Private Wells on Nantucket
Private Well Testing Requirements
Many homes on Nantucket are served by private water dinking wells, particularly in areas outside the municipal water distribution system. As of January 1, 2024, the Town of Nantucket requires that private drinking water wells be tested before a property can be sold, conveyed, or transferred. This testing must include screening for PFAS, a group of chemicals sometimes referred to as "forever chemicals".
These regulations are part of the Town's efforts to ensure safe drinking water and provide transparency during real estate transactions.
Access the full Town of Nantucket: Private Well Regulations (Chapter 386) here: https://ecode360.com/NA0948/laws/LF1957067.pdf
Testing Your Well Water
Homeowners can obtain a water sampling kit through the Nantucket Department of Health & Human Services (131 Pleasant Street), or they may work with a certified laboratory to complete the testing process. To find a laboratory, use the MassDEP tool.
Helpful resources include:
Instructions on how to properly collect a water sample - click here
How to interpret your results - click here
PFAS testing information and FAQs - click here
Educational materials about water filtration options - click here and here
Testing ensures homeowners understand the quality of their well water and can take steps if treatment or filtration is recommended.
PFAS and Private Wells on Nantucket
The Town of Nantucket collects well sampling data from homeowners who voluntarily test their wells as well as from testing required under local well testing regulations. State agencies such as the Massachusetts Department of Environmental Protection also conduct investigations and sampling across the island.
Sampling efforts (received by the town between January 1, 2024 and February 26, 2025) indicate that:
PFAS are commonly detected on Nantucket but are also sometimes not detected.
Most detections are below the state's drinking water standard.
A smaller number of wells have exceeded the Massachusetts Maximum Contaminant Level (MMCL) of 20 nanograms per liter (ng/L) for PFAS6, but this is uncommon.
No samples in the dataset exceeded the imminent hazard threshold of 90 ng/L for PFAS6.
Because groundwater conditions vary across the island, neighboring properties may experience different test results depending on well depth, groundwater flow, and local environmental factors.
What This Means for Homeowners
Private wells remain a common and reliable source of water for many Nantucket properties. However, routine testing is important to ensure water quality and to stay compliant with local regulations.
If testing identifies contaminants such as PFAS, homeowners may consider installing point-of-use or whole-house filtration systems designed to reduce or remove these compounds.
Learn More
Homeowners and buyers can find additional guidance through the Town of Nantucket, including:
PFAS testing information and FAQs - click here
Water filtration guidance - click here
Guidance on interpreting laboratory results - click here
Understanding how private wells work - and how to properly test and maintain them - is an important part of responsible homeownership on Nantucket.