Uranium

Uranium (U) is a naturally occurring radioactive metal found in rocks, soil, air and water. In New Brunswick, uranium may be present in groundwater in some areas, particularly in water from private wells.

Uranium in drinking water most often comes from natural weathering and dissolution of uranium-bearing rocks and soils. As groundwater moves through these materials, uranium can dissolve into the water. Uranium levels in well water may be influenced by:

• local geology
• depth of the well
• groundwater chemistry
• length of time water is in contact with rock formations

Uranium has a health-based Maximum Acceptable Concentration (MAC) of 0.020 milligrams per litre (mg/L).

This guideline is based on chemical toxicity rather than radioactivity.

Laboratory testing is required to determine uranium levels in drinking water. Uranium cannot be detected by taste, smell or appearance. Testing recommendations include:

• use of an accredited laboratory
• collection of samples following laboratory instructions

For more information on water testing services, please see: Well water testing. Testing costs vary depending on the laboratory and the number of parameters analyzed.

Health risks from uranium in drinking water are related to long-term ingestion. Prolonged exposure to elevated uranium levels may affect kidney function. Health risks occur through ingestion only, including:

• drinking
• cooking
• brushing teeth

Water with uranium levels above 0.020 mg/L may still be used safely for:

• bathing
• handwashing
• dishwashing

When uranium levels exceed 0.020 mg/L, a second test is recommended to confirm the result. If elevated levels are confirmed, the following actions may reduce exposure:

• use an alternative water source for drinking, cooking and brushing teeth
• install treatment to reduce uranium levels

Boiling water does not remove uranium and may increase its concentration. Treatment systems may be installed at the point where water enters the home or directly at a tap. Effective treatment options include reverse osmosis, ion exchange and distillation.

Treatment systems should be certified to meet current NSF standards and installed and maintained according to the manufacturer’s instructions. More frequent testing is recommended to confirm treatment performance.

Additional information on treatment options is available through private water treatment companies or the nearest regional Health Protection Branch office.