What your utility's record covers, and what it can't
Every community water system must send its customers an annual water quality report, the Consumer Confidence Report, by July 1 each year (EPA). That report, and the monitoring records PurityMap reads, describe the water the system delivers and the samples the system takes. They are the right starting point, and you can look up your own water system on PurityMap to see what its records show.
What those records cannot show is what happens between the water main and your glass. EPA names lead pipes, faucets and fixtures as the most common sources of lead in drinking water. In homes with a lead service line (the pipe connecting the home to the main), that line is typically the largest source. In homes without one, EPA points to brass or chrome-plated brass faucets and lead solder. Because each home has different plumbing, EPA notes that results are likely to differ from home to home.
EPA also states that you cannot see, taste or smell lead dissolved in water, and that testing is the only sure way to know whether it is there. If your water comes from a private well, there is no utility record at all: private well water is not regulated under the federal Safe Drinking Water Act, nor by most states (EPA).
A utility report describes the system's water and its own samples. It does not measure what your service line, faucets and fixtures add at your address.
Screening kits and lab tests give two different kinds of result
Every kit PurityMap lists carries one of two labels.
Screening: quick check, not lab-grade. These are test strips, color tests and other at-home kits. You get a reading in minutes, but it is a rough range or a yes/no, not a measured number. A screening kit is useful for a first look, for checking hardness, or for seeing whether a filter or softener is doing its job.
Lab-certified results. You collect a sample, mail it to a laboratory, and get back measured concentrations. EPA recommends sending samples to a certified laboratory when testing for lead, and encourages anyone who wants their drinking water tested independently to contact a state-certified drinking water laboratory. EPA itself does not test residential water on request.
PurityMap's bar for the lab-certified label is strict. A kit gets it only when it names the lab that runs the analysis, that lab publishes its accreditation, we have opened that accreditation document ourselves, and its scope covers the key substances we list for that kit. A broad lab panel can report more results than the accreditation covers; when it does, the kit's card says so. If any of that is missing, the kit is labeled screening or not listed. Some accreditations we accept are ISO/IEC 17025 accreditations rather than a state drinking-water certification. If you need a result for a legal, lending or real-estate purpose, ask your state's laboratory certification program which labs it certifies; EPA publishes a list of state certification programs.
The kits shown after this guide follow those labels, with at most one of each, and each card says what that kit can't tell you. PurityMap may earn a commission when you buy through a kit link. That never changes which kits we list or the order they appear in.
A screening reading near a cutoff, or any positive for lead or bacteria, is a reason to confirm with a lab-certified test, not a final answer.
What to test for: lead, hardness and PFAS
Lead. Test for lead if your home may have a lead service line, older brass fixtures or lead solder. Start by asking your water utility whether it will test your tap for lead: EPA calls your local water authority your first source for testing and identifying lead in tap water, and notes that some states or utilities have programs that pay for water testing. EPA notes that lead pipes are more likely in older cities and in homes built before 1986. A screening kit can flag lead within a range; a lab-certified test gives you the measured level. EPA describes young children, infants and fetuses as particularly vulnerable to lead, so a lab test is the better choice in a home with a baby, young children or a pregnancy. EPA's free Protect Your Tap guide walks you through checking whether your service line is lead.
Hardness. Hardness is mostly dissolved calcium and magnesium. You notice it as spots and film on glassware, soap scum, and needing more soap or detergent to get things clean (USGS). It is not among the contaminants regulated in EPA's national primary drinking water regulations. A screening strip is usually enough to decide whether a softener is worth considering, or to check that one is working.
PFAS. PFAS are measured in parts per trillion with laboratory methods such as EPA Methods 533 and 537.1, so PurityMap treats PFAS testing as lab only. We have to be direct here: no mail-in PFAS kit we reviewed currently meets PurityMap's bar. None named an accredited drinking-water lab whose accreditation we could open, so we do not list a PFAS kit. None of the lab-certified kits we list tests for PFAS.
Until a PFAS kit passes that check, start with your water system's PFAS record on PurityMap. If you want your own tap tested, contact a state-certified drinking water laboratory directly and ask whether it analyzes drinking water for PFAS by EPA Method 533 or 537.1. For context, EPA's 2024 drinking-water rule set maximum contaminant levels of 4.0 parts per trillion for PFOA and for PFOS, and 10 parts per trillion for PFHxS, PFNA and HFPO-DA (GenX). In May 2026 EPA proposed keeping the PFOA and PFOS limits, with the option of until 2031 to comply, and rescinding the other three. Until a final rule, all five limits apply.
There is no PFAS kit on this page because none of the mail-in PFAS kits we reviewed names an accredited lab whose accreditation we could verify. We will add one only when it does.
Private wells: you are the water utility
EPA is plain about private wells: their owners are responsible for the quality of the water they deliver to their households. No utility samples it for you.
