Ozone is a powerful oxidizing agent whose reaction time is more than 3000 times faster than chlorine (EPRI 1993). Claudi and Mackie (1994) report that viruses and bacteria are completely removed within a 30-sec contact time by a dissolved ozone residual of less than 0.5 mg/l. It can be used to control other forms of biofouling as well. Ozone outperforms chlorine in terms of contact time and does not form trihalomethanes. It is effective against the zebra mussel and dissipates rapidly in water, leaving no residual in the discharge water. Its instability is a great advantage of ozone, and its "no impact" effect on the environment makes it user-friendly in relation to regulation compliance for environmental safety issues. This instability also poses a disadvantage to the user. Ozone is difficult to maintain in flowing systems and must be readministered at several points to maintain effectiveness throughout the course. Expensive equipment is required, and it is not approved in Canada. Ozone is explosive and has to be generated onsite.
Management and Control Contents