What Should You Test Your Well Water For?
Start with the CDC's annual baseline, then check off your situation to build a personalized water-testing checklist. Based on CDC & EPA guidance for private wells.
Test These Every Year
The CDC recommends every private-well owner test for these four things annually — no matter your situation. They're already on your checklist below.
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Total coliform bacteria
Signals whether surface contamination or sewage is reaching your well.
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Nitrate
High nitrate is especially dangerous for infants and pregnancy.
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Total dissolved solids (TDS)
A general read on overall mineral content and water quality.
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pH
Off-balance pH corrodes plumbing and can leach metals into your water.
The CDC also says to re-test after a new baby or pregnancy, a change in taste/odor/appearance, well repairs, flooding, or a known problem in your area.
Check What Applies to You
Each box you check adds the right extra tests to your checklist. Pick everything that fits your home, your land, and your plans.
What to Test Your Well Water For
4 recommended tests, based on the CDC baseline plus the situations you checked. Bring this list to a state-certified lab.
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Use a state-certified lab. Your state or county health department keeps a list of certified drinking-water labs — a certified lab is the only way to get results you can trust and act on.
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Private wells aren't federally regulated. The EPA's Safe Drinking Water Act covers public water systems — not private wells. Testing and treatment are the owner's responsibility, so it's on you to test.
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Re-test at least once a year — and any time after a new baby or pregnancy, a change in taste, odor or color, well repairs, or local flooding.
This is general guidance based on CDC and EPA recommendations for private wells, current for 2025–2026. It isn't a substitute for advice from your state-certified lab or a licensed well professional — confirm the right panel for your area locally.
Found Something in Your Water?
If your results come back with bacteria, nitrate, arsenic, or other problems, a licensed well driller can help you fix it — from disinfection and re-casing to a treatment system or a new well.
Find a Licensed Well Driller →