How Often to Test Well Water: A Simple Schedule
One lab test every year covers the basics. A few events, like a flood, a new baby or a change in the water, mean you should test right away.
The schedule
| When | Test for |
|---|---|
| Every year (same season each year) | Total coliform bacteria, nitrate, total dissolved solids, pH |
| New well or newly bought home | Broad panel: bacteria, nitrate, pH, hardness, iron, manganese, metals (arsenic, lead, copper), plus local concerns |
| Every 3–5 years (or as your health department advises) | Repeat the broad panel, especially arsenic, uranium or other local contaminants |
| Before buying treatment | Iron, manganese, hardness, pH, hydrogen sulfide, tannins: whatever the system will treat |
| After installing treatment | The same items, on the treated water |
The 3–5 year broad panel isn't a federal rule. It's a common, sensible interval for slow-changing natural contaminants. Your state or county health department may recommend something specific for your area.
Test right away if…
- Your well was flooded. See what to do after a flood.
- The water's taste, color or smell changes. See the symptom guides.
- You had well, pump or plumbing work done.
- Someone in the house gets repeated stomach illness.
- You're expecting a baby or have an infant. Test nitrate and bacteria before using the water for formula.
- There's new nearby activity: a septic system, livestock, chemical spills, or drilling.
Make it easy to remember
- Pick a fixed month, such as spring after the snow melts, when wells are most likely to show problems.
- Keep every lab report in one folder. Trends matter more than single results.
- Set a calendar reminder for next year as soon as you get results.
Ready to test? Follow our step-by-step testing guide.
Frequently asked questions
How often should I test my well water?
The CDC recommends testing every year for total coliform bacteria, nitrates, total dissolved solids and pH. Test more often, or right away, after flooding, well repairs, or any change in taste, color or smell.
Do I need to test a new well?
Yes. Test a new well (or a well on a home you just bought) with a broad panel. That gives you a baseline to compare future results against.
Should I test after installing a water treatment system?
Yes. Test the treated water after installation to confirm the system works, and keep testing the raw well water each year, because the well can change.
Is a home test strip good enough for the yearly test?
Not for bacteria or nitrate decisions. Strips are useful for quick screening between lab tests, but use a certified lab for the annual safety test.
Sources
- Guidelines for Testing Well Water, U.S. Centers for Disease Control and Prevention
- Private Drinking Water Wells, U.S. EPA
- National Primary Drinking Water Regulations, U.S. EPA
- Should I Have My Water Tested?, Pennsylvania Department of Environmental Protection
- What to Do After a Flood: Water Wells, Georgia Department of Public Health
Sources checked October 24, 2026. Found an error? Tell us and we will fix it.