What can I do?

Test your water when it makes sense

Household testing is most useful when it answers a specific question. If you receive water from a public system, begin with the utility’s water-quality report and other available monitoring information. Testing may add useful information when the concern involves your own plumbing, a particular faucet, or a contaminant that system-wide monitoring cannot resolve for your household.

Private wells are different because the owner is responsible for routine testing and maintenance. For a fuller discussion of when to test, what to test for, and how to choose a laboratory, see When should you test your drinking water?

Choose a filter or treatment system

Start with the contaminant, not the product. Household filters and treatment systems differ substantially in what they can remove, and a device that addresses one problem may do little or nothing for another.

Look for credible third-party certification for the specific contaminant or treatment claim you need, and follow installation and replacement instructions carefully. EPA also cautions that filter performance depends on choosing the appropriate technology and maintaining it correctly.

Testing or other reliable information should generally come before buying treatment equipment. Otherwise, a household can spend money without knowing whether the device addresses the actual concern. (EPA, 2026a)

Respond to a concerning test result

A laboratory number needs context before it becomes a decision.

Check the contaminant, concentration, units, sampling location, collection method, and the benchmark being used for comparison. A regulatory limit for a public water system is not always the same thing as a household action threshold, and one sample does not necessarily describe conditions at every faucet or at all times.

For private wells, EPA recommends contacting the local health department when a contaminant exceeds a health standard and repeating the test to confirm the finding before choosing a response. (EPA, 2026b)

Care for a private well

Private-well owners are responsible for protecting and monitoring their own supply. EPA recommends annual testing for total coliform bacteria, nitrates, total dissolved solids, and pH, with additional testing based on local geology, nearby land uses, changes in the well, or known contamination concerns. (EPA, 2026b)

Well condition matters as much as laboratory testing. Flooding, repairs, changes in taste or appearance, nearby contamination, or changes around the property can justify additional investigation. A state-certified laboratory or local health department can help identify appropriate tests. (EPA, 2026b)

Follow a water advisory

Not all drinking-water advisories mean the same thing.

A boil-water advisory generally concerns germs that can be killed by boiling. A do-not-drink advisory may involve chemicals or toxins; boiling may not make that water safe. A do-not-use advisory means contact with the water itself may be unsafe. (CDC, 2024)

Follow the instructions from the utility, health department, or other issuing authority rather than relying on a general rule. During a boil-water advisory, even filtered tap water generally still needs to be boiled unless officials say otherwise. (CDC, 2024)

Investigate a local water concern

Begin with information that already exists. Identify your water utility, read its Consumer Confidence Report, check public monitoring data, and look for current notices or violations. H2O IQ’s Explore Your Water tool can help locate public water-quality information.

Then ask what scale of problem the evidence actually supports. A result from one household faucet may point to household plumbing; a utility-wide monitoring result may describe a broader system. If something remains unclear, the water utility and the state drinking-water agency are logical next sources.

The useful sequence is usually identify the question → find existing information → test or investigate only what remains uncertain.