Uranium is a naturally occurring element found in bedrock and soil worldwide. In some areas it dissolves from the rock into groundwater used for drinking. Elevated levels are found mainly in private drilled wells and can only be confirmed by laboratory analysis.
Although uranium is radioactive, in drinking water it is often the chemical properties that pose the main health risk. Regular sampling is therefore important for water quality.
Where does uranium in water come from?
Uranium in water usually has a natural geological origin. Common sources include:
- Uranium-bearing bedrock
- Granite and pegmatites
- Fractures in rock formations
- Groundwater aquifers
- Mineral occurrences in soil and rock
- Former mining areas
In Sweden uranium occurs naturally in some parts of the country and is sometimes found in drilled bedrock wells.
Is uranium found in municipal drinking water?
Municipal waterworks carry out regular quality control and must meet applicable drinking-water requirements. If elevated levels are found, treatment can be applied. For private wells, the well owner is responsible for sampling and checking water quality.
See private well water and drinking water standards.
Can you see or taste uranium?
No. Uranium in water cannot normally be detected by colour, odour, taste or visible particles. The water can look completely normal even when levels are elevated.
Health risks
Long-term exposure to elevated uranium can pose health risks. That is why uranium is covered by national and international drinking-water guideline values. It is especially important to analyse private-well water if uranium has never been tested.
How is uranium detected?
Uranium can only be confirmed by laboratory analysis. Sampling often also includes arsenic, radon, iron, manganese, hardness and fluoride. Because these substances often share the same geological origin, several parameters can occur together in the same well.
Read more about water analysis.
How can uranium be removed from water?
The choice of treatment depends on uranium concentration, water quality and co-occurring substances. Common methods include:
- Ion exchange
- Specialized adsorption media
- Activated alumina
- Reverse osmosis (RO)
- Combined filter solutions
In some cases several treatment steps are used to address uranium, arsenic, iron and manganese together. See filtration and iron and manganese removal.
Uranium, radon and arsenic
Uranium often occurs together with other substances of natural bedrock origin: arsenic, radon, iron, manganese and fluoride. A complete water analysis therefore often gives the best picture of water quality and which treatment may be needed.
Frequently asked questions
- Is uranium common in private wells?
- In some geological areas uranium occurs naturally in groundwater and is found in water analyses.
- Can I see if my water contains uranium?
- No. Uranium is normally odourless, colourless and tasteless.
- How do I know if my well contains uranium?
- By laboratory analysis of water samples.
- Can uranium be removed?
- Yes. Several established techniques can reduce uranium in drinking water.
- Are uranium and radon the same thing?
- No. Uranium is an element; radon is a radioactive gas that can form when uranium decays naturally in bedrock.