data Collection at the Core
Ultimately, the data is now needed for compliance purposes – to help push toward long-term solutions and meet regulations. Data will also be needed to obtain funding; utilities will need to demonstrate contamination to qualify for funding, Scholl notes.
In addition to the final rule, EPA announced nearly $1 billion in newly available funding through the Bipartisan Infrastructure Law (BIL) to help states and territories implement testing and treatment at public water systems and for owners of private wells. It’s part of a $9 billion investment through the BIL to help communities with drinking water impacted by PFAS and more. An additional $12 billion is available through the BIL for general drinking water improvements, including addressing emerging contaminants such as PFAS.
In the short term, data will also be helpful for detecting contamination as early as possible and to mitigate potential impacts with any up-front activities to protect public health.
Near-term Actions
With the data in hand and based on the level of contamination, utilities can then plan next steps.
One next step might be to plan corrective action(s), such as disconnecting from a contaminated source and connecting to another, if applicable. Scholl notes the following example: in 2018 the city of Parchment, MI, found high PFAS levels in groundwater. That discovery led to Parchment taking the step to immediately disconnect with the community’s main water source and instead tie in with neighboring Kalamazoo, MI, where testing revealed PFAS below health advisory levels in the water supply.
Similarly, the collected data can help to drive public communication efforts. If PFAS is detected in the water, the community needs to know. Risk communication and proactive messaging benefits the customers and utility. After all, we live in an age where information is often just a tap or click away. Proactive and up-front messaging from the utility builds trust in the community and can elevate the utility agency’s standing, the American Water Works Association (AWWA) says.
In addition to risk communication packages at the state level, the Environmental Council of the States, Association of State and Territorial Health Officials, Water Research Foundation/American Water, and the AWWA have robust PFAS communication toolkits and best practices available to help support messaging.
The data collection effort may also spur development of an ongoing monitoring program for the water system.
Long-term Treatment Alternatives
The new EPA rule will spur the need for technologies that remove PFAS and those that destroy the contaminates.
Various treatment technologies, employed either specifically for PFAS or for other treatment needs, have been shown to effectively remove PFAS from drinking water, the Kiewit directors Scholl and Greseth said. These methods, highlighted by the EPA, include granular activated carbon (GAC) adsorption, anion exchange (AIX), membrane filtration, such as reverse osmosis (RO), and foam fractionation.
None of the removal technologies are a singular “silver bullet” for drinking water. Each comes with challenges and important considerations, such as scalability, regulatory target, capital cost, operating cost and site constraints. Further, an understanding of the type of PFAS to be removed, including long- and short-chain varieties, and the influent concentration – both brought to light by the data collection process – will influence decision-making. In addition, new developments continue to emerge, making the treatment technologies a continuously evolving space.
Wastewater treatment plants don’t generate PFAS chemicals, but they may receive discharges from sources that have used PFAS, the Water Coalition against PFAS says. As a result, according to the EPA, PFAS may be found in plant effluent, biosolids and potentially air emissions. In treating the wastewater, Greseth notes the water being treated has more turbidity, and this can diminish the effectiveness of the PFAS treatment/removal processes and drive costs upward. For biosolids, strategies like anaerobic digestion and incineration reduce biosolids, potentially offering sustainable solutions through biogas production or material development.
It’s important to note that EPA’s approach includes “getting upstream of the problem,” a focus on preventing PFAS from entering the environment by emphasizing monitoring, identification of “hotspots” in water and leveraging industrial pretreatment to help mitigate the issue by keeping PFAS from entering wastewater collection systems.
Removing PFAS from water is one thing, but getting rid of it permanently is another. PFAS destruction technologies help eliminate the problem entirely rather than move it to another part of the environment. Emerging technologies like pyrolysis/gasification, supercritical water oxidation (SCWO), electrochemical oxidation (EO), hydrothermal alkaline treatment (HALT), mechanochemical degradation, and thermal degradation/incineration aim to eliminate PFAS without harmful by-products.
Certain methods, like GAC thermal regeneration and incineration of spent AIX resin, show potential for PFAS destruction. However, incineration poses risk of airborne spread. HALT and EO demonstrate effectiveness in the abolishment of PFAS from liquid waste, while pyrolysis/gasification and SCWO offer promise for solid waste treatment, with the former producing biochar and synthetic gas for potential use.
Research continues to refine these technologies for more efficient and environmentally friendly PFAS removal and destruction; PFAS destruction technology continues to develop and mature.
Data Drives Results
The challenge of PFAS is a thorny one that will stick with the water industry for years. While many questions still need to be answered – far-reaching impacts to communities and industries, as well as PFAS destruction technologies chief among them – the bottom line to all is data.
Knowledge is indeed power, and starting the process to collect that data to inform decisions is a logical first step. The data from testing can reveal insights on the water system, and the insights can drive next steps, Scholl said.
Background on PFAS
According to the EPA, PFAS is a group of thousands of man-made chemicals that break down very slowly over time and are found in many different consumer and industrial products. The chemicals have been used since the 1940s because of their useful properties for making non-stick, water-repellent, stain- and grease-resistant products, according to the National Institute of Environmental Health Sciences. The EPA says there is evidence that exposure to PFAS can lead to adverse health outcomes in humans.
PFAS are made up of chains of carbon and fluorine linked together, forming one of the strongest bonds in nature. As such, the components of PFAS degrade very slowly over time. Some forms can take over 1,000 years to degrade. Hence, “forever chemicals.”
The compounds make their way into the environment in both manufacturing processes as well as through consumer use and eventual disposal, according to the EPA.
