Analytical methods for determining important components of fission and natural radioactivity found in water are reported. The discussion of each method includes conditions for application of the method, a summary of the method, interferences, required apparatus, procedures, calculations and estimation of precision. Isotopes considered are cesium-137, strontium-90, lead-210, radium-226 and 228, tritium, and carbon-14. When two methods are in use for an isotope, both methods are reported. Techniques for the collection and preservation of water samples to be analyzed for radioactivity are also discussed. (CS)