[Aquaman]

You are correct that carbon can provide a breeding ground for bacteria, however, this is only an issue if two things are in play. First there needs to be bacteria present, which is rare on municipal water supplies, and secondly even if bacteria is present, it will only have the opportunity to grow if the water is stagnant for long periods of time. If the system is being used on a daily basis, the constant flushing of the filter media will protect against bacterial infection.