EPA recommends testing a private well every year for total coliform bacteria, nitrates, total dissolved solids and pH, and testing for other substances if you suspect they are present. It suggests testing more often if small children or elderly adults live in the home, and notes that your local health department can tell you what is common in your area's groundwater and may offer private well testing for free. EPA's advice is to use only laboratories certified for drinking water testing.
Some context for the results. Coliform bacteria are not a health threat in themselves; EPA uses them to indicate whether other potentially harmful bacteria may be present. Nitrate has a federal maximum contaminant level of 10 mg/L (measured as nitrogen), and EPA warns that infants below six months who drink water with nitrate above that level could become seriously ill. Arsenic, which can come from natural deposits, has a federal maximum contaminant level of 0.010 mg/L. A broad lab panel is the way to see these alongside lead.
A screening kit made for wells can give a quick bacteria, nitrate and lead check between lab tests. It does not replace the yearly lab test EPA recommends.
Private well: water from a household well is not regulated under the federal Safe Drinking Water Act, nor by most states. Testing is up to the owner.
How to take a sample that means something
Follow the kit or lab instructions exactly, because the way you collect the sample changes the result. Sample from the tap you actually drink from, using cold water.
For lead, kits usually ask for the first water out of the tap after it has sat unused for several hours. EPA explains why: the more time water has been sitting in pipes, the more lead it may contain, so that first draw shows what your plumbing adds. Don't run the water first, don't remove the aerator unless the instructions say to, and don't sample through a filter unless you are testing the filter.
Use only the bottle supplied, don't touch the inside of the cap or bottle, and write down the date, the time and which tap you used. Mail a lab sample as soon as the instructions say, so it arrives while it can still be analyzed. A carelessly taken sample can mislead you more than no test at all.
How to read a result
Start with the units. Lead is usually reported in parts per billion (ppb), the same as micrograms per liter (µg/L). Nitrate and hardness are usually reported in milligrams per liter (mg/L), the same as parts per million. PFAS are reported in parts per trillion, also written ng/L. A lab report should give the concentration of each substance tested and may say whether it exceeds a national drinking water standard (EPA).
Then compare each number with the right benchmark, and know what that benchmark means.
Lead: EPA's health goal for lead is zero, because lead can be harmful even at low exposure levels. The 15 ppb figure you may see is the Lead and Copper Rule action level. It tells a utility when it must take further steps across its tap samples; it is not a line between harmless and harmful water at your tap. EPA's 2024 Lead and Copper Rule Improvements lower the lead action level to 10 ppb (10 µg/L); EPA expects water systems to begin complying in late 2027, three years after the final rule was published. Because the health goal is zero, the steps for reducing lead in the next section are worth considering at any detected level.
Hardness: the U.S. Geological Survey classifies 0 to 60 mg/L (as calcium carbonate) as soft, 61 to 120 as moderately hard, 121 to 180 as hard, and more than 180 as very hard.
Nitrate: first check how your kit or lab reports it. EPA's maximum contaminant level of 10 mg/L is measured as nitrogen, so a result reported "as N" (nitrate-nitrogen) compares with it directly. A result reported "as NO3" (as nitrate) is a larger number for the same water and cannot be compared with 10 mg/L as it stands. If the report does not say which, ask the lab. Coliform bacteria: a test reports present or absent.
For a screening kit, read the whole range the color falls in, not just its lower end. A reading on the edge between two ranges, or any positive for lead or bacteria, is a reason to confirm with a lab-certified test.
Non-detect: a result below the lowest level the method can report. It is not the same as zero; the substance may still be present below that level.
When to act
If a test finds lead, EPA recommends contacting your water system and your health department, and lists steps you can take separately or together. Use only cold water for drinking, cooking and making baby formula; boiling does not remove lead. Run your tap before drinking when water has been sitting, and ask your utility how long to run it. Clean your faucet's aerator regularly. If you use a filter, choose one certified to reduce lead and replace the cartridge on schedule. Find out whether your service line is lead. For children, EPA notes that a family doctor or pediatrician can perform a blood lead test.
If a private well test gives a positive coliform or E. coli result, or shows nitrate above the federal limit, EPA's private well guidance is to contact your public health department for the steps to follow and to have the well re-tested to confirm the result. Act quickly on a nitrate result in a home with an infant.
Hardness is a comfort and maintenance question, not a health finding. If your reading is in the hard or very hard range, our guide "Hard Water Explained: What the Grains Mean and When to Soften" walks through the trade-offs.
If you install a filter or softener, test again afterwards to confirm it is doing what it claims. EPA's Safe Drinking Water Hotline (1-800-426-4791) can answer questions about your results and your water system.
This guide gives general information about testing drinking water, drawn from the public sources cited below. It does not determine whether the water at any address is fit for a particular person, and it is not medical advice. For health questions, especially about lead, infants or pregnancy, talk to a licensed healthcare professional or your local health department, and follow EPA and state guidance for your own water. Rely on a certified laboratory for any result you will act on.