Public Notice Per- and Polyfluoroalkyl Compounds (PFAS)

The District has been working with the Massachusetts Department of Environmental Protection (MassDEP) to monitor our public water supply and make plans for any potential elevated concentrations of per- and polyfluoroalkyl substances, commonly called PFAS, at the four points of entry into our water distribution system.  These man-made compounds originated in the 1940s and are just about everywhere. The compounds can be found in clothing, non-stick cookware, rugs, fire-fighting foams, cosmetics, ski wax, food packaging, as well as many other products. PFAS has even been detected in rainwater. It’s therefore not surprising that PFAS compounds are being detected in drinking water supplies, although usually at very, very low concentrations.

Monthly sampling and analyses for PFAS have shown that our water supply remains consistently below the MassDEP’s newly promulgated maximum concentration limit (MCL) for the sum of six PFAS compounds of 20 parts per trillion (nanograms per liter). Generally the PFAS concentrations have been detected them in the 10-15 parts per trillion range.


In order to understand what a chemical measurement means, one needs to have a basic understanding of the type of measuring units used, and what they mean. As mentioned above, most of our contaminants are measured using concentration units such as ppm and ppb.  But what is a ppm, ppb, or ppt for that matterin plain English?

As an example, let’s use an example of liquid chlorine added to our water in the treatment process at 1.0 ppm. This value refers to one part of chemical (in this case liquid chlorine) found in one million parts of our water. To realize how small a value this actually is, read the analogies listed below:

  • One part per million (ppm) = 1 inch in 16 miles
  • One part per billion (ppb) = 1 inch in 16,000 miles
  • One part per trillion (ppt) = 1 inch in 16 million miles (600+ times around the earth)

The fact that we have detected PFAS compounds in our water and that the concentrations are relatively close to the state’s MCL has led us to take the following actions, both to be in compliance with MassDEP’s requirements and to be prepared for any higher concentrations in future samples:

  • Maintained and continue to maintain close communications with MassDEP and the Sudbury Board of Health (and other Town boards and groups) to keep everyone aware of our findings and plans.
  • Hired a firm with experience and expertise in PFAS monitoring and treatment.
  • Prepared a study that summarizes findings to date and prescribing a plan for building activated carbon treatment facilities at our two treatment plant sites, including phasing of early construction of long-lead items such as concrete pads and interconnecting piping.
  • Applied for and received a MassDEP grant of $111,169 to help offset the cost of the design of PFAS treatment at the Raymond Road Water Treatment Facility, the design of which is already underway.
  • Put financial plans in place for funding the construction of this new PFAS treatment facility and received approval for transfers and bonding at the District’s Annual Meeting on May 18, 2021.
  • Initiated plans for a temporary emergency treatment system to address potential elevated PFAS concentrations from future sampling.
  • Submitted a request for funding assistance for the project from the American Rescue Plan Act.
  • Entered into an agreement with a consortium of law firms with national expertise in PFAS litigation and subsequently filed a formal civil complaint in court on November 11, 2021, against manufacturers of aqueous film-forming foam (AFFF) for their involvement in the manufacture and sale of PFAS compounds that have contaminated some groundwater wells within the District’s service area. Through this and future legal actions, the District seeks to protect rate payers and mitigate damages caused by 3M, DuPont, and the other companies that sold and profited from their products containing PFAS.

The District will continue to update our website as new information is received to keep you apprised of the quality of water in terms of PFAS and all other elements and compounds that we monitor, as we receive new information it will be posted to our website. If you have questions or concerns regarding PFAS news please contact our Executive Director, Vincent Roy at (978) 443-6602.

Download PFAS Analytical Results



According to the United States Environmental Protection Agency, PFAS are a group of man-made chemicals that includes PFOA, PFOS, GenX, and many other chemicals. PFAS have been manufactured and used in a variety of industries around the globe, including in the United States since the 1940s. PFOA and PFOS have been the most extensively produced and studied of these chemicals. Both chemicals are very persistent in the environment and in the human body – meaning they don’t break down and they can accumulate over time. There is evidence that exposure to PFAS can lead to adverse human health effects.


  • Food packaged in PFAS-containing materials, processed with equipment that used PFAS, or grown in PFAS-contaminated soil or water.
  • Commercial household products, including stain- and water-repellent fabrics, nonstick products (e.g., Teflon), polishes, waxes, paints, cleaning products, and fire-fighting foams (a major source of groundwater contamination at airports and military bases where firefighting training occurs).
  • Workplace, including production facilities or industries (e.g., chrome plating, electronics manufacturing, or oil recovery) that use PFAS.
  • Drinking water, typically localized and associated with a specific facility (e.g., manufacturer, landfill, wastewater treatment plant, firefighter training facility).
  • Living organisms, including fish, animals, and humans, where PFAS have the ability to build up and persist over time.

Certain PFAS chemicals are no longer manufactured in the United States as a result of phase-outs including the PFOA Stewardship Program in which eight major chemical manufacturers agreed to eliminate the use of PFOA and PFOA-related chemicals in their products and as emissions from their facilities. Although PFOA and PFOS are no longer manufactured in the United States, they are still produced internationally and can be imported into the United States in consumer goods such as carpet, leather and apparel, textiles, paper and packaging, coatings, rubber, and plastics.


If you do not typically receive a water bill from the District and wish to receive future updates regarding PFAS, please visit this website periodically or send an email to with “Updates” in the subject line.  Please include your name, address, and email to be informed of new information and future developments related to PFAS.


Many people have tried to determine where the water serving them is from.  Our water system is a dynamic system that includes eight wells, two treatment plants, four water storage tanks, and over 135 miles of water main.  Because the water all pumps into the system, and system hydraulics (how the water moves around in the pipes) can change based on time of day, season, water demand, and how we are operating the various systems, it is difficult to pinpoint this information.


There are home water treatment filters capable of removing PFAS from drinking water for the countertop or under the sink.  Filters certified by NSF have been demonstrated to be effective in removing two of these compounds, PFOS and PFOA, to below the USEPA Health Advisory of 70 parts per trillion (ppt).  Many of these filters will likely be able to reduce PFAS levels to well below 70 ppt, however, MassDEP has no independently verifiable monitoring results demonstrating this performance.  If you chose to install a filter, you should check to see if the manufacturer has monitoring results demonstrating that the device can reduce PFAS to below your level of concern. For example, MassDEP recently proposed a drinking water limit, or Maximum Contaminant Level, of 20 ppt for the sum of the levels of six PFAS compounds.

Earth Day – PFAS Presentation 4/20/2024


USEPA PFAS Resources 

MassDEP PFAS Resources for Public Water Supplies

MassDEP PFAS Regulatory Process

MassDEP Bottled Water PFAS Results

MassDEP Certified Labs

Environmental Toxicology Program

Green Acton

Agency for Toxic Substances and Disease Registry (ATSDR) Guide for Clinicians

American Water Works Association PFAS Cycle

Safe Water Massachusetts