PFAS: News You Can Use

A previous Green Acton post described a family of emerging contaminants, called PFAS, which have recently been found in the drinking water supplies of Acton and many other towns. This post will help residents think about actions that they might want to take, whether that be learning more, installing a water filter in their homes, getting their private well tested, or advocating for a nationwide enforceable standard.

Massachusetts has recently set a Maximum Contaminant Level (MCL) for six of the most common members of the PFAS family of contaminants. Individually or collectively, the sum of PFOS, PFOA, PFNA, PFH_xS, PFH_pA, and PFDA cannot exceed 20 parts per trillion (ppt). The Acton Water District (AWD) is attuned to the PFAS situation and has modified its operations to keep the PFAS level in its delivered water below this threshold.

However, if a family member is part of a sensitive or vulnerable population, or you don’t get your water from the AWD, or you would like water with even less PFAS in it, there are steps you can take. The Environmental Working Group (EWG) recommends a limit of only 1 ppt for the sum of all PFAS. The federal Environmental Protection Agency (EPA), on the other hand, has a guidance level of 70 ppt. Subgroups sensitive to PFAS exposure include pregnant women, nursing mothers, and infants, as well as immuno-compromised people. 

Filtering Water

It’s not easy to choose a home water filtration system. Household water can be treated at different scales (and for different costs): whole house systems (also called point of entry), under-sink systems (which treat all the water going to one faucet), refrigerator filters (for filling one glass at a time in the door of your refrigerator), and free-standing pitcher filters. 

A group from Duke University and North Carolina State University recently tested the effectiveness of all of these types of filters in residential settings in North Carolina (press release, peer-reviewed journal article). Their clearest finding was that all the under-sink dual-stage and reverse-osmosis filters they tested showed nearly complete removal of the 11 PFAS compounds for which they tested. The point-of-entry filters, refrigerator filters, pitcher, and single-stage under-sink filters were uneven in their performance. Green Acton doesn’t recommend specific consumer products, but you can see the makes and models listed by name in Table S-9 of the supplementary documents of the North Carolina paper. Look for filtering products that show very low numbers, or “<MDL” (less than the method detection limit), after treatment.

NSF International develops public health testing standards and certification programs. It uses a standard for PFAS, until recently known as NSF P473: Drinking Water Treatment Units — PFOS and PFOA, and now incorporated into broader standards for drinking water water. NSF has certified 76 products by 10 manufacturers under NSF P473, which can be viewed in its database. However, the NSF standard deals only with two PFAS chemicals (PFOA and PFOS), and requires only that the level be reduced below the EPA guideline of 70 ppt.

Consumer Reports has user-friendly ratings and reliability guidelines for all types of water filters. CR did not test for PFAS removal, but one could combine CRs’ cost, reliability, and ease-of-use information with PFAS data from one of the other sources. (Consumer Reports can be accessed on line, using a Minuteman library card, through Acton Memorial Library’s e-resources webpage.) Alternately, contact the manufacturer directly to ask about PFAS removal with a filtration system that looks otherwise desirable in the CR ratings. Finally, an affiliate marketing site (for commercial vendors), RO-system.org, offers clear explanations of each type of system, as well as detailed product reviews sorted by reverse osmosis, whole-house filters, and countertop systems. The fine print in some of the reviews mentions PFAS, or PFOA and PFOS. (Please note that Green Acton is not endorsing this site, but merely identifying it as a source of useful information.)

Cautions about reverse osmosis options: Although reverse osmosis filters are successful at protecting the household from PFAS, they do not protect the environment. Reverse osmosis (RO) filters push water through a semipermeable membrane. In most RO systems, only about 25% of the raw water becomes drinking water; the other 75% becomes “reject water,” which must be discharged. Likewise, the PFAS and other materials retained on the membrane must be disposed of. In Massachusetts, it is prohibited under Title 5 law of to dispose of reverse osmosis reject water into a septic system; a separately permitted injection well is required for this purpose. It is not illegal to dispose of RO reject water into Acton’s municipal sewer system. However, the PFAS you send down your drain is not removed by the municipal wastewater treatment plant and thus, returns to the environment. [See also 9 November 2020 update.]

