Lithium is a naturally occurring element found in rocks, soil, and mineral deposits across the United States. While most people associate lithium with prescription medications used to treat bipolar disorder, relatively few know that this metal regularly appears in drinking water supplies, particularly in the Southwest and other regions with specific geological characteristics. Unlike regulated contaminants such as lead or arsenic, lithium has no federal drinking water standard, leaving millions of Americans uncertain about their exposure and potential health effects.
This comprehensive guide explains what lithium is, why it contaminates tap water, what science says about health risks, and how you can test and protect your household. Whether you live in a high-lithium area, take lithium medication, or simply want to understand your water quality better, this article provides the information you need to make informed decisions about your family's drinking water.
What Is Lithium and Why Is It in Drinking Water?
Lithium is a soft, silver-white metal that occurs naturally in the Earth's crust. It exists in trace amounts in most rock formations and mineral deposits. When water percolates through soil and bedrock over time, it dissolves small quantities of lithium and carries it into groundwater aquifers that supply wells and municipal water systems.
Unlike synthetic contaminants that enter water through industrial discharge or improper waste disposal, lithium contamination is almost entirely natural. It results from the geological makeup of a region rather than human pollution. However, the amount of lithium in drinking water varies dramatically depending on local geology.
Geographic Hotspots for Lithium in Tap Water
Lithium concentrations are highest in areas with specific mineral-rich geological formations. The U.S. regions most affected include:
- The Southwest, particularly Nevada, Utah, Arizona, and parts of California, where mineral-rich salts and lithium-bearing rocks are prevalent
- Parts of Texas and New Mexico, especially areas dependent on groundwater from deep aquifers
- Areas of the Great Plains with naturally saline or mineral-rich groundwater
- Certain regions in the Midwest with specific bedrock compositions
A 2017 study published in Science of the Total Environment found lithium concentrations in U.S. drinking water ranging from less than 0.5 micrograms per liter (µg/L) to over 100 µg/L in some wells, with an average around 25-40 µg/L in affected areas. For comparison, countries like Japan have set informal guidelines at 100 µg/L, though this is not a universal standard.
If you're concerned about lithium in your specific area, use free tools like ClearWater's ZIP code lookup at checkclearwater.com to check your local water quality data, though note that lithium is not always included in standard water quality reports because it's unregulated.
Health Effects of Lithium in Drinking Water
Understanding potential health risks requires distinguishing between therapeutic lithium doses (used as medication) and environmental exposure through drinking water. The health impact of chronic, low-level lithium exposure remains an area of active scientific investigation.
Thyroid Function and Lithium
The most thoroughly researched health effect of lithium involves thyroid function. Lithium can interfere with iodine uptake in the thyroid gland, potentially leading to hypothyroidism (underactive thyroid) or goiter (thyroid enlargement). This effect is well-documented in patients taking lithium medications at therapeutic doses, typically 600-1200 mg daily, which produce blood lithium levels of 0.6-1.2 millimoles per liter (mEq/L).
Drinking water lithium exposure produces vastly lower blood levels. A person consuming water with 50 µg/L of lithium daily would accumulate only about 0.01-0.05 µEq/L in their bloodstream, roughly 1-2% of therapeutic levels. However, some researchers raise concerns about cumulative effects over decades of exposure, particularly in populations with iodine deficiency or existing thyroid conditions.
Kidney Health Concerns
Lithium is primarily eliminated through the kidneys, and kidney function plays a crucial role in regulating lithium levels in the body. People taking lithium medication require regular kidney function monitoring because lithium can potentially cause chronic kidney disease with long-term use.
For environmental exposure at low levels, the risk appears minimal in people with normal kidney function. However, individuals with pre-existing kidney disease, diabetes, or other conditions affecting kidney function may theoretically face higher risk from cumulative lithium exposure. People taking lithium medications should be particularly cautious about additional exposure from drinking water.
Other Potential Health Effects
Emerging research suggests lithium may affect:
- Bone metabolism and calcium regulation
- Blood glucose control and metabolic function
- Neurological development in children (though evidence at low environmental doses is limited)
- Cardiovascular function at high doses
Most of this research involves therapeutic doses far exceeding environmental exposure. Large-scale epidemiological studies specifically examining health outcomes in populations with naturally high tap water lithium are limited, which is why the EPA has not yet established a Maximum Contaminant Level (MCL) for lithium.
