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Per- and Polyfluoroalkyl Substances are a group of chemical compounds called PFAS. Two PFAS chemicals, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), were extensively produced and are the most studied and regulated of these chemicals. Several other PFAS that are similar to PFOS and PFOA exist. These PFAS are contained in some firefighting foams used to extinguish oil and gas fires. They have also been used in a number of industrial processes and to make carpets, clothing, fabrics for furniture, paper packaging for food and other materials (e.g., cookware) that are resistant to water, grease and stains. Because these chemicals have been used in many consumer products, most people have been exposed to them.
While consumer products and food are the largest source of exposure to these chemicals for most people,drinking water can be an additional source of exposure in communities where these chemicals havecontaminated water supplies. Such contamination is typically localized and associated with a specific facility,for example, an airfield at which they were used for firefighting or a facility where these chemicals wereproduced or used.
On October 2, 2020, MassDEP published its public drinking water standard or Massachusetts MaximumContaminant Limit (MMCL) of 20 nanograms per liter (ng/L) or parts per trillion (ppt) – for the sum of theconcentrations of six PFAS. The six PFAS are: perfluorooctane sulfonic acid (PFOS); perfluorooctanoic acid(PFOA); perfluorohexane sulfonic acid (PFHxS); perfluorononanoic acid (PFNA); perfluoroheptanoic acid(PFHpA); and perfluorodecanoic acid (PFDA). MassDEP abbreviates this set of six PFAS as “PFAS6.” Thisdrinking water standard is set to be protective against adverse health effects for all people consuming thewater.
For information on the PFAS6 drinking water standard see: 310 CMR 22.00: The MassachusettsDrinking Water Regulations. For more information about the technical details behind the MMCL, see MassDEP’s technical support document at: Per- and Polyfluoroalkyl Substances (PFAS): An Updated Subgroup Approach toGroundwater and Drinking Water Values.
The MassDEP drinking water standard is based on studies of the six PFAS substances in laboratory animals andstudies of exposed people. Overall, these studies indicate that exposure to sufficiently elevated levels of thesix PFAS compounds may cause developmental effects in fetuses during pregnancy and in breastfed infants.Effects on the thyroid, the liver, kidneys, hormone levels and the immune system have also been reported.Some studies suggest a cancer risk may exist following long-term exposures to elevated levels of some ofthese compounds.
It is important to note that consuming water with PFAS6 above the drinking water standard does not meanthat adverse effects will occur. The degree of risk depends on the level of the chemicals and the duration ofexposure. The drinking water standard assumes that individuals drink only contaminated water, whichtypically overestimates exposure, and that they are also exposed to PFAS6 from sources beyond drinkingwater, such as food. To enhance safety, several uncertainty factors are additionally applied to account fordifferences between test animals and humans, and to account for differences between people. Scientists arestill working to study and better understand the health risks posed by exposures to PFAS. If your water hasbeen found to have PFAS6 and you have specific health concerns, you may wish to consult with your doctor.
If you get your water from a public water system, you should contact them for this information. For a contactlist for all public water systems in the Commonwealth you may visit:
https://www.mass.gov/lists/drinking-water-health-safety#contacts then under “Contacts” click on “MA Public Water Supplier contacts sorted By Town.” For private well owners see the Per- and Polyfluoroalkyl Substances (PFAS) in Private Well Drinking WaterSupplies FAQ for more information.