PFAS & water quality: the great challenge

If you look for PFAS —Per- and polyfluoroalkyl substances or “forever chemicals”— in most environments, no doubt you will find them. Even areas as remote as Antarctica have found traces of PFAS. But what do we need to know about PFAS or forever chemicals?

Joining environmental journalist and QTalks host Tom Freyberg to answer that question are three guests from different disciplines, but complementary viewpoints:

• Roberta Hofman-Karis PhD, Senior Scientific Researcher at KWR Water Research Insitute
• Jason Dadakis, Executive Director of Water Quality and Technical Resources at OCWD
• Mohamed Ateia Ibrahim, Environmental Engineer & Group Leader at US Environmental Protection Agency (EPA)

Enjoy the full episode below.

Tom began by providing some context around the size of the PFAS problem. He said that these chemicals — often referred to as forever chemicals since they’re extremely difficult to break down — contain multiple carbon fluoride bonds. 

Although they’ve typically been used in items such as non-stick frying pans and water-resistant clothing, they’ve since been found in food packaging, commercial household products, workplaces, drinking water, and even living organisms such as fish.

Tom asked the panel to provide context regarding their involvement and interface with the PFAS challenge. 

Jason said that the Orange County Water District is unique since it serves 2.5 million residents and comprises 77% of the local water supply. He said that their nexus with PFAS is with the groundwater basin that they manage on behalf of nineteen major retail agencies — eleven of which have had to previously shut down one or more of their wells due to PFAS detection above state advisory levels. 

Mohamed explained that he is leading research on the development and evaluation of novel treatment technologies with a specific focus on emerging contaminants, including PFAS. He referenced the EPA’s PFAS strategic roadmap, which is the body’s commitment to action on PFAS from 2021 to 2024, and said that within this there are three goals — research, restrict, and remediate. 

In terms of research, EPA invests in research and development to increase the understanding of PFAS exposure, toxicities to human health, ecological effects, and effective interventions that incorporate the best available science. Restriction is a proactive PFAS prevention strategy that aims to prohibit them from entering air, water, and land. Remediation intends to broaden and accelerate PFAS cleanup activities. 

Roberta explained her role in the water treatment and resource recovery team at the KWR Water Research Institute. She said that she is involved in researching and measuring the concentrations of different PFAS chemicals in surface water, groundwater, wastewater, and drinking water, and also works on research regarding how to treat water and remove PFAS.

Tom then asked Mohamed to comment on the EPA’s imminent proposal regarding the further limits of acceptable PFAS levels in drinking water. Mohamed said that the EPA’s standards are to be proposed under the Safe Drinking Water Act and will impact many activities in the water industry. 

He further explained that the proposal aims to set limits for hazardous chemicals in order to indicate them as safe for a certain purpose e.g. drinking or irrigation. 

Jason said that the EPA seems to be suggesting a slightly more complex and different regulatory framework that hasn’t typically been applied to chemical contaminants in the U.S. and that he’s interested to see the final proposal. 

He said that he hopes that the investments that have been made in treatment to date will be compatible with the new regulations. He said that he’s also interested to see how, when regulators set California’s enforceable standards, they will compare with those of the federal EPA. 

Roberta commented that the European Union is also working on standards and that this poses challenges for water treatment since these will likely adhere to the nanograms per liter measurement. She said that this could lead to the need for significant upgrades and investment in the existing infrastructure to be able to measure at this level. 

Tom asked Jason to share updates on the results from the award-winning pilot scheme run by the district and explain which technology solutions they employed to support it. 

Jason explained how, given the significant capital investments involved in the project, they wanted to first test the technologies that they would be deploying. He said that they started a pilot program in parallel with the initial design of the weather treatment systems testing granular activated carbon and emerging technologies in absorption. 

He mentioned how the first phase informed the design and construction of the initial systems and identified suitable products that would have a long life within reasonable costs. He said that in the long term, they envision having an ongoing program whereby they evaluate new technologies since their operating costs are highly dependent on how long the absorptive media used to remove contaminants can last.

Mohamed said that they are aware of the limitation of existing technologies and that they are also on the lookout for new innovative solutions with a long lifetime and high effectiveness. He said that he doesn’t envision a silver bullet or a one size fits all solution and that each case will be considered on an individual basis whereby they first identify the sources and concentrations and then identify the relevant solution.

Roberta said that KWR has started looking at common treatment procedures that they currently apply such as activated carbon or reverse osmosis. She said that activated carbon is less effective in general than they want it to be and that the reactivation frequency should be a factor four or higher than what is applied right now. 

Based on this, she said that their research is currently focused on improved absorbance and whether it’s possible to improve the characteristics of activated carbon or to use other types of assortments. 

She also queried whether it’s possible to degrade PFAS since only removing them means that they will enter the environment again somehow, commenting that this is simply shifting the problem as opposed to dealing with it.

Mohamed said that they envisioned that concentrated waste would require innovative or novel absorbance since they are more selective and can withstand harsher conditions. He said, however, that this is a work in progress and that the solutions that are highly effective in terms of separation have their own challenges. 

He said that while this is a complex, multi-scale, and multi-level problem, the good news is that there is a much better understanding surrounding separation than there was ten years ago, including the ability to measure tiny concentrations of contaminants. 

Jason said that they have not yet ventured into this area of applied research, but of the cases he’s heard of, conventional technologies are being used (taking concentrates to a GAC system where it’s easier to dispose of) which he sees as more of a stopgap solution. 

He said that he’s hopeful that the Department of Defense research and the remediation processes that are happening at places such as military facilities will contribute to a better understanding of the scale of the problem and what can be done about it. He also explained how he’s hopeful that these federal-level investments will also yield results at the municipal scale — as long as knowledge is shared between them.

Tom rounded off the session by asking the panel whether they are cautiously optimistic about being able to meet the scale of the PFAS challenge. 

Roberta said that based on the research that’s being carried out and the new materials and technologies being developed, she is cautiously optimistic. However, she also acknowledged that the challenges are still significant and that, especially in drinking water in Europe where concentrations are very low, this represents an extra obstacle to the PFAS challenge. 

Mohamed said that he’s pleased with the activities that are happening on the federal level, and that he is seeing a lot of improvements in the short and long term. On the whole, he said that he is optimistic about being in a better situation in five to ten years’ time.

Visit Qatium’s YouTube channel to watch this episode and previous ones.