Private wells are the owner’s responsibility. EPA rules that protect public drinking-water systems do not apply to privately owned wells, and officials do not routinely monitor your tap the way a utility does. Local health or environmental departments can still help you get testing and interpret results (CDC, Guidelines for Testing Well Water, dated July 1, 2024; EPA, Protect Your Home’s Water, last updated February 26, 2026).
Baseline: at least once a year
CDC and EPA both recommend testing private well water at least once every year for:
| Parameter | Role on the annual list |
|---|---|
| Total coliform bacteria | Indicator that other harmful germs may be present |
| Nitrates | Can make people sick, especially infants; often linked to fertilizer, septic, animal waste, runoff |
| Total dissolved solids (TDS) | Dissolved minerals and salts; affects taste, appearance, scaling |
| pH | Acidity/basicity; extremes can damage plumbing and mobilize metals such as lead |
CDC also says: check the well itself every spring for mechanical problems, and run that annual water panel at least once each year. Ask your local health or environmental department what other germs or chemicals matter where you live — geology, agriculture, industry, and well location change the list.
One clean annual test does not mean the water stays safe forever. This page only restates the federal baseline schedule.
When to test sooner
Test promptly if any of these apply (CDC and EPA):
- Known groundwater or drinking-water problems in your area
- Big changes near the well: flooding, land disturbance, new construction, or industrial activity
- You replace or repair any part of the well system
- Taste, odor, or color of the water changes
- Someone in the household becomes pregnant, or a child starts living with you
EPA adds you may want testing more often than yearly if small children or elderly adults live in the house, or if someone is pregnant or nursing.
After floods or other disasters, contact local/state health or environmental agencies before relying on the well again; use an experienced well/pump contractor when inspection and disinfection are needed. See also CDC’s How to Disinfect Wells After an Emergency and EPA’s flood notes on the Protect Your Home’s Water page.
Annual panel vs. extras
The yearly four-parameter panel is a starting point, not a full survey.
CDC calls out nitrates every year for all well owners. Ask locally about extras such as VOCs, lead, arsenic, mercury, radium, pesticides/herbicides, and other chemicals or germs of concern. Specialized tests can be expensive — start with the health department’s local priorities rather than ordering every analyte.
EPA’s conditions table on Protect Your Home’s Water maps nearby activities (intensive agriculture, mining, gas drilling, landfills, fuel odors, staining, salty taste, and more) to suggested analytes. Use it with local advice; it is a decision aid, not a diagnosis.
Who should run the test
Use a state-certified drinking-water laboratory. Local or state health/environmental departments often run bacteria and nitrate tests, or keep certified-lab lists. Some offer free or low-cost private-well testing — ask first. EPA maintains contact information for certification programs and certified laboratories.
Home strip kits are not a substitute for certified-lab results when you need a defensible reading on bacteria or nitrates. This site does not rank or review kits.
After results
If results show harmful germs or chemicals: use bottled or another known-safe source until you have local guidance; contact your health or environmental department; they may recommend more frequent testing. EPA: confirm with a re-test if a contaminant exceeds health standards; treatment depends on the contaminant and well condition — some cases need a new source or well.
This site does not prescribe treatment or declare water “safe to drink.”
Practical schedule
| Timing | Action |
|---|---|
| Every spring | Check wellhead, cap, casing, drainage away from the well |
| At least once per year | Certified-lab: total coliforms, nitrates, TDS, pH (+ local extras) |
| Pregnancy / infant / vulnerable household | Ask local health about more frequent testing |
| After flood, repair, taste/odor/color change, or nearby contamination | Test promptly; get agency advice after disasters |
| Ongoing | Keep lab reports and maintenance notes |
What we never claim
- That one annual test proves water is permanently safe
- Lab certifications or “safe to drink” verdicts we do not hold
- Invented prevalence rates, fake reviews, or “best kit” rankings
- Medical or treatment prescriptions
- Oil/gas production well testing, SCADA/OT, or AI consulting
Sources
- CDC. Guidelines for Testing Well Water. https://www.cdc.gov/drinking-water/safety/guidelines-for-testing-well-water.html — July 1, 2024. Retrieved 2026-09-04.
- EPA. Protect Your Home’s Water. https://www.epa.gov/privatewells/protect-your-homes-water — last updated February 26, 2026. Retrieved 2026-09-04.
Last verified: 2026-09-04