Abstract: Apparatus for filtering radioactive contamination from a contaminated medium by leaching the contamination from the medium into a liquid and removing the radioactivity from solution by passing it through an ion exchange resin. The apparatus includes a container having a base and side wall, a filter cartridge disposable on the base of the container and a basket having a wall through which fluid held in the container flows. The basket is disposable adjacent the cartridge in the container. The cartridge has a central cavity bounded by a first filter wall and a second filter wall spaced outwardly from the first filter wall, with the two filter walls having a selected mesh size to capture the contaminated medium. A first and second barrier extend in spaced relation to one another and between the first and second filter walls to define a filter medium enclosure surrounding the central cavity. A magnetic stirrer is used to induce liquid flow in the container, including flow through the cartridge and basket.