Special Populations at Higher Risk
Certain groups warrant extra attention regarding lithium exposure:
- People taking lithium medications for bipolar disorder or depression should coordinate with their prescribing physician about tap water lithium levels in their area
- Individuals with kidney disease should consider lithium testing and potentially use filtered water
- People with hypothyroidism or iodine deficiency may be more susceptible to thyroid effects
- Pregnant women and young children may warrant precautionary approaches, though direct evidence of harm at environmental doses is lacking
Current EPA Regulations and Drinking Water Standards
Lithium is not regulated under the Safe Drinking Water Act. The EPA has not established a Maximum Contaminant Level (MCL), which is the highest concentration of a contaminant allowed in public drinking water supplies. This means municipal water systems are not required to monitor for lithium or remove it.
Why Lithium Remains Unregulated
The EPA regulates contaminants through a lengthy process involving risk assessment, cost-benefit analysis, and public review. To date, lithium has not been prioritized for regulation due to several factors:
- Limited epidemiological evidence of widespread health problems from environmental exposure
- Uncertainty about what level poses genuine public health risk at low doses
- The natural origin of lithium versus synthetic pollutants (regulatory focus historically on pollution)
- High treatment costs relative to perceived risk in many areas
However, this doesn't mean lithium in water is necessarily safe. It simply means the evidence threshold for federal regulation has not been met. Individual states and water utilities may choose to monitor or limit lithium voluntarily.
State-Level Actions
Some states have begun addressing lithium independently. California, which faces elevated lithium in parts of its water supply, has conducted expanded monitoring and research into treatment options. Several states include lithium in voluntary monitoring networks even without formal requirements.
How to Test Your Water for Lithium
Because lithium testing is not standard, you'll need to take specific steps to determine your exposure.
Free Water Quality Reports from Your Utility
Start by contacting your local water utility or obtaining their annual Consumer Confidence Report (CCR). By law, public water systems must provide this report to customers. However, since lithium is unregulated, it may not appear in standard reports.
Ask your water utility directly whether they monitor for lithium and can provide results. Many utilities maintain more comprehensive data than they're required to publish.
Professional Water Testing
For comprehensive lithium testing, you'll need to hire a certified water testing laboratory. Costs typically range from $150-$400 depending on the number of contaminants tested and your location.
When selecting a lab, ensure they:
- Are certified or accredited (look for state or NSF certification)
- Specifically test for lithium using inductively coupled plasma mass spectrometry (ICP-MS)
- Provide detailed results including the detection limit for lithium
- Can explain what lithium level means for your household
DIY vs. Professional Testing
Consumer-grade home testing kits for lithium are not widely available and generally not recommended for accurate quantification. The analytical chemistry required to measure lithium at environmental concentrations requires laboratory equipment. While some in-home water testing kits include lithium screening, they lack the precision needed for reliable results.
Professional laboratory testing is the appropriate method for lithium detection in drinking water.
Checking Your Area's Water Quality Data
Before investing in testing, research your area's known water quality issues. Free databases like ClearWater's water quality lookup tool provide information on what contaminants have been detected in your area, though lithium data may be limited depending on your region's monitoring practices.
How to Remove Lithium from Drinking Water
If testing reveals elevated lithium in your water, several treatment options can reduce your exposure. The most effective methods require point-of-use (home) systems since municipal treatment may not address lithium.
Reverse Osmosis Systems
Reverse osmosis (RO) is one of the most effective methods for removing lithium from drinking water. This technology forces water through a semi-permeable membrane that blocks dissolved minerals, including lithium, while allowing purified water to pass through.
Effectiveness: Reverse osmosis typically removes 95-98% of lithium and other dissolved minerals.
Advantages:
- Highly effective against a broad range of contaminants
- No chemical additives required
- Systems available for under-sink, whole-house, or point-of-use applications
Disadvantages:
- Removes beneficial minerals along with contaminants
- Wastes 2-3 gallons of water for every gallon of purified water produced
- Membrane replacement required every 2-3 years
- Can be slower than tap water flow
Ion Exchange Resins
Ion exchange systems use special resins that bind to lithium and other mineral ions, exchanging them for less harmful ions like sodium or potassium. These systems work similarly to water softeners.
