Uranium in Tap Water
Uranium is a naturally occurring radioactive metal that dissolves into groundwater from uranium-bearing rock. It poses both a chemical (kidney) risk and a radiological one.
Natural erosion of uranium-bearing rock into groundwater; mining can increase local levels.
- 1Natural mineral deposits
- 2Mining activity
Most affected: Anyone on an affected system or private well over the long term.
A result is read with its context
This contaminant is tracked through federal and state compliance monitoring. Private wells in uranium-bearing geology are not covered by the federal rule and should be tested directly. PurityMap does not yet publish a per-system measured value for Uranium; this page is a reference explainer. To learn what is in your own water, check your utility’s Consumer Confidence Report (CCR) or use a certified home test.
- Above reference
- Evidence exceeds a reference level.
- Detected
- This substance was found in the monitoring record. Being present is not the same as being above a reference level, and this signal does not say which.
- Not detected
- Somebody looked and the laboratory reported nothing above its reporting limit. This is a result, and it is not the same as nobody looking.
- Not monitored
- No sampling for this substance has been reported for this system. Nothing is known either way, and an empty row is not a clean one.
2 cities with a health-based violation
A violation is a past event with a status, from the federal compliance record (EPA SDWIS, since 2016). It does not describe the water today.
PurityMap does not yet publish a per-system measured value for uranium. Check your utility’s Consumer Confidence Report, or use a certified home test.
What can carry a uranium reduction claim
- Reverse osmosis
Semi-permeable membrane separation removing dissolved minerals, heavy metals, and persistent fluorinated chemicals down to 0.0001 microns.
- Anion exchange
Synthetic polyvalent resin beads that exchange unwanted dissolved ionic contaminants for harmless benchmark ions.
- Coagulation / filtration
Boiling does not remove a dissolved chemical compound and can concentrate it. Many pitcher and refrigerator filters carry no verified claim for a compound like this at all.
A finding establishes the need, the need names the capability, the capability requires a verified certification. No product appears before that sequence completes. Filter Finder →
Frequently asked
Answers cite the same records as the page. How PurityMap analyzes water data
Uranium is a naturally occurring radioactive metal that dissolves into groundwater from uranium-bearing rock. It poses both a chemical (kidney) risk and a radiological one.
The enforceable federal limit is 30 µg/L (MCL). The health-based goal (MCLG) is 0. PurityMap reads every measurement against its stated benchmark and never sets its own.
Natural mineral deposits, Mining activity.
Long-term uranium exposure above the limit is linked to kidney damage from its chemical toxicity and to an increased cancer risk from its radioactivity. Because the risk is cumulative, the health goal is set at zero and the enforceable limit near the lowest feasible level.
Treatment technologies commonly certified to reduce Uranium include Reverse osmosis, Anion exchange, Coagulation / filtration. Match the exact certified claim to your water before buying. Holding a format is not the same as holding the claim.
In the federal compliance record (EPA SDWIS, since 2016), 2 cities in PurityMap's record across 2 states had a water system measure Uranium above the legal limit, most recently in 2026, including Dona Ana Mdwca, NM; Grand Island, NE. Each violation is a past event with a published status, not a description of the water today.