Answer to Question #1143 Submitted to "Ask the Experts"

Q

We live near a quarry and gravel pit which frequently blasts for its material. A recent series of water tests has revealed high levels of uranium in our housing development's wells. Does blasting affect water quality; that is, would the blasting "shake things up" below the surface and affect water quality?

A

After consultation with our local uranium-in-groundwater expert, I would have to say that blasting would probably not affect uranium levels in water in these circumstances. If there is uranium in groundwater and well water now, there was likely uranium in ground and well water before the quarrying activities. This appears to be the case whether the quarrying was for gravel or for hard rock. I cite the Manitoba, Canada, experience with the Underground Research Laboratory (URL). Baseline studies carried out in the area of the URL indicated that uranium was present in well water throughout the region (even well outside the influence zone of the URL) before the facility was constructed. Construction and operation of the URL does not appear to have influenced these levels significantly. Note that I have specified circumstances typical of simple quarrying. I do not know all the circumstances of the operations in question. For example: Are there waste rock materials that must be stockpiled or disposed of at the surface? Is surface water leaching of stored materials an issue? Also, what I have said only applies to uranium in groundwater. There may be potential for contamination by hazardous materials that are improperly handled in the operation of the facilities, including blasting materials, drilling muds, fuels, oils, etc. John Barnard Director of Facilities