EPA’s plan to regulate chemical contaminants in drinking water is a drop in the bucket

After more than a year of community meetings and deliberations, the U.S. Environmental Protection Agency announced in February 2019 that it would begin the process of regulating two drinking water contaminants, seeking to stem a growing national public health crisis. If EPA follows through, this would be the first time in nearly 20 years that it has set an enforceable standard for a new chemical contaminant under the Safe Drinking Water Act.

The chemicals at issue, PFOA and PFOS, have contaminated drinking water supplies across the country affecting millions of Americans. They belong to a class of synthetic chemicals called PFAS, or per- and polyfluoroalkyl substances, that are widely used in products including firefighting foams, waterproof apparel, stain-resistant furniture, food packaging and even dental floss.

These chemicals have been linked with numerous health problems, including cancers, thyroid disease, high cholesterol, low birth weight and effects on the immune system. Studies show exposure to PFAS in children can dampen the effectiveness of vaccines – a topic my colleagues and I are currently investigating as part of a project called PFAS-REACH. In laboratory studies, low levels of PFAS can alter mammary gland development, which could have implications for increasing breast cancer susceptibility later in life.

What’s more, PFAS are highly persistent. Once released into the environment, they don’t break down – a fact that has led many to dub these substances “forever chemicals.”

A 2016 study found that drinking water supplies for 6 million U.S. residents exceeded EPA’s lifetime health advisory levels for PFOS and PFOA. Hu et al., 2016., CC BY-ND

A persistent problem

PFAS have been used for decades, but only in the last few years have we begun to grasp the full extent of contamination. A 2016 study reported that over 16 million Americans are exposed to these contaminants in drinking water, and a more recent estimate put that number at 110 million.

PFAS find their way into water supplies from military fire training areas and airports, as well as industrial sites and wastewater treatment plants. For instance, in 2010 my colleagues and I at the nonprofit Silent Spring Institute, which studies links between environmental chemicals and women’s health, first detected PFAS in public and private drinking water wells on Cape Cod, Massachusetts. The Department of Defense has identified approximately 400 current or former military sites with known or suspected contamination, stemming mostly from use of firefighting foams.

Today there are more than 4,700 PFAS substances in use. All are chemically similar and highly persistent. The United States phased PFOS out of products in 2000 and PFOA in 2006, but they are still turning up widely in drinking water, which is why states want EPA to set standards specifying what levels of exposure are safe. Meanwhile, studies suggest that some newer PFAS chemicals have similar health effects, and most have not been studied at all.

Scientists are working hard to better understand these chemicals in order to mitigate the public’s exposure. For example, researchers at the STEEP Superfund Research Program, a multi-institutional effort which I am a part of, are investigating how these chemicals move through the environment, their chemical characteristics, how they accumulate in our bodies, and their impacts on our health.

[embedded content] PFAS contamination is a problem near many military bases, which use the chemicals in firefighting foams.

A shifting landscape

EPA has been considering regulating PFOS and PFOA in drinking water since 2009. The agency’s recent announcement is a step in the right direction, but still only addresses these two chemicals in drinking water and any new federal standard won’t be fully implemented for years.

Earlier this year my colleagues and I published an analysis in which we showed wide variation in the way state and federal regulators manage these contaminants in drinking water. We found that seven states have their own guideline levels for PFOA and PFOS. Of these, Vermont, Minnesota and New Jersey have adopted levels that are more stringent than EPA’s current non-enforceable levels.

More recently, New Hampshire, New York and California have also proposed guideline levels lower than EPA’s. The day after EPA announced its plan, Pennsylvania officials announced they would create their own standards, citing concerns about EPA’s sluggish efforts to address the issue.