[en] Overflow waters from the tailings pond in which liquid effluents in the form of barren liquors from uranium mill are discharged may contain 10 pci/litre of radium activity as against the maximum permissible discharge limit of 3 pci/litre and 10 mg/litre of soluble manganese as against the allowable limit of 0.3 mg/litre. These contaminants must be removed and/or made insoluble to ensure environmental safety. Studies were, therefore, carried out to develop methods for: (1) decontamination of both barren liquors and overflow waters and (2) their insolubilisation prior to their release in the pond. Based on the results, a scheme of treatment is formulated. Radium activity in the barren liquor is insolubilised by addition of 25 mg Ba²⁺/litre and precipitation. The liquor is then neutralised with lime. The sludges on liquid-solid separation are subjected to air digestion to stabilise manganese(II) to highly insoluble manganese(IV) oxide. Supernatant and the digested sludges are discharged to the tailings pond. Overflow waters from the pond are treated with 5 to 10 mgs/litre of permanganate to remove manganese and radium. The precipitates resulting in the process may be disposed as solid radioactive wastes and decontaminated water may be released to the environment or if it meets the mill specification, may be reused as process water thus ruling out even the slightest possibility of environmental pollution. The overall cost of chemicals required for the treatment mentioned above works out to be Rs. 0.30 per cubic metre of effluent. (M.G.B.)