Well Water Interpreter

Private well answer guide

PFAS 4 ppt in Well Water: Which Filter Should You Use?

PFAS at 4 ppt is low in absolute concentration but can still matter because some PFAS standards are measured in parts per trillion. Consider certified granular activated carbon, reverse osmosis, or ion exchange for drinking water, then verify with a PFAS-specific lab test.

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What to test

  • PFAS panel
  • PFOA
  • PFOS
  • TOC
  • pH

What to do next

  • Confirm which PFAS compounds were detected, such as PFOA, PFOS, PFNA, PFHxS, GenX, or PFBS.
  • Use a PFAS-certified lab method and retest if the result will drive treatment decisions.
  • Choose treatment certified for the specific PFAS compounds when possible: activated carbon, reverse osmosis, or ion exchange.
  • Replace cartridges on schedule because PFAS filters can break through when media is exhausted.

Common questions

Does a refrigerator filter remove PFAS?

Some carbon filters reduce some PFAS, but many refrigerator filters are not certified for PFAS reduction. Check the exact NSF/ANSI certification and compound list.

Is reverse osmosis good for PFAS?

Reverse osmosis can reduce many PFAS compounds at the kitchen tap when maintained correctly. Post-installation testing is the best way to confirm performance.

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Interpret once on the web. Track forever in the app.

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