Buying a Home With a Private Well: What to Test and Ask
Test before you close
Private wells aren't regulated like city water, so the buyer has to check. Order a test from a state-certified lab, ideally sampled by the lab or an independent inspector rather than the seller. Cover bacteria, nitrate, pH and TDS, plus local concerns like arsenic, uranium, radon, lead or PFAS. Some lenders and towns require specific tests.
Ask for records
- The well log or driller report: depth, casing, yield, date drilled.
- Past water test results and any treatment equipment manuals.
- Repairs, pump replacement dates, and shock chlorination history.
- Septic system location, size and pumping records.
Look at the wellhead
The casing should stick up above the ground with a tight, vented cap, and the ground should slope away from it. Note how far it is from the septic system, livestock areas and fuel tanks.
If a result is high
You can ask for a retest, a price reduction, or treatment before closing. Read treatment basics.
Sources
- EPA: Protect your home's water
- EPA: Learn about private water wells
- EPA: State drinking water lab certification programs
- EPA RadTown: Natural radionuclides in private wells
Questions
Who should take the water sample when buying a house?
Ideally the lab or an independent inspector, so the sample isn't taken from a treated tap or after the well has just been chlorinated.
Do I need a well inspection too?
A water test checks quality. A licensed well contractor can check the pump, pressure tank, yield and construction.
Free well water safety checklist
15 family-friendly steps based on CDC and EPA guidance. Print it, keep it on the fridge, and know when to call a certified lab.
More guides
- Flood Protection for Well Owners: Before, During and After a FloodRaise and seal the wellhead, know your pump shutoff, then disinfect and test with a certified lab after any flood.
- PFAS “Forever Chemicals” in Private Wells: Why You Should TestFederal PFAS rules protect public water systems — not private wells. Here’s what “forever chemicals” mean for well owners and how to get tested.
- Nitrates in Well Water and Blue Baby Syndrome: Who Must TestNitrate in well water can cause blue baby syndrome in infants. Learn who is at risk, when to test, and how to find a certified lab.
- Arsenic in Private Well Water: The Invisible Risk UndergroundArsenic in groundwater is often naturally occurring and invisible. USGS research shows millions of private-well users may be above the EPA drinking-water standard.