EPA legal limit
No federal limit
Maximum Contaminant Level
EWG health guideline
No guideline
Science-based, stricter target
Health effects
Lithium at therapeutic doses (600–1,200 mg/day) is used to treat bipolar disorder and has well-documented effects on the kidneys and thyroid. Trace levels in drinking water (typically under 10 µg/L) are far below therapeutic doses. Several epidemiological studies have found inverse associations between lithium in tap water and regional suicide and dementia rates, suggesting a possible neuroprotective effect at low doses — but causation has not been established. Higher-risk groups include people taking lithium medication (narrow therapeutic window), those with kidney disease (impaired lithium clearance), and pregnant women and infants.
Where it comes from
Natural sources: weathering of lithium-bearing minerals in groundwater aquifers. Industrial sources: battery manufacturing discharge, ceramic and glass production, and lithium carbonate pharmaceutical manufacturing. Agricultural: some lithium enters water via biosolids application.
How it's regulated
No federal EPA MCL. No WHO drinking water guideline established. Monitored for the first time under UCMR5 (2023–2025). EPA is reviewing whether a Maximum Contaminant Level is warranted based on UCMR5 occurrence data. No EWG health guideline established.
How to filter lithium
Not all filters address lithium. Look for independently certified filters — NSF International certification means the removal claim has been independently verified.
Water ionizers and alkalising systems do not remove dissolved lithium ions. Electrolysis changes pH and ORP but does not filter dissolved minerals. Reverse osmosis (NSF 58) or distillation is required for lithium reduction.
Frequently asked questions
What is lithium?
Lithium is a naturally occurring alkali metal that dissolves into groundwater from lithium-bearing mineral deposits including spodumene and lepidolite. It is also released from battery manufacturing, glass and ceramics production, and pharmaceutical waste. EPA's UCMR5 programme (2023–2025) is the first systematic national measurement of lithium in US public water systems. It is detected widely across the country, with higher concentrations in areas with lithium-rich geology such as parts of the Southwest and Mountain West.
What are the health effects of lithium?
Lithium at therapeutic doses (600–1,200 mg/day) is used to treat bipolar disorder and has well-documented effects on the kidneys and thyroid. Trace levels in drinking water (typically under 10 µg/L) are far below therapeutic doses. Several epidemiological studies have found inverse associations between lithium in tap water and regional suicide and dementia rates, suggesting a possible neuroprotective effect at low doses — but causation has not been established. Higher-risk groups include people taking lithium medication (narrow therapeutic window), those with kidney disease (impaired lithium clearance), and pregnant women and infants.
Is lithium regulated in drinking water?
No federal EPA MCL. No WHO drinking water guideline established. Monitored for the first time under UCMR5 (2023–2025). EPA is reviewing whether a Maximum Contaminant Level is warranted based on UCMR5 occurrence data. No EWG health guideline established.
Where does lithium come from?
Natural sources: weathering of lithium-bearing minerals in groundwater aquifers. Industrial sources: battery manufacturing discharge, ceramic and glass production, and lithium carbonate pharmaceutical manufacturing. Agricultural: some lithium enters water via biosolids application.
How do I remove lithium from tap water?
The most effective methods for removing lithium are: Reverse osmosis (RO), NSF 58 certified RO system, Distillation. Look for NSF-certified systems — independent certification confirms removal claims have been verified.
Is lithium in your water?
Enter your ZIP code to see the measured level in your specific utility.