Radioactivity is monitored by Belarus in the Pripyat (at Mosyr) and in the Lower Braginka (at Gdcn), and Ukraine monitors for lwCs and ’“Sr at transboundary monitoring stations. According to the results, concentrations of radionuclides arc insignificant, and do not exceed permissible limits. Groundwater monitoring is carried out by Belarus in four points in transboundary areas (levels, temperature, physical properties and chemistry), but there is no joint monitoring.