Important Information Regarding PFAS and the Sudbury Water District’s  Drinking Water Supply:

A suite of chemicals known collectively as per-and polyfluoroalkyl compounds (PFAS) have been found in public drinking water supplies across the country. Various classes of PFAS are used in the manufacturing of  products such as carpet and fabric protectants, non-stick cookware, surgical gowns, electronic devices, fire-fighting foams, ski wax, cosmetics, and cell phones.

The Sudbury Water District has been following the topic of PFAS ever since the US EPA identified PFAS compounds among a list of unregulated compounds of emerging concern in 2013. Soon after that, the District sampled the water system for PFAS, and the results showed concentrations well below any proposed concentration limits at that time.

Laboratory techniques have become more refined, enabling detection of PFAS compounds at extremely low concentrations (2 parts per trillion (PPT)).  In addition to the lowered detection limits, many states have established guidance levels that are lower than the current EPA Lifetime Health Advisory Level (LHAL) of 70 PPT for PFOS or PFOA individually or combined.  In January the Massachusetts Office of Research Standards and Guidelines (ORSG) established a guideline of 20 PPT as a combined limit for six specific PFAS chemicals.

The Sudbury Water District recognized the importance of knowing more about PFAS concentrations in the District’s public water supply.  Working together with the Sudbury Board of Health, we developed a plan for sampling and analysis of the District’s water supply at each source contributing to the water system, leading to a voluntary round of sampling and analysis in February 2020. The results presented in the table below show that concentrations of all PFAS compounds have an average sum of 12.8 PPT among our individual sources feeding the water system.

Since the confirmatory sampling, the Water District has committed to:

  1. Continue to sample the water supply to verify the presence or absence of these low levels of PFAS compounds, and
  2. Develop a feasibility study with an action plan should PFAS compounds exceed the ORSG guideline.

Furthermore, we will continue to update the public as we learn more about whether these PFAS compounds and their concentrations are present in the drinking water supply.


  • ND – Non Detect
  • ESWTP (East Street Water Treatment Plant) treats water from Well No 3, No 8 & No 10.
  • RRWTP (Raymond Road Water Treatment Plant) treats water from Wells No 2, No 7 & No 9.
  • Wells No 4 & No 6 provide chemical treatment at each respective facility and do not require filtration of iron and manganese as is the case for the other wells.
  • Well No 5 is currently off line because of elevated concentrations of iron and manganese, but note that no PFAS compounds were detected at Well No 5. It is only brought on line in case of emergencies. Treatment options are being considered for Well No 5 in the future.

Additional information on PFAS can be found at:

For questions or concerns regarding PFAS please contact Executive Director, Vincent Roy at (978) 443-6602.