Understanding the results of a well water analysis report from a laboratory may seem daunting. However, there are people and tools that can make this task easier. There are no regulations for well water, so we recommend comparing your results against the EPA's drinking water regulations which are used to monitor public water systems.
How do I read my results?
Verify that the lab sent you the results for YOUR water sample. Your name and sample information should all be listed at the top of the report.
Review which parameters, the specific physical, chemical, and biological properties that were tested for, are listed.
Figure 1: Well water analysis report with different parameters listed.
Look at the reporting units used. It's important to check which reporting units were used to avoid misinterpretation. For example, lead levels might be reported in micrograms per liter (µg/L), while the EPA’s safety standard is in milligrams per liter (mg/L).
Since 1 mg/L = 1,000 µg/L, a reported lead level of 15 µg/L is actually equal to 0.015 mg/L — exactly at the safety limit, not far exceeding it as the raw number might suggest. Understanding unit conversions ensures accurate assessment of your water quality and helps prevent unnecessary concern.
Figure 2: Well water analysis report with different reporting units listed.
Look for any flags that the lab has highlighted as a potential problem. These are the parameters you will want to look at first.
Once you have converted the numerical results into a reporting unit that matches the EPA's Drinking Water Standards, use the links below to compare your results to the EPA's primary and secondary maximum contamination levels (MCL).
If your results are at or below the EPA's listed limits, your well water is considered safe to drink. If any of your results are above the EPA's listed limits, steps will need to be taken to mitigate these contaminants.
IMPORTANT!
If your well water has elevated levels of any of the primary contaminants, DO NOT drink, brush your teeth, or cook with your well water until you have learned more about your situation.
If you need help figuring out your results, you can:
Speak with the lab: The laboratory may be willing to discuss the results and will inform the well owner of any major concerns. Laboratories typically do not offer guidance on what to do next.
Use the Be Well Informed Tool: Results from a water report can be entered into this tool, and it will help determine if there are any contaminants that may be of concern. This is just a guide and consulting with your local health authority or doctor is highly recommended if any constituent is above the regulatory standard.
Contact your local health department: They can help you interpret your sample results and may have information on the best treatment options for your situation. If they personally aren’t able to answer your questions, they will know who to contact who will be able to help you, likely at your state health department.
Contact us: If your local sources don’t work out for you, we may be able to help. We may be able to provide direct assistance, and/or direct you to a technical assistance provider in your area who can help answer your questions (This is a free service funded by the US EPA).
What do I do if my results show I have an elevated level of a contaminant?
If your well water has an elevated level of any contaminant, see if the contaminant is a health risk, a water quality indicator, or just a nuisance. Your next steps will be determined by which kind of contaminant you are dealing with.
Health risk (Primary contaminants)
Health risk (Primary contaminants)
STOP drinking, brushing your teeth, and cooking with your well water: If your well water only tested positive for bacteria and nothing else is elevated, you can boil your water to destroy the bacteria. For all other contaminants, you should switch to bottled water until you can add treatment or switch to a different water source.
Disinfect your well: If bacteria is present in your well, check out this article to learn how to disinfect your well: "How do I disinfect or bleach my well?"
Speak with a treatment specialist: We would recommend contacting a water treatment professional who has been certified through the Water Quality Association’s Professional Certification Program.
Do your research: Search online for information from credible sources such as public health departments or cooperative extensions. There are multiple agencies that provide guidance on different contaminants throughout the nation.
Retest your well water: You may want to consider retesting your well water to verify that the results are accurate.
Water Quality Indicators/Nuisance (Secondary contaminants)
Water Quality Indicators/Nuisance (Secondary contaminants)
Water quality indicators are parameters used to indicate the presence of harmful contaminants could be present. For example, if the pH is too high or too low, the water can be more corrosive, which might cause metals like lead or copper to leach into it. Depending on which indicator is present, you may need to add treatment to address problems such as high turbidity or total dissolved solids to improve your water quality.
Nuisance or secondary contaminants do NOT carry any health risk but cause an adverse effect such as a smell or a residue. Examples include iron bacteria, hydrogen sulfide, and hardness.
Depending on which contaminant is present, you may want to add treatment to address problems such as high turbidity or hardness to improve your water quality.
Speak with a treatment specialist: We would recommend contacting a water treatment professional who has been certified through the Water Quality Association’s Professional Certification Program.
Do your research: Search online for information from credible sources such as public health departments or cooperative extensions. There are multiple agencies that provide guidance on different contaminants throughout the nation.
Additional Resources
How to Interpret a Water Analysis Report. Penn State Extension. 2023.
Well Testing, Results, and Options. Minnesota Department of Health.
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