Read the full article by Ryan Felton (Consumer Reports)

“In 2014, residents of Horsham Township, Pa., near Philadelphia, learned that their water had been contaminated with potentially toxic chemicals linked to an array of health problems, including learning delays in children and cancer. Those residents include Frank and Lisa Penna, who allege in a lawsuit that their water was among the contaminated supplies.

Known as PFAS, for per- and polyfluoroalkyl substances, the chemicals in this class of approximately 5,000 substances have become notorious as much for their potential danger as for their perseverance: Because the chemical bonds that hold the compounds together don’t break down easily, they last a very long time—a reality that has led to a commonly used name for the group: ‘forever chemicals.’

PFAS compounds are also ubiquitous, used in a range of products, from food-delivery boxes to nonstick cookware to stain-resistant clothing. But one of the most troubling routes to PFAS exposure is drinking water that has been contaminated by discharges from factories and other facilities.

Indeed, PFAS have been detected in the drinking water of more than 1,400 communities in 49 states, according to research by the PFAS Project at Northeastern University in Boston and the Environmental Working Group (EWG), an advocacy organization that estimates that 110 million people may have tap water contaminated with the chemicals.

The Environmental Protection Agency, which regulates U.S. drinking water, has been investigating PFAS since the late 1990s. It set voluntary guidelines of 70 parts per trillion (ppt) for two of the compounds combined that are most studied and believed to be dangerous: PFOA, or perfluorooctanoic acid, and PFOS, or perfluorooctanesulfonic acid. (For context, 1 ppt is the equivalent of one grain of sand in an Olympic-sized swimming pool, according to some estimates.)

But despite the agency’s 20-plus years of information gathering, it still has not issued an enforceable nationwide standard on PFAS. The agency has failed to act even as more about the risks of the chemical group has become known, and even as some scientists and environmental organizations have concluded that a far lower concentration of PFAS in water—1 ppt—is a more appropriate limit.

The EPA won’t comment on a proposed 1 ppt limit, saying it would be ‘inappropriate to prejudge the outcome’ of a regulatory process now underway.

But David Andrews, senior scientist at the EWG, says the agency should enact the stringent standard. ‘The scientific research supports a value of 1 ppt or lower to be health-protective,’ he says…”