Are you worried that your well water might not be safe to drink?
How Do I Know If My Well Water Is Safe To Drink?
You rely on your well to supply drinking water, cooking water, and water for bathing and cleaning, so safety matters. This article guides you through testing, interpreting results, fixing problems, and keeping your well in good condition so you can feel confident about your water.
Why you should be proactive about well water safety
You manage your own water quality when you have a private well, so you’re responsible for testing and treating it. Regular attention helps you detect contamination early, protect your family’s health, and avoid expensive repairs later.
Common contaminants in well water
Knowing what can be in well water helps you decide what to test for and how urgently to act. Contaminants can come from natural geology, nearby land use, septic systems, agricultural runoff, or construction problems around the well.
| Contaminant | Typical source | Health concerns |
|---|---|---|
| Total coliform bacteria | Surface contamination, poor well sealing | Usually indicates possible contamination pathway; some coliforms are benign |
| E. coli (fecal bacteria) | Human/animal waste (septic leaks, livestock) | Causes gastrointestinal illness; indicates recent fecal contamination |
| Nitrate/Nitrite | Fertilizers, septic systems, manure | Dangerous for infants (blue baby syndrome); linked to pregnancy risks |
| Lead | Corrosion of plumbing or well components | Neurological effects, especially in children |
| Arsenic | Natural geology in some regions | Long-term cancer risk, skin and cardiovascular effects |
| Radon | Natural gas from bedrock | Lung cancer risk from inhalation of radon in indoor air above water |
| Uranium | Natural geology | Kidney damage and increased cancer risk |
| VOCs (benzene, MTBE, solvents) | Industrial spills, underground storage tanks | Various acute and chronic health effects, some are carcinogens |
| Pesticides/Herbicides | Agricultural runoff | Various health effects depending on compound |
| Iron, Manganese | Natural geology | Staining, taste/odor issues, not usually a direct health risk |
| Hardness (calcium, magnesium) | Natural geology | Scaling in pipes and appliances; aesthetic issues |
| Sulfate | Natural geology, agricultural | Laxative effects at high levels; taste |
How often you should test your well
Routine testing and event-driven testing give you the best protection. You’ll want regular screening for common microbial and chemical issues, and extra tests after events that could introduce contamination.
| Purpose | Tests recommended | Frequency / timing |
|---|---|---|
| Routine safety | Total coliform, E. coli, nitrates | At least once per year |
| New well or new homeowner | Full panel: bacteria, nitrates, major metals, hardness, pH, VOCs if near tanks | Test immediately and again after system commissioning |
| After flooding/heavy rain/septic issues | Bacteria, nitrates, possible VOCs | Immediately and again after repairs |
| Health concerns or pregnancy | Bacteria, nitrates, lead, arsenic, other site-specific toxins | Test immediately and consult health provider |
| Unusual taste, odor, or appearance | Bacteria, iron, manganese, sulfate, VOCs | Test immediately |
| Comprehensive check | Bacteria, nitrates, metals (lead, arsenic, uranium), VOCs, pesticides (if applicable), radon | Every 3–5 years or as local conditions demand |
How to collect a proper water sample
Collecting a proper sample is essential to get accurate lab results. If you don’t collect correctly, you could get false positives or false negatives.
- Use sterile sample bottles supplied by the lab; do not use random containers.
- Run cold water from the tap for several minutes to clear standing water and sample the source water.
- Remove aerators, screens, and filters before sampling (or sample before the point-of-use system).
- Avoid touching the inside of the cap or bottle rim.
- Fill the bottle as the lab instructs (some need a headspace for preservatives).
- Label the sample with your name, address, date, time, and the faucet sampled.
- Keep the sample cool (on ice) and deliver to the lab within the time specified (often within 24 hours).
- If in doubt, follow the lab’s sampling instructions or have a professional collect the sample.
Choosing an accredited lab and what their report will tell you
You should use a state-certified or accredited laboratory for drinking water testing. Accreditation ensures they follow standard methods and quality control.
- Look for state certification or accreditation on the lab’s website or by asking them directly.
- Ask about turnaround time, sample pickup, cost per test, and whether they include interpretive help.
- The lab report will list measured concentrations, detection limits, and reference values for comparison (often EPA Maximum Contaminant Levels or state standards).
- If you don’t understand terms (e.g., “