Ozone is a cheap, safe, effective alternative to chlorine.

Apparently Severn Trent use Ozonation for some of their water supplies - it would be interesting to learn more about this but haven't received a reply regarding more information from Severn Trent. The Health Protection Agency pointed me towards contacting water companies such as Severn Trent. US environmental protection agency information. Information for residents where ozone is used in drinking water : Massachusetts, San Diego . From the above info : Ozone may not kill large cysts and some other large organisms, so these should be eliminated by filtration or other procedures prior to ozone treatment. Ozone treatment can produce harmful by-products in drinking water. For example, if bromide is present in the raw water, ozone reacts with it to form bromate, shown to cause cancer in rats. "e U.S. Environmental Protection Agency (EPA) has set a drinking water standard for bromate in water at 0.010 mg/L. The disinfection process does not occur beyond the treatment unit. "is contrasts with chlorination treatment where the residual chlorine remains in the water and continues the disinfection process for some time. Ozone has an active residual time measured in minutes, whereas the active residual time for chlorine is measured in hours. Info from commercial companies eg. Lenntech, McClain, Earth Safe Zone, EnvronOzone