Start with your water supplier's available results. If you want to measure the water at your own tap or private well, a qualified laboratory can test a sample. Ask about its lithium reporting limit before ordering.
First, check what is already available
Our lithium water map brings together public-water-system measurements and regional estimates. Check the source label: a measured result describes samples collected from a water system; a modeled estimate is a prediction for an area. Neither is a fresh measurement from your kitchen tap.
Confirm your supplier on a water bill. A city can have more than one supplier, and the closest sampling point may not serve your home. You can also ask your utility for lithium results collected under EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR 5).
How to arrange a laboratory test
- Find a qualified drinking-water laboratory. Ask your state drinking-water program for laboratory resources, then confirm that the lab offers lithium testing for your type of water sample.
- Ask about the method and reporting limit. The lab must be able to measure the trace concentrations you want to investigate. Ask for the price, units, and expected turnaround.
- Use the lab's sampling kit and instructions. Container, preservation, collection point, and shipping can affect the result. Tell the lab whether you are testing tap water, well water, or filtered water.
- Read the result with its qualifiers. Keep the sampling date, units, reporting limit, and any notes with the number.
What does “non-detect” mean?
It means the laboratory did not report a quantified result at or above its reporting limit. It does not mean zero, and it cannot tell you the exact amount below that limit. UCMR 5 uses a lithium minimum reporting level of 9 µg/L; another laboratory method may use a different limit.
For example, “below 9 µg/L” should not be rewritten as 0, 4.5, or “probably low single digits.” Preserve the result as reported.
Is there a safe lithium level in drinking water?
There is no federal enforceable drinking-water limit for lithium. There are health-based reference values used to put monitoring data in context. EPA's UCMR 5 fact sheet lists a 10 µg/L health reference level; it is not a legal limit or a nutritional target. A result above a reference value is a reason to seek context from your water supplier or local public-health agency, not a diagnosis.
See EPA's lithium fact sheet for how that value differs from a reporting limit. Neither value tells you how much lithium to consume for brain health.
Can I use a home test strip?
A strip for hardness, chlorine, or lead does not measure lithium. For trace-lithium measurement, use a laboratory that specifically offers the test and reports its method and detection capabilities.
What if I use a filter or private well?
A private well may not have public lithium monitoring data, so a direct test can answer a question the map cannot. To evaluate a filter, ask the lab how to collect comparable samples before and after filtration. Our filter guide explains why performance depends on the system.
Frequently asked questions
Is lithium in every water-quality report?
No. Some suppliers publish lithium monitoring results; others may provide them on request. Check your supplier's current report and UCMR 5 information.
Does a non-detect mean my water has no lithium?
No. It means the amount was not quantified at or above the stated reporting limit. The exact concentration below that limit is unknown.
Can the map replace a tap-water test?
No. It provides existing system measurements or regional estimates. A laboratory sample is needed to measure your water at a specific place and time.