Using Bottled Water 

Green Acton and other environmental groups advocate against the use of bottled water because of the vast amount of plastic waste it generates, especially now that it has been revealed that most of the plastic that consumers place in recycling bins is actually being burned or landfilled rather than recycled.

Nonetheless, there may be occasions when bottled water is the only practical choice. In that case, be advised that water bottlers are not currently required to treat or test their products for PFAS. In 2019, MassDEP surveyed Massachusetts permitted bottled water companies and requested that they voluntarily share their testing results for posting on the MassDEP website. The dense, multi-page reports are downloadable, but hard to decipher. More recently, Consumer Reports tested 47 bottled waters for 30 PFAS chemicals, and created a more-user-friendly presentation. The highest PFAS concentration was 9.76 ppt. By far, the majority of waters tested at below 2 ppt.

Testing Private Wells

Only three labs in Massachusetts are approved to test for PFAS, according to a list distributed by MassDEP. The one closest to Acton is Alpha Analytical in Mansfield. The company’s technical sales assistant, Jeremy Thebodo, told Green Acton that they don’t serve individual households, but that they have arrangements with two companies that do household well testing in our area and subcontract their PFAS work to Alpha. Over the phone, Nashoba Analytical in Ayer quoted a price of $350 for one PFAS test. The protocol is this: pick up a test kit at Nashoba Analytical’s lab in Ayer, follow the provided directions to capture the water, bring the sample back to the lab, and receive results for 14 PFAS compounds in approximately three weeks. With the TapScore approach from the SimpleLab company, a test kit (with sampling bottles) is shipped to the consumer, samples are gathered (by following the provided directions), and the samples are returned to the lab, using the provided shipping labels. In the Specialized tests section of its website, TapScore lists a price of $289 (including shipping) for 14 PFAS compounds, with a 10-day turnaround.

Are this hassle and cost a good idea for your household? MassDEP suggests considering getting a private well sampled if it is located within a mile or two of a known source of PFAS, or other water supplies in which PFAS has been detected. The local sources of PFAS that have shown up in Acton water are not yet known; all that is currently known is the distribution of PFAS in the AWD wells. Below is a map of the location of the AWD wells, annotated with the PFAS readings for each site (map source; data source). 

Users of AWD water should NOT interpret the information on this map as an indicator of the water quality at a particular residence or business. AWD combines water from all sources, and uses different sources on different days in providing water to customers. At the moment, the North Acton sources — the sites of the higher readings back in April — are not being used. 

Advocacy

The federal regulatory stance on PFAS is weak. EPA currently maintains a non-enforceable health advisory that merely recommends that municipalities alert the public if PFOA and/or PFOS levels exceed 70 ppt in drinking water. In February 2019, EPA released a PFAS Acton Plan, which it updated in February 2020. In that same month, Massachusetts Senators Elizabeth Warren and Ed Markey were among a group of Senators urging the EPA to implement and improve on the PFAS action plan. EWG’s website shows 30 separate federal House and Senate bills related to PFAS, but it’s not clear which have a chance of moving forward. To follow the PFAS issue on the regulatory/legislative front, visit the websites of EWG and the Center for Health, Environment and Justice, which provide frequent updates.

Massachusetts is one of a handful of states that have placed an enforceable limit on PFAS in drinking water. If you would like to thank our state regulators for their foresight in protecting the public from this emerging contaminant, contact MassDEP Drinking Water Program officials through this email address: program.director-dwp@mass.gov.

Consumer Reports offers an opportunity to sign a petition directed to the International Bottled Water Association, asking the trade group to require a strict limit on PFAS in the bottled water its members sell. 

Join the Upcoming PFAS Panel Discussion!

Green Acton and the Acton Area League of Women Voters are sponsoring an educational panel discussion on PFAS and Acton’s water, featuring three expert speakers and a chance to ask questions, on October 14 via Zoom. More details here, and registration here.

