Uranium in Well Water

Uranium is naturally occurring in Nova Scotia groundwater and exposure to uranium can adversely affect kidney function. The Health Canada Maximum Acceptable Concentration for uranium in well water is 0.02 mg/L (or 20 µg/L).

Initial Discovery of Uranium in Well Water

Concerns over uranium in well water in Nova Scotia first emerged in the late 1970’s during a study by Dalhousie University on the concentrations of various heavy metals in the general population. Elevated levels of uranium were found in random hair samples of a subject in Harrietsfield relative to levels found in other subjects. The detection of elevated levels of uranium in the patient’s water well led to the formation of a provincial task force that investigated the occurrence of uranium, radium and radon in water wells in Nova Scotia. Some of the key findings of the task force were reported in an Interim Task Force Report.

Uranium in Well Water Risk Map

A review of historical research related to uranium in Nova Scotia well water was published in 2018 by the Nova Scotia Geological Survey Division as an Open File Report. The review found that bedrock geology was the dominant control on uranium levels in water wells. A second Open File Report was produced to develop a province-wide uranium in well water risk map based on bedrock geology. The purpose of the risk map is to communicate the risk of uranium contamination in drinking water to private well users and to prevent disease. The risk map is available as a web map application and divides the province into low-, medium- and high-risk zones.

Private Well Owners

About 42% of Nova Scotians rely on private wells, and it is estimated that 1 in 15 of these private well users may have unsafe levels of uranium in their untreated water. Testing your well water is the only way to find out whether uranium is a concern in your well so it is important to test your water no matter where you live. Well water should be tested every two years for chemicals, such as uranium, to ensure that it is safe for you and your family to drink. More information on uranium and well testing and treatment for private well owners can be found here.

A story map is also available, which brings together knowledge and resources for private well owners looking for information about drinking water hazards to private wells and how to test and interpret their drinking water quality.