Contamination of drinking groundwater sources by naturally occurring radioactive materials (NORM) is a rather common problem in several regions in the Middle East and the Arabian Gulf. This contamination which represents public health risks and threat to environment complicates the processes of water treatment and increases their cost. The present work summarizes results of treatment of contaminated groundwater for rejection of radioisotopes. The removal of radium,Ra-226,Ra- 228,Ra- (2+) uranium, as uranyl cation, UO22+, or carbonate complexes, UO2(CO3)(2)(2-) and UO2(CO3)(3)(4-), and radon, Rn-222, was investigated by reverse osmosis (RO) and nanofiltration (NF) in comparison with the most common conventional methods of ion exchange resins (IERs), chemical precipitation/softening, coagulation, and adsorption on surface active media. IERs and chemical softening realized radionuclide rejection from 32 to 95%, but with loss of process efficiency which attained 24% due to undesired parallel removal of similar ions. Removal by IERs was too dependent on resin form and water pH and required periodical shutdown for regeneration of resin which was slow and seldom complete. Softening required chemical dosing stoichiometric to isotope removal, disposal of contaminated sludge and subsequent water filtration. Coagulation failed to remove Ra. Its removal of U ranged from zero to 93% depending on pH due to formation of different U complexes. Only RO, parallel to water desalination, showed steady, high rejection of all isotopes which attained 99% without interference of similar ions, regeneration, or subsequent filtration. NF showed similar behavior, but with lower water desalination. (C) 2013 Elsevier B.V. All rights reserved.