For a regional overview of the PFAS situation, the 495/Metrowest Partnership is sponsoring a presentation on Massachusetts’ new PFAS drinking water standard on October 21 via Zoom. 

Thanks

Many people provided or helped track down information for this web post, including Sheryl Ball and Evan Carloni (Acton Health Department), Mike Thompson and Jack Troidl (Woodard & Curran, which operates Acton’s wastewater treatment plant), Matthew Mostoller (Acton Water District), Jeremy Thebobo (Alpha Analytics), Erik of ro-systems.org, reference librarian Heather at the Acton Memorial Library, and Acton residents Murray Bob, Lucy Kirshner, MaryLynn Miller, and Carolyn Platt. In addition, Dan Groher provided information for the previous PFAS 101 post. Thanks to all of them, but any mistakes remaining are the fault of the author, and not these generous sources and searchers. 

Updates:

13 October 2020: New data 

Since the map in this post was created, two new rounds of PFAS sampling have been completed at AWD wells. Results from August 31 sampling were: Conant 1: 22.6 ppt; Conant 2: 26.4 ppt; South Acton WTP: 19.4 ppt. Results from September 10 were: North Acton WTP: 14.04 ppt. Relevant for a private well owner trying to decide whether to test their well for PFAS, both Conant 1 and Conant 2 have now returned values above the Massachusetts drinking water standard of 20 ppt. Acton’s largest water source, the South Acton WTP, stayed within the drinking water standard. 

16 October 2020: More about residential reverse osmosis systems

MassDEP Title 5 regulations concerning septic systems(section 15.004 [8]) state forthrightly that “Backwash of water purification or filtration devices shall not be discharged to an on-site system,” and defines “on-site systems” to include septic systems and tight tanks (holding tanks with no outflow). However, recent guidance associated with the state’s new PFAS MCL carves out an exception, under some circumstances, for small reverse osmosis (RO) systems. This guidance is targeted toward households with private wells more than toward users of municipal water. The fine print:

• Point-of-entry RO systems (those that treat all the water entering a house) can never discharge into a septic system in Massachusetts.
• Septic systems that serve more than four residences cannot be used for discharge of RO wastewater in Massachusetts.
• For point-of-use systems (which treat only the water that flows to one outlet, such as the kitchen sink), discharge is allowed to a residential septic system if the PFAS concentration in the wastewater is calculated to be below the drinking water standard (now 20 ppt). 

This is a very narrow exception. The contaminant concentration in RO reject water will always be higher than the concentration in the water entering the RO system, so it will be hard to meet this standard unless the PFAS6 concentration in the water entering the house was already quite low. MassDEP gives the example of a household that has an incoming PFAS6 concentration of 10 ppt, and a RO system that discharges (as wastewater) 80% of the water entering the RO filter. For such a household, MassDEP shows the calculation as:

10 ppt PFAS6 x [100% ÷ 80%] = 12.5 ppt PFAS6

… and at 12.5 ppt PFAS6, discharge to septic would be allowed.

MassDEP’s calculation assumes that all of the incoming PFAS6 is concentrated into the wastewater, but in fact some might actually be retained on the filter. Moreover, a more-efficient RO system that produces a lower percentage of reject water is even more likely to fail the septic test. If the household in the example above were to invest in one of the newer RO systems that claim a ratio of one gallon of reject water to one gallon of treated water, the calculation would be:

10 ppt PFAS6 x [100% ÷ 50%] = 20 ppt PFAS6 

… and at 20 ppt PFAS6, such discharges would be prohibited. 

MassDEP boldfaces its bottom line: “MassDEP does not recommend RO treatment as your primary treatment option if your wastewater disposal method is to a Title 5 septic system.”

9 November 2020: IMPORTANT UPDATE on reverse osmosis systems

MassDEP’s PFAS in Private Well Drinking Water Supplies FAQ has been revised to remove the option of discharging wastewater from point-of-use (POU) reverse osmosis (RO) treatment systems to Title 5 septic systems, regardless of the PFAS level in the reject water. In other words, under the revised regulations, RO reject water can never be discharged to a home septic system.