Effectiveness: Ion exchange can remove 80-95% of lithium depending on the resin type and design.
Advantages:
- Good flow rate, doesn't waste water
- Can be regenerated and reused multiple times
- Effective for multiple contaminants simultaneously
Disadvantages:
- Requires regular regeneration with salt or other chemicals
- Some resins add sodium to water
- Less effective than reverse osmosis for lithium specifically
Distillation
Distillation heats water to create steam, which condenses into purified water while leaving dissolved minerals behind. This process removes virtually all dissolved contaminants, including lithium.
Effectiveness: 99%+ removal of lithium.
Disadvantages:
- Very slow process, requiring several hours for small quantities
- High energy consumption
- Removes all minerals, including beneficial ones
- Generally impractical for whole-house use
Activated Carbon Filters
Standard activated carbon filters are not effective for removing lithium. While these filters excel at removing chlorine, pesticides, and odors, they cannot remove dissolved minerals like lithium. Activated carbon works through adsorption (contaminants stick to the carbon surface), which works for organic compounds but not ionic minerals.
If you're considering a carbon filter primarily for lithium removal, this approach will not be effective.
Which System Is Right for You?
Choosing a treatment system depends on your specific situation:
- If your lithium level is elevated and you want maximum removal, reverse osmosis is most effective
- If you want to minimize water waste and still achieve good removal, consider ion exchange
- If you need to remove multiple contaminants simultaneously, reverse osmosis offers the broadest protection
- If lithium is your only concern and levels are moderate, ion exchange may be sufficient
Special Considerations for People Taking Lithium Medication
If you take lithium medication for bipolar disorder, depression, or another condition, drinking water lithium deserves special attention because it adds to your total lithium load.
Coordinate With Your Healthcare Provider
Before making any changes to your water consumption, discuss your water quality findings with the physician who prescribed your lithium medication. Your doctor can:
- Review your current lithium blood levels and dosing
- Assess whether additional water lithium exposure poses risk in your specific case
- Recommend testing your water if you live in a high-lithium area
- Adjust your medication dosing if necessary to account for water lithium
- Monitor kidney and thyroid function more closely if you're exposed to elevated water lithium
Minimizing Combined Lithium Exposure
If your healthcare provider recommends reducing water lithium exposure, you have several options:
- Install a point-of-use filter system (reverse osmosis is most effective)
- Use filtered water for drinking and cooking only
- Purchase bottled water with low or undetectable lithium levels (check bottling source)
- Combine approaches, using filtered tap water for most needs and monitoring total intake
Do not reduce water consumption to lower lithium exposure, as adequate hydration is essential for everyone, especially people taking lithium medications. Instead, focus on removing lithium from the water itself.
Key Takeaways and Action Steps
Understanding lithium in your drinking water empowers you to protect your family's health. Here's what you should do:
Immediate Actions
- Check your region's water quality history using available databases or contact your water utility
- Request your water utility's most recent Consumer Confidence Report and ask specifically about lithium monitoring
- If you take lithium medication, discuss water quality with your prescribing physician
If You Suspect Elevated Lithium
- Contact a certified water testing laboratory and request lithium analysis
- Share results with your healthcare provider if relevant to your medical situation
- Research treatment options suited to your lithium level and household water needs
- Install appropriate filtration system if testing confirms elevated lithium
Ongoing Monitoring
- Stay informed about EPA regulatory developments regarding lithium
- Replace water filter media according to manufacturer specifications
- Retest your water every 2-3 years or if your water source changes
- Maintain regular health monitoring if you take lithium medication
While lithium in drinking water is not currently considered a widespread public health emergency by the EPA, it's a legitimate concern for people in affected areas, particularly those taking lithium medications. By taking proactive steps to test and, if necessary, treat your water, you ensure your household has access to the safest possible drinking water. The good news is that effective, practical solutions exist for removing lithium when needed, and awareness of this issue allows you to make informed decisions tailored to your specific situation and health needs.