Continued efforts in the water industry have resulted in a push to address the latest drinking water contaminant: per- and polyfluoroalkyl substances (PFAS). The concern that these emerging contaminants are causing water providers is so great that the new infrastructure law has directed billions of dollars toward mitigating PFAS risks, including projects to eliminate certain PFAS compounds from drinking water and the environment.

In the last 10 years, testing for and treating PFAS compounds in drinking water has become a large focus, instigating specific courses of action as communities across the world address significant environmental impacts of PFAS. A well-known fact: PFAS have been used in a variety of commercial and industrial applications to provide life-saving benefits; they also are found in many household goods. During PFAS’ intended use and/or once discarded, the compounds may enter the ground and waterways.

There are multiple efforts underway to remove PFAS from the environment, including implementing regulations to limit and restrict the future use of PFAS; establishing protective standards for groundwater and drinking water resources; and funding projects to treat and remediate PFAS that have been released into the environment, says Brian Hoye, remediation manager and emerging contaminants leader at Burns & McDonnell. A major component of this response is the removal of PFAS from drinking water supplies by adding new technologies to affected water treatment plants.

“Making these investments in our water infrastructure will address the most pressing threat PFAS pose to the general public and allows time for environmental specialists to investigate and, if necessary, remediate PFAS under existing environmental programs,” Hoye says.

With safety of drinking water paramount, the ability to detect even lower levels of PFAS has become a high priority. State and federal regulators are enacting regulations to remove the contaminant from drinking water, in part due to the bioaccumulation and potential health effects attributed to certain PFAS compounds. Such regulations have made the presence of any PFAS compounds in drinking water a great concern and resulted in pressure to quickly design and apply treatment.

While historical testing performed under the Unregulated Contaminant Monitoring Rule (UCMR) 3 has identified PFAS compounds in certain drinking water resources, many water supplies still need to be tested. UCMR 5, which will require additional testing in coming years, was structured to significantly increase the number of water supplies tested, expanding the list of PFAS analyzed from six to 29 compounds. Some states are also implementing testing programs that require municipal water suppliers to analyze and evaluate for PFAS.

Funding recently has become available to help treat these contaminants. The new infrastructure law is the most recent in a long line of federally approved funding opportunities — including the American Jobs Plan and the Drinking Water and Wastewater Act — dedicating billions of dollars to helping utilities obtain the technologies needed to test for and minimize exposure to PFAS. As funding for PFAS treatment projects becomes available, utilities that have not already tested for PFAS may consider testing ahead of required deadlines to facilitate the design and programming of projects to treat PFAS.

Relatively conventional water treatment technologies — including granular activated carbon, ion exchange resins and reverse osmosis — are the most commonly selected solutions for PFAS removal from drinking water and wastewater. These options have proven to be cost-effective solutions capable of accommodating the flow rates associated with water production facilities and wastewater treatment plants. While other treatment approaches increasingly are becoming available, they are not yet scalable to meet the treatment demands of the average water treatment plant. However, these new approaches may provide advantages if included as a component of the treatment strategy and, at some point, may advance to a stand-alone treatment option.

When selecting a treatment technology, there are many aspects to consider. Which compounds require removal? How can spent media or rejected streams be managed, given the project location? What other benefits might a particular technology bring to the overall treatment process? Considering such factors might seem straightforward, but performance factors for certain PFAS-removal technologies can vary depending on application-specific variables and water chemistries and can greatly impact the cost to build and operate a solution. As a result, bench testing and pilot testing are necessary for identifying the product needed for a specific application and for accurately calculating system life cycle costs.

While advanced PFAS solutions are emerging and funding mechanisms are becoming available, these projects take time to design, procure and construct. Various project delivery methods might compress the project schedule; however, the earlier a utility can engage environmental and water specialists, the more likely it will meet regulatory deadlines on the horizon.

Testing water supplies for the presence of PFAS compounds is the first step in identifying where action needs to be taken. Discovering which PFAS are impacting drinking water resources is important in developing the correct approach to producing safe drinking water. There are two analytical methodologies that are certified to analyze PFAS in drinking water:

• Method 537.1 uses styrene-divinylbenzene media.
• Method 533 uses polystyrene divinylbenzene with a positively charged diamino ligand and isotope dilution.

When used together, these methods certified by the Environmental Protection Agency for the testing of drinking water can identify 29 PFAS compounds. Once the type and concentrations of PFAS in groundwater have been identified and the general water chemistry understood, desktop treatment evaluations may be performed and an approach to bench and pilot testing can be designed. These evaluations will generate the data needed to identify the most appropriate technology for this treatment application given the operator’s objectives.

“Each PFAS treatment technology has advantages and disadvantages that should be considered,” says Nathan Dunahee, associate environmental engineer at Burns & McDonnell. “The process evaluation starts with testing the water supply, understanding the level of contamination and determining finished water goals. Process opportunities and challenges that might impact the ideal treatment approach also should be considered.”

With awareness rapidly growing on the dangers of PFAS — as well as relevant technologies becoming increasingly more available to test and reduce exposure to these compounds — community pressures are mounting for water providers to take immediate action. Now is the time to protect customers and take advantage of the funding available to soundly identify and manage PFAS. Communities depend on and expect clean water — as they should — and new funding opportunities will help see that the safe, reliable delivery of clean drinking water continues.