Cross-flow microfiltration processing of radioactive liquids has been in use at Chalk River Laboratories for about four years. The separation process removes suspended particles from radioactive waste solutions. The clean liquid can then be treated with conventional reverse osmosis membranes to achieve volume reduction factors approaching 100. Microfiltration removes particles below the rating of 0.2 microns, in part from particle agglomeration. Operating experience relating to a 15 USGPM unit is presented. Coupling microfiltration technology with chemical treatment enhances the removal of soluble species. Research and development experience with the removal of soluble contaminants found in ground water and waste water will be discussed. The technology has advantages over other membrane technologies, namely lower energy costs, a lesser degree of fouling, and a higher recovery of processed solution. Future applications of the technology are addressed. (author). 10 refs., 3 tabs., 4 figs.