Water Quality

Please click here for an important notice regarding PFAS in your drinking water.

The Town of Yarmouth obtains its drinking water from 24 groundwater sources.  Fortunately, these sources are of very high water quality and require very little treatment to meet water quality standards.  However, we are constantly monitoring all of our sources to ensure that we continue to provide high quality water to our customers.  Each year we sample for hundreds of potential contaminants, as required by the Massachusetts Department of Environmental Protection (MassDEP) and the United States Environmental Protection Agency (EPA).  In addition, the Town takes part in the EPA's Unregulated Contaminant Monitoring Program.  This is a federal program to help identify potential contaminants that may need to be regulated in the future.   The Town is required to produce a report for its customers each year that discusses the results of the required sampling.  Yarmouth's latest water quality report can be found here.

In addition to continuous monitoring of water quality, the Water Division owns and protects over 963 acres of land surrounding well fields and aquifer recharge areas to help ensure continued high quality water sources.  We also inspect these areas regularly for any condition that could adversely affect the water quality.  Finally, our staff, in conjunction with the Health Department, reviews and comments on local land development plans near our well fields that could impact water quality.  


Currently, the Yarmouth Water Division is closely monitoring a family of chemicals called per- and polyfluoroalkyl substances (PFAS) that have been detected in some public water supplies in Massachusetts and across the nation. Recently, the Massachusetts Department of Environmental Protection issued a new drinking water standard for the sum of six PFAS compounds (PFAS6).  This new standard requires all Massachusetts public water suppliers to test for PFAS.  The sum of PFAS6 may not exceed 20 nanograms per liter (ng/L), also equal to 20 parts per trillion (ppt).  

PFAS are a family of chemicals used for nonstick, stain-resistant and water-proof coatings, and in numerous consumer products, industrial uses, and firefighting foams.  Manufacturing of certain PFAS was discontinued in the U.S. decades ago, but they may still be used in imported products.  PFAS are resilient and do not degrade easily.  As a result, they are widely found in the environment as products are disposed of and PFAS leaches into the soil and water, finding its way to food and drinking water sources.  

MassDEP recommends that consumers in a sensitive subgroup (pregnant or nursing women, infants and people diagnosed by their health care provider to have a compromised immune system), are advised not to consume, drink, or cook with water when the level of PFAS6 is above 20 ppt.   These individuals are advised to use alternative sources of water such as bottled water tested for PFAS or in-home filtration systems certified to remove PFAS by independent testing groups.

The Yarmouth Water Division completed initial and confirmatory sampling for PFAS compounds at all of our sources in April 2021, as per MassDEP requirements.  As shown in the table below, all samples collected were below the Massachusetts Maximum Contaminant Level (MCL) of 20 ppt for the six regulated chemicals (PFOS, PFOA, PFHxS, PFNA, PFHpA and PFDA).  Please note that we sampled all sources, however, those that had all results below the MRL are not included in the table.  MassDEP also requires that the lab test for an additional 12 PFAS contaminants that are not currently regulated.  All results above the MRL for these contaminants are also included in the table (only two of these other contaminants were found in our sources).  

The regulations require that sources with average results of greater than 10 ppt must be sampled monthly. Therefore, we are currently sampling at Wells 4 & 5, Well 10 and Wells 18 & 19 monthly.  All other sources will be sampled quarterly until they are determined to be consistently under the MCL. Those sources with reduced sampling, will still be sampled at minimum twice every three years, per the regulations.  

Monthly sampling of Wells No. 4 & 5 have resulted in one exceedance of the MCL.  Please see the Public Notice for more information.

The Yarmouth Water Department will continue to monitor any changes in PFAS levels in our sources.  In addition, we will continue to monitor for any changes to state and federal regulations.  As new technologies for testing and new data on the health effects of the various PFAS contaminants become available, the state regulations may be updated and federal regulations may be instituted. 

If you wish to learn more about PFAS, visit www.safewatermass.org, a website developed by the Massachusetts Water Works Association to provide information to our consumers and links to reliable sources of additional information.  If you have additional questions, feel free to contact Laurie Ruszala, Water & Wastewater Superintendent, at lruszala@yarmouth.ma.us or 508-771-7921.

PFAS Results

Additional PFAS Resources

The following links provide more information related to PFAS in drinking water.