Does the government test private wells?

No. The Safe Drinking Water Act covers public water systems, not private wells. Testing is entirely the owner's responsibility, and no compliance data exists for a private well.

How often should I test my well?

Bacteria, nitrate and pH annually; arsenic, lead and a metals panel on a multi-year cycle; PFAS and VOCs once if local land use suggests them; and any time after flooding, a nearby spill, or a change in taste, smell or appearance.

Are the PFAS results on this site relevant to my well?

Only as context. Those results describe public water systems in the area, which can indicate something about local groundwater, but they say nothing definitive about one well. A lab test of the well is the only answer.

Guides

Private wells: what system testing never covers

About 13 percent of Americans drink from a private well. No federal drinking water rule applies to any of them.

Updated 2026-09-03 - 5 min read

Nobody is testing your well

The Safe Drinking Water Act regulates public water systems. A private well serving one household is not a public water system, so no federal standard applies, no agency samples it, and no compliance report exists.

That means every dataset on this site about water quality, including the national PFAS testing round, describes public systems and says nothing about your well. Where a county page shows detections, that is the surrounding public systems, which is useful context about local groundwater and nothing more.

What to test and how often

Annually: total coliform and E. coli bacteria, nitrate, and pH. Nitrate matters acutely for infants.
Once, then every few years: arsenic, lead, manganese, fluoride, and a general metals panel. Arsenic in particular is geological and common in some regions at levels well above the federal limit.
Once, situationally: PFAS if you are anywhere near an airport, military installation, landfill, firefighting training ground or industrial site; VOCs if there is industrial or fuel-storage history nearby; radon in water in high-radon geology.
After any event: flooding, a nearby spill, new construction, or any change in taste, smell or colour.

Practical well ownership

Know where your wellhead is and keep the casing intact and above grade. Most bacterial contamination enters through a damaged or flooded wellhead rather than through the aquifer.

Keep a file of every test result. A single result is a snapshot; a decade of results is genuinely valuable information, and it is also what a buyer will want when you sell.

Treat according to what the tests find, not by default. Bacteria call for disinfection and wellhead repair, arsenic for adsorptive media or reverse osmosis, PFAS for reverse osmosis or properly specified carbon. Buying a treatment system before testing is how people spend money on the wrong problem.

Common questions

Does the government test private wells?: No. The Safe Drinking Water Act covers public water systems, not private wells. Testing is entirely the owner's responsibility, and no compliance data exists for a private well.
How often should I test my well?: Bacteria, nitrate and pH annually; arsenic, lead and a metals panel on a multi-year cycle; PFAS and VOCs once if local land use suggests them; and any time after flooding, a nearby spill, or a change in taste, smell or appearance.
Are the PFAS results on this site relevant to my well?: Only as context. Those results describe public water systems in the area, which can indicate something about local groundwater, but they say nothing definitive about one well. A lab test of the well is the only answer.

Want to know what applies to one specific address? The free check reports what is on the federal record near it, and says plainly when nothing is. Check an address

Umwelt publishes public records and explains the standards that govern them. This is not legal, engineering, environmental consulting or medical advice, and it does not assess any specific property or person.