PFAS - Links and Resources
(updated November 28, 2022)

PFAS READINGS in Parts Per Trillion (PPT)

DATE Well #1 Well #2 Well #4 Well #5 Well #6 Well #7 Well #8 #7 & #8 Combined #1, #2 & #6 Combined
Jul 2021 3.40 4.7 2.10   35.9 8.7 2.7 7.1 20.9
Aug 2021       ND       7.44 20.5
Sep 2021 7.19 2.61     37.2       24.7
Oct 2021 7.64 4.90     44.1       28.6
Nov 2021 7.21 2.43     39.0       25.1
Dec 2021 6.76 2.51     42.3       25.5
Jan 2022 6.64 4.74 2.60 ND 40.1     7.07 27.9
Feb 2022 5.98 2.36     39.4       23.9
Mar 2022 2.91 2.19     37.5       20.4
Apr 2022 6.23 2.63 3.14 ND 37.3       22.0
May 2022 3.40 4.46     29.8       18.1
Jun 2022 3.21 4.29     28.0       18.4
Jul 2022 3.30 2.23 2.82 ND 33.6     9.28 22.3
Aug 2022 6.28 4.91     35.3       23.5
Sep 2022 6.06 5.13     37.9       25.0
Oct 2022 6.99 3.1     47.6       27.2
Nov 2022 6.79 4.96     47.5       30.4

The table above shows the results of Hopkinton's PFAS6 testing of its water supply as compared to the MassDEP's Maximum Contaminant Level (MCL) of 20 ng/L. Some people who drink water containing PFAS6 in excess of the MCL of 20 ng/L may experience certain adverse effects. These could include effects on the liver, blood, immune system, thyroid, and fetal development. These PFAS6 may also elevate the risk of certain cancers. For more information on PFAS, see the links below.
What should I do?
For Consumers in a sensitive subgroup (pregnant or nursing women, infants less than one-year-old, and people diagnosed by their health care provider to have a compromised immune system)
     • Consumers in a sensitive subgroup are advised not to consume, drink, or cook with water when the level of PFAS6 is above 20 ng/L.
     • Consumers in sensitive subgroups are advised to use bottled water for drinking and cooking of foods that absorb water (like pasta).
     • For infant formula, use bottled water or use formula that does not require adding water.
     • Bottled water should only be used if it has been tested. The Massachusetts Department of Public Health requires companies licensed to sell or distribute bottled water or carbonated non-alcoholic beverages to test for PFAS.  See
For all other consumers not in a sensitive subgroup
     • If you are not in a sensitive subgroup, you may continue to consume the water because the 20 ng/L value is applicable to a lifetime consuming the water and shorter duration exposures present less risk.
     • If you have specific health concerns regarding your past exposure, you should see the Centers for Disease Control and Prevention’s link below and consult a health professional, such as your doctor.

Steps you can take to reduce your intake - Consider taking the following steps while actions are being implemented to address this issue:
     • For older children and adults (not in a sensitive subgroup), the 20 ng/L value is applicable to a lifetime of consuming the water. For these groups, shorter duration exposures present less risk. However, if you are concerned about your exposure while steps are being taken to assess and lower the PFAS6 concentration in the drinking water, use of bottled water will reduce your exposure.
     • Home water treatment systems that are certified to remove PFAS by an independent testing group such as NSF, UL, or the Water Quality Association may be effective in treating the water. These may include point of entry systems, which treat all the water entering a home, or point of use devices, which treat water where it is used, such as at a faucet. For information on selecting home treatment devices that are effective in treating the water for PFAS6 see MassDEP factsheet and weblinks below.
     • In most situations, the water can be safely used for washing foods, brushing teeth, bathing, and showering.
Please note: Boiling the water will not destroy PFAS6 and will somewhat increase its level due to the evaporation of some of the water.
Public Notice October 2022
Public Notice - August 2022

Public Notice - Hopkinton Water Has PFAS6 Levels Above the Drinking Water Standard

Press Release - 9/24/2021

Press Release - 12/8/2021 (PDF)
  12/8/21 (Google Docs version)

PFAS Public Informational Meeting - Recording From 10/26/21 (HCAM YouTube)

FAQ - Excerpted questions and answers from PFAS Public Educational Meeting

Drinking Water PFAS Public Education Mailing

Safe Water Massachusetts

USEPA PFAS Resources

MassDEP PFAS Resources for Public Water Supplies

MassDEP PFAS Regulatory Process

MassDEP List of Bottlers and Bottled Water PFAS Results

MassDEP Certified Labs


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

American Water Works Association PFAS Cycle

Where can residents with private wells get more information about PFAS in their water?