Nobody Tests Your Well But You. Here's What to Test For and How Often.
Updated: Oct 3
If your home gets water from a public utility, the utility tests the water and sends customers a Consumer Confidence Report each year. A private well works differently. The owner is responsible for deciding what to test, when to test, and what to do with the results.
That does not mean every well needs every available test. Start with a dependable baseline, then add tests that match the well, nearby land use, household needs, and any recent change.
Start with four measurements every year
EPA recommends testing a private well annually for:
Total coliform bacteria
Nitrates
Total dissolved solids, often shortened to TDS
pH
These measurements answer different questions. Total coliform is an indicator that can signal a possible pathway for contamination. Nitrate can enter groundwater from sources such as fertilizer, manure, and septic systems. pH describes how acidic or basic the water is and can help with corrosion or treatment decisions. TDS measures the combined amount of dissolved material in the water.
A result is evidence about the sample collected on that date. It is not a permanent guarantee about the well.
Test sooner when conditions change
Do not wait for the annual date if:
Flooding, land disturbance, new construction, or industrial activity occurs near the well.
The well system is repaired or a component is replaced.
The water's taste, color, or smell changes.
Local officials report a groundwater or drinking-water concern in the area.
EPA also says households with small children, older adults, or someone who is pregnant or nursing may want to test more frequently. Ask the local health department or a qualified laboratory which measurements are appropriate for that household and location.
Add tests that match the local situation
The annual four-item baseline is a starting point. Other tests depend on what is near the well and what decision the household needs to make.
For example, nearby agricultural activity may justify asking about pesticides or additional nitrate testing. Industrial or commercial land use may justify asking about volatile organic compounds or metals. Lead and copper questions often depend on the home's plumbing and sample location. Naturally occurring contaminants such as arsenic or radon vary by geology.
Your local health department or environmental agency is a useful first call because it can identify concerns seen in the area. Ask one plain question: What do private-well owners near me usually test for beyond the annual basics?
Use a certified drinking-water laboratory
EPA recommends using a laboratory certified to perform drinking-water testing. Ask the laboratory:
Is the laboratory certified for each measurement I am ordering?
What bottle, preservation, and collection instructions apply?
Will the report compare results with current drinking-water standards or guidance?
Who should I contact if a result is above a benchmark?
Available panels and prices vary. Confirm the exact list of measurements before ordering rather than assuming that every basic panel includes the same items.
Read the result with the right context
Private wells are not regulated under the federal Safe Drinking Water Act in the same way as public water systems. State or local requirements may still apply.
If a result is elevated or unexpected, contact the laboratory, local health department, or environmental agency before choosing treatment. They may recommend confirming the result, investigating a possible source, or collecting another sample using a specific method.
Testing works best when it answers a clear question. Start with the annual four-item baseline, add locally relevant measurements, and confirm that the exact item you care about appears on the laboratory's list.
Primary references
EPA: https://www.epa.gov/privatewells/protect-your-homes-water
EPA private-well information: https://www.epa.gov/privatewells
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