Residents of Acton were given a rude jolt recently when a notice from the Acton Water District (AWD) appeared in their mailboxes, describing a new contaminant, detected in Acton’s groundwater, with the cryptic name of “PFAS.” This post provides some basic education about PFAS, with links to sources of much more information. As is typically the case with any emerging contaminant, the situation with PFAS is complex and understanding is evolving rapidly. 

What Are PFAS Chemicals? 

PFAS compounds are a group of human-made chemicals that have been widely used because they resist heat, oil, stains, grease, and water. Water-resistant clothing, stain-resistant furniture and carpets, adhesives, cleaning products, food packaging, non-stick cookware, paints and varnishes, the insulation on electrical wire, and firefighting foam are among the common products that have been made with one or another of this group of chemicals, beginning in the 1950s.

The acronym is short for per- and polyfluoralkyl substances. “PFAS” represents not just one chemical, but a family of thousands of related chemicals characterized by a long carbon chain with many fluorine atoms attached. Some of the major PFAS chemicals are no longer manufactured in the United States, notably PFOS (perfluorooctanesulfonic acid), formerly in Scotchgard, and PFOA (perfluorooctanoic acid), used in Teflon, but they can still be imported into the country from overseas.

Model of a PFAS molecule from: https://www.mass.gov/info-details/per-and-polyfluoroalkyl-substances-pfas#development-of-a-pfas-drinking-water-standard-(mcl)-

 

Why Are PFAS of Concern?

PFAS are nicknamed “forever chemicals” because many of them resist breaking down in the environment, and bioaccumulate in organisms, including humans. When the U.S. Centers for Disease Control and Prevention (CDC) tested the blood serum of Americans across the country, they detected PFAS in nearly all test participants. When laboratory animals have been given PFAS in large doses, their growth and development, reproduction, thyroid function, immune systems, and livers have been affected.

Research on the impact of PFAS in humans is still in early stages, but the Agency for Toxic Substances and Disease Registry lists the following potential harmful effects in humans: impacts on the growth, learning, and behavior of infants and children; reduced fertility in women; interference with the body’s endocrine (hormonal) system; increased cholesterol levels; immune system impacts; and increased cancer risk. The European Environment Agency provides a graphic summary of the state of knowledge of human health risks:

Possible effects of exposure to PFAS, from: https://www.eea.europa.eu/themes/human/chemicals/emerging-chemical-risks-in-europe (shared under Creative Commons)

The Situation in Acton and Massachusetts

During 2013 and 2014, the AWD tested all of its treated water for six PFAS compounds as part of a program to test new contaminants under the federal Safe Drinking Water Act of 1974. All 16 Acton samples came back as non-detect using the analytical techniques available at that time; “non-detect” means the levels of a contaminant are so low that they are undetectable by the technology employed. 

In May 2016, the U.S. Environmental Protection Agency (EPA) issued a lifetime Health Advisory of 70 ppt, or parts per trillion (0.07 micrograms per liter), for the combination of two PFAS chemicals, PFOS and PFOA, in drinking water. A Health Advisory is non-enforceable, and EPA has not taken the next step of setting an enforceable legal limit (known as an MCL, or Maximum Contaminant Level). In the absence of federal action, many states, including Massachusetts, have developed their own guidance, regulations, or legislation to address PFAS in drinking water.

In June 2018, Massachusetts issued interim guidance for five PFAS chemicals (PFOA, PFOS, PFNA, PFHpA, and PFHxS). MassDEP’s (Massachusetts Department of Environmental Protection’s) Office of Research and Standards Guideline (ORSG) for the sum of all five chemicals was set at 70 ppt. 

On January 27, 2020, MassDEP added one more PFAS to the ORSG, and lowered the guideline to 20 ppt for the sum of the six PFAS. MassDEP has proposed setting the MCL drinking water standard for PFAS to this 20 ppt value, and this regulation is expected to be promulgated later this year. In connection with the 20 ppt guidance, MassDEP recommends that: 

  1. consumers in sensitive subgroups (pregnant women, and nursing mothers and infants) not consume water when the level of the six PFAS substances, individually or in combination, is above 20 ppt. 
  2. public water suppliers take steps expeditiously to lower levels of the six PFAS, individually or in combination, to below 20 ppt for all consumers. 

