Your presumption would be accurate based on the description that ozone is one of the final steps. Ozone will kill off microbial pathogens more effectively than the more commonly used chlorination.
While ozone is a more powerful oxidant it is usually more expensive to use, which is why ozone is not in as wide spread usage as chlorine. In addition, ozone will oxidize a variety of other compounds more effectively than chlorine, which is a good thing, except it often increases operating cost unnecessarily.
I find this an interesting development since I am an industrial wastewater treatment specialist (chemical engineer and microbiologist). I use aspects of these unit operations but am real curious what apparent breakthroughs they are claiming in order to rely solely on physical/chemical means to the extent that this scheme appears to use while being cost competitive.
Ozone also has no residual effect and this is why chlorine is used more routinely.