Federal or state agencies may have been testing water for PFAS in wells near or at your home. Testing for PFAS is usually only done when there is reason to think there is the possibility of well water contamination. Testing for these chemicals in well water is expensive and only done by a few laboratories.
If you are concerned about whether these chemicals are in your well water, contact one of our toxicologists to discuss whether testing your well water makes sense. Please call 866-292-3474 (tollfree in Maine), 207-287-4311, or Maine Relay 711.
Interpreting Results
Laboratory test results will have a number followed by the letters ng/L or ppt. The letters "ng/L" mean nanograms per liter, and the letters "ppt" mean parts per trillion. These are units of measurement, like grams of sugar per ounce of soda, and they refer to the same concentration of PFAS in water.
Current Drinking Water Standards
In June 2021, the Maine Legislature enacted a law that established a new State drinking water standard of 20 ng/L in public water supplies for the combined sum of six different PFAS: PFOA, PFOS, PFHpA, PFNA, PFDA, and PFHxS). If your water has more than 20 ng/L for the sum of these six PFAS, it does not necessarily mean you will develop health problems. It does mean that you should take action to reduce the amount of the contaminated water you are drinking or treat the water, so contamination is reduced or eliminated.
How to Treat
What you do depends on how much is in your water, how much water you use, and who is using the water. To quickly reduce the amount of PFAS you take in, you can switch to bottled water for drinking, and for making drinks such as coffee, tea, juice, and infant formula. Use of water for cooking, bathing, or watering your garden is unlikely to be a concern unless your water levels of these chemicals are very high. If used and maintained properly, some water filters can also reduce the amount of PFAS in your water. Commercial filtration systems certified with the code NSF/ANSI 53 (e.g. carbon filter) or NSF/ANSI 58 (reverse osmosis) can reduce concentrations of PFOA, PFOS, and other PFAS.
Additional Resources
- Read a tipsheet about understanding your water test results (PDF)
- Learn about other common contaminants in well water
- Find out about the Fund to Address PFAS Contamination
- Explore the Maine DEP's testing of well water website