The thousands of “forever chemicals” known collectively as PFAS are gaining attention as scientists study their prevalence in the environment and their potential effects on human health.

Much about PFAS remains unknown, but it’s all but certain that more and tighter regulations are in the future. Late in 2021, the U.S. EPA issued a PFAS Strategic Roadmap (www.ewg.org/news-insights/news-release/2021/10/pfas-roadmap-sets-new-direction-epa) that outlines plans to accelerate development of drinking water standards for the two most concerning PFAS, known as PFOA and PFOS.

In the meantime, the U.S. Congress passed the bipartisan Infrastructure Investment and Jobs Act, allocating billions of dollars for PFAS treatment and remediation, and for addressing the long-time problem of lead in drinking water.

The LaBella Associates engineering, consulting and construction company has developed expertise in helping municipalities deal with PFAS contamination. Company representatives Greg Senecal, environmental director; Dan Noll, senior environmental engineer; and Keith Garbrick, senior civil engineer, addressed a range of PFAS issues in an interview with Treatment Plant Operator.

How would you compare the health risks of PFAS against the risks of lead in drinking water systems?

Senecal: Lead is a single metallic compound that is well understood and well studied. The health effects of lead have been known for almost a century. PFAS is a group of 4,000 to 10,000 perfluoralkyl and polyfluoroalkyl compounds for which toxicological studies have been started only recently. As studies are unfolding across the globe, we see evidence that PFAS may correlate with health effects including lower birth weights and lowered immunological response in younger people.

What are the components of the EPA’s PFAS Strategic Roadmap?

Senecal: It is a four-year list of actions that follow three primary categories: research, restrict and remediate. The first of these focuses on EPA and other federal agency research, including classification of the thousands of similar PFAS compounds and efforts to understand the human health and ecological effects of the different classes.

What is likely to be involved in PFAS restriction under the Roadmap?

Senecal: The “restrict” portion directs the various EPA offices to build on the research and generate restrictive measurements for the various PFAS classes. For example, if warranted by the toxicology, the EPA could regulate certain classes of PFAS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability (CERCLA). Once that happens, the EPA Office of Water could generate national maximum concentration limits for drinking water, wastewater effluent and industrial wastewater discharges.

How would the Remediate side of the Roadmap play out?

Senecal: Once the “restrict” portions are completed, a national strategy would require testing for PFAS in any potable water supply that serves more than 3,000 residents. Once testing demonstrates the presence of certain classes of PFAS above a prescribed level, a municipality would be required to communicate that to the public and initiate remediation. Classification as a hazardous substance could make the remediation eligible for the Superfund program.

What challenges would a remediation program pose for a municipality?

Senecal: When PFAS contamination pops up, it’s a tough and time-sensitive issue for a municipality to deal with. Once contamination is discovered, they need to work quickly and communicate very carefully about what is going on. It’s essential to pull in and work with health and environmental agencies to arrive at a solution that is sound, well communicated and online as soon as possible.

What is the expected impact of the bipartisan infrastructure law on PFAS issues?

Senecal: We believe a lot of money will flow into communities with demonstrated needs. The money will flow through state revolving loan funds and through grants. The key for municipalities is to be ready. If they anticipate a need to avail themselves of the funding, leaders should be conducting engineering studies now to demonstrate the need and getting that into their capital plans for when the money becomes available.

What treatments have been proven effective in removing PFAS from water?

Noll: At present there are three basic technologies for PFAS treatment: high-pressure membrane filtration, granular activated carbon and ion exchange. Typically, one of these would be implemented on the back end of a treatment process to polish the water and address PFAS issues. The “remediate” portion of the EPA Roadmap calls for studies to explore developing other treatment technologies.

What form of membrane treatment would be the most applicable to PFAS?

Noll: Nanofiltration and reverse osmosis are the most effective. They are among the best methods for addressing PFAS, but they do have the drawback of creating a waste stream. These technologies work by separating out the contaminants from the water. That leaves about 10-20% reject water that concentrates whatever contaminants are removed. The reject water then has to be dealt with. Membrane treatment may not be the most cost-effective method; it is typically used on a smaller-scale municipal plants.

What are the pros and cons of granular activated carbon?

Noll: At present, granular activated carbon is the most widely used. It is the simplest and often the most cost-effective, but that depends on site specifics, such as daily flows, and what might be in the water. Activated carbon can be deployed rapidly by using point-of-entry treatment, where small units are installed at households until a full-scale system can be put in place. One drawback is that activated carbon is not effective for all PFAS compounds. It’s effective for longer-chains molecules, but less so for shorter chains. And the spent carbon has to be regenerated or sent out for disposal.

What are the benefits and limitations of ion exchange?

Noll: Ion exchange is not as cost-effective as carbon, although again that depends on the specific situation. In ion exchange, the positively charged resin captures the negatively charged PFAS molecules. There is also the manner of disposing of the spent resin.

Garbrick: We see industries popping up to explore capturing that ion exchange waste stream and turning to beneficial use. We’re currently working with one industry that is able to pull out some organic compounds which they condense down and mix with fertilizers to increase crop yields. The dissolved organic matter is used as a biostimulant for fruit and vegetable crops and for row crops, increasing yields 5-25%.

What are the implications of PFAS treatment for water and wastewater treatment plant operators?

Noll: The biggest thing is that there will be a need for sampling; some of that is already required and underway on the drinking water side. The sampling is not difficult, but there are some very specific things operators need to be careful of. For example, they should not wear a new GORE-TEX jacket that could have PFAS on it while collecting a sample; that could yield a false positive result. There also would be capital improvement projects to treat the water, and the ongoing maintenance and monitoring of any system.

Are there any issues specific to wastewater operations?

Noll: The discharges from wastewater treatment plants eventually will start requiring NPDES permits to investigate whether there is a need to do some effluent polishing at the discharge. There may also be issues on the biosolids side that affect plant operations and the land application or disposal of the material.

If in need of expertise in dealing with a PFAS issue, what factors should a municipality consider?

Senecal: A firm helping a municipality needs to investigate, gather and verify accurate data, and get out in front of the issue quickly. It should be able to drill wells, do sampling, remove sources of PFAS in soils and set up construction systems. It’s also important to have experience in aquifer testing and determining where the PFAS are coming from, because often the best temporary solution is install a new well or group of wells in an area not affected by PFAS. Finally, there should be expertise in the design and construction of treatments that work with the community’s existing potable water system.

Can you describe a couple of cases where your firm dealt successfully with a PFAS problem?

Noll: In Newburgh, New York, we worked under a contract with the state Department of Environmental Conservation to install point-of-entry treatment systems to address the immediate need and get acceptable drinking water to residents. Meanwhile we designed and built a full-scale granular activated carbon system to address the PFAS in the groundwater.

Senecal: We went from the point-of-entry systems to a 6 mgd supplemental add-on to the water treatment plant within six months. It’s about coordination and getting access to funding almost in an emergency fashion and making sure the team thinks through the problem to provide a well-engineered, long-term, safe solution.