Guide · Updated October 14, 2026

PFAS in Private Well Water

PFAS (per- and polyfluoroalkyl substances) do not stain a sink or smell like a rotten egg. The only honest next step on a private well is a certified-lab panel. A hardware-store strip cannot do this job. EPA’s drinking-water limits are written for public water systems. They do not become a kitchen-tap statute because a well is in your yard.

This page will not tell you a result is safe or unsafe. It will tell you which public-system numbers EPA still prints, which ones EPA has proposed to take back, how to order the test, and which treatment classes people compare after they have a sheet. Bacteria or nitrate on that same sheet still goes to the local health department.

Public-system numbers are not a kitchen-tap statute

EPA’s National Primary Drinking Water Regulations apply to public water systems. EPA’s private-well pages say the owner is responsible for testing. CDC’s annual floor is still total coliform, nitrates, TDS, and pH at a state-certified lab. PFAS is an add-on panel, not that yearly floor.

If a salesperson quotes “the EPA limit” as if it were your well’s legal line, ask which compound, which year, and whether they mean a public system. Then get your own sheet. The reading order for units and “ND” is how to read a well water lab report.

What EPA finalized in 2024

On April 10, 2024, EPA announced a final National Primary Drinking Water Regulation for six PFAS in public-system drinking water. Those numbers are still the ones on EPA’s PFAS drinking-water page. Compliance for public systems was set for April 2029. Units are parts per trillion (ppt), the same as nanograms per liter (ng/L).

Those are public-system maximum contaminant levels. They are a comparison on a private-well sheet, not a private-well enforcement number.

What EPA announced in May 2025 and proposed in May 2026

On May 14, 2025, EPA said it would keep the PFOA and PFOS maximum contaminant levels and that it intended to rescind and reconsider the regulations for PFHxS, PFNA, HFPO-DA, and the Hazard Index mixture of those three plus PFBS. It also said it intended to give public systems more time to meet PFOA and PFOS.

On May 18, 2026, EPA put two proposed rules out for comment that follow that path:

1. Keep the PFOA and PFOS MCLs at 4.0 ppt each, and let requesting public systems take until April 26, 2031 instead of April 26, 2029.
2. A separate Proposed PFAS Rescission Rule for PFHxS, PFNA, HFPO-DA, and the Hazard Index mixture.

Those 2026 actions are proposals. They are not a final rule. The comment period closed July 20, 2026. Until EPA finalizes a change, the 2024 public-system table remains the table on EPA’s page — including the 10 ppt lines and the Hazard Index. Do not read a proposal as those limits already being gone. Do not read either the 2024 rule or the 2026 proposals as a requirement that a private-well owner test or treat.

How to test a private well

Use a laboratory certified for drinking-water PFAS in your state. Ask for a current EPA drinking-water method — labs commonly name Method 533 or Method 537.1 — and for the list of compounds on the report. A chemistry certificate is not a PFAS certificate. A wastewater row is not a drinking-water row.

Start the official search at certified labs by state. A store strip is a screen, not this panel — well water test kits is that split.

State notes already on this site, without inventing a yearly PFAS statute:

• Michigan: MDHHS Care for Mi Drinking Water publishes PFAS “at least once” as private-well guidance. EGLE keeps separate Michigan and out-of-state PFAS certified-lab lists. That is not a kitchen-tap MCL.
• North Carolina: PFAS is not on the statewide new-well .3803 panel. NCDHHS points Fayetteville-area and lower Cape Fear wells at NCDEQ programs. That is not a yearly PFAS statute for every existing well.
• Minnesota: MDH’s published five-contaminant cadence is coliform, nitrate, arsenic, lead, and manganese. PFAS is not on that list. If you add a PFAS panel, confirm that analyte in ELDO.
• New York: NYS DOH’s PFAS pilot offers limited free PFAS testing in Dutchess, Orange, Putnam, Suffolk, Ulster, and Westchester when applications are open. That is not a yearly PFAS statute.

A mail-in certified-lab kit is still a kit until the method and the analytes are on the report. Tap Score / SimpleLab is an approved class example of that mail-in path, not a ranked pick (Awin tracked URL). Well Diagnosis may earn a commission if you buy through an approved affiliate link on this page. That does not change the price you pay. See the disclosure. Confirm each PFAS analyte on a current state certificate. Bacteria or nitrate still goes to the health department. There is no PFAS filter affiliate link on this page.

Reading the sheet

PFAS results are usually ng/L or ppt. Those are the same unit. 4.0 ng/L is 4.0 ppt. Do not compare a ppt line to a mg/L MCL from the metals table.

ND means the lab did not see that compound above its reporting limit. If you needed a look at 4.0 ppt and the reporting limit is 10 ppt, you bought the wrong test. Circle the reporting limit next to each compound before anyone talks about a tank.

A sales printout with no accreditation number is not this document. A present total coliform, a present E. coli, or nitrate at or above 10 mg/L as N is still the health-department pile — see coliform bacteria in well water. PFAS does not cancel that call.

Treatment classes after a number

Do not shop from a smell or a neighbor’s pitcher. After a certified-lab sheet, the classes people compare for PFAS are granular activated carbon, reverse osmosis, and anion-exchange resin. Search those claims in the NSF DWTU database under NSF/ANSI 53 (carbon) or NSF/ANSI 58 (reverse osmosis). A carton that says “PFAS” without a listing is a carton.

Carbon that is sized for chlorine taste is not automatically a PFAS device. An iron or sulfur oxidizer is a different job. A water softener is a hardness tank. Put any house stack in treatment order after the pressure tank: sediment first, then the chemical job the sheet actually named. This page will not pick a brand.

Bottom line

Order a certified-lab PFAS panel if you want a number you can compare to EPA’s public-system table. PFOA and PFOS at 4.0 ppt are the two limits EPA has said it is keeping. The 2024 10 ppt lines and the Hazard Index are still on EPA’s page while the May 2026 rescission proposal is pending. None of that is a private-well statute. Bacteria or nitrate still goes to the local health department.