What is the current Connecticut DPH drinking water Action Level for PFAS and how was it developed?

The CT DPH has derived individual health-based drinking water Action Levels (ALs) for four of the most widely studied PFAS that have also been detected in human blood more frequently and at much higher concentrations than other PFAS. These four compounds were included in our previous AL, “sum of CT 5” less than 70 ppt, set in 2016. The fifth compound, perfluoroheptanoic acid (PFHpA), lacks sufficient data to develop an individual AL. The current Action Levels are:

CT Drinking Water Action Level (parts per trillion, ppt)
Perfluorooctane sulfonic acid (PFOS)10
Perfluorononanoic acid (PFNA)12
Perfluorooctanoic acid (PFOA)16
Perflurohexane sulfonic acid (PFHxS)49

These Action Levels are based on the most sensitive, human-relevant effects seen in laboratory animals exposed to PFOS (immune effects); PFNA, PFOA (developmental effects); or PFHxS (thyroid effects). This new chemical-specific approach reflects the evolving scientific evidence on the toxicity of PFAS and is more protective of public health than our previous AL (sum of “CT 5” = 70 ppt). Also, the resulting individual ALs are within the range of drinking water guidance and standards more recently derived by another federal agency (Agency for Toxic Substances and Disease Registry, or ATSDR, 2018, 2020) and by other states, including most of our neighboring states.

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1. What are these chemicals and where do they come from?
2. What is the current Connecticut DPH drinking water Action Level for PFAS and how was it developed?
3. How do these chemicals get into drinking water?
4. There are thousands of PFAS chemicals. Why has CT only derived drinking water action levels for four of them?
5. If I have PFAS in my water, what precautions should I be taking for my pets, farm animals, home grown produce, and irrigation of my garden?
6. Can I remove PFAS by boiling my water?
7. I am a customer of a public water system. How can I find out if my water has been tested for PFAS?
8. How do I know if bottled water is safe?
9. How can PFAS affect my health?
10. Why have states set different acceptable levels for PFAS in drinking water?
11. Should I test my blood for PFAS?
12. How can I limit my overall exposure to PFAS?
13. I have a well, should I test the water for PFAS? How can I test my well for PFAS?
14. How does the State decide which wells are going to be tested for PFAS?
15. What happens if there are PFAS in my well?
16. Does the home water treatment system I have work to remove PFAS? What types of treatment address PFAS in drinking water?
17. What type of water treatment system will be installed if my PFAS levels exceed the Connecticut Action Levels? Who will maintain my treatment system, and how often?
18. CT DPH Contacts and Resources
19. External Resources