Nantucket PFAS Monitoring Newsletter - September 2025

This month's newsletter may sound repetitive if you read my first PFAS newsletter , but it stresses an important topic: the value of testing your well. In this edition, I'll highlight MassDEP's recommended testing schedules for PFAS and other contaminants and share new PFAS treatment resources recently added to the Town's website.

PFAS

MassDEP recommends that all well owners test for PFAS every ten years. If you've already tested your well and have detected PFAS, you may consider testing more frequently, but likely no more than once per year. Additionally, MassDEP recommends that everyone within 1 to 2 miles of detected PFAS also test for PFAS. PFAS are commonly detected throughout all of Nantucket. Check out our Private Wells page for an overview of where PFAS have been detected.

If you have not already tested your well for PFAS, I'd like to encourage you to follow MassDEP's guidance and test your well for PFAS.

Annual Testing

PFAS aren't the only concern. MassDEP also recommends testing nitrates and coliform bacteria each year. These are included in the "Routine" test kits available through our Health Department. Both contaminants occur widely in the environment, but proper well construction and testing schedule can help you protect your health. Exposure to nitrates and certain types of coliform bacteria can lead to acute illness, emphasizing the importance of annual well testing.

Testing Every 10 Years

MassDEP also recommends testing for certain parameters including lead and volatile organic compounds (VOCs) every ten years. Lead is naturally occurring to some extent, and was also used in indoor plumbing until 1986. In some cases, Nantucket's acidic groundwater can corrode lead pipes and contaminate your drinking water. Earlier this year, our Department of Health & Human Services (HHS) began requiring private well lead testing at property transfer, and several wells have already tested positive. VOCs are present in various industrial, commercial, and petroleum products.

Like certain PFAS, lead and some VOCs have maximum contaminant level goals (MCLGs) of zero, so you may consider taking action even if you have low levels of detection in your well.

Test kits for all these parameters are sold at HHS (131 Pleasant St), and further details are available on our website .

Private Well Water Treatment

Our team is available to discuss treatment options with you for PFAS and other contaminants. In the past few months, we have added some additional resources on PFAS filtration to our Private Wells page .

One of the challenges of PFAS is that existing filter certifications don't guarantee that a filter will achieve the Massachusetts state standard of 20 ng/L for the PFAS6, let alone the MCLGs of zero for PFOA and PFOS. Fortunately, MassDEP's Per- and Polyfluoroalkyl Substances (PFAS) Point-of-Use Treatment System Study has identified several filters that are both National Sanitation Foundation- (NSF-) certified and achieved non-detect results.

The Washington Department of Health has also prepared a helpful guide comparing filter costs and maintenance needs. When choosing a system, consider both the upfront investment and ongoing maintenance to ensure long-term protection.