7.6.6 Remedial measures

If remedial measures are contemplated, any strategy considered should first be justified (in the sense that it achieves a net benefit). Any decision that alters the radiation exposure situation should do more good than harm. This means that by reducing the existing exposure, it will achieve sufficient individual or societal benefit to offset the detriment it causes (ICRP 2007). Once the remedial action is justified, then protection should be optimised.

When source water contains unacceptably high concentrations of radionuclides, control options include the use of an alternative supply, controlled blending with another source or additional water treatment. Treatment plants with a combination of coagulation, sedimentation and sand filtration processes may remove up to 100% of the suspended radioactivity present in raw waters. Lime–soda ash softening plants can also remove practically all of the suspended radioactivity, depending on the radionuclide and on the proportion of radioactivity that might be associated with particulates.

A comprehensive review of the removal of dissolved radionuclides by water treatment processes has been undertaken (Brown et al. 2008).

The treatment of drinking water may result in materials with increased concentrations of radioactive material that may need to be managed in accordance with international best practice. Radioactive wastes arising from water treatment processes should be appropriately managed with the relevant health authorities or drinking water regulators.