FIELD: strontium-90 identification. SUBSTANCE: group of inventions is related to identification of strontium-90 in natural waters (surface fresh water, underground water) and waste waters for the purpose of radioecological monitoring of natural waters, as well as radiation monitoring of waters of control and observation wells on the territory of an industrial site and sanitary protection zones of radiation-hazardous objects. Strontium-90 is concentrated from water samples with a volume of 1-2 l with carbonate-containing zirconium hydroxide of grade T-3K by passing through a column at a rate of 0.5 l/h, desorbed with a solution of 1 M of HCl, the eluate is evaporated on a cuvette with a diameter of 4 cm and its radioactivity is measured using a semiconductor alpha-beta radiometer UMF-2000. EFFECT: reduction in the number of analysis stages to 4, avoiding the need for preliminary sample preparation, and a reduction in the consumption of reagents. 2 cl, 5 dwg.