Box 3 – Domestic Well Contamination Near a Waste Disposal Site
An example of a domestic well that has been contaminated by industrial activity is shown in Figure Box 3-1. This well is located adjacent to a construction and demolition debris disposal site in Nova Scotia, Canada. The site was used to store and transfer construction debris materials such as wallboard, concrete, and roofing shingles. The uranium concentration in this well increased from approximately 200 to 1,400 µg/L during the eight-year period of monitoring shown in Figure Box 3-1, which is 70 times greater than the Canadian drinking water guideline for uranium (20 µg/L).
In this case, there is no uranium in the leachate or waste materials at the site. However, it is suspected that leachate from the waste materials has migrated into the subsurface and caused naturally occurring uranium in the underlying bedrock aquifer to be mobilized (Letman et al., 2018). The leachate contains high levels of dissolved calcium, due to the dissolution of gypsum in waste wallboard, and this is suspected to have led to the formation of mobile calcium-uranyl-carbonate complexes. This example demonstrates how anthropogenic activities can cause unexpected contaminant mobilization that can affect domestic wells.

Figure Box 3–1 – Uranium concentration in a domestic well located adjacent to a construction demolition and debris disposal site (modified from Letman et al., 2018).