Multiple methods of Legionella disinfection exist, each with their own pros and cons. Copper-silver ionization, chlorine dioxide, monochloramine, ultraviolet light, hyperchlorination, point-of-use-filtration, and superheat-and-flush are all methods for disinfecting hospital water in an article from the Journal of Infection Control & Hospital Epidemiology. The authors of this article came up with a 4-step standardized approach to evaluate criteria for disinfection methods. They then go on to evaluate each of these methods in greater detail and decided that although many of the methods seem promising, more research is required. The authors also noted that, so far, the only method that fulfills all four criteria is the copper-silver ionization method.
To read a synopsis of this article, please visit the Journal of Legionella and the Law at http://www.legionlawjournal.com/2013/09/16/advantages-and-disadvantages-of-various-legionella-disinfection-methods/