A Glass of Realism

“Is the glass half full or half empty?” 

It’s a long standing psychological question that can reveal a lot about a person. Whether you lean towards optimism or pessimism, one thing unites most of us: realism. And the reality is that the glass contains water. End of story.

Another reality is that per- and polyfluoroalkyl substances (PFAS) are quite prevalent in our drinking water. 

Recent data on US drinking water systems, as part of the current Unregulated Contaminant Monitoring rule 5 (UCMR5) sampling initiative (1), show about 8 percent of samples tested contain PFOS or PFOA, as well as HFPO-DA and PFBS, at levels above 70 ng/L – which is the safety limit. Additionally, nearly 15 percent of large public water systems exceed the proposed maximum contaminant level of 4 ng/L (ppt). Nine additional PFAS compounds have been found in about 2,000 public water systems – while health advisories have not yet been established for other PFAS compounds. 

Exact figures are not yet available in the EU, but initial reports estimate that there are 17,000 PFAS-contaminated sites (2). In Veneto, Italy, it is estimated that roughly 25 percent of residents over 14 years old show blood levels of PFAS above 0.5 µg/L (ppb) – attributing this to contaminated drinking water (3).

Environmental Sciences Europe found that levels of PFAS in many cities in the eastern and southwest areas of China exceed levels set by US health advisories (4). Though there are no drinking water regulations in China, it has established health advisories citing maximum safe levels of 85 ppt for PFOA and 47 ng/L for PFOS. 

If you're enjoying this article, you may like to join our mailing list to receive new content every week: subscribe here

Similarly, there are currently no regulations for PFAS in the US. In March 2023, the Environmental Protection Agency (EPA) proposed the National Primary Drinking Water Regulation (NPDWR) for six PFAS compounds and is now working to finalize the regulation by the end of the same year (5). It establishes a maximum contaminant level of 4 ng/L (ppt) for PFOA and PFOS. 

In the EU, there is an established drinking water regulation that sets the limit of total PFAS at 0.5 µg/L (ppb). It remains to be seen if stricter limits will be imposed. At this point it’s too early to tell because many studies are still learning about the toxicity and scope of specific PFAS compounds. There are also studies around overall exposure from other sources, such as foods, which are still underway.

The EPA’s proposed regulation would require water systems to monitor for PFAS levels and mitigate excessive levels of the chemicals by removing the contaminated water sources or treating them.

The most common techniques to remove PFAS from water are activated carbon or reverse osmosis. Both technologies are well established for the purification of drinking water for a wide variety of contaminants. Large scale, modular systems can be delivered and integrated for online treatment. Though it should be noted that these technologies remove PFAS but still require a disposal process, which can lead to storage costs and future problems. 

Other technologies under development can break down PFAS altogether – so the problem truly goes away. The objective here is to break the carbon–fluorine bond (the strongest chemical bond we know of), which requires a radical electron. Usually this is achieved by incineration, but this approach is not always reliable and can often result in incomplete combustion and air emissions of PFAS or other chemical molecules. Another approach is to combine UV light with hydrogen peroxide, generating hydroxyl radicals. These highly unstable molecules are extremely reactive and will do the job. Indeed, all these techniques have been demonstrated in the lab, but scaling them up and reducing the cost are major hurdles.

I believe that sustainability and cost go hand in hand. We can clean everything from water in terms of organic contamination, but the cost is not practical at this time. It’s clear that our detection technology is very good, so we can measure PFAS or any contaminant at very, very low levels – even to concentrations where they don’t have a health effect. The goal then should be to have a removal target that brings levels down to safe concentrations. This approach would make cleaning more cost efficient. This is especially important for smaller utilities that have a lower tax base to fund water cleanup technologies, and/or don’t have the opportunity to dilute contaminated water with alternate clean water sources in order to meet safe drinking water standards.

At the same time, we need to devise alternative compounds that can replace PFAS altogether (for example, researchers are investigating alternative firefighting foams). 

The issue of PFAS toxicity is coming to light – and research efforts are underway to ban, replace, and ultimately remove them from us and the environment. Unfortunately, PFAS that are already in the environment will be causing issues for many generations.

We hope you found this article informative! Why not join our mailing list to receive new insight every week? Subscribe here