On June 15 the U.S. EPA issued updated health advisories for four perfluoroalkyl substances (PFAS) in drinking water that are significantly lower than those previously in place.

The National Association of Clean Water Agencies (NACWA) in a Clean Water Current notice on its website alerted water utilities to expect and prepare for questions from customers.

“Members should be prepared to receive questions from press and their community on EPA’s new health advisories and how they are proactively responding,” the bulletin said. It noted that the EPA has published a fact sheet for the public and an FAQ page with helpful information.

The bulletin further noted, “NACWA is developing helpful resources for members to use in addressing the PFAS challenge with their own policymakers and ratepayers. NACWA will also continue its strong advocacy with Congress and with EPA regarding PFAS.”

Drinking water health advisories are not regulation and are not enforceable. Instead, their aim is to give drinking water utilities technical information and to provide a basis for future regulatory policies. Still, according to NACWA, “the eye-popping drop in the advisory levels for PFOS and PFOA are likely to raise many questions from the public and the media about the dangers of PFAS in water and raise questions of what this means for clean water (wastewater) agencies alongside drinking water systems.”

The new drinking water health advisory levels — the concentrations at or below which adverse health effects are not expected to occur — are:

• 0.004 ppt for PFOA
• 0.02 ppt for PFOS
• 10 ppt for GenX chemicals
• 2,000 ppt for PFBS.

GenX and PFBS chemicals are fluorinated compounds that have been developed as replacements for PFOA and PFOS and integrated into consumer products and industrial applications because they have the desired performance but are more readily eliminated from the human body than PFOA and PFOS. The health advisories for GenX chemicals and PFBS are being issued for the first time.

The health advisories are designed to the reflect EPA’s assessment of the best available peer-reviewed science about the effects of the compounds. The new advisories supersede the EPA’s 2016 health advisories for PFOA and PFOS, which were set at 70 ppt in total. These levels set a concentration that utilities could use as a benchmark.

The newly released advisory levels refer to lifetime exposures and thus are calculated to protect the most sensitive populations through all life stages. NACWA notes that the new advisory levels for PFOA and PFOS are below those at which they can be detected and quantified under current laboratory analytical methods.

The NACWA bulletin observes, “Clean and drinking water utilities are seeing the challenges that PFAS pose for risk communication, and this announcement may further cloud the issue.”

EPA, in its press release, noted it is delivering the first $1 billion allotment of $5 billion of the Bipartisan Infrastructure Law grant funding for drinking water utilities to address PFAS and other emerging contaminants. While this money is significant, the costs to address PFAS from a municipal scale will be much steeper.

The EPA notes that hundreds of PFAS have been identified in water, soil, and air; many are environmentally persistent and bioaccumulative. The agency says the updated health advisories are based on human epidemiology studies, which have found associations between PFOA/PFOS on the immune system, the cardiovascular system, birth weight, and cancer.

“The most sensitive non-cancer effect, and the basis for the interim updated health advisories for PFOA and PFOS, is suppression of vaccine response (decreased serum antibody concentrations) in children,” according to the EPA notice.