Even before the arrival of this new state guidance, AWD was trying to get out in front of the PFAS situation. Staff briefed the AWD Commissioners in December 2019, and plans were laid for sampling all AWD water sources by the second quarter of 2020. The Acton Fire Department was consulted and reported no records of having used aqueous film forming foams, which historically have included PFAS ingredients (slides from AWD briefing: Intro to PFAS). As of now, AWD does not know the source(s) of the PFAS in the impacted wells. 

With MassDEP funding and guidance, AWD carried out two rounds of sampling of all raw water sources and treated water between January and June 2020, with work continuing through the Covid lock-down. A summary of the findings is below, with more detail available in the minutes of the AWD Commissioners from March 9 and April 2.

Data from: https://www.actonwater.com/assets/media/documents/PFAS%20Summary%20Table%206-22-2020.pdf

Four out of the five sources have PFAS values near or below the MassDEP guideline of 20 ppt. But the North Acton Water Treatment Plant (NAWTP) came in at 48.33 ppt, above the MassDEP guideline (although still below the federal Health Advisory level of 70 ppt). The NAWTP has a capacity to treat 0.5 million gallons per day (mgd) of water, a substantial fraction of Acton’s average usage of ~1.5 mgd. Right now, the NAWTP is off line while various options for reducing PFAS levels in finished drinking water are being considered. If you would like to receive updates from the AWD, send an email to wq@actonwater.com with “Updates” in the subject line, and provide your name, street address, and email address. 

A positive note in this PFAS situation is that the methodology for treating this group of contaminants is well understood. AWD is already using one of the recommended technologies, activated carbon filtration, at its Clapp/Whitcomb water treatment plant, and the Spring 2020 samples from that plant were all non-detect. More treatment costs more money, both for the installation of the equipment and for the regular replacement of the filters, but it can be done. 

PFAS in drinking water is not a problem specific to Acton. Surrounding towns are dealing with similar problems, as is the rest of the nation. The Environmental Working Group tested water samples from 44 places in 31 states; only one had no detectable PFAS. 

What Can I Do? 

The AWD notice suggests that sensitive subgroups, including pregnant women, and nursing mothers and infants, use bottled water. However, water bottlers (unlike public water suppliers) are not legally required to test their water for PFAS. In 2019, spring water in brands sold throughout Massachusetts was found to have PFAS at levels above EPA’s Health Advisory limit. Also, the plastic in bottled water can leach endocrine-disrupting phthalates into the water, and then the discarded bottles themselves become a problematic pollution source. If you do want to use bottled water, MassDEP maintains a list of bottled water brands that have voluntarily submitted PFAS data to Mass DEP, and provides links to the relevant lab reports. 

An alternative for sensitive subgroups to consider is a home water filter. The Michigan PFAS Action Response Team advises that you choose a filter that has been tested by an independent third party and shown to meet American National Standard 53. There are two types of home filtration systems that can reduce PFAS: granular activated carbon (GAC) and reverse osmosis (RO). An RO system treats the water at a single point, such as the kitchen sink, whereas a GAC system can treat all the water used in the home. A recent study reported in the journal Environmental Science & Technology found that under-sink, dual-stage and reverse osmosis systems showed near-total removal of the suite of PFAS chemicals for which researchers tested. They also tested pitcher filters, faucet-mounted systems, refrigerator filters, and a countertop filter, and found inconsistent results.

PFAS are a problem not only in drinking water. PFAS is also found in many consumer products, including personal care items such as shaving cream, sunscreen, and shampoo. The Environmental Working Group (EWG) advises being wary, as you squint at the fine print on toiletries, of any ingredient with “fluoro” in the name. EWG also provides an online database via which you can check specific products’ ingredients. Dental flosses could be a potential pathway of PFAS exposure, according to the Silent Spring Institute, along with nonstick cookware and some kinds of food packaging. 

Ensure that information you gather on this complicated topic comes from reliable sources, and don’t rely on information that shows up on social media. Especially if you have someone in your household with an existing medical condition or in one of the subgroups identified by MassDEP as sensitive, consult with a medical professional who is familiar with your specific situation. 

What Happens Next?

Scientists are still working to understand the nature of PFAS compounds, their fate in the environment, their toxicology, and the many and varied potential sources, and impacts, of human exposure. Similarly, regulators are continuing to evaluate the science and develop guidance and regulatory requirements. Meanwhile, water suppliers are analyzing new data and evaluating their options. As an interim solution, AWD has taken the NAWTP offline, thus lowering the PFAS level in Acton’s drinking water down below the MA guidance level. Green Acton, the Acton Water District, MassDEP, and other sources linked below will continue to share insights with the public as the situation evolves.

Learn More:

 

PFAS 101

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