Wastewater treatment plants in the United States have been identified as significant contributors to PFAS contamination in drinking water. These facilities discharge enough of the persistent “forever chemicals” to elevate concentrations above safe levels for an estimated 15 million people or more. Alongside PFAS, these plants also release long-lasting prescription drugs into the water supply.
While wastewater treatment facilities aim to cleanse water, they fail to eliminate all contaminants introduced upstream. The residual chemicals are subsequently released back into waterways that serve as sources of drinking water. “It’s a funnel into the environment,” explains an expert from New York University. “You capture a bunch of things from a bunch of different places, and it’s all released in one place.”
Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are particularly concerning due to their carbon-fluorine bonds, which render them highly persistent in the environment. Regular exposure to various PFAS types has been linked to numerous health issues, including liver damage and various cancers. Recently, the US Environmental Protection Agency (EPA) implemented strict drinking water limits for six of the most studied PFAS.
Wastewater treatment facilities are also a known source of PFAS contamination through the sewage sludge they generate, which can be repurposed as fertilizer. To assess whether similar contaminants linger in treated water, researchers measured the concentration of PFAS and other fluorinated molecules across eight major wastewater treatment plants nationwide.
The study findings indicate that wastewater treatment plants across the US annually discharge tens of thousands of kilograms of fluorine-containing compounds into the environment, with a substantial portion being PFAS. Once treated wastewater is released, it mixes with natural water bodies in rivers and lakes, potentially leading to downstream drinking water contamination.
The researchers projected that wastewater could elevate PFAS concentrations above EPA limits in drinking water for around 15 million individuals. During drought conditions, when natural water is scarce to dilute wastewater, estimates could increase to as many as 23 million people affected. These figures may be conservative, as they assume natural waters initially do not contain PFAS.
“It demonstrates that wastewater treatment plants are critical sources of these compounds,” states an expert from Johns Hopkins University, who was not affiliated with the study. While methods exist to remove or destroy PFAS in water, he notes that existing wastewater treatment infrastructure is inadequate for addressing this issue effectively.
In addition to PFAS, the research found that these chemicals constituted only a fraction of the total volume of fluorinated substances released by the plants. The majority were not PFAS but included compounds commonly found in pharmaceuticals, such as statins and SSRIs. These pharmaceutical residues also pose risks to ecosystems and human health.
“Another person could be drinking a cocktail of fluorinated prescription medication,” warns the researcher. However, the long-term effects of low-level exposure to these compounds are not well understood.
“We need to start discussions about the extensive use of fluorine in pharmaceuticals,” he adds. While fluorination is prevalent in drugs to enhance their effectiveness, he emphasizes that preventing chemical contamination should also be a priority.
